Cancer - Prostate

The evidence is heterogeneous regarding the following dietary factors, but overall the evidence suggests an association with a decreased risk of prostate cancer:

 

A small number of RCTs and cohort studies consistently suggest that while glycemic index may affect prostate cancer risk, glycemic load does not.

Although there is mixed evidence regarding the effect of dietary and supplemental selenium intake on the risk of prostate cancer, the highest quality studies show that selenium supplementation likely has no effect.

 

No significant associations have been found between prostate cancer risk and dietary vitamin E, dietary alpha-tocopherol or serum gamma-tocopherol. It is possible that a low plasma concentration of alpha-tocopherol may be associated with an increased risk of prostate cancer, although evidence is limited.

 

There is not enough evidence to suggest that the following factors have an effect on the risk of prostate cancer:

All Risk Factors
The 2018 revised expert report on diet, nutrition, physical activity, and prostate cancer by the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) drew no conclusions regarding any dietary factor and decreased risk of prostate cancer, although no studies more recent than 2014 were cited. This is an update from the 2007 WCRF/AICR report, which suggested that lycopene, selenium, alpha-tocopherol and pulses were associated with a decreased risk of prostate cancer.
Grade of Evidence D

Glycemic Index/Glycemic Load
A 2019 systematic review and dose-response meta-analysis of observational studies found a significant, non-linear relationship between glycemic index (GI) and the risk of prostate cancer, with the lowest risk correlating with a GI score between 40-60 (i.e. low to medium). There was no association between the risk of prostate cancer and glycemic load.
Grade of Evidence C

Soy
A 2019 systematic review and meta-analysis found that total soy intake was associated with a decreased risk of prostate cancer in men, although total isoflavone intake was not. This association was present in subgroup analysis of unfermented soy foods (e.g. tofu) but not in sub-analysis of fermented soy foods (e.g. miso). This association was not present in soy milk.
Grade of Evidence C

Lycopene
A 2018 systematic review and dose-response meta-analysis found a significant non-linear association between tomato consumption and the risk of prostate cancer, with risk reduction ranging from 9% for 100 g tomatoes weekly to 56% for 1350 g tomatoes weekly. The result was significant for unspecified tomato foods (i.e. the authors did not distinguish between types of tomato foods), cooked tomatoes and sauces but not for raw tomatoes or pizza.
Grade of Evidence C

A 2017 systematic review and meta-analysis found that the risk of prostate cancer decreased by 1% for every 2 mg of dietary lycopene consumed. This risk also decreased by 3.5% for every 10 μgdL−1 circulating lycopene. There was no relationship between dietary or circulating lycopene and the risk of advanced prostate cancer.
Grade of Evidence C

Dried Fruit
A 2019 systematic review suggested that frequent consumption of dried fruit (>5 days/ week) may be associated with a decreased risk of prostate cancer. This relationship did not hold for fresh or total fruit.
Grade of Evidence C

Coffee
A 2015 dose-response meta-analysis found a dose-dependent decrease in the risk of prostate cancer with coffee consumption, which reached significance at >4 cups/day.
Grade of Evidence C

 

Selenium
A 2018 Cochrane review’s meta-analysis of RCTs showed that selenium supplements had no effect on the risk of prostate cancer.

Grade of Evidence A 

 

The  2018 WCRF/AICR revised expert report on diet, nutrition, physical activity and prostate cancer found limited, suggestive evidence that a low plasma concentration of selenium may be associated with an increased risk of prostate cancer.

 

The World Cancer Research Fund and American Institute for Cancer Research’s 2018 revised expert report on diet, nutrition, physical activity and prostate cancer found no significant associations between prostate cancer risk and dietary vitamin E, dietary alpha-tocopherol, alpha-tocopherol supplements or serum gamma-tocopherol. However, the authors concluded that there was limited, suggestive evidence that a low plasma concentration of alpha-tocopherol may be associated with an increased risk of prostate cancer. 

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