No single habit can guarantee you won’t develop prostate cancer, but a combination of lifestyle choices, smart screening, and awareness of your personal risk factors can meaningfully lower your odds. Prostate cancer is the most common non-skin cancer in men, so the question isn’t academic. Here’s what the evidence actually supports.
Body Weight and Mortality Risk
The relationship between weight and prostate cancer is more nuanced than you might expect. Men with a higher BMI don’t appear to develop prostate cancer at higher rates overall. In fact, large-scale data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial found that for every 5-point increase in BMI, the rate of prostate cancer diagnosis actually went down slightly.
But here’s the catch: heavier men who do get prostate cancer are significantly more likely to die from it. The same study found a 21% increase in prostate cancer mortality for every 5-point BMI increase. The likely explanation is that excess body fat creates a hormonal and inflammatory environment that fuels more dangerous forms of the disease once it takes hold. It also makes tumors harder to detect through physical exams and can complicate treatment. Maintaining a healthy weight won’t necessarily prevent prostate cancer from forming, but it reduces the chance that a cancer becomes lethal.
Diet: What Helps and What Doesn’t
A diet built around vegetables, fruits, whole grains, and fish is consistently linked with better prostate health, though no single food has been proven to prevent the disease outright. Cooked tomatoes (rich in a pigment that acts as an antioxidant), cruciferous vegetables like broccoli, and foods high in omega-3 fatty acids show up repeatedly in observational research as potentially protective.
High calcium intake is one dietary factor with a clearer signal of harm. A meta-analysis of prospective studies published in the Journal of the National Cancer Institute found that men with the highest calcium intake had a 39% greater risk of prostate cancer compared to men with the lowest intake. The highest-intake groups were consuming roughly 1,300 to 2,250 mg of calcium per day, often through heavy dairy consumption. Men in the highest dairy category had an 11% elevated risk. This doesn’t mean you need to eliminate milk or cheese, but routinely exceeding 1,500 mg of calcium daily from food and supplements combined may not be doing your prostate any favors.
Supplements Can Backfire
One of the most important findings in prostate cancer prevention is a cautionary tale. The SELECT trial, a massive government-funded study, tested whether vitamin E and selenium supplements could prevent prostate cancer. They didn’t. Vitamin E taken alone actually increased prostate cancer diagnoses by 17%, translating to 11 extra cases per 1,000 men over seven years compared to placebo.
The selenium results were even more troubling for certain groups. Men who already had high selenium levels and then took selenium supplements nearly doubled their risk of developing aggressive, high-grade prostate cancer. Meanwhile, men with low selenium levels who took vitamin E also doubled their risk of high-grade disease. The takeaway is straightforward: supplementing with vitamin E or selenium for prostate health is not just ineffective, it’s potentially harmful. Getting these nutrients from food is fine. Megadosing in pill form is not.
Physical Activity and Sexual Health
Regular exercise lowers prostate cancer risk through several pathways: it reduces inflammation, improves insulin sensitivity, and helps regulate hormone levels. Most research points to at least 150 minutes per week of moderate activity (brisk walking, cycling, swimming) as a reasonable threshold, though more vigorous exercise may offer additional benefit. Exercise also helps maintain a healthy weight, compounding the protective effect.
There’s also the ejaculation question, which many men are curious about. A large Harvard study followed men for nearly two decades and found that those who ejaculated 21 or more times per month had a 31% lower risk of prostate cancer compared to men who ejaculated 4 to 7 times per month. The mechanism isn’t fully understood, but the theory is that frequent ejaculation may help clear the prostate of potentially carcinogenic substances. This was an observational study, so it can’t prove cause and effect, but the association was strong and consistent across age groups.
Know Your Personal Risk Level
Some men face substantially higher prostate cancer risk based on factors they can’t control, and knowing where you stand changes when and how aggressively you should approach screening.
Black men are more likely to develop prostate cancer than men of any other racial or ethnic group and more than twice as likely to die from it, according to CDC data. Family history matters too: having a father or brother diagnosed with prostate cancer roughly doubles your risk, and the risk climbs further with multiple affected relatives or relatives diagnosed young.
Men who carry BRCA2 gene mutations face an especially elevated risk. Researchers at the Institute of Cancer Research have called for men with BRCA2 mutations to begin regular PSA screening after age 40, earlier than the general population. If prostate cancer runs in your family, one practical guideline is to consider getting your first PSA test about 10 years before the age at which your youngest affected relative was diagnosed.
When Screening Makes Sense
Screening doesn’t prevent prostate cancer, but it catches it early enough to treat effectively. The current U.S. Preventive Services Task Force guidelines treat screening as a personal decision rather than a blanket recommendation. For men aged 55 to 69, the Task Force says the choice to get a PSA blood test should be made individually after discussing the benefits and tradeoffs with a clinician. For men 70 and older, the Task Force recommends against routine PSA screening, since the slow-growing nature of most prostate cancers means treatment side effects often outweigh the benefit at that age.
For Black men and men with a family history, the Task Force acknowledges higher risk but stops short of a separate formal recommendation due to limited trial data specific to these groups. The practical guidance is that these men should be informed of their elevated risk and given the opportunity to start screening conversations earlier, often in their 40s. If you fall into a higher-risk group, bringing this up proactively with your doctor is worthwhile rather than waiting for them to raise it.
Medications That Lower Risk
A class of medications originally designed to treat enlarged prostates has shown a clear ability to reduce prostate cancer incidence. Two large clinical trials, PCPT and REDUCE, found that these drugs lowered the rate of low-risk and intermediate-risk prostate cancers. However, both trials also found a small increase in high-grade, more aggressive cancers in the treatment groups. This led the FDA to issue a safety warning in 2011, and these medications have never been approved specifically for cancer prevention.
For most men at average risk, the potential downsides of taking a daily medication for years outweigh the benefit. But for men at elevated risk who are already taking one of these drugs for urinary symptoms, the cancer reduction may be a secondary advantage worth discussing with their doctor.
Putting It Together
The most actionable steps boil down to a short list: stay physically active, keep your weight in a healthy range, eat a plant-forward diet without excess calcium, skip the vitamin E and selenium supplements, and understand your personal risk profile based on race, family history, and genetics. If you’re in a higher-risk group, start screening conversations earlier. If you’re at average risk, have a thoughtful discussion about PSA testing in your mid-50s. None of these steps offers a guarantee, but together they represent the strongest evidence-based approach available.