UF/IFAS STUDY: WHEN IT COMES TO GLUTEN-FREE DIETS, UNFOUNDED BELIEFS ABOUND
From the FMS Global News Desk of Jeanne Hambleton Posted: 29-Jul-2014 University of Florida Institute of Food and Agricultural Sciences
Newswise — GAINESVILLE, Fla. – While necessary for some, many people eat gluten-free diets because they believe they will gain certain health benefits, but these beliefs are not all supported by research, a University of Florida nutrition expert says.
Those with celiac disease, or about 1 percent of the U.S. population, must follow a gluten-free diet because it’s the only treatment for their condition, said Karla Shelnutt, a UF assistant professor in family, youth and community sciences. But gluten-free diets can lack essential nutrients if a person does not eat a balanced diet and/or take a multivitamin supplement.
Unlike their conventional counterparts, refined gluten-free foods, for the most part, are not enriched or fortified with essential vitamins and minerals.
“If I am a college student, and I want to lose weight, and I read on the Internet that a gluten-free diet is the way to go, I may start avoiding products that contain essential nutrients such as those found in cereal grains fortified with folic acid,” Shelnutt said.
“The problem is you have a lot of healthy women who choose a gluten-free diet because they believe it is healthier for them and can help them lose weight and give them healthier skin.”
The $10.5-billion gluten-free food and beverage industry has grown 44 percent from 2011-13 as the rate of celiac disease diagnoses increases, along with awareness of gluten-free foods, according to Mintel, a market research company. Mintel estimates sales will top $15 billion in 2016.
One of Shelnutt’s doctoral students, Caroline Dunn, wanted to know if gluten-free labeling has any impact on how consumers perceive the foods’ taste and nutrition.
In a one-day experiment on the UF campus in Gainesville in February, 97 people ate cookies and chips, all gluten-free. Half were labeled “gluten-free”; the other half labeled “conventional.”
Participants then rated each food on a nine-point scale for how much they liked the flavor and texture. They also filled out a questionnaire, said Shelnutt, a faculty member with UF’s Institute of Food and Agricultural Sciences.
About a third of participants said they believed gluten-free foods to be healthier than those labeled “conventional,” a figure she thought would be much lower. While avoiding gluten-containing foods can reduce carbohydrate intake, thus helping some lose weight, many health experts say a gluten-free diet is no healthier than a conventional diet except for those with celiac disease.
Although such a small sample cannot be generalized to the public, Shelnutt said the experiment gives researchers insight into how the public views gluten-free foods.
For example, 57 percent of participants believed gluten-free diets can be used to alleviate medical conditions, and 32 percent said doctors prescribe them for weight loss. Thirty-one percent believed gluten-free diets improve overall health, 35 percent believed them to improve digestive health and 32 percent felt that eating them would improve their diet.
Gluten, a protein, is found in grains such as wheat, barley, rye and triticale, a cross between wheat and rye. A gluten-free diet is prescribed for those with celiac disease, a condition that can damage the lining of the small intestine.
The experiment’s results are published in the current edition of the Journal of Nutrition Education and Behavior.
BRAIN RESPONSE TO APPETIZING FOOD CUES VARIES AMONG OBESE PEOPLE
From the FMS Global News Desk of Jeanne Hambleton Released: 30-Jul-2014 Newsroom: Endocrine Society-Journal of Clinical Endocrinology & Metabolism
Newswise — Washington, DC—People who have the most common genetic mutation linked to obesity respond differently to pictures of appetizing foods than overweight or obese people who do not have the genetic mutation, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).
More than one-third of adults are obese. Obesity typically results from a combination of eating too much, getting too little physical activity and genetics. In particular, consumption of appetizing foods that are high in calories can lead to weight gain.
Highly palatable foods such as chocolate trigger signals in the brain that give a feeling of pleasure and reward. These cravings can contribute to overeating. Reward signals are processed in specific areas of the brain, where sets of neurons release chemicals such as dopamine. However, very little is known about whether the reward centers of the brain work differently in some people who are overweight or obese.
The most common genetic cause of obesity involves mutations in the melanocortin 4 receptor (MC4R), which occur in about 1 percent of obese people and contribute to weight gain from an early age. The researchers compared three groups of people: eight people who were obese due to a problem in the MC4R gene, 10 people who were overweight or obese without the gene mutation and eight people who were normal weight. They performed functional Magnetic Resonance Imaging (fMRI) scans to look at how the reward centers in the brain were activated by pictures of appetizing food such as chocolate cake compared to bland food such as rice or broccoli and non-food items such as staplers.
“In our study, we found that people with the MC4R mutation responded in the same way as normal weight people, while the overweight people without the gene problem had a lower response,” said lead researcher Agatha van der Klaauw, MD, PhD, of the Wellcome Trust-MRC Institute of Metabolic Science at Addenbrooke’s Hospital in Cambridge, U.K.
“In fact, the brain’s reward centers light up when people with the mutation and normal weight people viewed pictures of appetizing foods. But overweight people without the mutation did not have the same level of response.”
The scans revealed that obese people with the MC4R mutation had similar activity in the reward centers of the brain when shown a picture of a dessert like cake or chocolate as normal weight people. The researchers found that, in contrast, the reward centers were underactive in overweight and obese volunteers who did not have the gene mutation. This finding is intriguing as it shows a completely different response in two groups of people of the same age and weight.
“For the first time, we are seeing that the MC4R pathway is involved in the brain’s response to food cues and its underactivity in some overweight people,” van der Klaauw said.
“Understanding this pathway may help in developing interventions to limit the overconsumption of highly palatable foods that can lead to weight gain.”
To address the obesity epidemic, the Cambridge team is continuing to study the pathways in the brain that coordinate the need to eat and the reward and pleasure of eating.
Other authors of the study include: Julia M. Keogh, Elana Henning, Stephen O’Rahilly and Sadaf Farooqi of the Wellcome Trust-MRC Institute of Metabolic Science; and Elisabeth A.H. vom dem Hagen, Andrew D. Lawrence and Andrew J. Calder of the MRC Cognition and Brain Sciences Unit in Cambridge, U.K.
The study, “Obesity Associated Melanocortin-4 Receptor Mutations are Associated with Changes in the Brain Response to Food Cues,” was published online, ahead of print.
The study was funded by the Wellcome Trust, MRC and NIHR Cambridge Biomedical Research Centre.
Founded in 1916, the Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, the Endocrine Society’s membership consists of over 17,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Washington, DC.
TASTY: THE ART AND SCIENCE OF WHAT WE EAT
From the FMS Global News Desk of Jeanne Hambleton Posted on August 4, 2014 by Stone Hearth News
A fascinating and deeply researched investigation into the mysteries of flavor—from the first bite taken by our ancestors to scientific advances in taste and the current “foodie” revolution.
Taste has long been considered the most basic of the five senses because its principal mission is a simple one: to discern food from everything else. Yet it is really the most complex and subtle. Taste is a whole-body experience, and breakthroughs in genetics and microbiology are casting light not just on the experience of french fries and foie gras, but the mysterious interplay of body and brain.
With reporting from kitchens, supermarkets, farms, restaurants, huge food corporations, and science labs, Tasty tells the story of the still-emerging concept of flavor and how our sense of taste will evolve in the coming decades. Tasty explains the scientific research taking place on multiple fronts: how genes shape our tastes; how hidden taste perceptions weave their way into every organ and system in the body; how the mind assembles flavors from the five senses and signals from body’s metabolic systems; the quest to understand why sweetness tastes good and its dangerous addictive properties; why something disgusts one person and delights another; and what today’s obsessions with extreme tastes tell us about the brain.
Brilliantly synthesizing science, ancient myth, philosophy, and literature, Tasty offers a delicious smorgasbord of where taste originated and where it’s going—and why it changes.
If you are looking for more information John McQuaid has published a book called ‘Tasty, The Art & Science of What We Eat’.
See you tomorrow. Jeanne