Hold the Fries: Foods Linked to Prostate Cancer Risk
We all know that deep-fried foods like French fries, fried chicken, and doughnuts taste good but aren’t good for us. Now, researchers at Fred Hutchinson Cancer Research Center are presenting scientific evidence that these foods—when consumed once a week or more—are associated with an increased risk of prostate cancer. The effect appears to be slightly stronger with regard to more aggressive forms of the disease, defined as regional/distant stage, elevated Gleason score, or PSA level.
The team notes that previous studies have suggested that eating foods made with high-heat cooking methods, such as grilled meats, may increase the risk of prostate cancer, but this is the first study to examine deep frying in relation to prostate cancer risk. Deep-fried foods have previously been linked to cancers of the breast, lung, pancreas, head and neck, and esophagus.
For the study, the investigators analyzed data from two prior population-based case-control studies involving a total of 1,549 men diagnosed with prostate cancer and 1,492 age-matched healthy controls. The men were Caucasian and African-American Seattle-area residents and ranged in age from 35 to 74 years. Participants were asked to fill out a dietary questionnaire about their usual food intake, including specific deep-fried foods.
They found that men who reported eating French fries, fried chicken, fried fish, and/or doughnuts at least once a week had an increased risk of prostate cancer that ranged from 30–37% as compared to men who said they ate such foods less than once a month.Weekly consumption of these foods was associated also with a slightly greater risk of more aggressive prostate cancer. The authors also surveyed men about consumption of snack chips, but found no association between chips and increased risk of prostate cancer.
The researchers controlled for factors such as age, race, family history of prostate cancer, body-mass index, and PSA screening history when calculating the association between eating deep-fried foods and prostate cancer risk.
Possible mechanisms behind the increased cancer risk, the team suggests, include the fact that when oil is heated to temperatures suitable for deep frying, potentially carcinogenic compounds can form in the fried food. These include acrylamide, heterocyclic amines and polycyclic aromatic hydrocarbons, aldehyde, and acrolein. These toxic compounds are increased with re-use of oil and increased length of frying time.
Foods cooked with high heat also contain high levels of advanced glycation endproducts, or AGEs, which have been associated with chronic inflammation and oxidative stress. Deep-fried foods are among the highest in AGE content. A chicken breast deep fried for 20 minutes contains more than nine times the amount of AGEs as a chicken breast boiled for an hour, for example.
Because deep-fried foods are primarily eaten outside the home, it is possible that the link between these foods and prostate cancer risk may be a sign of high consumption of fast foods in general, the authors note, citing the dramatic increase in fast-food restaurants and fast-food consumption in the U.S. in the past several decades.
The study was recently published online in The Prostate, in a paper titled “Consumption of deep-fried foods and risk of prostate cancer”.