Movember: What Does the Research Say About Diet and Prostate Cancer Risk?

Dr. Matthew NagraArticles, Dairy, Plant-based Diet

It’s that time of year once again. Movember is back, and the month of moustached men has officially begun. You’ve likely heard the term before, whether from participating yourself or simply watching as your partner, father, brother, or friend get a little bushier above the lip. Whatever your connection may be, it’s time to prepare your eyes for a flashback to the 70’s stache.

What is Movember?

Movember is an annual charity event that occurs during the month of November. During this month, participants grow moustaches – hence the name Mo-vember – to raise awareness of men’s health issues, specifically prostate cancer, although it can extend to testicular cancer, mental health, and suicide prevention. This event is celebrated widely and loudly across the globe, raising millions of dollars each year for the Movember Foundation charity.

Prostate Cancer and Movember

The second most common cancer among men worldwide, 1 in 8 men will be diagnosed with prostate cancer in their lifetime according to the American Cancer society. As prostate cancer awareness is one of the driving forces behind this month-long event, I couldn’t let the month go by without sharing some research evaluating the association between diet and prostate cancer risk. So, is there a connection between prostate cancer and diet? Do certain foods increase men’s risk of prostate cancer? Does a plant-based diet improve these odds? Let’s take a look at the research.

Diet and Prostate Cancer Risk

There aren’t many clear associations between individual foods or food groups and a heightened risk of developing prostate cancer, but two food groups that are often associated with risk of at least certain types of prostate cancer are processed meat and dairy. However, in the case of dairy, it may depend on the type of dairy.

A 2022 meta-analysis found that each 400g increase in dairy or total milk consumption per day was associated with a 2% increase in risk, while each 40g of cheese was associated with a 1% increase and each 50g of butter was associated with a 3% increase. On the other hand, each 100g of whole milk was associated with a 4% reduction in risk! However, these are the results when pooling the results from the previous studies on the topic and without necessarily considering background diet quality or what dairy is replacing. Let’s look at some of the highest quality research we have on the topic from the Adventist Health Study-2.

Dairy and Prostate Cancer

For this study, 28,737 Seventh-day Adventist men in the USA and Canada were followed for an average of 7.8 years. During this time, 1254 cases of prostate cancer developed. Compared to those in the 10th percentile of dairy consumption, those in the 90th percentile, which would equate to consuming almost 2 cups of milk per day, had a 27% higher risk of developing prostate cancer. For advanced prostate cancer specifically, those with high consumption had a 38% higher risk.

These results remained similar when excluding vegans or only analyzing African American participants. The results were also similar if analyzing dairy consumption as a percent of calories rather than grams of dairy consumed. Interestingly, replacing dairy with soy was beneficial for prostate cancer risk, but soy consumption itself didn’t appear to result in significant benefit, so some of the benefits of soy for prostate cancer may actually be due to soy replacing dairy.

In an additional analysis that accounts for dietary measurement errors, high dairy consumption was associated with a 75% higher risk compared to those who consume very little. Lastly, they evaluated various types of dairy foods, and total dairy, full fat dairy, reduced fat dairy, total milk, and reduced fat milk were statistically significantly associated with higher risk of developing prostate cancer, while the results for cheese and yogurt were not statistically significant. Overall, this data supports previous analyses suggesting that certain types of dairy consumption may increase the risk of developing prostate cancer.

Processed Meat and Prostate Cancer

While the link between processed meat and prostate cancer remains uncertain, studies have shown that increased meat consumption may be associated with a higher risk of prostate cancer. In this meta-analysis of twenty-five prospective studies, nearly 2 million participants with 35,326 cases of prostate cancer were evaluated over the course of 6 to 23 years.

Throughout this meta-analysis, “red meat” was defined as red and unprocessed red meat (e.g., beef) while “processed meat” specifically referred to sausages, bacon, smoked beef, hamburger, ham, lunch meats, hot dogs, processed poultry, etc. In the various studies, the assessment of meat consumption was mostly done using a food frequency questionnaire (FFQ), however, a few studies used other methods.

Overall, those consuming the most processed meat had a 6% higher risk of developing prostate cancer and a 17% higher risk of developing advanced prostate cancer compared to those consuming the least. The dose-response analysis also suggests that each 50g daily serving of processed meat may increase risk of total prostate cancer by 4%. While we certainly need more data, this research does suggest that processed meat consumption may be a risk factor.

Plant-Based Diet and Prostate Cancer

While studies have shown a correlation between dairy and meat consumption and an increased risk of prostate cancer, are there foods that are protective against the disease? What about entire dietary patterns? Let’s take a look at the relationship between plant-based diets and prostate cancer risk in this Health Professionals Follow-up Study.

In this study, 47,239 men were followed for an average of 20.7 years. The participants completed questionnaires about their overall lifestyle and medical history every 2 years and on their diet every 4 years. This helps overcome some of the potential issues with other research in which data is only obtained at baseline and any changes to the participants’ diet or lifestyle overtime would not be accounted for. Using this data, they evaluated the impact of a plant-based diet, as determined by plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI) scores, on localized, advanced, lethal, and fatal prostate cancer risk.

The Results

Among men diagnosed before age 65, the highest PDI scores were associated with a 42% lower risk of advanced prostate cancer, and a 38% lower risk of lethal and fatal prostate cancer compared to those with the lowest PDI scores. High hPDI scores were also associated with a similarly low risk of lethal and fatal prostate cancer, as well as localized and total prostate cancer in those under age 65. Surprisingly, high uPDI scores were associated with a lower risk of lethal and fatal prostate cancer in those 65 and older, which may be due to unhealthful plant foods replacing animal foods. It may also partially be because the PDI scores are designed to evaluate outcomes such as CVD and type 2 diabetes, and they include foods like potatoes in the “unhealthful” category, when they don’t have a link to prostate cancer outcomes.

Overall, the benefits appear to be driven primarily by healthy plant foods. Mainly because when they evaluated the impact of animal foods, healthful plants, and unhealthful plants, after adjusting for the other two food groups, the healthful plant foods were most beneficial.

These results are in line with previous data that has found that plant foods are typically associated with lower or neutral risk of prostate cancer, whereas animal-based foods, particularly dairy products, are typically associated with either an increased or neutral risk.

What’s the Verdict?

In the spirit of Movember, why not improve your health with some plant-based foods? Whether you participate in growing a moustache or want to support in other ways, going plant-based for the month is a great way to support prostate awareness while simultaneously taking control of your own health. If you need some help getting started, I’m here to help. Become a member of “Dr. Nagra’s Nutrition Community” to gain access to live discussions, Q&A’s, exclusive educational nutrition catalogues, a private Facebook group, and much more. Or you can book a one-on-one consultation with me to discuss your specific health concerns and goals. Whichever way you choose to participate, I wish you a healthful and hairy Movember.