According to a new study conducted in the United Kingdom, 40% of patients suffering from or beyond colorectal, breast, or prostate cancer were using at minimum one dietary supplement each day.
A third of those who take supplements believed that supplements reduced the chance of recurrences of cancer.
However there is no evidence to support this belief.
The World Cancer Research Foundation as well as the American Institute for Cancer Research specifically state that dietary supplements aren’t advised for the prevention of cancer since randomized controlled trials have generally demonstrated no benefit from supplement use in this regard. In some instances, unexpected negative effects have been found.
Rana Conway, PhD from University College London, London UK and her colleagues wrote about the belief that diet supplements reduce the risk of recurrence of cancer is widespread and strongly associated with their use.
The authors recommend further research to understand why people who have survived cancer believe that dietary supplements reduce the chance of recurrence. Also, how practitioners can offer appropriate guidance to patients suffering from and beyond cancer.
The study was published online December 20 20, 2021 in Cancer.
ASCOT Study
For their study, Conway and colleagues used data from the Advancing Survival Cancer Outcomes Trial (ASCOT). Ten hospital sites across London and Essex sent out a questionnaire to patients who had been diagnosed with prostate, breast or colorectal cancers between 2021 and the year 2015, and the patients were required to fill out a 24-hour recall of their diet online or via telephone through the My Food24 program.
1049 participants completed the first baseline 24 hour recall. The participants were included in the present analysis. The majority of participants were White (94 percent), and more than half (62%) were female, with a a mean age of 64 .
In the study, among those who reported using supplements for their diet 40% of them took more than one supplement, whereas almost 10% took more than three supplements a day.
Fish oil Supplements, which include cod liver oil and omega 3s were the most frequently used by participants with 13% reporting that they had taken these products.
Researchers have found that calcium supplements with or without vitamin D, multivitamins, minerals, vitamin D and herbal supplements were the next most commonly utilized.
However, among the patients who had or following breast cancer, 15% used calcium without or with vitamin D. So, in this subgroup, calcium supplements were more commonly used fish oils.
19% of respondents believed that supplements to their diet could reduce the chance of recurrence from cancer.
Females were nearly 2.5 times more likely to take supplements than males. Participants who met the five-a-day fruit and veg recommended intake were 1.3 times more likely to use a supplement than those who did not.
The most important aspect in deciding if supplements were used was whether the individual believed that supplements could reduce the risk of recurrence of cancer.
Researchers found that people with such beliefs were three times more likely than those who did not to take supplements.
However the fact that being overweight reduced the likelihood that patients would take a dietary supplement by almost half, they add.
Conway and colleagues have noted that previous studies have revealed an increased intake of nutritional supplements in cancer patients and survivors. For instance in the systematic review of 32 studies between 64% and 81% of cancer survivors reported taking either supplements for minerals or vitamins.
However, a methodological difference could be the reason for the lesser intake of dietary supplements in this particular study, as only supplements taken before the 24-hour recall were included in the analysis. Researchers conclude that by capturing only DS (dietary supplements) use prior to the day it could have resulted in a decrease in recall error but missed intermittent supplement use.
Cancer Research UK funded the study. Conway reported no conflicts of interest.
Cancer. Online publication, December 20 and 2021. Full text
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