A Diet High In Unrefined Carbohydrates

From Raisins and Brown Rice Does Not Raise Serum Triglycerides

Los Altos, California, October 4, 1999 – Increasing carbohydrate intake—typically done by consuming foods such as cakes, cookies, pastries, and snack crackers made from refined flour and with little or no fiber or phytochemicals and lowering fat intake with many of the popular, refined fat-free foods—has been shown in several investigations to increase serum triglycerides. Increasing scientific evidence continues to point to the negative association between elevated triglycerides and heart disease in certain population subgroups, particularly when elevated triglycerides result from consumption of refined and simple carbohydrate foods.
Gene Spiller, Ph.D. of the Sphera Foundation presented the results of new research on the role in nutrition of sun-dried raisins and rice at the 40th Annual Meeting of the American College of Nutrition held in Washington, DC, September 30-October 3, 1999.
To test the hypothesis that plant foods high in unrefined carbohydrate do not raise serum triglycerides as refined digestible carbohydrates may do, Dr. Spiller fed a diet high in simple carbohydrates from sun-dried raisins and complex carbohydrates from brown rice to 13 men and women whose average age was 60 (41 to 75 years) and who had baseline total serum cholesterol levels that averaged 260 mg/dl and triglyceride levels that averaged 150 mg/dl.
The subjects consumed daily for four weeks rice and raisin dishes as part of a plant-based diet low in saturated fat and animal products. Nuts, oil seeds, beans and lentils were consumed to replace the animal products. Brown rice supplied fiber and B vitamins, and sun-dried raisins supplied fiber, tartaric acids and the polyphenols quercetin and kaempferol. Total serum cholesterol and serum triglycerides were measured twice at baseline and twice after four weeks on the study diet. While total serum cholesterol dropped from 260 to 236 mg/dl, there was no significant change either physiologically or statistically in triglycerides, notwithstanding an increase in carbohydrate calories, a decrease in animal protein from meat and poultry and some decrease in fat calories.
When unrefined plant foods such as the brown rice and raisin dishes fed in this study supply a large portion of the caloric intake, there is no rise in triglycerides, due probably to complex interaction with fiber and other phytochemicals.

Key points
o Total serum cholesterol level decreased in four weeks from baseline of 260 mg/dl to 236 mg/dl.
o In this study, when feeding unrefined rice and raisins, both with their fiber, phenolics and other phytochemicals present, and the tartaric acid from raisins, there was no significant rise in serum triglycerides.
o The expected outcome of increasing refined carbohydrates and decreasing fat in a diet is a significant rise in serum triglycerides—not seen in this study.

This study was supported by an unrestricted grant from Sun-Maid Growers of California in their effort to better understand the nutritional role of sun-dried raisins. Formed in 1912, Sun-Maid is owned by approximately 1,500 family operators farming in the Fresno, California area and markets its products throughout the United States and in more than 25 countries throughout the world.

November 27, 2001

Coming soon: Sun-dried raisins and almonds raise blood antioxidant status.

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