Vitamin E tocotrienols may reduce cholesterol: RCT data

08-May-2011 - Last updated on 10-May-2011 at 07:04 GMT

Carotech's ingredient is extracted from palm oil

Supplements containing a mixture of tocotrienols – forms of vitamin E – may reduce cholesterol levels by about 15 percent in people with raised cholesterol, says a new study from Malaysia.

According to findings published in Functional Foods in Health and Disease, an open-access online journal, 300 millgrams per day of a tocotrienol-rich palm oil extract for six months may reduce LDL cholesterol levels by 17 percent and total cholesterol by 11 percent.

“Lowering of the total and LDL cholesterol levels in hypercholesterolemic subjects could be achieved through supplementation with mixed tocotrienols, and was accompanied by a significantly higher serum tocotrienol concentration relative to the tocopherol level,” wrote the researchers, led by Professor KH Yuen from the University of Science Malaysia.

“The cholesterol lowering activity can be attained after 4 months of supplementation,” they added.

The study used Carotech’s Tocomin SupraBio-branded ingredient. The study was funded by Hovid, the parent company of Carotech.

The vitamin E family

Tocotrienols are a form of vitamin E that have traditionally been in the shadow of the more popular vitamin E form – tocopherols.

Overall, there are eight forms of vitamin E: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). Alpha-tocopherol (alpha-Toc) is the main source found in supplements and in the European diet, while gamma-tocopherol (gamma-Toc) is the most common form in the American diet.

Tocotrienols (TCT) are only minor components in plants, although several sources with relatively high levels include palm oil, cereal grains and rice bran.

Cholesterol reduction

One of the earliest reports to link tocotrienols to heart health – via cholesterol reduction – was a paper by Dr Asaf Qureshi at the USDA. Writing in the Journal of Biological Chemistry (Vol. 261, pp. 10544-10550.) in 1986, Dr Qureshi and his co-workers reported that the a cereal’s ability to reduce cholesterol concentrations was directly linked to its tocotrienol concentrations, with barley and oats coming out on top, followed by rye, wheat and then corn.

Another study of note followed in 1992 from researchers at Bristol-Meyers Squibb (again involving Dr Qureshi), which reported that gamma-tocotrienol was 30 times more active than the alpha-tocotrienol form at inhibiting cholesterol synthesis.

Human studies followed, with Dr Qureshi again leading the charge. In 1991, a pilot study (Am. J. Clin. Nutr ., Vol. 53, pp. 1021S-1026S) reported that supplementation with palm-derived tocotrienols was associated with a reduction in cholesterol levels in hypercholesterolemic subjects, with gamma-tocotrienol again identified as “the most potent cholesterol inhibitor in the [tocotrienol-enriched fraction of palm oil used in the study]”.

The new results “are consistent with those reported by Qureshi et al. and Tan et al.”, wrote the researchers.

Study details

Professor Yuen and his co-workers recruited 32 healthy individuals with high blood cholesterol levels.

The participants were randomly assigned to receive either placebo (soybean oil) or the Tocomin SupraBio product providing a daily dose of 300 mg of mixed tocotrienols: 30.8 percent alpha-tocotrienol, 56.4 percent gamma-tocotrienols and 12.8 percent delta-tocotrienol, as well as 22.9 IU of alpha-tocopherol.

After four months of supplementation, the researchers noted a decrease in total cholesterol of 9 percent, with the decrease recorded as 11 percent after six months.

In addition, LDL cholesterol levels were decreased by 13 and 17.5 percent after four and six months of supplementation, respectively.

No changes were observed in the placebo group.

“In view of the erratic oral bioavailability of the tocotrienols, they might best be given via a suitable delivery system that could ensure more consistent and higher oral bioavailability such that the beneficial effects of the tocotrienols could be attained,” wrote the researchers.

Happy Carotech

The research was welcomed by WH Leong, vice president of Carotech Inc: “The patented SupraBio system plays an important role and function in ensuring absorption and significantly raised total tocotrienol blood level, while alpha-tocopherol is only slightly raised and has no significant effect on blood lipids.

“Since an increase in tocotrienols’ blood level brings about significant cholesterol reduction, it is therefore important to ensure consistent and increased absorption of tocotrienol,” he added.

Source: Functional Foods in Health and Disease
Volume 3, Pages 106-117
“Effect of Mixed-Tocotrienols in Hypercholesterolemic Subjects”
Authors: K.H. Yuen, J.W. Wong, A.B. Lim, B.H. Ng, W.P. Choy