A new study has found that the presence of certain diet-associated molecules in the gut are linked to the development of aggressive prostate cancer.
The research, conducted at the Cleveland Clinic and published in the journal Cancer Epidemiology, Biomarkers & Prevention, suggests that dietary and lifestyle choices may dampen the risk of being diagnosed with the deadly disease. “We found that men with higher levels of certain diet-related molecules are more likely to develop aggressive prostate cancer,” said Nima Sharifi, the director of Cleveland Clinic’s Genitourinary Malignancies Research Center.
“As we continue our research in this area, our hope is that one day these molecules can be used as early biomarkers of prostate cancer and help identify patients who can modify their disease risk by making dietary and lifestyle changes.”
Prostate cancer is the fourth most common cancer in Canada — and number one among men — with an estimated 23,300 people receiving a diagnosis in 2020, according to the Public Health Agency of Canada. Roughly one in nine Canadian men will be diagnosed with prostate cancer at some point in their lives, with 99 per cent of cases occurring in men over the age of 50. The likelihood of surviving at least five years upon diagnosis is 93 per cent.
To arrive at their findings, researchers determined the baseline levels of certain nutrients and metabolites — byproducts created during the digestive process — present in the blood serum of nearly 700 patients. They compared the serum levels in healthy patients to those who were later diagnosed with prostate cancer and discovered that men with heightened levels of a metabolite called phenylacetylglutamine (PAGln) were two to three times more likely to receive a deadly diagnosis. PAGIn is produced in the gut when microbes process phenylalanine, an amino acid found in animal and plant-based food sources such as meat, soy and beans.
They also found that elevated levels of choline and betaine — two nutrients commonly found in animal products such as red meat and egg yolks — were also connected to increased incidence of aggressive prostate cancer. The metabolite and these two nutrients have been linked to heart health in the past but this is the first time they have been studied clinically in relation to prostate cancer.
Stanley Hazen, one of the authors of the study, was the first to connect the metabolite to an elevated risk of cardiovascular disease in previous work.
“Interestingly, we found that PAGln binds to the same receptors as beta blockers, which are drugs commonly prescribed to help lower blood pressure and subsequent risk of cardiac events,” said Hazen, the director of Cleveland Clinic’s Center for Microbiome & Human Health and chair of Lerner Research Institute’s Department of Cardiovascular & Metabolic Sciences. “This suggests that part of beta blockers’ potent efficacy may be due to blocking the metabolite’s activity.”
The team now intends to explore the potential of PAGIn, choline and betaine as early biomarkers of an impending case of aggressive prostate cancer and potential ways in which dietary changes might mitigate risk. “New insights are emerging from large-scale clinical datasets that show use of beta blockers is also associated with lower mortality due to prostate cancer,” Sharifi said.
“We will continue to work together to investigate the possible mechanisms linking PAGln activity and prostate cancer disease processes in hopes of identifying new therapeutic targets for our patients.”
Dave Yasvinski is a writer with Healthing.ca