How to prevent prostate cancer? Hormonal and Nutritional Factors

Prostate cancer is an excellent tumor type for chemoprevention strategies, due to its high incidence and its occurrence at advanced ages.

Any delay in prostate cancer carcinogenesis could lead to a decrease in its incidence. Similarly, the presence of premalignant lesions can serve as a target for chemoprevention. Early diagnosis by the urology specialist can be key.

Nutrition and prostate cancer

Scientific evidence on mortality and incidence of prostate cancer suggests that environmental elements influence its appearance and development.

Likewise, some nutritional factors have also been associated with an elevated risk of developing prostate cancer, especially high consumption of animal fat and dairy products.

On the other hand, there are nutritional factors that have a lower incidence in prostate cancer. They are observed, above all, in populations that consume a higher amount of selenium, vitamin E, fruits and tomatoes.

Hormonal agents

There are some hormonal agents related to prostate cancer.

Testosterone, once inside the prostate cell, is metabolized by 5 alpha-reductase. This enzyme is present in the body in the form of two iso-enzymes (type 1 and 2). Finasteride is a selective inhibitor of the type 2 enzyme, while Dutastaeride inhibits both types.

  • Finasteride. In a 7-year investigation comparing the effect of finasteride versus placebo, a higher prevalence of prostate cancer was demonstrated in the finasteride group versus the placebo group. This represents a significant reduction in risk between the two treatment groups. In addition, an absolute reduction was found in patients treated with Finasteride regardless of whether it was detected by a causal biopsy at the end of the study.
  • Dutasteride. The incidence of prostate cancer in patients receiving Dutasteride was half lower than the incidence in patients assigned to the placebo group.

Antioxidant agents

Oxidative stress is one of the factors that promote carcinogenesis. Tissue oxidation can lead to cancer-causing genetic mutations. For this reason, it is believed that antioxidants may be preventive in several tumor types. The most commonly used are:

  • Vitamin E. It has a high antioxidant and antiproliferative capacity. It is found in vegetable oils, nuts, avocados, eggs and cereals. The recommended daily dose is 15 mg and it is not recommended to exceed 95 mg per day. It is also recommended to suspend its consumption 10 days before a biopsy, radical prostatectomy, brachytherapy or cryotherapy, since vitamin E is a platelet antiaggregant.
  • Selenium. The concentration of selenium depends on the content in the soil where the product was grown. It is found in meat, cereal grains and seafood. The recommended daily dose is 0.87 µg/kg and the tolerable limit is 400 µg/day for 7 years. Several studies have shown that selenium supplementation inhibits the growth of both androgen-sensitive and androgen-resistant prostate cancer cell lines.
  • Lycopene. It is a very potent antioxidant of the carotenoid family found in high concentrations in tomatoes, which give them their red color, and in derived products. As it is not an essential nutrient, there are no recommendations on the amount of daily consumption, although it is suggested to consume 5 measures of tomatoes or tomato derivatives per week as part of a healthy diet. In an “in vivo” study, the association of tomato and broccoli was more effective in reducing tumor growth than consuming them separately.
  • Green tea. Tea contains many polyphenolic compounds, with epigallocatechin gallate (EGCG) being the most studied. Its mechanism of action has not been determined but it is believed that it may work through inhibition of proteolytic enzymes that prevent metastasis, anti-angiogenesis and act on intercellular communications. A clinical study demonstrated the efficacy of green tea catechins with only a 3% incidence of prostate cancer in patients treated with it versus a 30% incidence in patients treated with placebo.
  • Soy and Isoflavones. The use of soy products in the prevention of prostate cancer is based on the same principle as the use of green tea and that is that in Asian countries, where the consumption of soy and isoflavones is high, the incidence of prostate cancer is low. The diet of Asian countries includes 10 times more soy products than those consumed in the Western diet. A recent meta-analysis has estimated that the relative risk of prostate cancer in patients with high soy consumption is lower than in subjects who do not consume soy.
  • Pomegranate. Pomegranate juice and its extract have demonstrated a strong antitumor effect in prostate cancer patients. A study from the University of California proved the efficacy of pomegranate juice, which increased the doubling time of PSA by up to 6 months. In fact, several studies have shown that pomegranate juice results in the death of hormone-resistant prostate cancer cells and also increases cell adhesion and decreases cell migration.
  • Polyphenol-rich supplements. A clinical study conducted at the University of Cambridge showed that treatment of prostate cancer patients with pomegranate extract, broccoli, green tea and turmeric slows cancer progression compared to patients who were treated with placebo. After 6 months, in the group of patients treated with capsules with the dietary supplement the mean PSA rose, while in the group treated with placebo it did not.
  • Non-steroidal anti-inflammatory drugs. There is evidence that prostaglandins are involved in the development of several cancers. Cyclooxygenase (COX) of which there are two isoforms (COX1 and COX2) is a very important enzyme in the synthesis of prostaglandins. COX2 occurs in high concentrations in various tumors, including prostate cancer. For this reason, non-steroidal anti-inflammatory drugs and selective COX2 inhibitors (Rofecoxib, Celecoxib, Exisulind, etc.) appear as potential agents in prostate cancer tumor prevention, since they decrease prostaglandin synthesis. Several studies on the effects of aspirin on the risk of developing prostate cancer have detected an opposite relationship.
  • Coffee. Recently it has been observed that the consumption of 4 cups of coffee a day was associated with a lower risk of developing prostate cancer compared to patients who drank less than one cup a day.
  • Physical exercise. The University of Rochester demonstrated that physical exercise reduces the production of interleukin 6 (IL-6), which is produced by depression and inflammatory processes, thus reducing the progression of prostate cancer. Patients receiving conventional treatment with radiotherapy or hormonal block showed an increase in IL-6 production, while patients who were also treated with a physical exercise program showed a decrease in IL-6. Similar results were observed with interleukin-8 (IL-8).