New insights on the relationship between diet, body weight, inflammation and chronic disease will be presented by nutritional experts in the field at a symposium, “Taming the Fires of Inflammation Through Diet,” sponsored by the California Strawberry Commission at the American Dietetic Association Food and Nutrition Conference and Expo in Honolulu, Hawaii on September 16, 2006. Zhaoping Li, MD, PhD, Associate Professor of Medicine, Center for Human Nutrition, David Geffen School of Medicine at University of California, Los Angeles will share a detailed look at the process of inflammation, discuss the effects of inflammation in normal weight adults, and emerging research from clinical trials looking at strawberry consumption’s impact on inflammation in normal weight adults. Britt Burton- Freeman, PhD, Assistant Research Nutritionist, Department of Nutrition, University of California, Davis will discuss the effects of inflammation in overweight and obese adults and emerging research from clinical trials looking at strawberry consumption’s impact on inflammation in overweight and obese adults. Below is a summary of their presentation.
Zhaoping Li, MD, PhD – “The Secret Killer,” a Time magazine cover story in February 2004 brought inflammation center stage, discussing the role of inflammation in cancer, diabetes, and cardiovascular, pulmonary, neurological, and autoimmune diseases. Inflammation is the first response of the immune system to infection or irritation, causing the production of cytokines. A cascade occurs as various leukocytes cause the initiation and maintenance of inflammation, further stimulated by lymphocytes such as T cells, B cells and antibodies. C-reactive protein (CRP) is produced by the liver in response to cytokine production. High-sensitivity CRP (hs-CRP) has been suggested to predict future cardiovascular events in healthy men and women. In fact, a meta-analysis published in the New England Journal of Medicine indicated that hs-CRP is a stronger predictor of future cardiovascular events than the total cholesterol/HDL cholesterol ratio, LDL cholesterol, total cholesterol, and homocysteine.
A correlation has been established between inflammation and diet. There is an inverse relationship between phytonutrients, non-nutritive compounds found in fruits and vegetables, and CRP. In a study published in the American Journal of Clinical Nutrition, participants who consumed eight servings of fruits and vegetables per day had significantly lower CRP levels than those who consumed two and five per day. Researchers at UCLA are identifying phytonutrients in strawberries, developing methods to detect strawberry phytonutrients and their biological activities in human blood and urine. They have found that strawberry phytonutrients include flavanoids such as anthocyanins and flavonols, hydrolyzable tannins such as ellagic acid and glycosides, and phenolic acids such as hydroxycinnamic acids and esters. Their research has suggested that bioactives of compounds in human plasma and urine have desirable effects on hs-CRP and inflammation.
Britt Burton-Freeman, PhD – Obesity is a major risk factor for many chronic diseases and increasing adiposity is associated with increased CRP. In fact, multiple studies showed that CRP was significantly higher in overweight and obese individuals than normal weight individuals. Adipose tissue is actually a dynamic tissue with endocrine function. Obesity represents a pro-inflammatory state and weight loss decreases the inflammatory state. Obesity can be a model for studying inflammatory response and researchers are asking the following questions: Can changing the dietary pattern, independent of weight loss, decrease the pro/anti-inflammatory response profile, and reduce disease risk? Can changing the dietary pattern in addition to weight loss augment/enhance the anti- inflammatory benefits of weight loss? Dietary intervention that increases phytonutrient intake does make a difference according to research published in the American Journal of Clinical Nutrition. These bioactive compounds quiet the endothelium, increase anti-oxidant activity, and decrease cytokine synthesis.
Research at UC Davis is focusing on human studies in overweight and obese subjects. Individuals are being fed a Strawberry Intervention diet (4 servings per day) or a Standard Diet. Endpoints being investigated include changes in lipid profile, the inflammatory profile, endothelial function, and oxidative stress.