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 reports, see 1950-51530-009-01S (Epidemology, nutrition and problems of aging)
1. LAB: Nutritional epidemiology: Lycopene and tomato product intake reduce incidence of cardiovascular disease (CVD). The limited number of prior studies examining the relationship between CVD and lycopene intake, a carotenoid derived mainly from tomatoes, failed to show any benefits of lycopene intake in spite of experimental evidence suggesting the opposite. We used repeated measurements of diet for up to ten years to characterize usual long-term intake of lycopene and tomato products in order to fill the gap in availability of longitudinal data. We observed that incidence of CVD was 15-25% lower among those with the highest lycopene intakes compared to those with the lowest intakes; similar results were seen based on the intake of tomato products. Including more tomato products as part of a healthy diet pattern may provide added benefit against the development of CVD, which remains a major public health concern for Americans.
2. LAB: Nutritional epidemiology: Better vitamin D status slows the age-related increase in fasting blood glucose (sugar) levels. There is a growing belief that poor vitamin D status is associated with a higher risk of type 2 diabetes, but there is little evidence to suggest that vitamin D effects pre-diabetic metabolic conditions related to the development of diabetes, such as impaired fasting glucose. To help address this gap in our knowledge, we examined the relation between vitamin D status using previously validated vitamin D score and increases in fasting plasma glucose concentrations among adults without type 2 diabetes. We observed that blood glucose levels among individuals with lower vitamin D scores, indicative of poor vitamin D status, were 50% greater than levels for those individuals who had high vitamin D scores after 7 years of follow-up. These findings suggest that a better vitamin D status might be one means to slow the age-related increase in fasting glucose levels resulting in lower risk of impaired fasting glucose, consequently helping to prevent the later development of type 2 diabetes.
Hazra, A., Krafts, P., Lazarus, R., Chen, C., Chanock, S.J., Jacques, P.F., Selhub, J., Hunter, D.J. 2009. Genome-wide significant predictors of metabolites in the one-carbon metabolism pathway. Human Molecular Genetics. 18(23):4677-4687.