Vitamin E and lycopene combo tested in humans

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Vitamin E and lycopene combo tested in humans

 

01/10/2004 - After confirming that a combination of vitamin E and

lycopene has a positive effect on the growth of prostate tumours in

mice, scientists in the Netherlands have initiated a trial in men

suffering from the disease.

 

Researchers led by Dr. Jacqueline Limpens from the Erasmus Medical

Center in Rotterdam, said yesterday that the combination slowed the

growth of prostate tumours in mice and that a study testing the

compounds in cancer patients is now under way.

 

She and her team tested low and high doses of synthetic lycopene, the

carotenoid found naturally in tomatoes, alone and combined with

vitamin E against a placebo in mice injected with human prostate

cancer cells.

 

" It was the low dose of both lycopene and vitamin E that was the most

effective, demonstrating that 'more does not necessarily equal

better', " said Limpens.

 

She reported that the combination reduced the growth of the tumors by

73 per cent by the forty-second day of the trial.

 

" We would certainly recommend that all men regularly eat lycopene and

vitamin-E-rich foods including processed tomato products, papayas,

pink grapefruit and watermelon, wheat germs, whole grains, mangoes,

leafy green vegetables, nuts and olive oils, " she added.

 

Earlier this year, researchers from DSM were the first to discover -

in experiments carried out on a rat model - that lycopene may reduce

the risk of prostate cancer by inhibiting the male hormone's effect on

the prostate, and that feeding the rat vitamin E and lycopene in combo

caused an enhanced killing rate of tumour cells.

 

Their analysis revealed that both nutrients affected gene expression

directly in the tumours: lycopene interfered with local androgen

activation by down-regulating 5-alpha-reductase, the key enzyme for

the transformation of testosterone to its most active form

dehydrotestosterone (DHT). As a consequence, the expression of

androgen-regulated target genes was also reduced.

 

In addition, lycopene decreased the expression of two prostatic

cytokines, IGF-I and IL-6, both regarded as risk factors for prostate

cancer. Vitamin E reduced androgen signaling without affecting

androgen metabolism.

 

Prostate cancer is one of the biggest cancer killers in industrial

countries and affects more than 500,000 men worldwide every year. This

number is expected to increase with the ageing population.