Do Not Use Supplements For Cancer Prevention
Aim To Meet Nutritional Needs Through Diet Alone
WHAT ARE DIETARY SUPPLEMENTS?
Dietary supplements are generally a blend of vitamins, minerals, herbs or plant material. They can be taken in pill, capsule, tablet or liquid form. On the island of Ireland, one in four of us are taking dietary supplements at any given time, often to make up for what we feel is a lack in our normal diet.
“For most people consumption of the right food and drink is more likely to protect against cancer than dietary supplements“
WCRF Expert report 2018
CAN DIETARY SUPPLEMENTS REDUCE OUR RISK OF CANCER?
It can be difficult to find reliable information about dietary supplements and their usefulness in preventing cancer, as media reports tend to exaggerate claims about supplements and health. Supplements are also marketed in a way that can make you believe they are capable of dramatically improve your health and wellbeing.
Our best available evidence shows that while certain high-dose dietary supplements may be protective against cancer, others can actually increase your cancer risk. However, the studies that showed these effects were all carried out on very specific groups of people – like smokers, people exposed to asbestos and those with known nutrients deficiencies – so they may not be relevant to the general public.
The World Cancer Research Fund recommends that dietary supplements are not taken for the purpose of cancer prevention. Instead, they recommend that we meet nutritional needs through diet alone. For most people, eating a healthy, balanced diet will give a better chance of protecting against cancers than any supplement ever could.
DOES ANYONE REALLY NEED TO TAKE SUPPLEMENTS?
While taking supplements cannot fully correct a poor diet, they can be very useful where somebody is ill or has a poor diet. For instance, frail older people with a poor food intake might benefit from a regular, low-dose multivitamin and mineral supplement. In Ireland, all women who could become pregnant are recommended to take a 400μg folic acid supplement daily, to protect against the risk of neural tube defects in babies. In addition, during pregnancy many women are advised by their doctors to take an iron supplement. Likewise, it is recommended that babies in Ireland are given a 5μg vitamin D supplement daily from birth to twelve months to protect against vitamin D deficiency in this group.
WHAT ABOUT PEOPLE GOING THROUGH CANCER TREATMENT?
Dietary supplements are widely used by people with cancer to help fight their cancer or make them feel better.
While most supplements are safe for people to use alongside conventional cancer treatments, there is a risk that some type of supplements could interact with particular types of cancer drugs. For this reason, it’s really important for cancer patients to get advice from their doctor before starting to take any dietary supplement.
During the course of cancer treatment, your doctor may prescribe dietary supplements in certain situations. For example, if your treatment involves hormonal therapy that could weaken your bones, your doctor may prescribe calcium and vitamin D supplements. Or if you are finding it difficult to eat a normal, balanced diet due to the cancer or its treatment, your doctor may recommend a good quality, daily multivitamin and mineral supplement, to be taken at the stated dose.
WHAT SHOULD WE TAKE INSTEAD OF DIETARY SUPPLEMENTS TO PREVENT CANCER?
In a nutshell – good food! At the moment, we have no reliable evidence that any type of dietary supplement can help to prevent cancer in most people. But we do know that a healthy diet with plenty of fruit and vegetables can reduce cancer risk for everybody. Without a doubt, the best source of nourishment is food. Foods and drinks contain a whole host of potentially beneficial food constituents that we simply cannot get from supplements alone. They also give us natural combinations of nutrients that work together to keep us healthy, something that supplements cannot achieve as well.
A healthy, balanced diet that follows the recommendations within this book will give a far better chance of avoiding cancer than any individual dietary