Study: Alpha-Tocopherol Intake Does Not Deplete Tocotrienols

EDISON, N.J.A recent animal study in rats proves regular vitamin E alpha-tocopherol intake does not deplete tocotrienols and gamma-tocopherol levels in various tissues, and it does not increase the excretion of their metabolites into urine (Lipids. 2013 Jul;48(7):687-95).

The study also revealed stimulation of -hydroxylation of the other vitamin E-isoforms by alpha-tocopherol in the liver has no significant effect on tissue concentrations of other tocopherol and tocotrienol in vivo.

Japanese researchers fed rats a gamma-tocopherol-rich diet (150 mg/kg) for six weeks, followed by a gamma-tocopherol-free diet with or without alpha-tocopherol (100 mg/kg) for seven days. To investigate the effect of alpha-tocopherol on tocotrienol depletion, researchers fed rats with a tocotrienol-rich diet (103 mg alpha-tocotrienol/kg and 150 mg gamma-tocotrienol/kg) for six weeks, followed by a tocotrienol-free diet with or without alpha-tocopherol (100 mg/kg) for seven days.

Results showed dietary alpha-tocopherol did not influence gamma-tocopherol and tocotrienol concentration in the serum and tissues, including liver, adrenal glands, small intestine, heart, muscles and adipose tissues. The researchers concluded dietary alpha-tocopherol did not accelerate the breakdown of the other vitamin E isoforms (including gamma-tocopherol and tocotrienol) in vivo. Also, it did not influence the tissue concentration of the other vitamin E isoforms in serum and almost all tissues.

We have stressed numerous times that nature makes both tocopherols and tocotrienols, and therefore, there is no reason (scientifically or otherwise) to purposely remove tocopherol or limit tocopherol intake with tocotrienols," said WH Leong, vice president of Carotech. "We need to take vitamin E as nature makes itin a wholesome and full-spectrum formula. Mimicking nature is the best way for dietary supplementation, as nature knows best."

Another recent study revealed d-mixed tocotrienol and alpha-tocopherol supplementation improved liver health and non-alcoholic steatohepatitis (NASH) in rats. The study found four weeks of supplementation significantly reduced triglyceride accumulation in the liver and inhibited liver fibrosis.