Dietary alpha-linolenic acid is as effective as oleic acid and linoleic acid in lowering blood cholesterol in normolipidemic men

The relationship between coronary heart disease (CHD) and high blood levels of cholesterol and fats (lipids) is well established. Previous studies have shown that the diet plays an important role in determining blood cholesterol levels. There is evidence that saturated fatty acids (SFAs) promote cholesterol formation, while unsaturated fatty acids, such as linoleic acid (LA) and oleic acid (OA), lower blood cholesterol levels. More recently, it has been suggested that alpha-linolenic acid (LNA) may be beneficial in reducing the risk of CHD because it can reduce blood clot formation. However, it is not clear whether LNA is as effective as LA or OA in lowering blood cholesterol levels. To clarify this issue, eight men with normal blood cholesterol levels (normolipidemic) followed each of four different diets, containing different amounts of OA, LA and LNA, each for an 18-day period. The four experimental diets included sunflower and olive oil; canola oil; soybean oil; or sunflower, olive, and flax oils. A mixed-fat (typical) diet containing twice as much saturated fat as the other diets was fed for six days before and after each experimental diet. All diets, except for the mixed-fat diet, reduced total cholesterol, low-density-lipoprotein cholesterol, very-low-density-lipoprotein cholesterol, apolipoprotein B and A-I, by 18 percent, 22 percent, 41 percent, 19 percent and 9 percent, respectively. All the experimental diets were equally effective in lowering cholesterol and apolipoprotein levels. These findings indicate that dietary OA, LA and LNA are equally effective in lowering blood cholesterol levels. (Consumer Summary produced by Reliance Medical Information, Inc.)