On May 4, 2007, the Department of Foods and Nutrition at Purdue University sponsored Get the Facts: Hot Topics in Nutrition. Nutrition research leads to many apparent controversies. This is true partly because the role of diet in health depends on the particular population being studied. Secondly, the public follows each new finding with interest rather than waiting for a consensus opinion from the scientific community. Several of the leading controversies of today and new areas of interest were addressed at this conference.
The NIH Women’s Health Initiative provided many surprises compared to earlier, smaller studies. The WHI is the largest clinical trial and observational study in history involving 161,808 generally health postmenopausal women. Dr. Connie Weaver discussed the overall findings that showed low dietary fat and calcium plus vitamin D interventions did not specifically reduce instance of breast cancer, cardiovascular disease or bone fractures and hormone therapy had undesirable side effects. However, subgroups that were compliant and had unhealthy baseline levels responded favorably. Continued follow-up may show benefits as chronic diseases have long latency periods.
Tea is the most popular beverage, second only to drinking water. Dr. Dorothy Morre connected the benefits of drinking green tea to cancer prevention, weight loss and cardiovascular health. Her basic work that shows green tea extracts can suppress tumor growth is now in clinical trials.
It is well understood in nutrition that the nutrient composition of foods, determined instrumentally, may not equal the concentrations of nutrients biologically available to the consumer. Multiple mechanisms may be responsible. In nutrition science, there is widespread awareness of factors that may influence the absorption of nutrients from the gastrointestinal tract and their distribution throughout the body. This is referred to as bioavailability. However, there is another set of important determinants that act at the level of release of nutrients from the food matrix. These factors determine the bioaccessibility of nutrients. Ultimately, it is the combined effects of these factors that determine the nutritional value of a food. Dr. Peter Ellis from King’s College in London, provided an overview of bioaccessibility and described mathematical models his team is developing to predict the release of nutrients from different foods.
The increasing prevalence of obesity and its attendant complications has prompted intensive research on the possible origins of the problem. Many implicate dietary changes. One shift that coincides with the rise of obesity is increased caloric beverage consumption. Dr. Richard Mattes reviewed the literature on the link between ingestion of energy in fluid form, energy balance and weight gain. He presented a case that beverages, in particular, were likely causally related to weight gain because they elicit very weak satiety and energy compensation. Importantly, he emphasized that the association was strong with a variety of beverages thus implicating the food form rather than energy source (e.g., high fructose corn syrup).
Dr. James Fleet discussed how one’s genetic profile can influence the role of diet and health. Dr. Qing Jiang shared her latest research related to the cardiovascular benefits of Vitamin E. Dr. Kim Buhman clarified issues related to the effects of trans fatty acids on obesity and food labeling for packaged foods.
The conference closed with wise reflections by Karen Konzelman, former program director of EFNEP for Purdue Extension and former National Program Leader for Maternal and Infant Health. More information regarding Get the Facts: Hot Topics in Nutrition can be obtained by contacting Marleen Troyer at firstname.lastname@example.org.