Tocotrienols are fat-soluble substances closely related to vitamin E. Like vitamin E, they have
, and help protect fatty substances in the body from being damaged by free radicals. In the 1990s, antioxidant supplements were thought to offer great potential for preventing a variety of diseases, including cancer and heart disease, and on this basis tocotrienols were offered on the market as healthful supplements. Tocotrienols have also been proposed for reducing cholesterol. However, subsequent studies have tended to pour cold water on all these hopes. At present, there is no reliable evidence that tocotrienols offer any meaningful health benefits.
Tocotrienols are not essential nutrients. They occur naturally in the oil extract of barley, palm fruit, rice bran, and wheat germ. Most commercially available supplements are made from rice bran oil or palm oil.
A typical recommended dose of tocotrienols is 200 mg daily.
open human trials
seemed to suggest that tocotrienols can correct
properly designed studies failed to find benefit.
Test-tube and animal studies, as well as one double-blind human trial have found promising hints that tocotrienols may help prevent cancer.
The double-blind study among these specifically found that tocotrienols might help prevent DNA damage, which could, in theory, help prevent many disease associated with aging, not just cancer.
However, none of this evidence rises above the level of "highly preliminary."
The hypothesis that tocotrienols can prevent heart disease simply by virtue of their antioxidant actions has lost favor, since the same hypothesis proved incorrect with
The bottom line: The health benefits of tocotrienols, if there are any, remain to be established.
Tocotrienols are thought to be safe substances. However, maximum safe doses have not been determined.
Qureshi AA, Mo H, Packer L, et al. Isolation and identification of novel tocotrienols from rice bran with hypocholesterolemic, antioxidant, and antitumor properties.
J Agric Food Chem
Nesaretnam K, Guthrie N, Chambers AF, Carroll KK.
Effect of tocotrienols on the growth of a human breast cancer cell line in culture.
Goh SH, Hew NF, Norhanom AW, Yadav M. Inhibition of tumour promotion by various palm-oil tocotrienols.
Int J Cancer
Yu W, Simmons-Menchaca M, Gapor A, et al. Induction of apoptosis in human breast cancer cells by tocopherols and tocotrienols.
Mo H, Elson CE. Apoptosis and cell-cycle arrest in human and murine tumor cells are initiated by isoprenoids.
Nesaretnam K, Stephen R, Dils R, Darbre P. Tocotrienols inhibit the growth of human breast cancer cells irrespective of estrogen receptor status.
He L, Mo H, Hadisusilo S, et al. Isoprenoids suppress the growth of murine B16 melanomas in vitro and in vivo.
Theriault A, Chao JT, Wang Q, et al. Tocotrienol: a review of its therapeutic potential.
Khor HT, Chieng DY, Ong KK. Tocotrienols inhibit liver HMG-CoA reductase activity in the guinea pig.
O'Byrne D, Traber MG, Packer L, et al. Supplementation with alpha-tocotrienyl acetate enhances LDL oxidative resistance without lowering serum cholesterol in hypercholestrolemic humans [abstract].
Parker RA, Pearce BC, Clark RW, et al. Tocotrienols regulate cholesterol production in mammalian cells by post-transcriptional suppression of 3-hydroxy-3-methylglutaryl-coenzyme A reductase.
J Biol Chem
Pearce BC, Parker RA, Deason ME, et al. Hypocholesterolemic activity of synthetic and natural tocotrienols.
J Med Chem
Qureshi AA, Bradlow BA, Brace L, et al. Response of hypercholesterolemic subjects to administration of tocotrienols.
Qureshi AA, Bradlow BA, Salser WA, et al. Novel tocotrienols of rice bran modulate cardiovascular disease risk parameters of hypercholesterolemic humans.
J Nutr Biochem
Qureshi AA, Qureshi N, Hasler-Rapacz JO, et al. Dietary tocotrienols reduce concentrations of plasma cholesterol, apolipoprotein B, thromboxane B2, and platelet factor 4 in pigs with inherited hyperlipidemias.
Am J ClinNutr
. 1991;53(4 suppl):1042S–1046S.
Qureshi AA, Qureshi N, Wright JJ, et al. Lowering of serum cholesterol in hypercholesterolemic humans by tocotrienols (palmvitee).
Am J Clin Nutr
. 1991;53(4 suppl):1021S–1026S.
Qureshi AA, Sami SA, Salser WA, et al. Synergistic effect of tocotrienol-rich fraction (TRF 25) of rice bran and lovastatin on lipid parameters in hypercholesterolemic humans.
J Nutr Biochem
Szapary PO, Cirigliano MD. Tocotrienols in the management of hypercholesterolemia and atherosclerosis.
Teoh MK, Chong JM, Mohamed J, et al. Protection by tocotrienols against hypercholesterolaemia and atheroma.
Med J Malaysia
Wan Nazaimoon WM, Sakinah O, Gapor A, et al. Effect of palm olein tocopherol and tocotrienol on lipid peroxidation, lipid profiles and glycemic control in non-insulin diabetes mellitus patients.
Watkins T, Lenz P, Gapor A, et al. gamma-Tocotrienol as a hypocholesterolemic and antioxidant agent in rats fed atherogenic diets.
Mustad VA, Smith CA, Ruey PP, et al. Supplementation with 3 compositionally different tocotrienol supplements does not improve cardiovascular disease risk factors in men and women with hypercholesterolemia.
Am J Clin Nutr
Kerckhoffs DA, Brouns F, Hornstra G, Mensink RP. Effects on the human serum lipoprotein profile of beta-glucan, soy protein and isoflavones, plant sterols and stanols, garlic and tocotrienols.
Mensink RP, van Houwelingen AC, Kromhout D, et al. A vitamin E concentrate rich in tocotrienols had no effect on serum lipids, lipoproteins, or platelet function in men with mildly elevated serum lipid concentrations.
Am J Clin Nutr
Ajuluchukwu JN, Okubadejo NU, Mabayoje M, et al. Comparative study of the effect of tocotrienols and -tocopherol on fasting serum lipid profiles in patients with mild hypercholesterolaemia: a preliminary report.
Niger Postgrad Med J
Chin SF, Hamid NA, Latiff AA, et al. Reduction of DNA damage in older healthy adults by Tri E® Tocotrienol supplementation.
2007 Sep 19. [Epub ahead of print]
Last reviewed August 2013 by EBSCO CAM Review Board
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