If taking a vitamin every day prevented cancer, people would be lining up at the drugstore.
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In lab research, we have found that vitamin E may do exactly that, at least for certain patients. Among people with the genetic disorder Cowden Syndrome, vitamin E may slow or stop the cell damage that leads to cancer.
This is especially important to people with Cowden Syndrome because they have an 85 percent lifetime risk of breast cancer and a 35 percent risk of thyroid cancer. Everything we can do to reduce those risks matters.
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How vitamin E works for prevention
Around one in 200,000 people has Cowden Syndrome, and it probably is under-diagnosed. Among these people, mutations in genes such as succinate dehydrogenase (SDH) are the culprits behind cancer risk.
“I doubt that any single agent — vitamin E included — is the answer on its own. But it may become a powerful addition to other treatments.”
Charis Eng, MD, PhD
Founding Chairwoman of the Genomic Medicine Institute
SDH plays a big role in energy production. In most people, it prevents what we call “oxidative stress.” Basically, SDH prevents the buildup of reactive oxygen species (ROS), which are molecules that damage cells. Unfortunately, people with SDH mutations don’t get this benefit.
That is why we started studying vitamin E. Vitamin E can be a powerful antioxidant, so we wondered: Could vitamin E prevent oxidative stress?
In my team’s lab studies, the answer is yes. We used vitamin E on the cells of people with SDH mutations. As a result, we were able to reverse resistance to cellular apoptosis (apoptosis is a natural process of cell death) and the process that leads to disease.
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Getting the dose right
Not all studies have been so positive. For example, in the SELECT trial for prevention of prostate cancer, vitamin E was shown to actually increase the risk for patients.
Why? We think the dose matters. In SELECT, researchers gave people 800 mg of vitamin E. Based on our Cowden studies, we believe that dose may be too high. We compared doses equivalent to 800 mg and 400 mg and found that 400 mg was effective and did not raise risk.
This is good news. The goal of medicine is to give people the smallest effective dose of any drug or supplement. In this case, less turned out to be more.
The type of vitamin E matters, too. There are water-soluble (able to dissolve in water) and lipid soluble (able to dissolve in fat) versions. In our study, we used a lipid-soluble version.
What this means for patients
Before you rush to the drugstore, keep in mind this was only a lab study. To really prove that vitamin E helps prevent cancer — in Cowden Syndrome patients or anyone else — clinical trials are necessary.
That said, taking vitamin E has many benefits. Because it is an antioxidant, it can help the body fight cell damage. It can improve eye and skin health and may prove to help prevent diseases ranging from cancer to heart disease. The key is to work with a doctor to make sure you are taking the right kind of vitamin E at the right dose. As studies have shown, taking too much can cause problems.
When it comes to cancer, I doubt that any single agent — vitamin E included — is the answer on its own. But it may become a powerful addition to other treatments.