Don’t use supplements for cancer prevention

Don't rely on supplements graphicAim to meet nutritional needs through diet alone.

Despite the promises made by some manufacturers, we advise against taking supplements to protect against cancer.

Whole foods provide more than just vitamins and minerals. For example, they contain fibre which is important for bowel health. For this reason, you should aim to meet your nutritional needs by eating a varied, healthy, balanced diet rather than using supplements.

What are supplements?

Supplements are a substance, often in tablet or capsule form. They’re consumed in addition to the usual diet. Dietary supplements typically refer to vitamins or minerals, though other components of foods may also be included. These include:

  • phytochemicals
  • lycopene (found in tomatoes)
  • herbs and plant materials such as ginseng, garlic
  • and green tea.

Can supplements cause cancer?

Some supplements can support our daily nutritional requirements but some are in high-doses that far exceed levels that would be consumed by eating foods with these nutrients in.

There’s strong evidence that some high-dose supplements can actually be harmful. As the effect of other supplements on cancer risk is unclear, it is best not to use them to protect against cancer.

Who may benefit?

Most people can meet their nutritional needs by eating a healthy, balanced diet, although some authorities recommend that we should all take a vitamin D supplement. However, some groups may benefit from taking other supplements, such as:

  • Frail, older people with a poor appetite.
  • Women of childbearing age and new mothers.
  • Children under the age of five.
  • People with darker skin and those who are not exposed to much sun such as housebound people or those who cover their skin.
  • People with bowel diseases or those who are being treated for or have survived cancer may not be able to absorb enough nutrients from their diet or to eat a normal diet, so they may also benefit.

In such cases, a doctor, dietitian or specialist nurse will be able to provide advice.