The Vitamin E Debate

After its exciting discovery in 1922 as a nutrient essential for successful pregnancies in laboratory rats, vitamin E was used in the 1930s by Dr. Evan Shute, a Canadian obstetrician, to reduce the likelihood of miscarriage in his female patients. Researchers called it a sex hormone and controversy began to brew.

By the early 1940s, Shute and his cardiologist brother, Wilfred, noticed dramatic improvements in heart function and blood flow in patients they treated with vitamin E. From that time on, the medical community was divided, with one side touting vitamin E as a startling discovery–a treatment for heart disease–and the other side discrediting it as a cure in search of a disease.

What’s Going On?

Early in 2005 the controversy heated up again with the report of a meta-analysis of 19 studies that suggested taking daily doses exceeding 400 international units (IU) of vitamin E increased the risk of death. A few months later, the Heart Outcomes Prevention Evaluation Study Extension (HOPE-TOO) study was published in the Journal of the American Medical Association. Expected to show that vitamin E reduced cancer risk or major cardiovascular events, instead the study discovered that participants experienced a slightly increased risk of developing congestive heart failure.

Criticism was swift. The meta-analysis was discredited because it combined dissimilar studies and pooled data on mixed dosages and natural and synthetic forms of vitamin E. Subjects in the HOPE-TOO study were shown to have had a history of heart disease, stroke, or diabetes and to be taking a combination of medications, including blood thinners and blood pressure and cholesterol drugs.

Serious Science

Part of the problem has to do with the biochemical nature of vitamin E, which causes the synthetic vitamin to differ from its natural counterpart. To confuse the issue even more, vitamin E in its natural form is actually a family of eight related compounds, including the tocopherol group and the tocotrienol group, each with alpha, beta, gamma, and delta types. Alpha-tocopherol is the predominant form of vitamin E found in human tissues. It was also the only form addressed in the controversial studies. Recent research, however, has found that each different tocopherol and tocotrienol exhibits a unique function and may contribute an important anti-inflammatory, cardioprotective, or anticancer effect.

Great Gamma

Gamma-tocopherol, in particular, has the ability to protect against nitrogen-based free radicals, which alpha-tocopherol cannot do. Nitrogen-based free radicals play an important role in diseases associated with chronic inflammation, including cancer, heart disease, and degenerative brain disorders such as Alzheimer’s disease. Research out of Purdue University also found that gamma-tocopherols induce death in lab-cultured human prostate and lung cancer cells while leaving healthy cells alone.

Not to be outdone, research involving tocotrienols has shown their ability to reverse atherosclerotic blockages in the carotid artery, significantly reducing the risk of stroke.

Mix It Up

The scientific focus is slowly shifting away from vitamin E to specific tocopherols and tocotrienols. New evidence suggests that the benefits of alpha-tocopherol may be significantly enhanced when combined with other forms of vitamin E. Just as we have learned that the intake of mixed carotenoids is preferable to supplementing with beta-carotene alone, supplementing with mixed tocopherols and tocotrienols may offer greater benefits than alpha-tocopherol alone.

Natural vitamin E, labelled as d-alpha-tocopherol, has greater biological activity than synthetic E, which is labelled as dl-alpha-tocopherol. Supplements containing a wide variety of vitamin E forms are generally referred to as “mixed tocopherols” or “mixed tocotrienols.”

Researchers are still writing the book on vitamin E. Despite all the controversy, what is clear is that people who eat a wide variety of colourful vegetables and fruit, whole grains, nuts and seeds, healthy oils, and lean proteins enjoy better health than those who don’t.

Major Food Sources

1/4 cup (60 mL) raw sunflower seeds - 13.5 mg
1 medium baked sweet potato - 5.9 mg
1 cup (250 mL) steamed Swiss chard - 2.4 mg
2 Tbsp (30 mL) wheat germ - 2.3 mg

What You Need Daily

1-8 years - 7 mg
9-13 years - 11 mg
14+ years - 15 mg
pregnant women - 15 mg
lactating women - 19 mg

Source: National Academy of Science, 2000

Vitamin E and Your Child’s Asthma Risk

A study of over 1,800 healthy pregnant women and their children has shown that children born to mothers who had a low intake of vitamin E during pregnancy were more likely to develop asthma (American Journal of Respiratory and Critical Care, September 2006).

At the five-year follow-up, children whose mothers consumed the highest levels of vitamin E during pregnancy demonstrated significantly better lung function.