Tocotrienols

Claims, Benefits: A better form or vitamin E, the best way to lower cholesterol and protect the heart and arteries.

Bottom Line: The research in humans has been very limited, and the results conflicting. No one knows how much you should take, or which supplement is best. Do not stop taking regular vitamin E (tocopherols) capsules.

Full Article, Wellness Letter, October 1999:

The other vitamin E's

Since 1994 the WELLNESS LETTER has recommended that everyone take a daily supplement of vitamin E for its potential cardiovascular (and other) benefits. But things are not so simple. As we've discussed, "vitamin E" is not a single substance, but eight related compounds. Four of these are called tocopherols; of these, alpha-tocopherol is best known, being the main type in the body and in supplements. The other four forms of E are tocotrienols.

Researchers around the world are investigating the different biological and antioxidant effects of these various forms of vitamin E. Meanwhile, some experts are already recommending tocotrienols, which are now turning up in supplement form, under such names as EvolvE. These capsules are being loudly promoted as the best way to lower cholesterol and protect the heart and arteries. Should you take tocotrienols?

What the studies show—and don't show

Tocotrienols and tocopherols are nearly identical chemically, but have important molecular differences that affect their functions. Tocotrienols occur naturally in cereal brans (such as barley, rice, and oats). Studies have shown that these foods can lower cholesterol, and their tocotrienol content may be one factor in this. Tocotrienols are also found in palm oil.

Some animal studies have found that tocotrienols can lower blood cholesterol. These substances presumably prevent the synthesis of cholesterol in the liver. In contrast, tocopherols (that is, what's in regular vitamin E capsules) don't lower cholesterol, but as antioxidants they help protect against heart disease by preventing the oxidation of LDL ("bad") cholesterol. (Oxidation makes LDL more likely to promote the buildup of fatty plaque in artery walls.) Tocotrienols are also powerful antioxidants: in fact, alpha-tocotrienol is far more powerful than alpha-tocopherol, at least in the test tube. In addition, test-tube studies suggest that tocotrienols, like tocopherols, reduce blood clotting.

The research in humans, however, has been very limited, and the results conflicting. Two studies found that tocotrienol supplements have beneficial effects, while three found none. For instance, one study found that large doses of tocotrienol supplements lowered LDL cholesterol by 10%. But the most recent study, a Dutch one in the American Journal of Clinical Nutrition in February, found no beneficial effects on the blood.

Wait for more answers

Many questions about tocotrienols remain unanswered:

• What's in the tocotrienol supplements on the market? Most are made from rice-bran oil, some from palm oil. Some also contain tocopherols. Which formula will lower cholesterol? EvolvE contains a substance called P-25 that is made from rice bran via a patented process. Despite the claims, there is nothing "natural" about P-25. In fact, it is more like a drug than a dietary supplement, one whose safety and efficacy have never been tested.

• How much should you take to get the proposed benefits? The studies have used much larger doses than the labels recommend.

• Is it okay to take tocotrienols and tocopherols? Some scientists claim that tocopherols may negate some of the benefits of tocotrienols. The interactions are unclear. Does that mean you would have to stop taking your regular vitamin E capsules?

What to do

It would be a serious mistake to stop taking regular vitamin E capsules. Vitamin E has many functions not performed by tocotrienols. The WELLNESS LETTER continues to recommend 200 to 800 IU of vitamin E a day, preferably "natural" tocopherols. At this point, there's no evidence that tocotrienols would be a better option. If, despite the many unanswered questions, you decide to take tocotrienols, remember that they can't take the place of your other vitamin E capsules.

If you have elevated cholesterol levels and haven't been able to lower them via diet and other life-style changes, talk to your doctor about proven, well-studied cholesterol reducers: "statin" drugs (see WELLNESS LETTER, August 1998) or the dietary supplement Cholestin, which is also a "statin."

And by the way: Another way to get tocotrienols is simply to eat wheat bran, wheat germ, barley, oat bran, and rice bran, which contain other healthful substances as well.

UC Berkeley Wellness Letter, October 1999