New research is again pointing a finger at men who like to drink milk, which could be raising their odds of prostate cancer. The study published in the June 2022 issue of The American Journal of Clinical Nutrition found that men with a higher intake of dairy foods, but not non-dairy calcium, had a higher risk of prostate cancer than men consuming a lower amount. Named the Adventist Health Study, participants included almost 29,000 Seventh-Day Adventist men in the U.S. and Canada.
At this time, researchers with the study and other prostate cancer experts agreed that this study is not suggesting that dairy is a culprit in directly causing prostate cancer risk and that it’s too early to conclude. However, this study found that men who consumed 1 ¾ cups of milk daily, when compared to men who consumed a mere 1 or 2 teaspoons of milk each day, had a 27% greater risk of developing prostate cancer. Also, milk-consuming men, when compared with men who consumed no dairy at all, had a 60% higher likelihood of getting a prostate cancer diagnosis.
The study also found that milk consumption was associated with increasing the risk of all forms of prostate cancer, including aggressive prostate cancer. But, neither yogurt or cheese consumption had a link back to increasing this disease.
Why would milk raise the risk of men developing prostate cancer? It is believed that dairy food consumption – especially milk consumption – increases the level of a hormone called insulin-like growth factor-1. For prostate cancer to grow, it requires hormones such as insulin-like growth factor-1.
Putting it into perspective
Prostate cancer is a complex disease with multiple factors that increase a man’s risk. Genetics, ethnic background, environmental influences, and diet likely play a role in whether a man is diagnosed with this disease.
This latest study was not designed to show if men who drink milk have a greater chance of developing prostate cancer. Rather, it was to discover if this narrative fits into the broader understanding of the influence of the Western dietary patterns in the U.S. and Canada on all cancers, tied together with increasing prostate cancer.
Like all studies, this one did have limitations to take into account. First, study participants were asked to recall foods eaten over a period, which is usually unreliable. Many of us struggle to remember what we ate yesterday, let alone weeks, months, or years ago. Secondly, up to 60% of men are either overweight to obese. We know that consuming too many calories and not enough exercise can lead to excess weight gain, increasing the risk of prostate cancer, especially the aggressive form. Thirdly, a study should be designed to research men who drink milk yet have normal body weight, exercise regularly, and eat a balanced diet including fruits and vegetables, and whether they also have a greater risk of developing prostate cancer.
A 2021 systematic review published in The World Journal of Men’s Health studied the association between the types of milk, classified by fat content (skim, low-fat, whole), and the risk of developing prostate cancer. Findings from this study showed that it is still unclear if prostate cancer risk is related to the dietary fat in milk or non-fat components of the milk.
At this time, the best approach is for men to be advised by their primary care physician on the risks and benefits of drinking milk. The answer may depend on each man’s family history of this disease, their current body mass index, and exercise status. Suppose it is found that certain men should avoid or limit their milk consumption. In that case, the patient should also be counseled on receiving appropriate calcium intake and about vitamin D supplementation. Milk is a primary source of vitamin D, which is necessary for the body to absorb calcium. Therefore, these factors must be considered when making dietary decisions and how they will affect a man’s overall health.
Dr. David Samadi is the Director of Men’s Health and Urologic Oncology at St. Francis Hospital in Long Island. He’s a renowned and highly successful board certified Urologic Oncologist Expert and Robotic Surgeon in New York City, regarded as one of the leading prostate surgeons in the U.S., with a vast expertise in prostate cancer treatment and Robotic-Assisted Laparoscopic Prostatectomy. Dr. Samadi is a medical contributor to NewsMax TV and is also the author of The Ultimate MANual, Dr. Samadi’s Guide to Men’s Health and Wellness, available online both on Amazon and Barnes & Noble. Visit Dr. Samadi’s websites at robotic oncology and prostate cancer 911.