Dairy Increases Risk of Prostate Cancer. What to Eat to Lower Your Risk

November is dedicated to men’s health issues such as prostate cancer, testicular cancer,  and mental health issues, as part of a movement called Movember — when men grow mustaches to also grow awareness of physical and mental health issues. One is prostate cancer, the second most common cancer for men after lung cancer, and the second leading cause of cancer-related death.

Now one prominent medical researcher is leading the way to educate men about the connection between dairy and prostate cancer, and the overwhelming research shows that while dairy is dangerous, eating more plant-based foods can lower prostate cancer risk as well as its recurrence. Prostate cancer affects over 10 million men worldwide and prostate cancer accounted for 34,130 deaths in the US in 2021.

Dr. Shireen Kassam, MBBS, FRCPath, Ph.D., founder and director of Plant-Based Health Professionals UK and consultant hematologist and honorary senior lecturer at King’s College Hospital, London, wants men to know that there is a connection between dairy consumption and prostate cancer risk, according to scientific studies. Dr. Kassam helped develop the first University-based course on plant-based nutrition in the UK, at the University of Winchester.

Prostate cancer is even more deadly for black men who are 1.7 times more likely to have new cases of prostate cancer and twice as likely to die from prostate cancer than white men. Doctors don’t fully understand the reason why prostate cancer is more common in blacks than whites, Dr. Kassan says, but it’s likely due to a combination of factors, including genetics, environmental factors, diet and other lifestyle choices, as well as issues related to access to healthcare and the disparities in health outcomes.

In terms of dairy’s link to prostate cancer, a recently published systematic review on milk consumption and prostate cancer concluded: “The overwhelming majority of the studies ... were suggestive of a link between milk consumption and increased risk of developing prostate cancer.” In addition, research reveals that dairy consumption following a diagnosis of prostate cancer may increase the risk of death.

“There is a consistent association between the consumption of dairy and an increased risk of prostate cancer in men," she explains. "For example, a combined analysis of 32 observational studies published in 2015 found that for every 400 grams of dairy consumed there was a 7 percent increased risk of developing prostate cancer, and this risk applied to both milk and cheese,” she says. Another analysis of 47 studies published in 2019 investigated the association between the consumption of plant-based foods and cancer risk, and found that dairy consumption had the strongest link to prostate cancer, whereas the consumption of plant-based foods reduced the risk of prostate cancer.

Still another study from Japan looked at the dietary habits of 26,464 men who were tracked from 1990 until 2009. The research found that the risk of prostate cancer in men consuming the most milk (almost one serving every day) was 37 percent higher compared to men consuming the least (defined as those who seldom had dairy, or once or twice a month).

Those who eat a more plant-based diet also fare better when it comes to prostate cancer risk according to yet another study of 1,344 American men, which “showed that those consuming a diet full of healthy plant foods and low or absent in animal and processed foods had a much lower risk of elevated PSA level. PSA levels," which are Prostate-Specific Antigen hormones that are a reliable marker of prostate cancer that can be measured in the blood.

Consuming dairy products can increase the risk of prostate cancer but the risk goes up if you are also overweight, studies find. Eating dairy products increases the occurrence of prostate cancer in overweight men, and also drives up the chance of the disease leading to death.

“One important reason why dairy and indeed diets high in animal foods increase the risk of prostate cancer may be because this results in higher blood levels of IGF-1," explains Kassan. "This growth factor stimulates cells to grow and is associated with an increased risk of cancer in general. We know that the levels of IGF-1 [insulin-like growth factor 1] in people that don’t consume animal products are significantly lower than in those that do," she adds.

"The risk of prostate cancer is lower in those following a vegan diet,” explains Dr. Kassam. Being overweight in general also increases the risk of cancer, including prostate cancer. “This is because carrying too much fat increases inflammation and levels of growth hormones that drive cancer growth,” she explains.

Eating more plant-based foods has been shown to protect your prostate health. “Several studies have shown that the consumption of lycopene, the antioxidant in fruits and vegetables that gives them a red color, is associated with a lower risk of prostate cancer,” says Dr. Kassam. “Tomato consumption, in particular, may have a protective effect, although the association is strongest for cooked rather than raw tomatoes.”

Dr. Kassam also touts the benefits of cruciferous vegetables like broccoli, kale, cabbage and Brussel sprouts, as some of the most beneficial vegetables for cancer prevention and include. “For example, one study showed men with prostate cancer who ate the most cruciferous vegetables had a 50 percent lower chance of the cancer progressing compared to those men who ate the least,” she says. “A more recent study demonstrated how a compound in cruciferous vegetables can activate genes that are implicated in suppressing the growth of prostate cancer cells.”

In general, a healthy plant-based diet has been shown to lower the risk of prostate cancer the chances of dying from prostate cancer.

In short, dairy consumption is harmful to your health, whether we’re talking about prostate health, skin health, diabetes risk or more.  Fully “70 percent of the world’s population have lactose malabsorption after weaning, and therefore the inclusion of dairy in the diet for these individuals will result in distressing abdominal symptoms. Dairy consumption is linked to the development of eczema, asthma, and acne, conditions that negatively impact a child’s quality of life,” says Dr. Kassam. “In addition, there is concern that dairy consumption increases the risk of type 1 diabetes in children and cow’s milk is the commonest cause of death from anaphylaxis in UK children,” she explains, adding that some studies have also shown that cow’s dairy products increase the risk of breast cancer in women.

For more convincing, check out 7 reasons you’ll want to stay away from dairy.

“The best swap for dairy products would be fortified soy drinks and foods such as tofu, soy milk, tempeh... [since] consumption of soy foods has been associated with a lower risk of prostate cancer in a number of studies. In fact, soy milk has also been associated with a lower risk of prostate cancer, so if you are looking to swap out your dairy milk, then soy would be a good option for prostate health,” says Dr. Kassam. If you already have a diagnosis of prostate cancer, it may not be too late to see the positive impacts of soy foods.

“One study examined the impact of soy intake on prostate cancer progression. Men awaiting prostate surgery were randomly assigned to either eating a diet high in soy or not,” says Dr. Kassam. “In the soy group, there was a significant decrease in the PSA level when compared to the control group. Soy foods are associated with a number of health benefits, including lower cholesterol, better kidney, and bone health.”

A healthy plant-based diet has been shown to lower the risk of prostate cancer and the chances of dying from prostate cancer. Eat more cruciferous vegetables like broccoli, which contain tumor-suppressing compounds, and tomato sauce high in lycopene.