Prostate cancer is the second most common cancer in men worldwide, according to the World Cancer Research Fund International.
In the United States alone, one in seven men will be diagnosed with prostate cancer in their lifetime. The American Cancer Society estimates a staggering 220,800 new cases and 27,540 deaths from prostate cancer in 2015.
While family history and age are two factors that increase the risk of prostate cancer, there is an undeniable link with diet.
Dietary fat intake, in particular, plays a critical role in promoting oxidative stress and in the development of prostate cancer, according to a research article published in the journal Nutrients.
Normal cells may become cancerous when oxidative stress, brought on by an imbalance of antioxidants and reactive oxygen species, leads to DNA damage. Some mutations caused by DNA damage may lead to the development of tumors.
Animal fats, trans fats and saturated fats such as those present in the Western diet have been positively associated with prostate specific antigen levels (PSA), increased risk of prostate cancer risk and death due to prostate cancer. On the other hand, monounsaturated fatty acids, polyunsaturated fatty acids and vegetable fats such as those present in the Mediterranean diet are associated with decreased risk of developing prostate cancer or death from prostate cancer.
To determine if changing the Western dietary pattern of prostate cancer patients would influence DNA damage and markers of inflammation, researchers at the University of Auckland, New Zealand asked 20 men with prostate cancer to adapt a modified Mediterranean style dietary intervention for three months. At the end of the study, they assessed DNA damage using alkaline comet assay, which is an ideal biomarker for the assessment of the influence of food on cancer.
The men were asked to follow a modified Mediterranean diet that included an intake of 30-50 grams of mixed unsalted seeds, 15 mL of extra virgin olive oil and oily fish once a week. The diet reduced dairy intake to one portion daily, substituted butter with olive oil-based spread and decreased red meat intake to less than 400 grams. Additionally, the men were to avoid processed meats, meats cooked at high temperature, and to substitute red meat with oily fish or white meat. To facilitate adherence to the diet, researchers provided the subjects salmon and extra virgin olive oil.
The results of the study were encouraging. The researchers found that DNA damage decreased as adherence to the modified Mediterranean diet increased and there was an inverse association between olive oil intake and DNA damage. On the other hand, DNA damage was reported to increase with increased consumption of dairy products and red meat.
The authors also found that higher levels of whole blood monounsaturated fatty acids and oleic acid were associated with decreased DNA damage, while high levels of omega-6 polyunsaturated fatty acids were associated with increased DNA damage.
The benefits of the modified Mediterranean diet extended to include weight loss and a feeling of general well-being at the end of the three-month period by some subjects.
Overall results indicate that changing the Western dietary pattern to a modified Mediterranean dietary pattern that includes fish and olive oil can be beneficial in decreasing DNA damage in men with prostate cancer.