For years, I took vitamin C and vitamin E every morning with breakfast. It felt like the healthy thing to do.
Vitamin C was supposed to keep colds away, and vitamin E was often promoted as good for the heart. But newer research is showing that these supplements may not do what we thought — and, in some cases, they can actually cause harm.
A huge study of more than 14,000 male doctors looked at high-dose vitamin C and E for eight years. The results? No fewer heart attacks, strokes or heart-related deaths. Even more surprising, vitamin E slightly increased the risk of dangerous bleeding strokes. A well-known medical review later confirmed this, showing a 22% higher risk of hemorrhagic stroke in people taking vitamin E.
One study funded by the National Cancer Institute found that smokers who took vitamin E had a slightly higher risk of lung cancer. Another major review showed that neither vitamin C nor vitamin E lowered the risk of prostate cancer or overall cancer. So the idea that these vitamins protect against cancer doesn’t hold up in supplement form.
A clinical trial published in Neurology found no benefit from taking vitamins C or E when it came to preventing dementia. And, in another study, people with mild to moderate Alzheimer’s actually declined faster when they took these supplements.
This one is surprising: In healthy young men, vitamins C and E interfered with normal insulin function and weakened the body’s natural ability to handle oxidative stress. In another well-designed trial, these supplements even blunted muscle gains from strength training. Essentially, they may short-circuit the body’s natural response to exercise — especially if you’re trying to improve metabolism, prevent diabetes or build strength.
None of this means fruits and vegetables are bad. Quite the opposite. Diets like the Mediterranean diet — rich in naturally occurring antioxidants — do help protect against heart disease, cancer and dementia. The concerns are specifically about high-dose vitamin C and E supplements, not the vitamins found in whole foods.
Dr. Brian Grieves is a doctor of chiropractic with a master’s degree in public health and a member of the Shawano Community Health Action Team (CHAT). Call 715-524-8722 for information.
