New Study Links Plant-Based Diets with Lower Risk of Fatal Prostate Cancer

New research provides fresh evidence that plant-rich diets may protect against prostate cancer. 

The study, published in the November 2021 issue of The American Journal of Clinical Nutrition, leveraged data from the Health Professionals Follow-Up Study (HPFS)—a large-scale study that has tracked the diets and health outcomes of more than 40,000 male participants since 1986. Between 1986 and 2014, 6,655 HPFS participants developed prostate cancer. 

While previous research has looked at associations between specific plant foods, such as tomatoes, and prostate cancer, this latest study examined what impact an overall plant-rich eating pattern might have. 

“We were very interested to look at dietary patterns, [because of] these previous findings and the fact that people consume an overall diet, not just one food,” Dr. Stacy Loeb, MD, PhD, who co-authored the study, said in an interview this week with Urology Times. 

When Loeb and her team of researchers compared the dietary habits and prostate cancer risk among HPFS participants, they found that those who ate more plant-based foods were significantly less likely to develop fatal prostate cancer. Additionally, they found that younger men (under age 65) who ate more healthful plant-based foods were less likely to develop aggressive forms of the disease.

The authors put forth a few possible explanations for the associations, citing the antioxidant and anti-inflammatory components of fruits and vegetables. They also note that milk and other dairy products have been shown to increase levels of insulin-like growth factor 1, a hormone that has been linked to multiple forms of cancer.

The findings of the newly published study reinforce those of a 2016 study that linked a vegan diet with a 35 percent lower risk of prostate cancer. Meanwhile, animal products, particularly dairy products, have been linked to a heightened risk. A 2020 review of 20 studies stated, “The overwhelming majority of the studies included in this systematic review were suggestive of a link between milk consumption and increased risk of developing prostate cancer.” Other research has implicated red meat.

The second-most common cancer in men, prostate cancer has a five-year survival rate of 99 percent when caught early. Most men with localized prostate cancer die not of the disease but of other, preventable causes, such as cardiovascular disease—a point that Loeb emphasized in her interview with Urology Times. “At every stage, it’s very important that we focus on healthful lifestyle behaviors, because we can improve [patients’] overall survival and cardiovascular health,” Loeb said. “And some of these changes may also be beneficial in terms of prostate cancer, too.”