Multivitamins linked to prostate cancer

May 16 2007

According to a new study men who take a large number of multivitamins might be increasing their risk of developing prostate cancer.

The study by researchers at the National Cancer Institute in Bethesda examined data on 29,534 men and focused on the link between consuming excess multivitamins and the risk of developing prostate cancer.

The researchers led by Karla Lawson found in a five year follow-up period that 10,241 of the men developed prostate cancer; 8,765 had localized cancers, while the remaining 1,476 were diagnosed with advanced cancers.

The researchers say while there was no link between localized prostate cancer and use of multivitamins, they found a definite link as far as advanced cancers were concerned.

They suggest that men who use multivitamins over seven times a week increase their risk of developing a fatal cancer as compared to those who did not use multivitamins.

They say their findings indicated the risk of advanced prostate cancer is 32% higher in men who take multivitamins more than once a day than in those who do not take them at all and the risk of fatal prostate cancer was almost double.

The link was strongest for men with a family history of the disease, and who also took selenium, beta-carotene or zinc supplements.

The researchers say it is unclear why the multivitamins may increase the risk of certain types of prostate cancer but many experts say there is conflicting evidence on the benefits of vitamin supplements and such products do not appear to offer the same benefits as vitamins that naturally occur in food.

People are urged to eat a diet rich in fibre, vegetables and fruit, and low in red and processed meat if they want to reduce their risk of cancer.

Prostate cancer is one of the most commonly diagnosed cancers in the U.S. in 2003 (the most recent year for which statistics are currently available), 185,891 men were diagnosed with prostate cancer and 29,554 men died from the disease.

Prostate cancer is the second leading cause of cancer death in men and kills one man every hour in the UK.

The study is published in the current issue of the Journal of the National Cancer Institute.