Can certain dietary intake, such as omega-3 fatty acids, increase the risk of prostate cancer?

Doctor's Answers 1

It is quite clear that diet does play a role in the development of prostate cancer.

Japanese men have 3x less prostate cancer than men born in the United States. However, the sons of Japanese immigrants to the United States have a higher rate of prostate cancer that approaches that of Caucasians born in the United States. Much of this increase in prostate cancer is likely from the adoption of the “Western” diet and lifestyle [1].

This is further supported by a recent analysis of the available evidence based on population studies. It found that the habitual consumption of a diet high in saturated fat, well-done meats, and dairy products/calcium confers an increased risk of advanced prostate cancer [2].

Based on this, I recommend the following dietary habits to reduce your risk of prostate cancer:

Meat

red-meat-variations

  • Try to eat no more than 500g of cooked red meat a week (700 to 750g before cooking).
  • It is best to avoid or reduce your intake of processed meats such as ham, bacon and some sausages, and bak kwa.
  • Try to avoid eating lots of meat cooked at very high temperatures (such as barbecued, grilled or fried meat). It may also increase your risk of advanced cancer. This may be caused by chemicals that are made when meat burns, as they can damage cells.

Dairy foods and calcium

dairy-variations

Dozens of research studies have looked at potential connections between calcium and dairy products and prostate cancer risk. Unfortunately, those research presents a very mixed picture.

Some studies suggest that calcium in excess of >2000mg/day can increase prostate cancer risk [3]. On the other hand, it appears that eating moderate amounts of dairy (three or fewer servings per day) and/or dietary calcium is not associated with increased prostate cancer risk.

Moreover, calcium is important to health. Not getting enough calcium can increase the risk of osteoporosis, even among men. Getting enough calcium without overdoing is the goal. The recommended calcium intake is as follows : [4]

  • For men up to 70 years of age: 1,000 mg per day.
  • For men over 70 years: 1,200 mg per day.

One serving of dairy, such as 250ml of yogurt or milk, provides between 300 and 400 mg of calcium. This means that if you eat three servings dairy every day, you probably do not need calcium supplements.

Calcium can also be found in non-dairy foods such as:

  • Fortified milk substitutes (soy, almond, or rice milk)
  • Fortified juices
  • Cereals
  • Bread products.

Fat

healthy-fats-variations

The increased cancer risk observed in developed countries may be, in part, due to the fact that a high-fat diet stimulates testosterone levels, which is known to be associated with prostate cancer growth [5]. Most researchers agree to aim for 20 percent of your total calories from fat, with less than 10 percent of total calories from saturated fat.

There are different types of fat. Replacing animal fats with vegetable oils may help reduce your chance of developing prostate cancer [6].

I recommend the following:

  1. Reduce intake of Saturated Fat

    • Limit use of butter, mayonnaise, baked goods and regular salad dressing due to their high saturated fat and total fat content.
    • Limit cheese consumption. Cheese is typically between 60 to 80 percent fat, much of which is saturated fat.
  2. Limit intake of Trans Fat

    Trans fatty acids are known to be atherogenic, or heart disease causing. They also may cause an imbalance in hormonal systems that regulate healing, lead to the construction of defective membranes and encourage the development of cancer.

    They are found in products such as margarine, fried foods and processed foods, which are high in harmful trans fatty acids. When you read that a product contains "hydrogenated" or "partially-hydrogenated" oils, you may want to consider putting it back on the shelf.

  3. Reduce intake of Omega-6 Fatty Acids

    Omega-6 fatty acids may stimulate growth of prostate cancer cells [5].

    These fatty acids are found in corn oil, safflower oil, sunflower oil, cottonseed oil, soybean oil and other polyunsaturated oils.

    Consider using olive oil instead of your current cooking oil, but remember to use in moderation. These oils are rich in monounsaturated fats, which have not been shown to increase cancer risk.

  4. Limit consumption of Nuts

    Nuts are highly concentrated in monounsaturated fatty acids, which are neutral in terms of stimulating cancer growth and may be beneficial for heart disease. They are, however, high in fat.

    Minimise consumption of nuts due to their high fat content. This includes peanuts, macadamia nuts and pistachios.

  5. Omega 3 Fatty Acids

    Part of the reason for the low incidence of prostate cancer in Japanese men may be related to their high consumption of fish rich in omega-3 fatty acids.

    In the most recent systematic review on this topic published in 2017, data from 44 studies were reviewed. They dealt on the safety and efficacy of fish-derived omega-3 fatty acids in the incidence and progression of prostate cancer.

    Overall, the findings were mixed. Some of the studies suggested a decrease in inflammation and other cancer markers as well as a lower risk of prostate cancer-related death. On the other side, other studies did not show positive findings.

    The investigators concluded that “An association between higher omega-3 intake and decreased prostate cancer mortality may be present but more research is needed.” Thus based on a summary of the latest evidence, omega-3 fatty acids may or may not help reduce prostate cancer incidence, but has not been found to increase the risk.

    Dietary sources of omega-3 fatty acids include cold-water fish (such as salmon, trout, herring and sardines), flaxseeds, walnuts, soybeans and canola oil.

    It may be wise to consume fish at least twice weekly to obtain an adequate amount of omega-3 fatty acids.

    Fish and plant-based foods contain different types of omega-3 fatty acids:

    • Fish contains EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). They are two specific fatty acids that have shown promising results in research.
    • The plant-based omega-3 fatty acid sources, such as flaxseed and others listed above, contain ALA (alpha-linolenic acid).

References

1. Prostate Cancer Rates Are 3x Less In Japanese Men: Here’s Why. prostate.net. Published June 5, 2019. Accessed August 1, 2019.

2. DiNicolantonio JJ, McCarty MF, Lavie CJ, O’Keefe JH. Do omega-3 fatty acids cause prostate cancer? Missouri medicine. 2013;110(4):293-295. Accessed August 1, 2019.

3. Wilson KM, Shui IM, Mucci LA, Giovannucci E. Calcium and phosphorus intake and prostate cancer risk: a 24-y follow-up study. The American Journal of Clinical Nutrition. 2014;101(1):173-183. doi:10.3945/ajcn.114.088716

4. Office of Dietary Supplements - Calcium. Nih.gov. Published 2017. Accessed August 1, 2019.

5. Nutrition and Prostate Cancer. University of California San Fransisco Medical Center. Published 2019. Accessed August 1, 2019.

6. Chan JM, Van Blarigan EL, Kenfield SA. What should we tell prostate cancer patients about (secondary) prevention? Current Opinion in Urology. 2014;24(3):318-323. doi:10.1097/mou.0000000000000049

Similar Questions

When should men start to undergo prostate cancer screening?

Men without any family history of prostate cancer should undergo annual prostate checks from the age of 50 years old. Men with a family history of prostate cancer should start prostate checks from the age of 40 years old. These annual checks should be conducted till the age of 70 years old. The checks can be done by specialists such as urologists, or family physicians. The checks involve a prostate finger examination and PSA (prostate-specific antigen) blood tests.

Photo of Dr Siew Hong Ho

Answered By

Dr Siew Hong Ho

Urologist

What are the chances of cancer spreading beyond my prostate in the case of prostate cancer?

After prostate cancer is diagnosed, doctors will do staging tests involving CT/MRI scans and bone scans to see is cancer has spread beyond the prostate. Staging refers to determining the extent of disease. The cancer is still localised in the prostate in stage I and II. Prostate cancer has spread beyond the prostate in stage III and IV. Singapore Cancer Registry statistics for 2009-2013 showed that 61. 6% of men were diagnosed with prostate cancer that had not spread beyond their prostate (Stage I and II). On the other hand, 10. 6% and 27.

Photo of Human

Answered By

Human

Ask any health question for free

I’m not so sure about a procedure...

Ask Icon Ask a Question

Join Human

Sign up now for a free Human account to get answers from specialists in Singapore.

Sign Up

Get The Pill

Be healthier with our Bite-sized health news straight in your inbox