Introduction:

Prostate cancer remains a significant health concern for men worldwide, accounting for 27% of all male cancers and the second most common cancer among men (excluding skin cancers). In January 2016, the American Journal of Clinical Nutrition published a groundbreaking study that explored the association between vegetarianism and prostate cancer risk. This large-scale study, conducted on over 26,000 men as part of the Adventists Health Study-2, revealed compelling evidence suggesting that a vegan diet could confer considerable protection against prostate cancer. This article aims to delve into the study’s key findings, the potential mechanisms behind this protective effect, and the phytonutrients found in plant-based foods that may be crucial in inhibiting prostate cancer development.

The Study’s Key Findings:

The research conducted by Tantamango-Bartley et al. involved a comprehensive analysis of a large cohort of men, with 1079 cases of prostate cancer identified during the study period. Of particular interest were the findings related to vegan men, who exhibited an impressive 35% lower risk of developing prostate cancer than their non-vegan counterparts. This observation suggests a protective association between vegan diets and prostate cancer risk. The study also noted that this protective effect was particularly pronounced among white male vegans, with a similar, albeit slightly weaker, trend observed in black male vegans.

Mechanisms Behind the Protective Effect:

The reduced risk of prostate cancer observed among vegan men can be attributed, at least in part, to the presence of various phytonutrients abundant in plant-based foods. These bioactive compounds have been shown to possess potent anti-cancer properties, particularly for prostate cancer. Some of the critical mechanisms include:

1. Cruciferous Vegetables:  Cruciferous vegetables, such as broccoli, Brussels sprouts, cabbage, cauliflower, bok choy, and turnips, contain indole-3 carbinol and sulforaphane. These compounds have demonstrated powerful anti-cancer effects, including inhibiting prostate cancer cell growth and the induction of cancer cell death.
2. Cooked Tomatoes: Tomatoes are a rich source of lycopene, a carotenoid pigment with potent antioxidant properties. Numerous studies have linked lycopene consumption to a reduced risk of prostate cancer.
3. Soy Products:  Soybeans and soy-based products are abundant in isoflavones and protease inhibitors, which have shown promise in preventing prostate cancer or improving outcomes in prostate cancer patients.
4. Legumes: Peas and beans are excellent sources of lignans and protease inhibitors, compounds that may play a role in reducing prostate cancer risk.
5. Green Tea: Green tea contains catechins, a type of polyphenol with potent antioxidant and anti-cancer properties. Studies suggest that regular green tea consumption may lower the risk of developing prostate cancer.
6. Pomegranate Juice: Pomegranate juice is rich in ellagic acid, a compound with potential anti-cancer effects, inhibiting prostate cancer cell growth.
7. Ground Flaxseed: Flaxseed is a source of enterolactone and enterodiol, associated with preventing pre-cancerous prostate cells from progressing into full-blown cancer.

Supporting Studies:

The findings from this study align with a growing body of evidence from various research endeavors. Numerous studies have independently validated the protective effects of these plant-based nutrients against prostate cancer. Consistent consumption of foods rich in these compounds has been associated with a lower risk of prostate cancer in diverse populations. Furthermore, scientists have synthesized some of these beneficial nutrients into supplements, showing promising results as adjunctive interventions for prostate cancer patients or preventive measures.

Conclusion

The study’s results published in the American Journal of Clinical Nutrition present compelling evidence supporting the association between vegan diets and a lower risk of prostate cancer. Although not everyone may adopt a strict vegan lifestyle, incorporating more plant-based foods with proven anti-cancer properties represents a prudent approach to reducing the risk of prostate cancer.

Additionally, it is essential to recognize that many of the same plant-based foods and phytonutrients shown to lower prostate cancer risk have also demonstrated protective effects against breast cancer in various studies. Therefore, these dietary recommendations may extend to women as well.

As with any health-related advice, individuals should consult with their healthcare providers before significantly changing their diets or lifestyles.

Reference

Tantamango-Bartley Y, Knutsen SF et al. Are strict vegetarians protected against prostate cancer? American Journal of Clinical Nutrition, vol 103, issue 1. 2016. (Link: http://ajcn.nutrition.org/content/103/1/153.abstract).

Eat Smart, Live Well, Look Great!

Dr. James Meschino