GOAL III:A Healthy and Well-Nourished Population Who Have Knowledge, Desire, and Means to Make Health Promoting Choices.

Analysis of Results:This goal is the focus of much of ARS. research related to human nutrition and health. Under Goal III, 11 Indicators are aligned under 3 Performance Goals. Because of the unique and dynamic nature of research, several Indicators were added to the Report that did not first appear in the Annual Performance Plan for FY 1999. This was done to ensure that significant accomplishments that were not anticipated last year were reported. While it is not possible to report research accomplishments numerically, the progress projected in all 11 Indicators was completed or substantially completed during FY 1999.

OBJECTIVE 3.1:Nutritious food: 'Maintain an adequate and nutritious ... supply of food to meet human nutritional needs and requirements.'

Indicators:

During FY 1999, ARS will

determine the role of various nutrients in providing maximum health benefits to the population, including children and the elderly. This information is needed to develop meaningful dietary recommendations for individuals throughout the life cycle.

ACCOMPLISHMENTS:A number of projects were completed addressing the role of various nutrients in providing maximum health benefits to the population throughout the life cycle. ARS researchers found that:

Vitamin K may be a modifiable risk factor for osteoporosis.

In a randomized trial examining the effect of a multivitamin/mineral supplement on nutritional status, immune responses, and plasma homocysteine in older adults with moderately elevated homocysteine levels: among apparently healthy and well nourished older adults, and subsequent to the mandated fortification of flour with folic acid, RDA levels of supplementation significantly increased micronutrient status and lowered total plasma homocysteine, an independent risk factor for heart disease.

The intake of vitamin E contributes to reducing the risk of atherosclerosis and cancer through modulation of immune and endothelial cell interaction, production of several chemokines, proinflammatory cytokine IL-6, and modulation of angiogenesis.

In older men and women smokers, less efficient calcium absorption is one mechanism by which smoking accelerates bone loss.

One mechanism by which dietary saturated fat and cholesterol decreases HDL apoA-I is the restriction of these constituents in the diet which lowers LDL cholesterol and LDL apoB by enhancing its fractional clearance via the LDL receptor mediated catabolism. The predominant reason that HDL apoA-I is decreased with such diets is because of decreased production.

One benefit of maintaining a diet rich in vitamin C (antioxidants) early in life may be to limit the risk for eye disease later in life.

Nutritional deficiencies that affect nerve function, such as B12 and thiamine, may alter nerve muscle interactions and affect sarcopenia.

A new cultivar of high soluble fiber barley was more effective than oats in reducing both glucose and insulin response.

Chromium may be involved in the control of blood sugar levels in people with glucose intolerance and diabetes.

Factors in soy protein isolate, the sole protein source of most soy infant formulas, can reduce the incidence of breast cancer and colon cancer and can improve metabolism.

Iron stores are a primary determinant of the amount of manganese absorbed from a meal, but retention of manganese was regulated independently of absorption by means of variable excretion. Thus, there is a need to consider the iron stores of humans when attempting to determine the optimal intake of manganese.

Glycation, the undesirable binding of sugar to proteins, is enhanced by dietary copper deficiency. Because glycation is a process that is increased in diabetes and aging, this finding suggests that reduced copper intake may worsen the consequences of these two conditions.

Nickel is homeostatically controlled by absorption and retention processes, and that tissue nickel is metabolized by at least three different mechanisms.

Changes in dietary fat can modify mineral metabolism.

People with adequate iron stores do not fully adapt to prevent increased iron stores with supplementations, but women with low iron stores may need continuing iron supplementation to counterbalance high rates of iron excretion.

Moderately low folate levels adversely affects blood homocysteine levels and DNA composition.

Adequate iron status is required to maintain optimal cognitive performance on attention-based tasks in both men and women.

Cellular content of lycopene and other tomato-related carotenoids can be increased through intake of tomato products.

IMPACT/OUTCOME:Findings from these studies add to the body of knowledge on the role that nutrition has in maintaining and improving health. Many of these findings result in scientific recommendations which may lead to changes in dietary recommendations and nutrition policy which affect food assistance programs.

continue to define the relationship between nutritional status of a host and the ability of viruses to change their virulence and cause infection by studying the variety of nutrients that might be involved and determining the viral agents that might be similarly affected. This information is needed to determine the role of nutrition in understanding viral pathogens known to cause disease in humans.

ACCOMPLISHMENTS:It has been demonstrated that a gold compound known to act as a metabolic antagonist of selenium caused a benign coxsackie virus to exhibit virulence. The research was expanded to determine whether other selenium antagonizing heavy metals of ecological interest might behave similarly, such as mercury or arsenic. The results showed that the pathogenicity of the virus can be influenced not only by the nutritional status of the host but also by the exposure of the host to various toxic environmental contaminants.

IMPACT/OUTCOME:The economic loss to the Nation due to illnesses caused by infection is staggering. Little is known about the role of the nutritional status of the host. A long series of investigations have led to the realization and understanding that a diet inadequate in antioxidants renders an organism vulnerable to numerous pathological changes. These studies have shown that dietary oxidative stress increases viral virulence apparently by changing the genetic nature of the virus as it replicates within the host.

use molecular biology to determine how nutrients and other dietary constituents act to turn on the synthesis of the proteins required for their metabolism and use in the body. With this information, meaningful dietary advice can be formulated for individuals who are at increased risk for particular diseases.

ACCOMPLISHMENTS:ARS scientists demonstrated that a common vitamin D receptor genotype in premenopausal women is not related to bone density. The genesis of genotype specific difference in bone mineral density is likely to reside elsewhere.

Researchers also demonstrated the role for the enzyme, lipoprotein lipase (LPL), in the tissue uptake of dietary vitamin A using gene knockout and transgenic systems.

Researchers found that copper deficiency during pregnancy suppresses the expression of protein kinase C-gamma in the cerebella of female neonates to a much greater extent than in the cerebella of male neonates. Since protein kinase C expression regulates brain development, the present findings are significant because they indicate that copper deficiency targets the cerebellum as a region of the neonatal brain where development is impacted through the suppression of protein kinase C gamma.

IMPACT/OUTCOME:Understanding the basic mechanisms of the metabolic process is important for developing potential targets for nutritional interventions.

Indicators:

During FY 1999, ARS will

provide information to the EPA and the public related to food consumption patterns of children for use in developing estimates of usual daily intake. This information is needed by EPA to develop regulations on the allowable intake of pesticides in foods as required by the Food Quality Protection Act.

ACCOMPLISHMENTS:Data collection was completed for the Supplemental Children. s Survey to the Continuing Survey of Food Intake by Individuals (CSFII) 1994-1996. Dietary data were collected from over 5,200 children from birth through nine years of age.

IMPACT/OUTCOME:The CSFII provides the data needed to monitor and assess food consumption in a very select group of individuals, children.

complete a pilot project to test the feasibility of using telephone technology to conduct food intake surveys. If successful, it will help reduce the cost of conducting food consumption surveys such as the CSFII.

ACCOMPLISHMENTS:Food intake by individuals in telephone and nontelephone households, interviewed in person or by telephone, was reported not to be different.

IMPACT/OUTCOME:The present study demonstrates that telephone conducted 24 hour dietary recall interviewing is a valid method for collection of food intake information in the rural Delta of Arkansas, Louisiana, and Mississippi.

continue to develop methods of analysis that will be useful in the determination of a variety of phytonutrients in foods in order to develop a database of such information to allow for epidemiological studies of the relationship between the phytonutrients and the incidence of diseases such as heart disease and cancer.

ACCOMPLISHMENTS:A robust high performance liquid chromatography system was developed that separates and quantifies about 20 flavonoids in less than an hour.

Indicators:

During FY 1999, ARS will

determine the nutritional quality of various kinds of commodity products and foods consumed. This is an ongoing process to include new and ever changing nutritional data in the National Nutrient Database.

ACCOMPLISHMENTS:As part of the National Food and Nutrient Analysis Program, the following objectives have been met: application of a statistically-based conceptual framework for the selection of representative samples of the food supply; development of unique sampling plans for specific foods and nutrients; and chemical analysis of food samples for nutrient content under rigorous quality control programs.

ARS scientists also developed:

In collaboration with Perkin-Elmer Corporation, a new atomic absorption spectrometer that provides more accurate determinations of trace metals in foods.

A new method for the analysis of the carotenoid content of fruits, vegetables and other foods which can replace the traditional long high performance liquid chromatography system.

A more refined and robust method to determine resistant starch.

A robust system for the extraction and analysis of individual naturally occurring folates and folic acid which is added to many foods.

IMPACT/OUTCOME:Food composition data that reflects current commodity products and foods consumed is important in assessing nutritional quality and its role in a population. s health status.

examine hybrid plants with increased mineral content which may have beneficial effects on human health.

ACCOMPLISHMENTS:A group of zinc inefficient mutants in the model plant, Medicago truncatula , that exhibit symptoms of zinc deficiency when grown on normally adequate zinc concentrations was investigated. Studies have shown that these plants are not limited in their ability to absorb zinc, since the leaves will exhibit symptoms of deficiency even when total leaf zinc levels are comparable to those of nonmutant control plants.

IMPACT/OUTCOME:These mutants will serve as useful tools to determine how zinc nutrition is regulated within crop plants.

determine bioavailability of essential nutrients in plant foods selected for improved nutrient density. Consumption of foods with increased amounts of certain nutrients has potential for their beneficial effects on human health.

ACCOMPLISHMENTS:ARS scientists demonstrated that iron uptake by intestinal epithelial cells is enhanced by factors in meat. Complete identification of this so-called 'meat factor' may lead to the development of improved dietary iron supplements and contribute to improved nutritional health because of improved iron bioavailability.

ARS researchers also showed that:

Tomato carotenoids phytofluene and phytoene are much more bioavailable than would be expected based on their content in tomato products.

Molybdenum was highly available from kale, but less available from soy. The results show that the bioavailability of molybdenum must be taken into account when establishing dietary recommendations.