Page Banner

United States Department of Agriculture

Agricultural Research Service

2010 Annual Report

1a.Objectives (from AD-416)
Develop processed foods that prevent insulin resistance, obesity related and chronic diseases, and assess their effectiveness in animal models. Process and/or genetically enhance grains, legumes and fruits, and their under-valued co-products to increase the concentration or bioactivity of dietary fiber, antioxidants or other components that prevent obesity and related chronic diseases.

1b.Approach (from AD-416)
The insulin resistance will be induced in the Syrian hamster model. Soluble fiber and unsaturated fats prevent insulin resistance in this model. The physical properties of fiber, the physiological, digestion and metabolic analysis of other nutrition components will be determined. Antioxidant components of plant foods will be incorporated into processed foods and their ability to suppress markers of chronic diseases will be evaluated in animal models and human subjects. Similar characteristics will be evaluated by human panels.

3.Progress Report
This project supports NP306: Quality and Utilization of Agricultural Products, Problem Area 2.a. New Processes, New Uses, and Value-Added Foods and Biobased Products: New Product Technology, Problem Area 2.b. New Uses for Agricultural By-products and NP107: Human Nutrition, Problem Area 3A. Prevention of Obesity and Related Disease: Understand the Causes and Consequences of Obesity and Related Disorders and 3B. Develop and Evaluate Strategies to Prevent Obesity Related Diseases.

We determined the metabolic mechanism underlying the prevention of obesity related chronic diseases by soluble dietary fiber in an animal model. Fat fed hamsters become insulin resistant, develop high blood cholesterol and triglyceride, and all of the similar characteristics of human metabolic diseases. We used a semisynthetic cellulose fiber that we have shown is not absorbed by the body or broken down by colonic bacteria but still possess strong antidiabetic properties. Examination of the genes expressed by healthy fat fed animals compared to unhealthy fat fed animals show that the cholesterol and bile acid pools were depleted in the healthy fat fed animals resulting in lower blood cholesterol levels. In the liver fat, was being oxidized instead of synthesized so that less fat was accumulating in the liver and other organs. The prevention of metabolic diseases by these soluble dietary fibers has resulted in six patent applications. This research was published in one of the most highly regarded nutrition journals and highlighted in the society’s newsletter.

Bioactive peptides from rice bran, millet, and other cereal or seed proteins are being developed in collaboration with Jiangnan University, Wuxi, China. Rice bran and millet proteins were extracted and hydrolyzed by various food grade enzymes. The original intact protein and its hydrolysates were evaluated for cholesterol reducing properties by an in vitro method. Bile acid micelles containing cholesterol that mimic intestinal cholesterol absorption were used to evaluate the ability of the protein hydrolysates to block absorption. A few model peptides were purchased to evaluate their ability to block cholesterol absorption in animal models as well as act as positive controls for the in vitro and in vivo studies. Ultimately, these methods will be used to identify peptides that have antidiabetic properties that will be tested in animal models.

1. Soluble dietary fibers prevent metabolic disease in an obese animal model. Obesity and related chronic diseases such as diabetes and cardiovascular disease are at alarming high levels and threaten our economic well being as well as health. ARS Researchers in the Processed Foods Research Unit, Albany, CA have previously shown that all of the characteristics of obesity related metabolic diseases such as high blood cholesterol and triglycerides, abdominal fat accumulation, fatty liver, high blood pressure, insulin resistance, and high fasting glucose and insulin are prevented by soluble dietary fiber. The current research demonstrated that bile acid and cholesterol excretion by soluble fiber feeding results in significant changes in fat and cholesterol metabolism as demonstrated by changes in expression of genes for fat oxidation, cholesterol and bile acid synthesis, and transport of cholesterol and bile from the liver. This research demonstrates that increased soluble fiber consumption can improve health and reduce disease.

2. Prostate cancer growth is slowed by walnut intake. Prostate cancer is one of the most common cancers in men. In a mouse model of prostate cancer, ARS researchers in the Processed Foods Research Unit, Albany, CA in collaboration with University of California, Davis scientists found that modest amounts (2.4 oz walnuts /2000 cal) of walnut intake reduced the rate of growth of prostate tumors. A protein called insulin-like growth factor (IGF-1) that circulates in the blood in humans is associated with increased likelihood of developing prostate cancer. Mice fed walnuts had lower levels of circulating IGF-1. This research demonstrates the benefits of consuming walnuts to reduce prostate cancer growth.

Review Publications
Prasopsunwattana, N., Omary, M.B., Arndt, E.A., Cooke, P.H., Flores, R.A., Yokoyama, W.H., Toma, A., Chongcham, S., Lee, S.P. 2009. Particle Size Effects on the Quality of Flour Tortillas Enriched with Whole Grain Waxy Barley. Cereal Chemistry. 86(4):438-451

Hung, S., Bartley, G.E., Young, S.A., Albers, D., Dielman, D., Anderson, W.H., Yokoyama, W.H. 2009. Dietary Fiber Improves Lipid Homeostatis and Modulates Adipocytokines in Hamsters. Journal of Diabetes. 1:1-13.

Young, S.A., Julka, S., Bartley, G.E., Gilbert, J.R., Wendelburg, B., Hung, S., Anderson, W., Yokoyama, W.H. 2009. Quantification of the Sulfated Cholecystokinin CCK8 in Hamster Plasma Using Immunoprecipitation-Liquid Chromatography-Mass Spectrometry/Mass Spectrometry. Analytical Chemistry. 81:9120-8.

Villanueva, M., Yokoyama, W.H., Hong, Y., Bartley, G.E., Ruperez, P. 2010. EFFECT OF HIGH-FAT DIETS SUPPLEMENTED WITH OKARA SOYBEAN BY-PRODUCT ON LIPID PROFILES OF PLASMA, LIVER AND FAECES IN SYRIAN HAMSTERS. Journal of Food Chemistry. Doi:10.1016/j.foodchem.2010.05.106.

Kalgaonkar, S., Gross, H., Yokoyama, W.H., Keen, C. 2010. Effects of flavonol-rich diet on select cardiovascular parameters in a Gold Syrian Hamster model. Journal of Medicinal Food. 13(1): 108-115. doi:10.1089/jmf.2008.0295.

Langhorst, M., Hastings, M.J., Yokoyama, W.H., Hung, S., Young, S.A., Cellar, N., Kuppannan, K. 2010. Determination of F2-isoprostanes, biomarkers of oxidative stress in hamster urine samples by on-line solid phase extract. Journal of Agricultural and Food Chemistry. 58 (11), pp 6614–6620. DOI: 10.1021/jf101146q.

Last Modified: 11/26/2015
Footer Content Back to Top of Page