f identical twins eat and exercise equally, must they have the same body weight? By analyzing the fundamental equations of body weight change, NIH investigators Carson Chow and Kevin Hall find that identical twins with identical lifestyles can have different body weights and different amounts of body fat.
The study, published March 28th in the open-access journal PLoS Computational Biology, uses a branch of mathematics called dynamical systems theory to demonstrate that a class of model equations has an infinite number of body weight solutions, even if the food intake and energy expenditure rates are identical. However, the work also shows that another class of models directly refutes this, predicting that food intake and energy expenditure rates uniquely determine body weight. Existing data are insufficient to tell which is closer to reality, since both models can make the same predictions for a given alteration of food intake or energy expenditure.
Given the ongoing obesity epidemic, Drs. Chow and Hall are interested in what factors determine human body weight and its stability. Of particular importance is whether a treatment for obesity would have to be administered repeatedly over a lifetime or could be given only until a target body weight is reached. As a particular example, the study considers whether weight lost from a liposuction procedure is permanent. For the class of equations with an infinite number of body weight solutions, fat removal through liposuction could lead to permanent results. However, the opposing models predict that the body would eventually return to its original weight.
Chow and Hall note that neither class of models accounts for the many variables affecting how much a person tends to eat, an important factor determining bodyweight. Nevertheless, for any food intake rate this latest research suggests that an individual may have an infinite number of possible body weights. The study outlines the mathematical conditions underlying this possibility and suggests how future experiments could determine if it is true.
"The Dynamics of Human Body Weight Change"
Chow CC, Hall KD (2008)
PLoS Comput Biol 4(3): e1000045. doi:10.1371/journal.pcbi.1000045
Are You What You Eat? New Study Of Body Weight Change Says Maybe Not
Keeping In Good Shape In Old Age Is Harder For Women Than Men
Women over the age of 65 years have a more difficult time preserving muscle than their male counterparts, which probable impacts their ability to stay as strong and fit, according to new research published on March 26, 2008 in the open-access journal PLoS ONE.
Muscle maintenance is very important in reducing the risk of falls in the elderly, one of the major causes of premature death. After the age of 50, people lose up to 0.4% of their muscle mass every year. This makes them less mobile, more at risk for fracture, and more at risk for potentially life threatening falls.
Of elderly people who suffer a serious fall, one half die within to years. But, it is thought that the number of falls can be curtailed if muscle mass is maintained. This would keep knees and hips more properly supported and strong.
Until now, no differences had been found between men and women in muscle protein synthesis, the process the body uses to build muscle. However, recently, it has been found that the female body's response to food and exercise declines in the mid- to late-60s. Women are at a higher risk for muscle loss because they already tend to have less muscle and more fat than men in early and middle age, so when they reach their 50s and 60s, they are already closer to becoming frail.
Now, scientists have shown for the first time that it is actually more difficult for women to replace naturally lost muscle as they get older, and this difficulty is linked to a key difference in the way men's and women's bodies react to food.
Experts at the Washington University School of Medicine in St Louis, Missouri, USA, and at The University of Nottingham, UK, funded by the US National Institutes of Health, studied 29 men and women aged 65-80 years old who were in good health. They examined the ability to respond to food meant to build muscle mass. It was found that post-menopausal women were less able to respond to this food than men, who were able to store protein in the muscle.
The scientists attribute this change to hormonal adjustments that occur with menopause. Specifically, the suspicion falls on estrogen, which is already known to be necessary in both women and men to help maintain bone mass. According to the researchers, these findings corroborate other preliminary results indicating that women are less able to repsond to build muscle after resistance exercise, such as lifting weights in the gym. Younger men and women, who have not reached menopause, do not seem to show any discrepancy in muscle mass potential.
Regarding this finding, Michael Rennie, Professor of Clinical Physiology at The University of Nottingham, said: "Nobody has ever discovered any mechanistic differences between men and women in muscle loss before. This is a significant finding for the maintenance of better health in old age and reducing demands on the National Health Service."
There is advice for older women to help combat this degeneration. These new results underscore the importance of a diet sufficient in protein, including foods such as eggs, fish, chicken, and lean red meat, as well as resistance exercise.
"Rather than eating more, older people should focus on eating a higher proportion of protein in their everyday diet. In conjunction with resistance exercise, this should help to reduce the loss of muscle mass over time. There is also a case for the beneficial hormonal effect of limited HRT, although this has to be balanced against the other risks associated with such treatment," continues Rennie.
About the Contributing Universities
Washington University School of Medicine is ranked in the US's Top 5 Medical Schools and the World's Top 35 universities by the U.S. News & World Report and the Times Higher (THES) World University Ranking.
The University of Nottingham is ranked in the UK's Top 10 and the World's Top 70 universities by the Shanghai Jiao Tong (SJTU) and Times Higher (THES) World University Rankings. It provides innovative and top quality teaching, undertakes world-changing research, and attracts talented staff and students from 150 nations. Described by The Times as Britain's "only truly global university", it has invested continuously in award-winning campuses in the United Kingdom, China and Malaysia. Twice since 2003 its research and teaching academics have won Nobel Prizes. The University has won the Queen's Award for Enterprise in both 2006 (International Trade) and 2007 (Innovation - School of Pharmacy).
Its students are much in demand from 'blue-chip' employers. Winners of Students in Free Enterprise for three years in succession, and current holder of UK Graduate of the Year, they are accomplished artists, scientists, engineers, entrepreneurs, innovators and fundraisers. Nottingham graduates consistently excel in business, the media, the arts and sport. Undergraduate and postgraduate degree completion rates are amongst the highest in the United Kingdom
4,000 Women Attempt New World Record at 2008 Lady of America/Ladies Workout Express Ab Crunch Challenge
Women Get a Six Pack While Giving Back Through Fitness Fundraiser for St. Jude Children's Research Hospital(R)
FORT LAUDERDALE, Fla., March 28 /PRNewswire/ -- Four thousand women across the country will "feel the burn" as they crunch their abs for one hour straight during the Ab Crunch Challenge taking place tomorrow (Saturday), March 29. More than 200 local Lady of America, Ladies Workout Express and Workout Express gyms will host the fitness challenge, with a goal to raise $1 million for St. Jude Children's Research Hospital and make history by creating a new Guinness Record for the most abdominal crunches done in one hour by a group.
Omega-3 Fatty Acids Protect the Spinal Cord, Heart, Brain and Eyes
DENVER, March 28 /PRNewswire/ -- Long-chain (seafood) omega-3 polyunsaturated fatty acids (PUFAs) continue to prove their value in heart, brain and eye health, according to recent research summarized in the March 2008 Fats of Life and PUFA Newsletter electronic publications. Groundbreaking studies also show that omega-3s may improve recovery from spinal cord injury and dry eye syndrome.
The effect of fish oil consumption on arterial elasticity, which allows for more rapid blood flow, was examined in China in overweight patients with high blood pressure. Participants who took 900 mg of seafood omega-3s daily for eight weeks had a 21% increase in arterial elasticity.
"While blood pressure did not change in these participants, their arterial elasticity significantly improved," said Editor Joyce Nettleton, D.Sc. "This observation suggests another way in which these omega-3s protect heart health."
A US study reported that marine omega-3s prevented atrial fibrillation- uncontrolled rapid trembling -- from developing in animals with fast heartbeats. By increasing the heart's recovery time, the omega-3s prevented abnormal rhythms from becoming established.
Investigators in the Netherlands recently examined the relationship between children's omega-3 status at birth, which depends on the mother's omega-3 intake during pregnancy, and their motor development at age seven. Those with the highest levels of the omega-3 DHA (docosahexaenoic acid) at birth had significantly higher total motor scores than children born with less DHA.
"This means that a mother's consumption of seafood omega-3s during pregnancy is important for her child's later motor development," Nettleton said.
Two other studies covered by the e-newsletters report improvement in mental disorders with dietary seafood omega-3s. Treating substance abuse patients with these omega-3s, mainly EPA (eicosapen-taenoic acid), for example, resulted in significantly lower scores for anxiety and anger. In adults diagnosed with neuroticism, researchers found the condition was related to low blood levels of EPA.
Groundbreaking animal research suggests that human treatment with DHA within the first hour after a spinal cord injury could be effective in limiting the extent and spread of damage. Also included in the e-newsletters is a report of significantly reduced inflammation and corneal damage in dry eye syndrome with eye drops containing the plant omega-3, alpha-linolenic acid.
The quarterly Fats of Life and PUFA Newsletter, sponsored by DSM Nutritional Products, are at http://www.fatsoflife.com/ and by complimentary subscription.
Source: Fats of Life
CONTACT: Angela Dansby of Fats of Life, +1-773-697-7686,
angela@fatsoflife.com
Web site: http://www.fatsoflife.com/
Why Can Grapefruit Interfere With Some Medications?
People are discouraged from consuming grapefruits or grapefruit juice while taking certain medications because they can affect the way the medications are metabolized. Now scientists are closer to understanding why this dangerous interaction occurs. Johns Hopkins Health Alerts reports on the latest research.
New York, NY (PRWEB) March 13, 2008 --Johns Hopkins Health Alerts' recent Prescription Drug Health Alert reported on new research regarding the reason why grapefruit juice can potentially cause a dangerous interaction with certain of the medications you take.
FOOD AND DRUG INTERACTIONS
Certain foods and drinks don't mix well with certain medications. For example, grapefruits or grapefruit juice may interact badly with a number of medications, because natural grapefruit contains a substance that affects the activity of an enzyme in the intestines and liver that processes these medications. This could result in a dangerous increase in the level of the drug in your blood.
Another potentially dangerous interaction is between the blood thinner warfarin (Coumadin and generic brands) and vitamin K. The vitamin, present in many multivitamins and supplements, neutralizes or reduces the effect of the medication warfarin. This raises the risk of a blood clot, which the warfarin is intended to prevent.
GRAPEFRUIT AND DRUG INTERACTIONS
Now scientists have identified the specific chemical in grapefruit juice responsible for many drug-food interactions, according to an article in the American Journal of Clinical Nutrition (Volume 83, page 1097).
Previous research implicated a family of chemical compounds called furanocoumarins (FCs) as the culprit in grapefruit juice. To confirm this suspicion, the scientists created FC-free grapefruit juice and compared its effects with those of whole grapefruit juice or orange juice (the control group in the study).
GRAPEFRUIT AND DRUG INTERACTION STUDY
Eighteen study volunteers drank 8 oz of whole or FC-free juice along with a dose of felodipine (Plendil), a blood pressure medication.
The blood concentration of Plendil was nearly THREE times higher when people took it with 8 ounces of whole grapefruit juice, compared with blood levels after subjects took it with the FC-free grapefruit juice or orange juice (the control group in the study).
This means that the blood level of Plendil was higher when taken with whole grapefruit juice, potentially causing dangerously low blood pressure.
The researchers said their finding could assist in the study of other drug-food interactions.
Grapefruit has also been known to diminish the absorption of some drugs in the body. So always follow the guidelines given on your medications with regard to food and drug interactions.
One further note: In reference to the control group in the study, regular orange juice was found to be safe to drink with Plendil. However, you may want to avoid Seville oranges in juice or marmalade, as they are the only type of oranges to contain furanocoumarins.
You can learn more about the latest research on prescription drugs in the annual Johns Hopkins Prescription Drug White Paper:
The Johns Hopkins White Paper: Prescription Drugs
Medical Disclaimer: This information is not intended to substitute for the advice of a physician.
http://www.johnshopkinshealthalerts.com
Daycare Program To Prevent Obesity Benefits Preschoolers
A preschool-based intervention program helped prevent early trends toward obesity and instilled healthy eating habits in multi-ethnic 2- to 5-year-olds, according to a report presented at the American Heart Association's Conference on Nutrition, Physical Activity and Metabolism.
"Nobody would dispute that we are experiencing an epidemic of obesity in this country," said Ruby Natale, Ph.D., Psy.D., author of the study and assistant professor of clinical pediatrics at the University of Miami, Miller School of Medicine in Miami, Fla. "Children as young as 7 years old are experiencing health consequences of being overweight, suggesting that intervention must occur as early as possible and involve the entire family.
"Inner-city minority children spend many hours of the day in preschool, making it a significant influence in many aspects of their lives. Children depend on their parents for nutrition and physical activity choices at this age, so the home environment must be accounted for as well."
Natale and colleagues studied 2- to 5-year-old children from ethnically diverse, low-income families in eight subsidized childcare centers in Miami Dade County, Fla. The intervention group received a six-month home- and school-based obesity prevention program with two tiers.
The classroom-based (tier one) program included menu modifications and education:
* The menu promoted water as the primary beverage for staff and children; offered only skim or 1 percent milk; limited juices and other sweetened beverages; and incorporated fruits and vegetables in snacks as much as possible.
* Classroom teachers were educated weekly about how to incorporate nutrition and physical activity curriculums and how to better understand and overcome children's cognitive, cultural and environmental barriers to implementing a healthy low-fat, high-fiber diet.
The family-based (tier two) program reinforced what the children learned at childcare, including:
* Monthly parent dinners to educate parents about food labels, the food guide pyramid and portion sizes.
* Newsletters focusing on topics such as picky eaters, healthy cooking tips, healthy fast food options and recipes for healthy snacks.
* At-home activities such as sampling different vegetables and various types of lower-fat milks.
Comparing data from the intervention group to a control group of children, researchers found that intervention is an effective obesity prevention strategy.
"While 68.4 percent of children were at normal weight at the start of the study, this increased to 73 percent at follow-up," said Sarah E. Messiah, Ph.D., M.P.H., lead author of the study and research assistant professor in the Division of Pediatric Clinical Research, University of Miami, Miller School of Medicine. "Also, the percentage of children who were at risk for overweight decreased from 16 percent to 12 percent."
From the beginning to the end of the intervention, children changed the amounts and types of foods they ate. Those at two intervention sites ate less junk food, more fresh fruits and vegetables, and drank less juice and more 1 percent milk compared to those at control sites.
Specifically, on average in the intervention groups:
* Chip consumption decreased from daily to no consumption.
* Cookie consumption decreased 50 percent.
* Fresh fruit and vegetable consumption increased 25 percent.
* Juice consumption decreased 50 percent and was replaced with a 20 percent increase in water consumption.
* One percent milk consumption increased 20 percent.
"In the control sites, cake and cookie consumption actually increased 35 percent and 75 percent, respectively, while average fresh fruit and water consumption decreased," Messiah said. "We are hoping that our study will impact policy around the country leading to healthier standards for meals served at childcare centers. If we are successful in improving attitudes toward nutrition and physical activity in early childhood, we can potentially influence adult behavior and begin to hope that the public health epidemic of obesity can be ended."
----------------------------
Article adapted by Medical News Today from original press release.
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Other co-authors are: Lee Sanders, M.D.; Gabriela Lopez-Mitnik, M.A.; and Jennifer Barth, Ph.D.
Children's Trust of Miami Dade funded the study.
Statements and conclusions of abstract authors that are presented at American Heart Association/American Stroke Association scientific meetings are solely those of the abstract authors and do not necessarily reflect association policy or position. The associations make no representation or warranty as to their accuracy or reliability.
Source: Karen Astle
American Heart Association
Rheumatoid Arthritis Patients Display An Anti-Inflammatory Response To The Vegan Diet
Rheumatoid arthritis (RA) patients who eat a gluten-free vegan diet could be better protected against heart attacks and stroke. RA is a major risk factor for these cardiovascular diseases, but a gluten-free vegan diet was shown to lower cholesterol, low-density lipoprotein (LDL) and oxidizedLDL (OxLDL), as well as raising the levels of natural antibodies against the damaging compounds in the body that cause symptoms of the chronic inflammatory disease rheumatoid arthritis, such as phosphorylcholine. These findings are reported in the open access journal Arthritis Research & Therapy.
The idea that we can influence our health by changing our eating habits has become a fashionable idea among lifestyle and consumer magazines. There is evidence that dietary changes can bring about health benefits but specific results are not widespread.
Now, Johan Frostegard of the Rheumatology Unit at the Karolinska University Hospital in Stockholm and colleagues divided sixty-six RA patients randomly into two groups. They randomly assigned 38 of the volunteers to eat a gluten-free vegan diet, and the other 28 a well-balanced but non-vegan diet for one year. They analysed the levels of fatty, lipid molecules in blood samples using routine analytical methods at regular periods. They also measured oxLDL and anti-phosphorylcholine (antiPC) factor at the beginning of the experiment, at 3 months and again at 12 months.
The researchers found that the gluten-free vegan diet not only reduced LDL and oxLDL levels and raised antiPC antibodies but lowered the body-mass index (BMI) of the volunteers in that group. Levels of other fatty molecules, including triglycerides and high-density lipoprotein (HDL) stayed the same. In contrast, none of the indicators differed significantly for the control groups on the conventional healthy diet.
AntiPC antibodies are studied within CVDIMMUNE, an European consortium led by Dr Frostegard with the hypothesis that such antibodies can protect against cardiovascular disease and can be used as diagnostic and therapeutic factors.
Frostegard and colleagues have now shown that diet could be used to improve the long-term health of people with rheumatoid arthritis. They concede that a bigger study group will be needed to discern which particular aspects of the diet help the most.
Diet And Colorectal Cancer Risk
According to Heinz-Josef Lenz, M.D., professor of medicine, Keck School of Medicine, USC and the USC/Norris Comprehensive Cancer Center, diet may have a major impact on people's risk of developing cancer. Colorectal cancer is the third most-common cause of cancer-related death in men and women in the nation.
The most important risk factor is red meat, particularly beef, he says. The countries with the highest beef consumption are the ones with the highest colon cancer risk. White meat such as chicken and pork don¹t seem to be associated with colon cancer risk.
Alcohol consumption is another major risk factor, particularly for women, Lenz notes. To reduce risk, people should limit themselves to one glass of wine per day.
Avoiding alcohol and decreasing intake of red meat can decrease your risk of colon cancer significantly, he says.
People should have rich sources of calcium intake, such as dairy products, daily. It is also important to include fiber-rich foods such as fruits and vegetables and reduce intake of fatty foods. One of the most powerful ways to reduce colon cancer development is vitamin D and calcium.
With easy adjustments in your diet, supplements such as calcium and modest exercise you can reduce your risk of colon cancer by more than 50 percent,² says Lenz.
For more information on colorectal cancer, visit Dr. Lenz¹s blog at www.revolutionhealth.com/pages/colon-cancer
deCODE Obesity Study Sheds Light on How Genetics Affects Risk and Onset of Common Diseases
REYKJAVIK, Iceland, March 16 /PRNewswire-FirstCall/ -- In a paper published online today in the journal Nature, a team of deCODE scientists detail a major mechanism through which genetic factors contribute to major public health problems. In its work on the inherited components of dozens of common diseases, deCODE has discovered gene variants that significantly affect individual susceptibility or protection against disease. In the common forms of these conditions -- such as obesity, type 2 diabetes and cardiovascular diseases -- deCODE has previously shown that genetic variants confer increased or decreased risk by upregulating or downregulating the activity of major biological pathways. As a result, these variants place individuals on a spectrum of risk, with most of the population clustered at roughly average risk and a smaller number of people at either significantly higher or lower risk.
In today's paper, the deCODE team and collaborators from Merck demonstrate one of the principal ways in which the activity of biological pathways is functionally perturbed in a quintessentially complex condition: obesity. Through analysis of adipose tissue from some 1700 Icelandic participants in obesity research cohorts, the deCODE team showed in data derived from primary human tissue that variations in gene expression -- in the up-regulation or downregulation of how genes are translated into proteins -- have a major impact on several parameters of clinical obesity. The deCODE team then used its unique resources for genome-wide linkage and association analysis to demonstrate that variability in gene expression, like overall risk for disease, has a significant inherited component that can be linked to specific versions of genetic markers. The paper, "Genetics of gene expression and its effect on disease," is published today on Nature's website, www.nature.com, and will appear in a subsequent print edition of the journal.
"One of the observations we have made in our work on the isolation of disease genes is that the genetic risk of common diseases is often conferred by variations in the sequence of the genome that affect expression of genes. Hence, one of the ways to approach the study of common diseases is through the analysis of gene expression. This paper provides a substantial contribution towards the understanding of gene expression in man and one example of how it can be used to expand our knowledge of one disease, namely obesity," said Kari Stefansson, CEO of deCODE.
Secrets For Healthy Eating With Rachael Ray
Stacey Antine, MS, RD and founder of HealthBarn(R) USA was honored today on The Rachael Ray Show as part of Ray's Incredible People & Healthy Eating series sponsored by The American Egg Board (www.rachaelrayshow.com/incrediblepeople/). Antine joins an all-star team of people recognized for their important contributions to helping communities lead healthier lives at the grass roots level.
"It's gratifying to be recognized by Rachael Ray's Incredible People & Healthy Eating series," said Stacey Antine, founder and CEO, HealthBarn USA, Inc. "We've seen first-hand how HealthBarn USA, the leader in proven, hands-on healthy-lifestyle education for children and families, can transform children's eating habits benefiting the whole family."
Antine went on to say that "We empower children with fundamental knowledge about healthy food and nutrition. We've found that when kids take part in growing and preparing a variety of different vegetables and other natural foods, they start asking their parents to serve more veggies and fruits at home."
Moreover, by teaching thousands of children ages 3-15, and their families, over the past three years to grow, cook, and taste a variety of fresh, seasonal foods and dishes, Antine and her team of nutritionists have identified secrets to getting children to eat vegetables. Here are some tips she shared with Rachael Ray on today's show:
-- Be a Role Model: Kids eat vegetables, often it's parents who don't;
-- Listen to Kids Opinions: If a vegetable or food gets rejected at the
table, ask why? At HealthBarn USA, we learn directly from the children
what works and what doesn't;
-- Use Positive Language: YUK! is a four letter word at HealthBarn USA.
Kids give the thumbs up or down only after trying new foods;
-- Be Creative with Food Preparation and Presentation: Kids love to cook
and eat hands-on recipes, e.g. add bell peppers to the typical
scrambled egg breakfast, wrap it up, and it becomes an exciting
breakfast burrito -- watch their faces light up;
-- Go Fresh: Serve a variety of raw seasonal vegetables because they
taste better all-natural before being altered in the cooking process.
According to the Centers for Disease Control (CDC), a growing body of research shows that fruits and vegetables are critical to promoting good health. "The key to our success lies in HealthBarn USA's healthy-lifestyle philosophy rooted in common sense and fun for the whole family," said Antine. "There's a lot of focus on obesity, diabetes, and chronic disease among children and adults; but what's different about HealthBarn USA is that we are helping children and their parents learn how to read labels to make better food choices and to cook simple, nutritious and delicious meals for the whole family. Taking time to eat together as a family completes the HealthBarn picture."
HealthBarn USA, located at Abma's Farm, Wyckoff, NJ, developed the hands- on innovative curricula in conjunction with Rutgers Cooperative Extension and its esteemed advisory board. The core concept is to educate children, ages 3- 15, and their families through year-round farm programs, summer camp, and school assemblies and workshops. Information on the programs including the one-of-a-kind recipe book -- a "must-have" for parents 'in the know' -- can be obtained online at www.healthbarnusa.com.
CONTACT: Julie Meyer, RD
201-891-2066
press@healthbarnusa.com
Source: HealthBarn USA
Contact: Julie Meyer, RD, of HealthBarn USA, +1-201-891-2066,
press@healthbarnusa.com
Web site: http://www.healthbarnusa.com/
http://www.rachaelrayshow.com/incrediblepeople/
More Vitamin D In Childhood Cut Risk Of Adult Diabetes?
Researchers claim that vitamin D supplements in early childhood could prevent the development of Type 1 diabetes in later life.
The research showed that children given additional vitamin D were around 30 per cent less likely to develop Type 1 diabetes compared with those not given the supplement.
It suggested that the higher and more regular the dose, the lower the likelihood of developing the disease.
Potential to prevent Type 1 diabetes
Dr Victoria King, Research Manager of leading health charity, Diabetes UK, said: "This study suggests that taking vitamin D in childhood has the potential to prevent the development of Type 1 diabetes.
"However, much more research, in particular controlled trials which compares the results when one group of people are given vitamin D supplements and one group is not, are needed before we can confirm a concrete association between vitamin D and Type 1 diabetes."
The results come from the analysis of five separate studies published previously.
Tooth Erosion Caused By Popular Energy Drinks
For more than 10 years, energy drinks in the United States have been on the rise, promising consumers more "oomph" in their day. In fact, it is estimated that the energy drink market will hit $10 billion by 2010. While that may be great news for energy drink companies, it could mean a different story for the oral health of consumers who sometimes daily rely on these drinks for that extra boost.
Previous scientific research findings have helped to warn consumers that the pH (potential of hydrogen) levels in beverages such as soda could lead to tooth erosion, the breakdown of tooth structure caused by the effect of acid on the teeth that leads to decay. The studies revealed that, whether diet or regular, ice tea or root beer, the acidity level in popular beverages that consumers drink every day contributes to the erosion of enamel.
However, in a recent study of General Dentistry, the Academy of General Dentistry's (AGD) clinical, peer reviewed journal, the pH level of soft drinks isn't the only factor that causes dental erosion. A beverage's "buffering capacity," or the ability to neutralize acid, plays a significant role in the cause of dental erosion.
The study examined the acidity levels of five popular beverages on the market. The results proved that popular "high energy" and sports drinks had the highest mean buffering capacity, resulting in the strongest potential for erosion of enamel.
According to the study, the popularity of energy drinks is on the rise, especially among adolescents and young adults. Their permanent teeth are more susceptible to attack from the acids found in soft drinks, due to the porous quality of their immature tooth enamel. As a result, there is high potential for erosion among this age demographic to increase.
In fact, Raymond Martin, DDS, MAGD, AGD spokesperson, says he treats more patients in their teens to 20s for tooth erosion. "They drink a great deal more sodas, sports drinks, and energy drinks," he says. "The results, if not treated early and if extensive, can lead to very severe dental issues that would require full mouth rehabilitation to correct," says Dr. Martin.
Drink responsibly for your oral health:
* Use a straw positioned at the back of the mouth so that the liquid avoids the teeth
* Rinse the mouth with water after drinking acidic beverages
* Limit the intake of sodas, sports drinks and energy drinks
Personal Counseling And Web-Based Strategies Show Modest Success For Sustaining Weight Loss, According
Adults who lost weight in a six-month program were able to keep at least some of the weight off for 2.5 years with the help of brief monthly personal counseling, according to a new study from the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. A Web-based intervention also helped participants keep the weight off for two years, but the benefit waned during the last six months of the trial.
The results of the Weight Loss Maintenance Trial, the largest and longest duration trial to test different weight-loss maintenance strategies, are published in the March 12, 2008, issue of the Journal of the American Medical Association. Results will also be presented at the American Heart Association's Nutrition, Physical Activity, and Metabolism Council Meeting on March 12 in Colorado Springs, Colo.
"Maintaining a healthy weight is a key tenet of every heart disease prevention plan. We have well-tested techniques for successful weight loss, but preventing weight re-gain is especially challenging. This study provides insight into best practices for practical interventions that can help adults keep the weight off and therefore lower their risks for heart disease and other conditions," said Elizabeth G. Nabel, M.D., director, NHLBI.
The study initially enrolled 1,685 overweight or obese adults with high blood pressure or high cholesterol or both. Of those, 1,032 lost an average of 18.7 pounds during an initial six-month weight loss intervention involving 20 weekly group-counseling sessions which emphasized a heart-healthy dietary pattern and three hours per week of physical activity. They were then randomly assigned to one of three strategies for weight loss maintenance: monthly personal counseling on diet and physical activity, a Web-based intervention with the same advice, and self-direction, where participants received minimal further intervention from study staff.
At the end of the study, participants receiving personal counseling retained an average weight loss of 9.2 pounds, compared to an average of 7.3 pounds for those using the Web-based intervention and 6.4 pounds for those in the self-directed group.
Personal counseling sessions were brief and mainly by telephone. The Web site was developed to provide the same advice as personal counseling. Both interventions were designed to be practical to implement in a variety of settings.
"Most people in the study regained at least some of the weight they initially lost. However, both the personal counseling and the Web-based program modestly alleviated weight re-gain for up to two years, with the personal counseling ultimately proving to be the most beneficial by the end of the 2.5 year study," said Laura Svetkey, M.D, a professor of medicine at Duke University Medical Center, and the study's lead author.
Maintaining a healthy weight is an important part of heart disease prevention. Weight loss is shown to lower blood pressure, lower LDL "bad" cholesterol, and help prevent type 2 diabetes. Each 2.2 pounds of weight loss can lower blood pressure by one point and can lower the risk of developing diabetes by 16 percent in high-risk adults.
"The relatively long-term, 24-month success of the Web-based intervention shows promise particularly because of the potential to reach a large number of adults at a relative low cost per person," said Catherine Loria, Ph.D., program officer at NHLBI, and a study co-author. "We need to continue working to improve both interventions so that they are more effective and can be implemented widely."
Approximately 38 percent of participants were African-American and 37 percent of participants were men.
Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at http://www.nhlbi.nih.gov.
Some Diet Risk Perceptions
How good are we at judging what's risky to our health?
Some of our perceptions of risks in our diet fly in the face of science, according to a new survey by the Food Standards Agency. The survey investigated how consumers perceive the risks associated with various food issues in comparison to the scientific evidence.
Survey results
Bird flu - 90% of people would be concerned about eating chicken from a factory contaminated with bird flu. In reality, there's no scientific evidence to show that the food chain has a role in the contraction of bird flu in humans. People can't catch bird flu through eating properly cooked chicken.
Raw milk - nearly a quarter of people, and particularly those aged over 66, thought that there is a very low risk, or no risk at all, from drinking raw (unpasteurised) milk. The science, however, says that raw milk cannot be guaranteed free from germs, even when produced under the best possible hygiene conditions. A study carried out in 1995-96 showed that 60% of samples tested were contaminated with faecal matter. Another study in 1996-97 also showed that 4% of raw milk contained harmful bacteria that could make people ill. Vulnerable groups such as the elderly, the very young and pregnant women are particularly at risk.
Genetically Modified (GM) food - 65% of people were concerned about the safety of consuming GM food. The scientific evidence tells us that the GM foods currently available are as safe as their non-GM counterparts, and pose no additional risk to the consumer. There is general agreement that foods containing GM material need to be labelled to allow consumers to make a choice.
Trust - people are more likely to trust the advice of a friend or a family member on health issues than scientists, even independent scientists.
The survey did, however, show that there is now little concern about the safety of eating beef. There was good awareness of the risks associated with eating too much salt and of the food safety dangers of eating old leftovers.
GACS meeting
The survey was conducted for the launch of the first meeting of the independent General Advisory Committee on Science (GACS) chaired by leading scientist Professor Colin Blakemore, on Tuesday 11 March. GACS will be holding an open panel debate in the afternoon to look at the question 'Should we trust what scientists say about food?'. Panellists will include the Guardian's 'Bad Science' columnist Ben Goldacre.
Prof Colin Blakemore said: 'This survey is just a snapshot of people's opinions about food and risk but it prompts some interesting questions about how and why we judge some food to be risky. The good news is that people are clearly more aware of the impact of some risks to their health - particularly too much salt in their diet and some food safety issues. However, it also seems to show people are more likely to listen to advice about risk from friends than from scientists. It's clear that scientists need to communicate reliable evidence in a way that everyone can understand and to find constructive ways of engaging with the public on areas of concern. It's a challenge that the Food Standards Agency will have to rise to.'
Notes
The overall purpose of the General Advisory Committee on Science (GACS) is to offer independent challenge and advice on how the Food Standards Agency (FSA) collects and uses scientific evidence. The membership of the committee includes 13 expert members and two lay members.
The FSA survey was designed to assess:
- the level of risk consumers associate with various activities, particularly looking at food related issues
- who consumers would trust to tell them about the risk associated with each activity
A series of questions were placed on the RSGB Omnibus survey, which interviewed a representative (in terms of gender, age, and working status) sample of 2,019 UK adults (aged 16+) between the 20 and 24 February 2008. Data was weighted at the analysis stage to ensure that the sample was demographically representative.
Eating chicken from factory contaminated with bird flu
- 90% associated risk with this activity (73% associated high risk with this activity)
- The Advisory Committee on the Microbiological Safety of Food (ACMSF) Avian (Bird) Influenza Risk Assessment considered this issue in May 2007.
Drinking raw (unpasteurised) milk
- 22% considered this to be no or negligible concern
- Older consumers (particular those aged over 66) were more likely to think there is no/negligible risk (28%)
- 1995-1996 Research by ADAS on behalf of the Department of Health. 1996-1997 Research by Public Health Laboratory Service (PHLS). Information on both surveys in paragraph 7-9 of FSA Board Paper.
- Further information also available from FSA Board discussion paper, executive summary, March 2002.
Consuming genetically modified (GM) food
- 65% of people associated risk with this activity
- The Board of the Food Standards Agency stated in June 2000 that it was satisfied that the safety assessment procedures for GM foods were sufficiently robust and rigorous to ensure that approved GM foods were as safe as their non-GM counterparts, and posed no additional risk to the consumer. For more information see the FSA Board Paper.
Eating meat leftovers three days after cooking
- 88% of people associated a risk with this activity
- If you're reheating leftover meat, or other food, always make sure it's piping hot all the way through before you eat it. And don't reheat more than once. Ideally, try to use leftovers within 48 hours. For more information see the Eatwell website.
Eating beef
- 63% of people considered this to be no or negligible concern
- The number of BSE cases in Great Britain has declined from a peak of over 36,000 in 1992 to 53 cases in 2007. Further information is available on the Defra website.
Eating too much salt
- 89% of people associated a risk with this activity
- Eating too much salt can raise your blood pressure. People with high blood pressure are three times more likely to develop heart disease and stroke and twice as likely to die from these conditions than people who have normal blood pressure levels. High blood pressure contributes to 170,000 deaths in England alone every year. The current, daily average salt consumption of people in the UK is 9g. The Government health recommendation is that people should aim to eat no more than 6g of salt per day. More information on salt can be found on the Agency's Salt website.
For more information on the GACS panel debate go to:
- http://www.food.gov.uk/news/newsarchive/2008/feb/debate
Trust
In the survey consumers were asked 'Who would you trust to tell which of the activities posed the most risk to health?'
Percentage of people rating the person/organisation they would trust as their first, second or third choice:
- health professional (such as a doctor) 81%
- someone close to you 48%
- independent scientist 42%
- the Government 21%
- the media 16%
- a charity 13%
- health insurance company 10%
- supermarkets 7%
Food Standards Agency
Broccoli May Help Boost The Aging Immune System
Eat your broccoli! That's the advice from UCLA researchers who have found that a chemical in broccoli and other cruciferous vegetables may hold a key to restoring the body's immunity, which declines as we age.
Published in this week's online edition of the Journal of Allergy and Clinical Immunology, the study findings show that sulforaphane, a chemical in broccoli, switches on a set of antioxidant genes and enzymes in specific immune cells, which then combat the injurious effects of molecules known as free radicals that can damage cells and lead to disease.
Free radicals are byproducts of normal body processes, such as the metabolic conversion of food into energy, and can also enter the body through small particles present in polluted air. A supercharged form of oxygen, these molecules can cause oxidative tissue damage, leading to disease for example, triggering the inflammation process that causes clogged arteries. Oxidative damage to body tissues and organs is thought to be one of the major causes of aging.
"The mysteries of aging have always intrigued man," said Dr. Andre Nel, the study's principal investigator and chief of nanomedicine at the David Geffen School of Medicine at UCLA. "While we have known for some time that free radicals are important in aging, most of the past attention has focused on the mechanisms that produce free radicals rather than addressing the pathways used by the body to suppress their production."
A dynamic equilibrium exists in the body between the mechanisms that lead to increased free radical production and those antioxidant pathways that help combat free radicals.
"Our study contributes to the growing understanding of the importance of these antioxidant defense pathways that the body uses to fight free radicals," said Nel, a practicing clinical allergist and immunologist at the Geffen School. "Insight into these processes points to ways in which we may be able to alleviate the effects of aging."
The delicate balance between pro-oxidant and antioxidant forces in the body could determine the outcome of many disease processes that are associated with aging, including cardiovascular disease, degenerative joint diseases and diabetes, as well as the decline in efficiency of the immune system's ability to protect against infectious agents.
"As we age, the ability of the immune system to fight disease and infections and protect against cancer wears down as a result of the impact of oxygen radicals on the immune system," Nel said.
According to the UCLA study, the ability of aged tissues to reinvigorate their antioxidant defense can play an important role in reversing much of the negative impact of free radicals on the immune system. However, until this current study, the extent to which antioxidant defense can impact the aging process in the immune system was not properly understood.
"Our defense against oxidative stress damage may determine at what rate we age, how it will manifest and how to interfere in those processes," Nel said. "In particular, our study shows that a chemical present in broccoli is capable of stimulating a wide range of antioxidant defense pathways and may be able to interfere with the age-related decline in immune function."
The UCLA team not only found that the direct administration of sulforaphane in broccoli reversed the decline in cellular immune function in old mice, but they witnessed similar results when they took individual immune cells from old mice, treated those cells with the chemical outside the body and then placed the treated cells back into a recipient animal.
In particular, the scientists discovered that dendritic cells, which introduce infectious agents and foreign substances to the immune system, were particularly effective in restoring immune function in aged animals when treated with sulforaphane.
"We found that treating older mice with sulforaphane increased the immune response to the level of younger mice," said Hyon-Jeen Kim, first author and research scientist at the Geffen School.
To investigate how the chemical in broccoli increased the immune system's response, the UCLA group confirmed that sulforaphane interacts with a protein called Nrf2, which serves as a master regulator of the body's overall antioxidant response and is capable of switching on hundreds of antioxidant and rejuvenating genes and enzymes.
Nel said that the chemistry leading to activation of this gene-regulation pathway could be a platform for drug discovery and vaccine development to boost the decline of immune function in elderly people.
"This is a radical new way of thinking in how to increase the immune function of elderly people to possibly protect against viral infections and cancer," Nel said. "We may have uncovered a new mechanism by which to boost vaccine responses by using a nutrient chemical to impact oxidant stress pathways in the immune system."
Kim said that although there is a decline in Nrf2 activity with aging, this pathway remains accessible to chemicals like sulforaphane that are capable of restoring some of the ravages of aging by boosting antioxidant pathways.
The next step is further study to see how these findings would translate to humans.
"Dietary antioxidants have been shown to have important effects on immune function, and with further study, we may be adding broccoli and other cruciferous vegetables to that list," Nel said.
For now, Nel suggests including these vegetables as part of a healthy diet.
Nel said that these findings offer a window into how the immune system ages.
"We may find that combating free radicals is only part of the answer. It may prove to be a more multifaceted process and interplay between pro- and antioxidant forces," he said.
The study was funded by the National Institute on Aging, the UCLA Claude D. Pepper Older Adults Independence Center, and the National Institute of Allergy and Infectious Diseases.
Other study authors included Berenice Barajas and Dr. Meiying Wang.
University of California, Los Angeles (UCLA), Health Sciences
924 Westwood Blvd., Ste. 350
Los Angeles, CA 90095
United States
http://www.ucla.edu
Higher Antioxidant Properties In Torrefacto-Roasted Coffee
Torrefacto-roasted coffee has higher antioxidant properties than natural roast, according to the dissertation defended by a biologist of the University of Navarra, Isabel López Galilea. She has emphasized in her study that the addition of sugar during the roasting process increases the development of compounds with high antioxidant activity.
The researcher of Department of Food Sciences, Physiology and Toxicology of the University of Navarra analyzed eleven varieties of commercial coffee for her study, which was entitled "The Influence of Torrefacto Roasting on the Principal Components of Coffee and its Antioxidant and Pro-oxidant Capacity."
As this scientist of the School of Sciences emphasized, numerous studies have shown the benefits of this drink. In particular, it is considered to be one of the best sources for antioxidants in the diet; these substances help to protect us against free radicals, which are a cause of premature aging and certain diseases. Coffee has an antioxidant capacity which is ten times higher than other drinks, such as red wine and tea.
The antioxidant capacity varies according to the preparation method
In order to carry out this research, Isabel López analyzed the coffee consumption habits of the inhabitants of Navarra, via 300 surveys. The results showed that Navarrans consume an average of 125 ml of coffee per day, with consumption slightly higher among women. In addition, they primarily consume ground coffee resulting from a mixture of natural roast and torrefacto-roast coffees, and the coffee is generally prepared with Italian or mocha coffee makers, followed by the filter, espresso and pump methods.
After confirming the increased antioxidant capacity of ground coffees roasted using the torrefacto process, she showed how these properties were present in the brewed coffee, which is the typical form of coffee consumption. In regard to the different preparation methods, she discovered that espresso machines produce a drink with the highest antioxidant capacity, more than coffee produced by the Italian, filter and pump methods. These properties may be due to the greater content of 'brown compounds' [compuestos pardos] developed during the roasting process, as well as to polyphenic compounds and caffeine.
In addition, she demonstrated that both the compounds contained in coffee as well as its aroma are affected by the type of roast and the system of extraction; nevertheless, this is a topic that will require further study in order to identify results under varying conditions. In her study, Dr. López identified 34 volatile compounds with high aromatic impact on coffee drinks, and new aromatic compounds were detected, such as octanol, which produces an intense orange aroma.
Vegetables And Decreased Risk Of Breast Cancer
When your mother told you to eat your vegetables it appears that maternal wisdom had a scientific basis. Researchers with Vanderbilt-Ingram Cancer Center and the Shanghai Cancer Institute in China have discovered a possible link between a diet rich in certain vegetables and a decreased risk for breast cancer. The study appears in the March issue of the American Journal of Clinical Nutrition.
Corresponding author Jay Fowke, Ph.D., assistant professor of Medicine at Vanderbilt-Ingram, said 3,035 women diagnosed with breast cancer were identified through the Shanghai Cancer Registry. They were closely matched with 3,037 women randomly chosen from the general population there. The women filled out questionnaires about their diet, including consumption of cruciferous vegetables like Chinese cabbage, bok choi and turnips. Americans typically eat more broccoli, kale and cauliflower in the cruciferous vegetable family.
"Cruciferous vegetables contain some compounds that may have a cancer-inhibitory effect," explained Fowke. "Here we were able to identify a group of women who seem to particularly benefit from a high intake of these vegetables."
While there was only a small positive relationship between a diet high in these vegetables and a reduction in breast cancer risk for the overall study population, there was a striking risk reduction 50 percent among women with a certain genetic profile. Researchers identified three forms of the GSTP1 genotype among the cancer patients: Ille/Ile, Ile/Val and Val/Val.
"Women who consumed more of these cruciferous vegetables and who also had the Val/Val genetic polymorphism had a lower breast cancer risk. So we cautiously interpreted this as diet being a factor that may reduce the impact of genetic susceptibility in overall breast cancer risk," said Fowke.
The Vanderbilt-Ingram researchers focused on cruciferous vegetables because they contain two chemicals called isothiocyanates and indole-3-carbinol which may affect carcinogenesis by triggering cell death or by shifting estrogen metabolism. Studies by other researchers have suggested cruciferous vegetables may reduce the risk of lung, stomach, colorectal and bladder cancers.
"We have known for some time that certain foods, like soy foods, appear to interfere with the development of breast cancer because they contain plant estrogens," said Fowke. "The protective effect from cruciferous vegetables in this study was certainly suggestive of a risk reduction, but researchers need to replicate this finding in other studies."
Scientists were able to isolate the specific genetic profile linked with a positive dietary impact because the women in the study submitted DNA through blood and cheek cell samples. Wei Zheng, M.D., Ph.D., professor of Medicine at Vanderbilt-Ingram is the principal investigator for the Shanghai Breast Cancer study.
"The Shanghai Breast Cancer Study is one of the largest and most comprehensive epidemiological studies conducted to date for this common cancer," according to Zheng. "We have published over 100 research papers in this study addressing a large range of significant issues related to the etiology and survival of breast cancer. The results reported by Dr. Fowke may have significant implications in breast cancer prevention."
While women in this study answered questionnaires about their diets, researchers want to measure more precisely the intake of cruciferous vegetables. To aid in future studies they are collecting urine samples which contain biomarkers for the beneficial chemicals.
Authors for this paper include: Sang-Ah Lee, Wei Lu, Chuangzhong Ye, Ying Zheng, Qiuyin Cai, Kai Gu, Yu-Tang Gao, Xiao-ou Shu and Wei Zheng.
Vanderbilt University Medical Center
D-3237A Medical Center North
Nashville, TN 37232-2390
United States
http://www.mc.vanderbilt.edu
Supplement Containing Blueberry And Green Tea Protects Against Stroke Damage
A unique dietary supplement called NutraStem ® has been shown to have beneficial effects following experimental stroke. A nutritional supplement product, NutraStem also known as NT-020, is a proprietary formulation of blueberry, green tea, vitamin D3 and carnosine extracts - a combination of nutritional ingredients thought to be potent in protecting against brain damage.
"Stroke is the third leading cause of death and the leading cause for disability in the U.S. with two of every 1,000 adults experiencing their firsts stroke in any given year," said Cesar V. Borlongan, PhD, of the Medical College of Georgia, lead author of a study that tested NT-020 post stroke effects in animal models. "We explored how increasing the nutritive diet through NT-020 supplementation might render a therapeutically potent neurogenesis following stroke."
NutraStem was developed by Natura Therapeutics, Inc., based in Tampa, Florida and founded by neuroscientists from the University of South Florida.. NutraStem was designed to encourage the proliferation of adult stem cells, which have the potential to develop into most tissues and bone cells in the body and have the capacity to migrate toward problem or damaged areas.
A study, conducted jointly by scientists at the University of South Florida College of Medicine (Tampa) and the Medical College of Georgia (Augusta), examined two groups of laboratory animals in a double-blind procedure. One group received the dietary supplement for two weeks prior to undergoing surgical stroke. The second group did not receive the dietary supplement. Results, published online in the high-impact journal REJUVENATION RESEARCH), showed that the group receiving NutraStem had greatly reduced neural damage in the brain and demonstrated significantly reduced motor deficits.
"The numbers of new neurons found in the damaged brain of the treated rats was significantly higher," said co-author Paula Bickford, PhD, of the University of South Florida College of Medicine and co-founder of Natura Therapeutics, Inc. "An important feature of our results is that the combination of agents used was 100 times more potent than previously published study results that examined each of the individual ingredients used by themselves."
Co-author Cyndy D. Sanberg, PhD, of Natura Therapeutics, Inc., noted that while eliminating detrimental calories has been found to be protective against stroke by reducing oxidative stress, the nutritive diet of NutraStem could enhance and augment that approach.
"Our study found robust neuroprotective effects of the NT-020 formula," said Borlongan. "Two weeks of NutraStem therapy lessened stroke-induced behavioral deficits, reduced stroke-induced infarcts and promoted the birth of new neurons. Our results provide a critical advance in the scientific and clinical arena by demonstrating the advantage of a multi-agent over a single agent regimen."
Low-Fat Diets More Likely To Reduce Risk Of Heart Disease Than Low-Carb Diets
Low-fat diets are more effective in preserving and promoting a healthy cardiovascular system than low-carbohydrate, Atkins'-like diets, according to a new study by researchers at the Medical College of Wisconsin in Milwaukee.
The study, published in the February edition of the scientific journal Hypertension, was led by David D. Gutterman, M.D., Northwestern Mutual Professor of Cardiology, professor of medicine and physiology, and senior associate dean of research at the Medical College. Shane Phillips, M.D., a former Cardiology faculty member at the Medical College, and now assistant professor in the department of physical therapy at the University of Illinois - Chicago, was the lead author.
Public awareness of the "obesity epidemic" has resulted in various dietary weight loss strategies. In America, it is estimated that 45 percent of women and 30 percent of men diet to lose weight.
"The nutrient-specific effects of these diets on cardiovascular health are largely unknown," says Dr. Gutterman.
"Low-carbohydrate diets are significantly higher in total grams of fat, protein, dietary cholesterol and saturated fats than are low-fat diets. While a low-carbohydrate diet may result in weight loss and improvement in blood pressure, similar to a low-fat diet, the higher fat content is ultimately more detrimental to heart health than is the low-fat diet suggested by the American Heart Association," points out Dr. Phillips.
"The higher fat content of a low-carbohydrate diet may put dieters at an increased risk of atherosclerosis (hardening of the arteries) because low-carbohydrate diets often reduce protection of the endothelium, the thin layer of cells that line the blood vessels of the circulatory system. The reduced production from the endothelium of nitric oxide, a specific chemical, puts the vessel at higher risk of abnormal thickening, greater clotting potential, and cholesterol deposition, all part of the atherosclerosis process," says Dr. Gutterman.
Over a six-week period, the researchers found reduced flow-mediated dilation in the arm artery in participants who were on the low-carbohydrate diet. Reduced flow-mediated dilation, as measured in this study, is an early indicator of cardiovascular disease. On the other hand, flow-mediated dilation improved significantly in participants on the low-fat diet suggesting a healthier artery which is less prone to developing atherosclerosis.
"We observed a reduction in brachial artery flow-mediated dilation after six weeks of weight loss on a low-carbohydrate, Atkins'-style diet," Dr. Gutterman says.
Low-carbohydrate diets were also found to have significantly less daily folic acid than low-fat diets. Folic acid is thought to be helpful in reducing the likeliness of heart disease. This protective effect results from the antioxidant property of folic acid and its ability to lower levels of homocysteine, a naturally occurring amino acid that can be dangerous at elevated levels.
The low-carbohydrate diet provided 20 grams of carbohydrates daily and was supplemented with protein and fat content according to the Atkins' diet recommendations. The low-fat diet provided 30 percent of the calories as fat, and was modeled after the American Heart Association's recommendations.
"The composition of diet may be as important as the degree of weight loss in determining the effect of dietary interventions on vascular health," Dr. Gutterman notes.
Twenty participants between the ages of 18 to 50 with a body mass index ranging from 29 to 39 were monitored for the study, and the type of diet was randomly assigned to participants. Weight loss, flow-mediated dilation, blood pressure and insulin and glucose levels in the participants were measured every two weeks for the six-week study.
Daily Breakfast Eating Linked To Lower BMI Among Teens
US researchers have found that teenagers who ate breakfast every day were more likely to have a healthier diet, exercise regularly and have a lower Body Mass Index (BMI) five years later compared to same age counterparts who skipped breakfast.
The study is the work of epidemiologists working on the University of Minnesota School of Public Health Project Eating Among Teens (EAT) at the University of Minnesota in Minneapolis and is published in the March online issue of the journal Pediatrics.
Body Mass Index is the ratio of a person's weight in kilos to their height in metres squared.
Cross sectional studies looking at teenagers of different ages have already linked skipping breakfast with higher BMI, but there have been few studies that follow groups of children as they get older.
Study author Dr Mark Pereira said this study makes an important contribution in this less examined area because of its duration and size.
"The dose-response findings between breakfast frequency and obesity risk, even after taking into account physical activity and other dietary factors, suggests that eating breakfast may have important effects on overall diet and obesity risk, but experimental studies are needed to confirm these observations," said Pereira.
The past 20 years have seen a doubling in American childhood obesity rates, and for teens the rate has nearly tripled.
57 per cent of adolescent girls and 33 per cent of adolescent boys frequently use unhealthy approaches to control weight, and the researchers said estimates show between 12 and 24 per cent of children and teenagers regularly skip breakfast. And the number who do so goes up with age.
The researchers examined the link between breakfast eating frequency and change in body weight after 5 years in 2,216 teenagers.
Project EAT (Eating Among Teens) was a 5-year longitudinal study that looked at teenagers' eating patterns and weight concerns.
Participants completed questionnaires during 1998 and 1999 (first round) and then again during 2003 and 2004 (second round, five years later).
Using statistical linear regression analysis the researchers explored the link between how often the teenagers had breakfast and their change in BMI. The figures were adjusted for age, race, physical activity, socio-economic group, their BMI in round 1, and other diet and weight factors at the start of the study.
The results showed that:
* At the start of the study, the teenagers who ate breakfast more frequently were more likely to be white, physically active, have the highest carbohydrate and fibre intake, and have higher socio-economic status.
* On the other hand, the teenagers who ate breakfast less frequently were the ones who were most likely to smoke, drink alcohol, and use dieting and other ways to control their weight.
* Cross sectional analyses of data taken at the start and at the end of the study showed that the link between less frequent breakfast eating and higher BMI was mostly independent of all the potential confounders.
* Factors related to weight, such as concerns, behaviours and pressures, did not explain the link between breakfast eating and BMI.
* Prospective analyses (where the group is followed), showed that frequency of breakfast eating was inversely linked with BMI in a dose-response pattern.
Pereira and colleagues concluded that these findings:
"Support the importance of promoting regular breakfast consumption among adolescents."
"Future studies should further examine the role of breakfast habits among youth who are particularly concerned about their weight," they added.
They also pointed out that because the study was not an experimental design, they cannot say that skipping breakfast caused the higher BMI. An experimental study would have to be done to establish a causal link, they said.
However, principal investigator of Project EAT, Dr Dianne Neumark-Sztainer, said this study confirmed the importance of helping teenagers learn to start the day "right" by eating breakfast. Although they may think:
" That skipping breakfast seems like a good way to save on calories, findings suggest the opposite," she said.
"Eating a healthy breakfast may help adolescents avoid overeating later in the day and disrupt unhealthy eating patterns, such as not eating early in the day and eating a lot late in the evening," explained Neumark-Sztainer.
"Breakfast Eating and Weight Change in a 5-Year Prospective Analysis of Adolescents: Project EAT (Eating Among Teens)."
Maureen T. Timlin, Mark A. Pereira, Mary Story, and Dianne Neumark-Sztainer.
Pediatrics 2008; 121: e638-e645.
March 2008, Volume 121, Issue 3.
Tighter Tummies: A New Way To Combat Weight Gain
Two cell proteins that relax the gut and help accommodate a big meal have been identified by UCL (University College London) scientists. The proteins could offer a future drug target against weight gain, by preventing the stomach from expanding.
In a paper published in this month's issue of the Journal of Pharmacology and Experimental Therapeutics, Dr Brian King and Dr Andrea Townsend-Nicholson explored the molecular basis of relaxations of the gut. In the study, the authors identified two protein receptors - P2Y1 and P2Y11 - involved in fast and slow relaxations of the gut. These proteins were identified in the guinea pig, but are also present in the human gut, and thus offer the potential as a future target for drug treatment. Further research by the UCL team will focus on the human isoform of the P2Y11 protein receptor.
Dr Brian King of the UCL Department of Neuroscience, Physiology and Pharmacology says: "The mechanisms we have identified are important to the normal workings of the stomach - a hollow organ which actively relaxes to help accommodate the size of your meal. The human stomach has a 'resting' internal volume of 75 millilitres but, by relaxing its muscular wall, can expand to an internal volume of two litres or more - a 25-fold increase in the volume it can accept. This expansion is controlled by nerves inside the stomach wall and these nerves release molecules that stimulate the P2Y1 and P2Y11 receptor proteins embedded in muscle cells in the gut wall.
"The mechanism of slow relaxation of the stomach might represent a future drug target in the fight to control weight gain and reverse obesity. We are looking to identify drugs that would block the P2Y11 receptor and, therefore, prevent slow relaxation of the stomach. As a result of blocking the P2Y11-based mechanism, meal size would be smaller, offering the person a better chance of regulating their food intake.
"This would be a brand new approach to weight control. At present, the most successful way to help obese patients lose weight is gastric banding or stomach stapling, both of which reduce the maximum volume of the stomach. But these are also tricky surgical procedures, not without attendant risks. A pill that could replace this surgery, yet have the same effect, might be a useful alternative."
'Involvement of P2Y1 and P2Y11 Purinoceptors in Parasympathetic Inhibition of Colonic Smooth Muscle' is published in the March edition of the Journal of Pharmacology and Experimental Therapeutics (Volume 324 (Issue 3), 1055-1063).
