Drinking a lot of whole milk increases the risk that an overweight man’s prostate cancer will return, a study suggests.
The results did not apply to men of normal weight who consume low-fat dairy products, the researchers said.
The study, published in the journal The Prostate, is titled “Milk and other dairy foods in relation to prostate cancer recurrence: Data from the cancer of the prostate strategic urologic research endeavor (CaPSURE™).”
The relationship between the consumption of dairy products and prostate cancer has been a focus of research for decades. A number of studies have suggested that a diet rich in dairy foods, particularly whole milk, increases the risk of prostate cancer among healthy men.
Not nearly as much research has been done on whether consuming dairy products after a prostate cancer diagnosis increases the risk that the disease will progress, however.
One study indicated that men with prostate cancer fwho consume whole milk more than four times a week double their risk of dying of the disease, compared with men who consume less.
Researchers decided to see whether dairy-product intake would increase the chance that a man’s prostate cancer will recur.
They asked 1,334 American men with prostate cancer that had not spread to another part of their body about their dairy product intake. Researchers obtained their names from a registry known as the Cancer of the Prostate Strategic Urologic Research Endeavor, or CaPSURE. All of the men had been diagnosed with the cancer at least two years.
Researchers defined a recurrence as a post-treatment increase in a biomarker known as prostate-specific antigen, or PSA; an additional treatment; the cancer spreading to bones; or a patient’s death from prostate cancer.
During a median follow-up period of eight years, the team discovered that the prostate cancer of 137 men had returned.
They said men of normal weight who consumed whole milk more than four times a week had a 73 percent higher chance of their prostate cancer returning than men who consumed less than three servings a month.
When men were overweight or obese, consuming whole milk more than four times a week tripled their risk of prostate cancer recurring, compared with men of normal weight who consumed less than three servings a month.
There was no increased risk of recurrence in men of normal weight who consumed low-fat milk and other dairy foods besides whole milk.
Overall, the results showed that “whole milk consumption after prostate cancer diagnosis was associated with increased risk of recurrence, particularly among very overweight or obese men,” the researchers said. “Men with prostate cancer who choose to drink milk should select non-fat or low-fat options,” they concluded.