High dairy intake after prostate cancer diagnosis may be associated with increased mortality risk

This study examined the association between dairy intake after prostate cancer diagnosis and mortality risk. Researchers reported increased mortality risk among men with high dairy intake after prostate cancer diagnosis. 

Advances in treatment and early detection of prostate cancer have increased survival and have led to a growing number of men living with prostate cancer. Identifying risk factors that could impact the long-term prognosis of prostate cancer is becoming increasingly important. Diet and nutrition appears to play a key role in prostate cancer development. A number of studies have linked high dairy intake with increased prostate cancer risk. However, whether dairy intake affects prostate cancer progression and survival has not been fully studied. 

The aim of this study was to examine the association of dairy intake and prostate cancer outcomes.

926 men with localized (confined) prostate cancer were included in this study. All men completed food frequency questionnaire measuring their usual dairy intake per day. 1 serving of dairy was rated approximately equal to 8 oz. of whole milk or 1 cup of yogurt. The average dairy intake after prostate cancer diagnosis was 1.7 servings per day. The questionnaire was completed about 5 years after diagnosis. Patients were then followed for an average of 10 years.

333 men died during the study period. Of these, 56 died from prostate cancer. Men consuming 3 or more servings of dairy products per day had a 76% higher risk of mortality from all causes compared to those consuming 1 serving per day. The risk of mortality from prostate cancer was 2.41 times higher. This analysis accounted for smoking status, treatment received, height and weight, physical exercise routine, cancer markers, and family history. 

Mortality risk was more pronounced, but not significantly different, for high-fat dairy intake compared to low-fat dairy intake. One serving increase of high-fat dairy was associated with a 30% increase in cancer-specific mortality risk. In contrast, one serving increase of low-fat dairy was associated with a 16% increase in cancer-specific mortality risk. 

This study concluded that greater dairy intake after prostate cancer diagnosis may be associated with increased mortality risk. 

The results regarding prostate cancer-specific mortality are based on only 56 deaths. Larger studies are needed to confirm these findings. 

Ask your doctor how your diet can impact your long-term health.