I was watching public TV with my wife a couple of years ago when a researcher was being interviewed about the Beta Carotene and Retinol Efficacy Trial (CARET), in which 18,314 smokers took either beta carotene and Vitamin A or a placebo. He embarrassedly stated that the beta carotene (found in carrots and orange vegetables) and Vitamin A, even though they are 'anti-oxidant' and theoretically should prevent heart disease and cancer, actually increased it in their trial. In fact, people on supplements equal to four carrots a day had 17% more heart disease and were 17% more likely to die than people on a placebo.
I found that pretty surprising, especially since you hear those natural health guru types yapping on the radio all the time about the benefits of anti-oxidant vitamins.
I later visited my sister-in-law Rossana (pronounced ROE - SSSS - ana, as my kids always point out) in the US Virgin Islands. Rummaging in her refrigerator while she was at work (Hey -- I didn't have anything else to do!) I found several large bottles of vitamins and supplements. I looked at the ingredients and found that she was taking Vitamin A at several times the recommended daily levels. When she got home from work I confronted her about it.
Doug: "Rossana, why are you taking so many vitamins and supplements?"
Rossana: "I don't have time to cook meals and eat enough vegetables, so this gives me what I need."
Doug: "But did you realize that the amount of Vitamin A you are taking may cause osteoporosis?"
[It's true-- women taking the highest amounts of Vitamin A supplements doubled their risk of fracture, leading Denmark to ban vitamin fortified Kellogg's breakfast cereals. You can see a goofy picture I made about the topic here.]
I don't want to be dodgy and name the company that made the vitamins and supplements she was taking, but I looked them up on the internet, and if you followed their recommendations, you would be spending $7,128 dollars per year on their products!
When I got home I read up more on vitamins. In the Alpha-Tocopherol, Beta Carotene (ATBC) Cancer Prevention Study smokers treated with beta-carotene and alpha tocopherol (Vitamin E) had an 8% increase in death, while those with a prior history of heart attack had a 75% increase in heart attack with beta carotene therapy. People on Vitamin E had a 2% increase in mortality.
Looking at all studies put together, there is an increased risk of heart disease with Vitamin A and beta carotene and no heart disease prevention with Vitamin E. Vitamin A and beta carotene when taken together are associated with a 29% increase in mortality.
Even though in the laboratory there has been shown some connection between oxidative stress and heart disease, and in spite of the known role of vitamins C and E as anti-oxidants, you can't get around the fact that there is now a large body of research -- including studies with tens of thousands of patients -- that shows that vitamins do not prevent heart disease or lengthen your life.
In fact, they may actually have the opposite effect.
One study of Vitamin E combined with Vitamin C showed that vitamins actually accelerated the progression of thickening of the coronary arteries, and doubled the risk of dying of heart disease. Another study of a combination of anti-oxidants, including Vitamins E, C, beta carotene, and selenium, showed that vitamins actually blocked the effects of anti-cholesterol treatment (simvastatin plus niacin) on reducing atherosclerosis and preventing heart attacks and strokes. The vitamins in this study interfered with the ability of the other medications to raise HDL (good) cholesterol. Looking at all studies combined in which Vitamin E was given with beta carotene, there was a 10% overall increase in mortality.
I think the vitamins may be giving a boost to little tumors that wouldn't have been a problem otherwise.
Based on these studies, I believe there is no role for vitamins in the treatment or prevention of heart disease.
Doug Bremner MD is author of Before You Take That Pill: Why The Drug Industry May Be Bad For Your Health.