Saturday, March 17

Vitamin E and Prostate Cancer - Raised risks in vitamin E supplements

Does vitamin E supplementation increase the risk of prostate cancer?
The risk of prostate cancer was found to increase when vitamin E supplements were given for a long period. JAMA (the Journal of the American Medical Association) published a study on the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and concluded that "Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men."

Vitamin E in the form 'Alpha-Tocopherol' increases prostate cancer risk

The initial report of SELECT trial found no reduction in the occurrence of this cancer either with selenium (200 μg/d from L-selenomethionine) or with vit. E (400 IU/d of all rac-α-tocopheryl acetate). However in the longer follow-up studies the occurrence of prostate malignancy in healthy SELECT subjects has established a relationship of this cancer with 'all rac-α-tocopheryl acetate'.

The point to be noted here is that 'all rac-α-tocopheryl acetate' was the form of alpha-Tocopherol used in this SELECT trial. In fact vit. E is a group of compounds which are fat-soluble and comprise four types of tocopherols and four types of tocotrienols. In natural food all the eight types are present in different proportions.

Alpha-Tocopherol constitutes the major source of vit. E in European diets while in North American diet gamma-tocopherol is the major constituent. Though early research had focussed on alpha-tocopherol, of late the higher beneficial traits of gamma-tocopherol and tocotrienols are being recognized.

Vitamin E in the form of Tocotrienols has been found to help in prevention of cancer, reduction of cholesterol, protection from stroke-induced brain cell injury, lowering tumor formation, protection against DNA and cell damage and suppression of cancer of pancreas, breast, prostate gland and skin.

Vitamin E in the form 'Gamma-tocotrienol' is effective against prostate cancer

Recent studies by Luk Su et all have reported that vit. E in the form of Gamma-tocotrienols (γ-T3) can be an effective therapeutic agent against  prostate cancer stem cells (CSCs) and advanced stages of malignancy. Alpha-tocopherol is found to interfere with tocotrienols benefits by interfering with their absorption and increasing their catabolism.

Synthetic alpha-tocopherol is produced and marketed as vit. E supplement whereas synthetic tocotrienol is not produced as a supplement though technically possible. Further research in these lines and production and marketing of alternatives like Gamma-tocotrienols is required.

It can be safely concluded that vitamin E as 'Alpha-Tocopherol' increases the risk of prostate cancer while in its 'Gamma-tocotrienol' form can be an effective therapeutic agent against this malignancy.

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