1a. Objectives (from AD-416):
LAB: Epidemiology 1. Using an epidemiologic approach, investigate the role of whole grains, selected nutrients, other bioactive food components, and healthy dietary patterns in preventing age-related development of metabolic risk factors for type 2 diabetes mellitus, cardiovascular disease, cancer and musculoskeletal disorders, and age-related eye disease. 1A. Determine if higher whole-grain intake is associated with less visceral adiposity and a lower waist circumference. 1B. Determine if diet differs between “metabolically healthy but obese" (MHO) individuals and “metabolically abnormal obese” (MAO) individuals. 1C. Determine if higher intakes of various classes of flavonoids are associated with a healthier profile of intermediate markers of CVD risk. 1D. Determine if a plant-based diet will improve the diet quality and consequently affect disease risk through its effects on underlying inflammation, lipid metabolism, insulin sensitivity and endothelial function. 1E. Determine if higher whole grain intake is associated with a lower risk congestive heart failure (CHF) 2. Determine the validity of biomarkers for whole grain intake, their use in assessing relationships between whole grain intake and disease risk, and the relationship between these biomarkers and insulin resistance phenotypes. 3. Using an epidemiologic approach, examine determinants of adherence to the recommended dietary patterns in the Dietary Guidelines for Americans (DGA) and the relation between adherence to these patterns and prevention of age-related weight gain, abdominal obesity, and related metabolic disorders such as inflammation, endothelial dysfunction and insulin resistance. 4. Using an epidemiologic approach, investigate safe upper limits for the dietary intake of folic acid. 5. Using an epidemiologic approach, determine relationships between dietary intake and nutrient status and the prevention of age-related cognitive decline in humans. 6. Using an epidemiologic approach, investigate the role of nutritional factors in limiting the coromorbidities such as CVD and premature mortality in individuals with chronic kidney disease (CKD). LAB: Dietary Assessment 1. Use an epidemiologic approach to determine if micronutrient intake and dietary patterns are associated with bone status and fracture risk in older adults. 2. Use an epidemiologic approach to determine if micronutrient intake and dietary patterns are associated with depression and cognitive function in older adults. 3. Use an epidemiologic approach to identify behavioral factors that are associated with obesity in diverse population groups. 4. Use an epidemiologic approach to determine how genetic polymorphisms modify dietary effects on risk of diabetes in older adults. 5. Use an epidemiologic approach to determine associations between stress, diabetes and physical disability in older Puerto Rican adults, and the role of dietary patterns in moderating these associations.
1b. Approach (from AD-416):
LAB: Epidemiology Many age-related conditions, such as cardiovascular disease, diabetes, dementia, cancer, musculoskeletal disorders and age-related eye disease, appear to have strong nutritional components. Improved nutrition through public health recommendations and interventions could have a tremendous impact on the economic and societal costs associated with these disabilities, but development of recommendations and interventions requires a greater understanding of the presumptive role that nutrition plays in delaying the onset of disease and disability. Epidemiologic methods applied to community-based investigations of aging populations provide a valuable tool to help meet this need. We will use these methods to address project objectives. LAB: Dietary Assessment We will achieve project objectives by continuing to work with existing cohorts of aging adults in the US population, including our own Boston Puerto Rican Health Study and Nutrition and Memory in the Elderly Study, and through active collaboration with the Framingham Studies, the Baltimore Longitudinal Study on Aging and the VA Normative Aging Study. In each of these, we either collect and analyze or interpret dietary intake and/or biochemical measures and relate them to health outcomes. In addition, we will collaborate across the ARS Human Nutrition Research Centers to conduct a new multi-center assessment of barriers and facilitators of adherence to dietary guidelines to prevent obesity. Together this body of work will contribute to a better understanding of the importance of specific foods, nutrients and dietary patterns in health maintenance with aging and in prevention of obesity and related chronic conditions.
3. Progress Report:
This progress report includes the work of one subordinate project at the HNRCA funded through a Specific Cooperative Agreement with TUFTS UNIVERSITY. For further information and progress report, see 1950-51530-009-01S (Epidemology, nutrition and problems of aging).
1. Dairy consumption slows age-related gains in weight and waist circumference. The possibility that consuming dairy products may influence body weight has been considered in a number of randomized controlled trials (RCTs) and prospective observational studies. Collectively they have not fully accounted for weight maintenance or prevention of weight gain, or have largely failed to account for the changes in dairy intake during follow-up, the higher overall diet quality of dairy consumers, and possible differential effects of dairy food type (e.g., high vs. low fat, fermented vs. not fermented). To overcome deficiencies of earlier studies, ARS funded researchers at JMUSDA-HNRCA at Tufts University at Boston, Massachusetts used data from a cohort with several repeated measurements on dietary intake, overall diet quality, body weight and waist circumference (WC) to examine the association between consumption of different types of dairy products and long-term changes in weight and WC among American adults over an average follow-up period of 13-years. Participants who consumed 3 or more servings per day of total dairy had 50% smaller rate of weight gain per year than those consuming <1 serving per day. Participants who consumed 3 or more servings per week of yogurt also gained 50% less weight and 20% less waist circumference per year than those consuming <1 serving per week. Skim/low-fat milk, cheese, total high-fat or total low-fat dairy intake were not associated with long-term change in weight or WC. These results provide evidence for the need to include specific dietary guidance for food product categories in the fight against obesity.
2. High folic acid increases cognitive decline in vitamin B12 deficient individuals. Questions remain about the safety of high folic acid intakes. Accumulating evidence suggests that high folic acid intake interacts with vitamin B12 deficiency in a manner that masks the most common symptoms of vitamin B12 deficiency while precipitating the development of neuropathy associated with B12 deficiency. This may be a special concern among older adults in whom vitamin B-12 deficiency is highly prevalent due to the diminished ability to detach vitamin B-12 from food protein because of age-related achlorhydria. ARS funded researchers at JMUSDA-HNRCA at Tufts University at Boston, Massachusetts demonstrated that cognitive decline was significantly faster in persons with low plasma vitamin B-12 levels and that having a high plasma folate concentration associated with folic acid intake or using folic acid supplements enhanced this decline in cognitive function. Results of this study will help inform recommendations for vitamin B12 and folic acid intakes, particularly for safe upper limits for folic acid intake.
3. Higher flavonol intakes as associated with a lower type 2 diabetes incidence. There is growing evidence based on in vitro and animal research that flavonoids, a class of polyphenols, can improve glucose homeostasis, and enhance insulin secretion and sensitivity. There are relatively few clinical studies that examined the effect of flavonoid interventions in humans on glucose homeostasis and insulin resistance, but a recent systematic review of cocoa trials (cocoa being a good source of the flavonoid flavan-3-ol) showed that cocoa interventions improved insulin resistance. These findings would suggest that flavonoids might reduce the risk of developing type 2 diabetes (T2D). The purpose of the present study was to examine the hypothesis that higher intakes of three flavonoid classes previously shown to relate to glucose homeostasis and insulin resistance, specifically the flavonols, flavan-3-ols and anthocyanins, are associated with a lower incidence of T2D. ARS funded researchers at JMUSDA-HNRCA at Tufts University at Boston, Massachusetts observed that a 2.5-fold increase in flavonol and flavan-3-ol intakes were associated with a 26% and 11% lower incidence of T2D, respectively. Our observations support previous experimental evidence of a possible beneficial relationship between increased flavonol intake and risk of T2D, a largely preventable condition with serious health consequences, including a greater risk of heart disease, stroke, peripheral neuropathy, renal disease, and vision loss.
Morris, M.S., Jacques, P.F. 2012. Total protein, animal protein, and physical activity in relation to muscle mass in middle-aged and older Americans. British Journal of Nutrition. 2:1-10.