Vitamin E: Which Type Best for Prostate Cancer?
Some Foods are Better Sources Than Others for a Key Form of Vitamin E
March 1, 2005 -- Vitamin E supplements may not deserve all the credit for the vitamin's reputation for curbing prostate cancer.
Vitamin E is a family of various antioxidants. Gamma tocopherol is the most prevalent form of vitamin E in the American diet. Another form of vitamin E, known as alpha tocopherol, is the predominant form found in the blood.
The amount of vitamin E in the blood -- before popping vitamin E supplements -- also plays a role in prostate cancer prevention, says a new study.
In the study, men with the highest blood levels of the two forms of vitamin E had the lowest prostate cancer risk. Their risk of prostate cancer was even lower when they took alpha tocopherol supplements.
Rate Your Diet for Vitamin E
With that in mind, scan your kitchen (or take-out menu) for items containing vitamin E.
Do you snack on almonds, hazelnuts, or sunflower seeds? Eat a lot of spinach? Cook with olive oil and canola oil? If so, give yourself high marks. Those are some of the healthiest vitamin E food sources, Maret G. Traber, PhD, tells WebMD.
Those foods contain vitamin E's alpha tocopherol form. But most people get vitamin E from soybean oil and corn oil, says Traber, an Oregon State University professor of nutrition and exercise science. Soybean and corn oils favor the vitamin's gamma tocopherol form.
"The body requires alpha tocopherol. It gets rid of gamma tocopherol," Traber tells WebMD.
Even if you eat an ideal diet, it's hard to get enough vitamin E from foods alone. For instance, a cup of cooked spinach has about 1 mg of alpha tocopherol, but most adults need 15 mg per day, says Traber, who's also on staff at the Linus Pauling Institute.
Even Popeye might balk at eating 15 cups of spinach every day. Nuts may not be the perfect answer, either. Although rich in vitamin E, nuts are also laden with calories.
Best Results From Food and Supplements?
The new findings come all the way from Finland. That's where a large study showed a 32% drop in prostate cancer cases among men who took daily alpha tocopherol supplements for five to eight years when compared with men who took a placebo.
Those results were first reported in 1998. Recently, experts from the National Cancer Institute took another look at the data. This time, they focused on the two forms of vitamin E and their blood levels before taking supplements.
The original study included more than 29,000 Finnish male smokers aged 50-69. From that group, the researchers picked 100 participants who had developed prostate cancer, matching them to 200 healthy men. At the study's start, the men's blood levels of alpha and gamma tocopherol were measured.
The researchers found that the men with the highest blood levels of alpha and gamma tocopherol had lower prostate cancer risk. Men with the highest levels of both forms of the vitamin were 30%-40% less likely to develop prostate cancer as those with the lowest levels.