Increase with age of serum lipid peroxides: implications for the prevention of atherosclerosis.

There is considerable support for the concept that oxygen free radicals and related lipid peroxides play a key role in the pathogenesis of normal senescence and of age-related chronic degenerative diseases, including atherosclerosis. This has led to a great deal of interest regarding peroxidized LDL, which seems to be more atherogenic than LDL. In contrast, the relationship of total serum or plasma lipid peroxides (which also have a marked atherogenic action) with both aging and atherogenesis are not well understood. In view of the above, we have determined the level of serum lipid peroxide (expressed as thiobarbituric acid reactive substances) in a sample of 100 healthy men and women ranging in age from 20 to 70 years. Our data show that there is an age related increase in the concentration of lipid peroxide, with men showing higher or about equal values than women until about 60 years, after which age women show the higher values. Our data also suggest that in certain men and women, aging is linked to a decline in the competence of the oxyradical-detoxifying mechanisms, which results in increased serum lipid peroxidation. Further research is needed to find out if lowering the serum peroxide levels of aging subjects by diet supplementation with antioxidants will decrease that risk. An adequate intake of antioxidants seems especially indicated in post-menopausal women because of their apparent greater sensitivity to age related oxygen stress.

Effects of the antioxidant turmeric on lipoprotein peroxides: Implications for the prevention of atherosclerosis.

Extracts from the rhyzome of Curcuma longa are widely used as food additives in India and other Asiatic and Central American countries. It has been shown that these extracts ("turmeric"), as well as "curcumin" and related phenolic compounds isolated from Curcuma, have a powerful antioxidant action when tested in in vitro systems. Moreover, previous research from our laboratories has shown significant decreases in the levels of lipid peroxides in the blood of both mice and human subjects administered "turmeric." Our present research complements the previous data, showing that a daily intake of turmeric equivalent to 20 mg of the phenolic antioxidant curcumin for 60 days decreases the high levels of peroxidation of both the HDL and the LDL, in vivo, in 30 healthy volunteers ranging in age from 40 to 90 years. The effect was quite striking in the persons with high baseline values of peroxidized compounds in these lipoproteins, while no apparent change took place in the persons having low baseline values. In view of current concepts on the atherogenic role played by peroxidized HDL, and especially by peroxidized LDL, as inducers of foam and smooth cell proliferation in the arterial wall, this preliminary experiment suggests that the Curcuma phenolic antioxidants, because of their high antioxidant activity and lack of toxicity, might be a useful complement to standard hypo-lipidemic drugs in the prevention and treatment of atherosclerosis.