Dietary supplements have been found to be used by 40% of adults diagnosed with breast, prostate and colorectal cancer
Dietary supplements (DS) are used by 40% of adult patients diagnosed with either breast, prostate or colorectal cancer according to research by a team from the Department of Behavioural Science and Health, University College London, UK.
Survival from cancer appears to be increasing, with a 2018 global surveillance study finding that survival trends are generally increasing, even for some of the more lethal cancers. While evidence supporting various strategies aimed at reducing cancer risk in those living with and beyond cancer is rather limited, a 2018 report by the World Cancer Research fund and the American Institute for Cancer research, is clear in its view that ‘high-dose dietary supplements are not recommended for cancer prevention’, encouraging individuals to meet their nutritional needs through diet alone. Nevertheless, some data shows that cancer survivors tend to report a higher usage of DS than those with the disease.
For the current study, the authors sought to gain a better understanding the range of and reasons for, use of DS among survivors of breast, prostate and colorectal cancer. They undertook a cross-sectional survey using data from the Advancing Survival Cancer Outcomes Trial (ASCOT) and asked respondents with each of the three cancers, their thoughts about lifestyle and cancer, use of specific foods, e.g. fruits, vegetables, meat and high calorie foods together with information on the use of DS and any other non-prescribed treatments such as herbal extracts. Respondents were asked to express their views (using a Likert scale) on the perceived importance of supplements as an approach to prevent cancer reoccurrence.
A total of 1049 participants with mean age of 64.4 years (62.1% female) provided usable data for analysis. Breast cancer was the most common (54.4%) among respondents, followed by prostate (25.2%) and colorectal (20.4%). In addition, the majority were of white ethnicity (94%) and 68% had either no (34.9%) or at least one co-morbidity.
In total, 40% of respondents reported DS use, of whom, 32% believed that these supplements were important for a reduction in cancer recurrence. The most commonly used form of supplements were fish oils (13.1%), followed by calcium and vitamin D (9.1%) and multivitamin and minerals (8.2%).
Using regression analysis, the only factors significantly associated with DS use were meeting the requirements for fruit and vegetable intake (odds ratio, OR = 1.36, 95% CI 1.02 – 1.82, p = 0.039), a belief in the importance of supplements to prevent cancer recurrence (OR = 3.13, 95% CI 2.35 – 4.18, p < 0.001) and the absence of obesity (OR = 0.58, 95% CI 0.38 – 0.87, p = 0.010).
The authors concluded that DS use among cancer survivors was common and influenced by patient’s beliefs about recurrence. They added that further work was required to better understand the reasons for such beliefs and how best to provide appropriate supplement advice to those living with a cancer diagnosis.