Issue Date: February 10, 2002
4 theories: How antioxidants help your heart
Hard proof is still lacking, but research looks good.
Whether vitamins E and C and other nutrients known as antioxidants benefit hearts is a hot topic. Virtually all experts agree that you can cut your heart disease risk by eating antioxidant-packed fruits and vegetables. New Harvard findings say each extra serving of fruits and vegetables, especially leafy green vegetables, you eat each day reduces your risk of heart disease by 4%. But should you take pills, too? It makes theoretical sense, according to a decade of research, although absolute proof is slow in coming. And recent headlines mistakenly said antioxidants cause harm by blocking cholesterol-reducing statin drugs.
The latest on antioxidants and statins
In a recent small study at the University of Washington, heart patients took daily doses of the statin Zocor to lower "bad" LDL cholesterol, plus 1,000 milligrams of niacin to increase very low "good" HDL cholesterol. Adding antioxidants (vitamins E and C, beta carotene, selenium) interfered with niacin's ability to lift HDLs, says study author Greg Brown, a cardiologist. In spite of news reports, he says, antioxidants did not "work against" the ability of statins to lower LDLs. So unless you are one of the few people taking high doses of niacin, don't worry about interference. Also, a new six-year study in Britain of 20,000 heart patients found no harm from combining statins and antioxidants (nor did it find that vitamin E cut heart attacks).
Antioxidants may help hearts 4 ways
1. By detoxifying cholesterol. LDL cholesterol actually may be benign unless "oxidized," or converted to a toxic form that fosters plaque buildup in blood vessels. Antioxidants are thought to thwart heart disease by preventing oxidation. In new Japanese research, oxidized LDL was four times higher in heart attack victims than in healthy people. The more oxidized LDLs, the more severe the heart disease. Ishwarlal Jialal, of the University of Texas Southwestern Medical Center, found that 400 to 800 IU of vitamin E daily reduced LDL oxidation in normal people up to 40%. Other antioxidants -- including vitamin C, alpha lipoic acid, and fruit and vegetable pigments -- can reduce LDL oxidation.
2. By fighting inflammation. Antioxidants combat chronic inflammation, which is a newly recognized villain in clogged arteries, heart attacks and strokes. Inflammation and arterial disease are found in those with low blood levels of vitamin C, reports new Belgian research. And research at Johns Hopkins found a connection between inflammation and low blood levels of beta carotene. Taking 800 IU of vitamin E daily cut inflammation by half in diabetics at high risk of heart disease, according to recent research in New Zealand.
3. By improving vascular function. How the inner walls (endothelium) of arteries relax, dilate and respond to inflammation is a major factor in heart attacks. Daily megadoses of vitamin C (500 to 1,000mg) or E (300 to 1,200 IU) improve such vascular function, says a new Harvard review. For instance, taking 1,000mg of vitamin C improved artery dilation in healthy people in a week; 300 IU of vitamin E restored good vascular function in heart patients in a month.
4. By discouraging blood clots. Vitamin E suppresses platelet stickiness, acting as an anticoagulant to discourage the formation of clots that lead to heart attacks. Vitamin C decreases a blood factor needed to build clots.
Bottom line
Get all the antioxidants you can from five to 10 daily servings of fruits and vegetables. And take pills as insurance.
Top antioxidant researcher Jeffrey Blumberg of Tufts recommends healthy people take these daily: 100 to 400 IU vitamin E, 200 to 500mg vitamin C, a multivitamin/mineral supplement with beta carotene and, for women and those who eat few dairy foods, 500 to 600mg calcium.
Even if antioxidants don't save your heart, they may discourage cancer, Alzheimer's disease, macular degeneration and cataracts. They may boost your immune functioning and prolong your life. In a study at UCLA, 300mg daily of vitamin C, including 150mg in supplements, added six years to the lives of middle-aged men.
Keep things in check: I still recommend you get all the antioxidants you can from fruits and vegetables -- and take pills for insurance.
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Scientific sources for this article
Fruits and vegetables reduce heart disease risk
-- Joshipura KJ. Ann Intern Med 2001 Jun 19: 134(12): 1106-14
Antioxidants and statins
-- Cheung MC. Arterioscler Thromb Basc Biol 2001 Aug; 21 (8): 1320-6
-- Presented at American Heart Association scientific sessions, Anaheim, CA, November 11, 2001 Antioxidants and LDLs
Antioxidants and cholesterol
-- Ehara S. Circulation 2001; 103
-- Jialal I. Thrombosis and Vascular Biology 1995; 15(2): 190-98
Antioxidants and inflammation
-- Langlois M. Circulation 2001 Apr 10; 103(14):1863-8
-- Erlinger TP, Arch INtern Med 2001 Aug 13-27; 161(15):1903-8
-- Uprichard JE. Diabetes Care 2000 Jun;23(6): 733-8
Antioxidants and vascular function
-- Brown, A.A and Hu, Frank B. American Journal of Clinical Nutrition, 2001; 73:673-86
Antioxidants and blood coagulation
-- Bakaltcheva I., Platelets, 2001, Nov. 12 (7): 389-94
-- Khaw, KT, BMJ, 1995, Jun 17; 310: 1559-63
-- Salonen JT. J Intern Med 2000 Nov; 248(5): 377-86
Antioxidants and longer life
-- Enstrom J.E. Epidemiology 1992; 3:194-202
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