What Dietary Supplements Can Be Used for Prostate Cancer?
Reviewed by: HU Medical Review Board | Last reviewed: July 2022
In recent years, there has been a trend toward complementing or replacing treatment options with dietary supplements. Dietary supplements, also referred to as nutraceuticals, are substances that contain specific nutrients, including vitamins, minerals, and plant extracts, among other ingredients, that are used for medicinal purposes.1
While some nutraceuticals may help improve health or support important bodily functions, there is little evidence on their ability to significantly impact, or cure, chronic conditions. In regard to prostate cancer specifically, no direct link between any vitamin, mineral, or plant extract supplement has been found to decrease the risk of developing prostate cancer or slow down the cancer’s progression.2-5
What does the research say about dietary supplements?
Very few large, controlled studies have been performed on dietary supplements and their effect on prostate cancer, which is a major contributing factor to lack of evidence on the issue. Of the studies that do exist, many are small and have results that are contradicting of one another. The rise in popularity of nutraceuticals has increased the desire and need to know more about these kinds of supplements, and a growing number of larger, controlled trials are in the works. Hopefully, these will lead to further information, but for now, the link remains unclear. Nonetheless, many individuals still utilize nutraceuticals in hopes that they may be beneficial to their prostate cancer. If you do choose to utilize supplements during your prostate cancer battle, it is very important to discuss with your doctor first, since not all supplements are what they are advertised to be, and some can decrease the effect of prostate cancer medications or treatments.
Some common dietary supplements used by individuals with prostate cancer are:
Antioxidants are naturally occurring in many healthy foods like fruits and vegetables, and protect our body against free radicals, also called oxidants. Oxidants are naturally produced by our body to fight off bacteria and viruses, however, when our body is making too much of these, or is exposed to additional oxidants from cigarette smoke, alcohol, air pollution, and other environmental sources, they can cause damage to our cells. No definitive evidence has been found that links antioxidants to decreasing the risk of developing prostate cancer or slowing its progression.2-6 Several examples of antioxidants taken by individuals with prostate cancer include:
- Lycopene: Healthy prostates typically have high concentrations of lycopene. Lycopene can be found in tomatoes, grapefruit, and watermelon. Small studies have indicated that lycopene may reduce the risk of developing aggressive prostate cancer or slow the progression of the cancer when taken in high dosages, but no concrete link has been found.2,7,8
- Vitamin A: Involved in healthy immune function, vision, reproduction, and cell growth. Conflicting evidence has been reported as to whether or not Vitamin A could reduce the risk of developing prostate cancer.3-5
- Vitamin E and Selenium: Vitamin E helps play a role in neurological functioning and gene expression in addition to many other roles. Selenium is a trace element that helps certain enzymes in our body function. Selenium is naturally found in nuts, fish, meat, and mushrooms. Few small trials have suggested that these could reduce prostate cancer risk, however, when investigated further in The Selenium and Vitamin E Cancer Prevention Trial (SELECT Trial), these were not found to be associated with a reduced risk of developing prostate cancer.2-4,9
- Polyphenols (flavonoids): Polyphenols are synthesized by vegetables, fruits, and other plants that are thought to have anti-inflammatory and anti-cancer properties. Flavonoids make up the largest family of polyphenols. Examples of sources of polyphenols are berries, tea, pomegranate juice, lettuce, and spinach. Most studies have found a very minimal, if any, association with polyphenols and prostate cancer.2-5,10
Other vitamins and minerals
Several other vitamins and minerals that are not thought to be antioxidants have been studied, and have also been found to have no definitive beneficial connection to prostate cancer. One example of these, calcium, has even been associated with a potential increased risk of developing prostate cancer when taken in high dosages.2-5,11 On the other hand, some medications used to treat advanced prostate cancer that has metastasized to the bones may require you to take calcium and vitamin D supplements. Examples of other vitamins and minerals include:
- Vitamin D
- Vitamin C
Similar to all of the other supplements there is no definitive link between herbal extracts and prostate cancer. Some herbal extracts, like St. John’s wort, interact with many medications and can actually decrease the effectiveness of some cancer drugs. Other plant extracts, like saw palmetto, may help treat benign prostatic hyperplasia (BPH), which is the non-cancerous growth of the prostate gland during the aging process, however, no strong evidence has shown that saw palmetto decreases the risk of prostate cancer or helps prevent prostate cancer.2,12,13
Important things to note about dietary supplements
There are still many benefits of taking dietary supplements in general to keep your body healthy and functioning. However, having too much of certain vitamins or minerals can be dangerous, interact with, or reduce the effectiveness of treatments you’re on, so it is critically important to talk with your doctor about any supplement you are considering trying. Also, there is no FDA regulation process for supplements, which can lead to misleading information. For example, it could be possible that the active ingredient you’re looking to take may not even be in the supplement, or may vary significantly from the advertised dosage. Also, since there is no regulation process, some supplements can contain other ingredients than what is advertised, including hormones or toxins.
Patients should take their medication, and any dietary supplements, as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding a dietary supplement regimen.