OSTEOPOROSIS is a generalised, degenerative disorder of the skeleton. As a person ages, the bone will lose its density and become thinner and more porous. This will make the bone more susceptible to fractures.
There are many causes of osteoporosis, such as lack of the sex hormones oestrogen and testosterone, which occurs as a woman or a man ages, heavy smoking, calcium and vitamin D deficiency, as well as excess of thyroid and steroid hormones.
The most common cause of osteoporosis is oestrogen deficiency, which occurs after menopause. With increased life span of people in developed and developing countries, the incidence of osteoporosis and its complications are increasing, and has become a social and financial burden to the community.
Vitamin E is a naturally occurring antioxidant found in various plants. There are two types of vitamin E, tocopherol and tocotrienol. Tocopherols and tocotrienols are subdivided into alpha, beta, gamma and delta isoforms, depending on their chemical structure. In nature, different plants may have different amounts of each isoform or may not have all the isoforms.
Palm oil, which is widely found in Malaysia, contains about 75 per cent of alpha, gamma and delta tocotrienols, and only about 25 per cent of alpha-tocopherol. Gamma-tocotrienol is most abundant in palm oil.
Our research group in the Faculty of Medicine, Universiti Kebangsaan Malaysia, has been studying the effects of tocotrienols on osteoporosis for more than 10 years.
We have found that tocotrienols, which was mostly derived from palm oil, had beneficial effects on bone health. Tocotrienols are able to prevent and reverse osteoporosis in laboratory rats, which was induced by various stressors, such as oestrogen deficiency, testosterone deficiency, steroid excess, thyroid hormone excess as well as nicotine toxicity. The doses of tocotrienols we used were low, that is, far below the toxic doses reported.
Among the tocotrienol isoforms, we found that gamma-tocotrienol was the most effective. Our findings indicated that the tocotrienol vitamin E has the potential to be developed into an anti-osteoporotic medication. It can also be used as supplements to increase peak bone mass in young adults.
The effective dose in humans needs to be confirmed by clinical trials. Our research findings have been published in more than 70 scientific journals and have won several awards locally and internationally.
Recently it has been reported in the media that too much vitamin E might cause osteoporosis. However, the report is misleading as the original article which appeared online in the Nature Medicine journal described research done using high dose alpha-tocopherol.
That study showed that high dose alpha-tocopherol induced osteoporosis in laboratory mice. However, other isoforms, including alpha-tocotrienol, did not induce osteoporosis.
We also studied the effects of alpha-tocopherol on osteoporosis and found that it has marginal benefits, significantly less than tocotrienols.
However, we did not find any detrimental effect on bone caused by alpha-tocopherol. This may be because our dose was almost 10 times smaller than the dose in the above study. Therefore, there were no toxic effects seen in our dose.
In conclusion, our pre-clinical studies have shown that vitamin E of the tocotrienol type is effective as an anti-osteoporotic agent, and no toxic effects were observed in the doses that we used.
Prof Dr Ima Nirwana Soelaiman, Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia