When it comes to cancer, many people are looking for natural cancer prevention, because they don’t want to take medicines or chemicals that could have side effects. A health-conscious person may not want to risk side effects from a preventative treatment for a health problem that they don’t even have yet.
The problem with trial and error of natural cancer prevention products is that there is no way to accurately measure if the product is working for you personally. If you are trying a natural product for sinusitis, you can feel if it is working within a short period of time (if not, stop using it). When trying lifestyle changes or natural supplements for cancer prevention, you may feel more energised or healthier, but that does not provide meaningful information about whether the risk of cancer is reduced. So reviewing the scientific evidence that exists from larger studies of healthy people over several years can provide some worthwhile insights especially in this area. Clinical science isn’t perfect, but it is a good starting point on this topic.
When I accessed The Cochrane Library (http://www.cochranelibrary.com/) on 1 February 2016, there were 653 systematic reviews under the topic “Complementary and Alternative Medicine”. Of these, 34 were for treatments related to cancer. Of these, 8 covered cancer-prevention products:
- vitamin D,
- supplements for preventing lung cancer in healthy people,
- lycopene for preventing prostate cancer,
- green tea,
- antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, selenium for preventing gastrointestinal cancers,
- dietary calcium supplementation to prevent colorectal cancer, and
- dietary fibre for the prevention of colorectal carcinomas.
- Selenium seemed to show significant beneficial effect on gastrointestinal cancer occurrence , but not for other cancers. There were some risks observed with long-term selenium supplementation such as non-melanoma skin cancer and type 2 diabetes. In observational studies, higher body levels of selenium were associated with lower risk of cancers, however these studies do not prove a causal effect. These studies however measured selenium levels from all sources, mainly foods. Selenium has possibly not been studied sufficiently to determine if increasing intake of Brazil nuts and other food sources may be protective.
- Patients with previous colorectal adenomas may have a moderate protective effect of daily intake of 1,200 g of dietary calcium, from developing recurring adenomas. This finding was based on randomised controlled trials, the highest quality clinical study design. Whether this translates into a lower risk of colorectal cancer is not known as the trials would have to be much larger. In contrast, there is currently no evidence from randomised trials to suggest that increased dietary fibre intake will reduce the recurrence of colorectal adenomatous polyps I (studies were only out to 2 or 4 years).
- There was limited to moderate evidence that the consumption of green tea reduced the risk of lung cancer.
In prostate cancer, observational studies with higher methodological quality and the only included RCT suggested a decreased risk in men consuming higher quantities green tea or green tea extracts.
- Anti-oxidants did not show any noteworthy protective effect for cancer. There were some risks observed, ranging from yellowing of the skin and belching, to an increased risk of non-melanoma skin cancer and type 2 diabetes. There was more scientific data than I had expected on natural cancer prevention. There is a general consensus that lifestyle and diet are environmental factors that influence the incidence of cancer. It is uncertain whether any one component plays a dominant role, however the scientific findings that are available in the literature now may help you decide what to spend your money on, if anything, for natural cancer prevention.