Blood lipids in young and old individuals.

HAVE BEEN INTERESTED in the blood lipids and lipoproteins in relation to the process of aging and to the incidence of cardiovascular disease. Studies on the serum lipoproteins as measured by the cholesterol distribution in zone electrophoresis and on other changes of the blood lipids with age have been made (1, 2). Recently the effects of the amount and type of fat in the dietary intake on the cholesterol and lipoprotein distribution and on its relation to the incidence of cardiovascular disease has received considerable attention (3, 4). It has been claimed that when ingested over long periods of time vegetable fats are less likely to cause a rise in cholesterol level or change in lipoprotein pattern than animal fats and may even cause a lowering of the cholesterol level. The pertinent difference between these types of fats is believed to be that the vegetable fats contain, in general, a larger proportion of the long-chain poly-unsaturated fatty acids than do animal fats (5, 6). A number of studies have been made on the effect of the ingestion of vegetable fats on the cholesterol level (2), but there is little information in the literature on the effect of these fats on the total fatty acids and, in particular, on the unsaturated fatty acids of the serum (8). We were interested in determining what changes could