The effect of walnuts on heart disease risk factors: a human feeding trial

A six year population study among California Seventh Day Adventists revealed an association between nut consumption and the risk for developing heart disease. The study showed that frequent consumption of nuts was associated with a substantial reduction in the incidence of heart disease. These results prompted the development of this study which examined the effect of walnuts on serum lipids and blood pressure.

Eighteen men, ages 21 through 43, participated in an eight week study. All men were free of hypertension and heart disease, and habitual nut consumption was minimal. Prior to initiation of the study, all men consumed a reference diet for five days. Following consumption of the reference diet, the men were randomly divided into two groups. One group consumed a walnut-rich diet for four weeks while the other group consumed a diet that conformed to the Step 1 Diet of the National Cholesterol Education Program. After four weeks, the group consuming the walnut-rich diet switched to the Step 1 diet and visa versa. The two diets were identical with respect to fiber, fat, protein and carbohydrate content. Total fat content for both diets was 30% of total calories. However, 20% of the fat in the walnut-rich diet was derived from walnuts.

Publications: J Sabaté J., Fraser GE, Burke K, Knutsen SF, Bennett H, Lindsted KD. Effects of walnuts on serum lipid levels and blood pressure in normal men. N Engl J Med 1993; 328:603-607. full text

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Jaceldo KB, Sabaté J. Plant-based alpha-linolenic acid in serum cholesterol esters: Effect on n-3 eicosanoids. Third International Congress on Vegetarian Nutrition. Loma Linda, California, March 1997. abstract

Sabaté J, Fish D. Consumption of a high polyunsaturated fat food and the oxidability of LDL in normacholeterolemic males.10th International Symposium on Atherosclerosis. Montreal, Canada, October 1994. [Atherosclerosis 1994;109:53] abstact

Sabaté J. The impact of walnut fat on blood lipids: A controlled feeding trial. 85 th American Oil Chemists’ Society Annual Meeting, Atlanta, Georgia, May 1994. abstract

Knutsen SF, Sabaté J, Blankenship JW. Omega-3 fatty acids of plant origin – Effect on fatty acids in cholesterol esters. 3 rd International Conference on Preventive Cardiology, Oslo, Norway, June 1993. abstract

Sabaté J, Fraser GE, Knutsen SF, Lindsted KD. The cholesterol-lowering effect of walnuts: A human feeding trial. 3 rd International Conference on Preventive Cardiology, Oslo, Norway, June 1993. abstract

Blankenship JW, Sabaté J. The impact of moderate dietary intake of α-linolenic acid on thromboxane metabolism in men. Experimental Biology ’93, New Orleans, Louisiana, March 1993. abstract

Sabaté J, Blankenship JW, Knutsen SF, Franson A. Changes in serum cholesterol ester fatty acids following a diet high in Omega-3 fatty acids of plant sources. 76 th Annual Meeting, Federation of American Socieities for Experimental Biology, Anaheim, California, April 1992. abstract

Date: 1990

Funded by: The California Walnut Commission