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 grains 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 B-vitamin status, homocysteine levels, genetic mutations 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 two subordinate projects at the HNRCA funded through a Specific Cooperative Agreement with TUFTS UNIVERSITY. For further information and progress reports, see 1950-51530-009-01S (Epidemiology, Nutrition and Problems of Aging) and 1950-51530-009-02S (Dietary Assessment and Epidemiology).
1. LAB: Nutritional Epidemiology. Whole-Grain and Refined-Grain Intakes have Opposite Relationships with Visceral Fat. Given the emerging evidence that the visceral adipose tissue (VAT) compartment is more strongly related to metabolic risk factors than subcutaneous adipose tissue (SAT), ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, examined the association of whole- and refined-grain intake on these body fat depots in a large population-based cohort of ambulatory adults to gain further insight into the relation between grain intake and cardiometabolic risk. They observed that increasing intakes of whole-grain intake was associated with less VAT whereas increasing intakes of refined-grain intake was associated with more VAT; however, the association between higher whole grain intake and less VAT was not seen among those who consumed 4 or more servings per day of refined grain. This research suggests that higher intakes of whole grains may help limit the amount of harmful visceral adipose tissue, but that this beneficial effect of whole grains may be negated by consuming more 4 or more servings of refine grains per day. At this time the mechanism(s) by which whole and refined grains interact to influence VAT is unknown.
2. LAB: Nutritional Epidemiology. Higher Predicted Vitamin D Status is Associated with a 40% lower Risk of Type 2 Diabetes. The relation between vitamin D and bone health is well established, but there is accumulating evidence that vitamin D might have other functions, including involvement in the development of type 2 diabetes (T2D). To further explore the potential benefits of improved vitamin D status on risk of developing T2D, ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, examined the relation between predicted vitamin D status and risk of T2D in a large population-based cohort of ambulatory adults, free of T2D. They demonstrated that individuals with the highest vitamin D status at baseline had a 40% lower incidence of T2D over 7 years of follow-up than those with the lowest predicted vitamin D status. These findings suggest that maintaining optimal vitamin D status may be a strategy to help prevent the development of T2D.
3. LAB: Dietary Assessment and Epidemiology. An increase in dietary protein is associated with reduced hip fractures in the elderly. More than 25 million Americans over the age of 50 years have either osteoporosis or osteopenia. Osteoporotic fractures result in higher morbidity and increased mortality compared with similar aged adults and also have significant costs associated with fracture aftercare. ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, examined the association between protein intake and hip fracture risk in elders and found that the risk of hip fracture was reduced in the groups whose intake of protein was in the upper levels compared with the group with the lowest intake. These findings suggest that higher protein intake in elderly adults may protect against hip fracture.
4. LAB: Dietary Assessment and Epidemiology. Greater variety in fruit and vegetable intake is associated with lower inflammation in Puerto Rican adults. Heart disease is the leading cause of death in the United States. The global total mortality rate attributable to inadequate consumption of fruit and vegetables is estimated to be up to 2.64 million deaths per year. However, little is known about how variety in fruit and vegetable intake affects CVD risk. Furthermore, there is a concerning lack of research on the association between fruit and vegetable intake and heart disease risk in Puerto Ricans—the second largest Hispanic subgroup in the United States. Older Puerto Ricans experience a significantly greater prevalence of comorbidities than do non-Hispanic whites residing in the same neighborhood, and these differences remained after adjusting for age, sex, income, and education. ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, found that variety in fruit and vegetable intake, but not quantity, appears to be important in reducing inflammation.
Bhupathiraju, S., Lichtenstein, A.H., Dawson-Hughes, B., Tucker, K.L. 2011. Adherence index based on the AHA 2006 diet and lifestyle recommendations is associated with select cardiovascular disease risk factors in older Puerto Ricans. American Journal of Clinical Nutrition. 141(3):460-469.