Supplements: Vitamins such as beta carotene and vitamin E may increase cancer risk


The market for dietary supplements, which include multiminerals, multivitamins, vitamins, proteins, minerals, is booming. However, widespread use of vitamin and mineral supplements remains controversial because the health claims do not often stand up to scientific scrutiny. In fact, dietary supplementation may even promote the progression of cancer.

That’s the conclusion of a recent book entitled “Dietary Research and Cancer“.

In the chapter “Market of Dietary Supplements: Analysis of Health Benefits and Risk in Cancer, Rajesh N. Gacche, Professor and Head of the Department of Biotechnology of Savitribai Phule Pune University, India, wrote: “In the current state of the art, there is widespread usage of dietary supplements (DSs) by cancer patients both during the cancer treatment and during the drug holidays as well.

“However, there is a lack of empirical data in relation to their safety or efficacy.

“The available research data show that there should be judicious usage of DSs by cancer patients, which otherwise may aggravate the progression of cancer.”

READ MORE: Supplements warning: Three pills that may ‘set the stage’ for cancer – expert insight

Beta Carotene is a compound that gives vivid yellow, orange, and red colouring to vegetables.

The BMJ article also cites “The α-Tocopherol, β-Carotene Cancer Prevention Study”, which reported an 18 percent increase in relative risk among smokers randomised to beta carotene (20 mg/day) compared with those who did not.

The “β-Carotene and Retinol Efficacy Trial” also found that beta carotene (30 mg/day) plus vitamin A increased risk by 28 percent among smokers and workers with occupational exposure to asbestos.

What’s more, the BMJ analysis pointed to the “Selenium and Vitamin E Cancer Prevention Trial”, which found that vitamin E (400 IU/day) supplementation was associated with a 17 percent increase in prostate cancer risk among men.

Despite the potential harms, it acknowledges that “use of supplements contributes substantially to total vitamin and mineral intakes at the population level”.

“Intake of vitamin B6, thiamin, and riboflavin among US adults is at least five times higher from supplements than from foods, and intakes are 15 to 20 times higher for supplements for vitamins B12 and E.”

The BMJ article concludes: “Consequently, supplement use considerably reduces the proportion of the general population with inadequate nutrient intake.”

However, most people do not need to take vitamin supplements and can get all the vitamins and minerals they need by eating a healthy, balanced diet.

Many people choose to take supplements but taking too much or taking them for too long could be harmful.

The Department of Health and Social Care recommends certain supplements for some groups of people who are at risk of deficiency.

According to the NHS, this means eating a wide variety of foods in the right proportions, and consuming the right amount of food and drink to achieve and maintain a healthy body weight.

The Eatwell Guide shows that to have a healthy, balanced diet, people should try to:

  • Eat at least five portions of a variety of fruit and vegetables every day
  • Base meals on higher fibre starchy foods like potatoes, bread, rice or pasta
  • Have some dairy or dairy alternatives (such as soya drinks)
  • Eat some beans, pulses, fish, eggs, meat and other protein
  • Choose unsaturated oils and spreads, and eat them in small amounts
  • Drink plenty of fluids (at least six to eight glasses a day).

“If you’re having foods and drinks that are high in fat, salt and sugar, have these less often and in small amounts,” advises the NHS.

General symptoms of cancer to watch out for include unexplained pain or ache, very heavy night sweats and explained weight loss.



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