Vitamin E cuts risk of bladder cancer

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http://nutraingredients.com/news/news-NG.asp?n=50986-dietary-vitamin-e

 

Dietary vitamin E cuts risk of bladder cancer

 

29/03/2004 - A diet rich in vitamin E appears to protect against both

prostate cancer and bladder cancer, according to new research that

lifts hopes for the vitamin after disappointing recent studies, writes

Dominique Patton.

 

A case-control study found that diets high in alpha-tocopherol could

more than halve the risk of bladder cancer compared to people with a

low intake (abstract 3921). Other findings reported at the American

Association for Cancer Research annual meeting this weekend suggest

that vitamin E from both diet and supplements offers strong protection

against prostate cancer.

 

Previous studies have found an association between higher intake of

vitamin E and lower incidence of cancer of the prostate and breast.

However, a recent investigation into the impact of diet on

postmenopausal breast cancer in over 18,000 women failed to find

evidence to support the vitamin's protective effect.

 

The vitamin has also been hailed as a safeguard against heart disease

but the most recent trials have not confirmed the connection between

the nutrient and reduced heart attacks or strokes.

 

The new findings will be welcomed by many in the supplements industry,

seeing falling interest in vitamin E in recent years. Natural forms of

the vitamin, said to be more potent than synthetic, are on the rise

however with Cognis recently reporting a surge in the volume of its

natural vitamin E sales of some 9 per cent last year.

 

Scientists from the University of Texas M.D. Anderson Cancer Center

and Texas Woman's University are the first to report evidence for

vitamin E's role against bladder cancer, the fourth leading cause of

death in men in the US and high in other industrialized countries such

as Canada, France, Denmark, Italy, and Spain.

 

" High intake of vitamin E from dietary sources alone was associated

with a 42 per cent reduced risk of bladder cancer, whereas high intake

of vitamin E from dietary sources and supplements combined reduced the

risk by 44 per cent, " said researcher Ladia M. Hernandez.

 

Hernandez and colleagues interviewed 468 bladder cancer patients and

534 healthy, cancer-free controls, for information on their diets and

supplement use. A database with values assigned to the tocopherol

content of foods, based on published values, was developed

specifically for the study.

 

But while gamma-tocopherol is the most common tocopherol in the US

diet, the researchers, the first to test the effects of this form of

vitamin E on cancer risk, found it to have no protective effect

against bladder cancer.

 

In the second study however (abstract 1096), researchers from the US

National Cancer Institute, the Fred Hutchinson Cancer Research Center

and the National Public Health Institute of Finland found that both

alpha- and gamma-tocopherol lowered the risk of prostate cancer, by as

much as 53 per cent and 39 per cent, respectively.

 

The scientists selected 100 men with prostate cancer and 200 without

from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

cohort of 29,133 Finnish men, aged between 50 and 69 years.

 

The ATBC study had previously demonstrated a 32 per cent reduction in

the rate of prostate cancer among men who took 50 mg of

alpha-tocopherol daily for a period of five to eight years.

 

The new study included those not taking supplements, to evaluate serum

levels of alpha-tocopherol and gamma-tocopherol exclusively derived

from dietary intake. But in keeping with earlier findings, the men who

were randomized to receive a vitamin E supplement as part of the ATBC

trial and who had the highest serum vitamin E levels at baseline

displayed the lowest risk of prostate cancer.

 

The studies appear to support an increase in dietary alpha-tocopherol,

found in greater concentrations in the blood than the gamma form. This

is in part because a protein in the liver called alpha-tocopherol

transfer protein preferentially binds alpha-tocopherol and secretes it

into the plasma.

 

Dietary vitamin E comes from nuts and seeds, wholegrain products,

vegetable oils, salad dressings, margarine, beans and other

vegetables. Spinach, green and red peppers and sunflower seeds were

found to be excellent sources of alpha-tocopherol.