Dairy increases risk for prostate cancer
Research shows men who consume dairy, especially milk, have a higher risk of prostate cancer than those consuming little or no milk. This study found that men consuming 430 grams of cows’ milk (1¾ cups) a day had a 27 per cent higher risk compared to those consuming 20 grams (half a cup) a week and a 63 per cent higher risk than those consuming none at all.
The biggest increases in risk were seen at relatively low intakes of dairy and there was little difference between full-fat and low-fat products. Non-dairy sources of calcium such as plant milks did not increase the risk and the authors say that the difference could be due to sex hormones in dairy milk. Up to three-quarters of lactating cows are pregnant, when their hormone levels are high, and prostate cancer is a hormone-responsive cancer. It may also be due to the growth hormone IGF-1, which promotes certain cancers, including prostate.
Professor Gary Fraser, the study’s principal investigator, said: “The parallels between our breast cancer in women paper a year ago and this paper relating to men, are striking. It seems possible that the same biological mechanisms are at work.” He added: “If you think you’re at higher-than-average risk, consider the alternatives of soya, oat, cashew and other non-dairy milks.”
Orlich MJ, Mashchak AD, Jaceldo-Siegl K et al. 2022. Dairy foods, calcium intakes, and risk of incident prostate cancer in Adventist Health Study-2. American Journal of Clinical Nutrition. Epub ahead of print.