Healthy Diet Slows Prostate Cancer

A healthy diet may help prevent low-risk prostate cancer from progressing more aggressively during active surveillance, a study from the Johns Hopkins University (JHU) School of Medicine finds. Active surveillance is when doctors carefully monitor the growth of a tumor and is an alternative to treatment that could have adverse effects.
“These men are motivated to make changes that may improve their prognosis, which is why we began collecting data on their diets, lifestyles and exposures 20 years ago,” he added.
The Gleason score is the older classification system, but many hospitals report both Grade Groups and Gleason scores. The Gleason score is based on a tissue sample of the prostate, with lower numbers meaning the cancer is less aggressive and less likely to spread.
At enrollment, the men completed a food frequency questionnaire, which the researchers used to calculate a healthy eating index (HEI) score. This measures how much a person’s diet adheres to the Dietary Guidelines for Americans.
To determine correlations, the researchers reassessed the men 6.5 years after diagnosis.
The researchers found that the healthier the diet, the lower the risk of cancer progression to a higher grade requiring treatment. According to senior author Dr. Christian Pavlovich, a professor in urologic oncology at the JHU School of Medicine and director of the Brady Urological Institute’s prostate cancer active surveillance program, each increase of 12.5 points in the HEI score was associated with a roughly 15 percent decrease in reclassification to Grade Group 2 and a 30 percent decrease in reclassification to Grade Group 3 or higher. Grade Groups 2 and 3 indicate that the prostate cancer poses an intermediate risk compared to Grade Group 1’s low or very low risk.
“We hypothesized before conducting the study that inflammation would be associated with progression to a higher grade (more aggressive disease),” Trock told The Epoch Times in an email. “We know that inflammation plays an important role in the development of cancer.”
However, the researchers found a lack of association between inflammation and prostate cancer progression. This was surprising because some studies have found that men who develop prostate cancer have a more inflammatory diet than men who don’t, he continued.
Inflammation doesn’t act in isolation, Trock explained. Diet can influence an array of other important mechanisms, such as immune function, intestinal microbiome, and activation of specific genes. The HEI likely captures many other effects of the diet independent of inflammation.
“One possible explanation for the lack of association is that inflammation plays a greater role in the initial transformation from a healthy prostate to one that has cancer,” he said.
“In other words, this direct support to damaged cells may slow down the multiplication of cancerous cells, thereby providing more value to active-surveillance patients than a simple word on dieting,” he explained.
“Vegetables belonging to a cruciferous group, as well as dark leafy green vegetables, contain the compound sulforaphane, which has been found to lower the expression of androgen (male sex hormone) receptors,” he said.
The below chart shows some of the primary differences between the two diets:
“In the Dietary Guidelines for Americans, there are certain dietary recommendations that have proven to be effective in the risk reduction for prostate and other cancers,” he said.
“Yet there is a plethora of publications in the scientific journals that have been trying, with very little success, to convince and entice medical doctors to prescribe dietary measures to their patients,” he added.
Contreras referred to the Johns Hopkins study as research that, for the first time, indicated a dietary protocol could help keep low-grade prostate cancer patients from progressing to more dangerous states during active surveillance. He hopes similar studies will follow so patients of all malignancies will be encouraged to change their diets to improve prognosis and longevity with a good quality of life.
“At our facility, we have been promoting a similar diet for over 60 years to our patients,” said Contreras.
This diet includes a high intake of fruits and vegetables, particularly those containing lycopene, an antioxidant in tomatoes that has been associated with reduced prostate cancer risk. The diet also involves whole grains, legumes, and healthy fats, such as those found in nuts, seeds, and avocadoes.
Additionally, Contreras advises reducing the intake of red and processed meats, refined carbohydrates, and saturated and trans fats.
“I am convinced that this is one of the reasons for our better-than-average survival rates in our patients with prostate and other malignancies,” he said.