Did you take your vitamins today? Many of us have been so seduced by the idea that supplements help protect us against ill health that we happily pop one, two or even more a day — and feel guilty if we forget. While this might be keeping the manufacturers in a healthy state, are vitamin pills really so good for us?
For decades the message has been clear: supplements deliver vital nutrients often missing from our diets, particularly antioxidants such as vitamins A, C and E, which help fight the damaging action of free radicals. Free radicals are derived from oxygen and are produced by factors as varied as pollution and breathing.
Worryingly, free radicals have been linked to a host of serious ailments, including cardiovascular disease, degenerative diseases such as Alzheimer’s, autoimmune conditions, diabetes and cancer.
So the thinking has been, free radicals bad, antioxidant pills good. But increasingly scientists are questioning the benefits of antioxidant pills, and even suggesting that some might actually cause us serious harm.
Most recently, a study published last month by the University of California found no good evidence that they reduce the risk of cancer in healthy people. More alarmingly, the researchers, who looked at numerous studies assessing the impact of antioxidants (as well as folic acid, calcium and vitamin D), suggested that large doses of some could help promote cancer. These were beta carotene (a form of vitamin A) and vitamins C and E.
And these were not isolated findings. A worrying body of research now shows the antioxidant pills you’re taking to protect your health may, in fact, be increasing your risk of disease, and even premature death.
One early study from 1994 found regularly taking beta carotene supplements (a 20mg pill) increased the risk of death from lung cancer by 8 per cent. A 2002 study found large doses of vitamin C (1g) and E (800 iu - the unit by which some vitamins are measured) almost trebled the risk of premature death among postmenopausal women. In 2010, scientists found that taking antioxidant supplements (vitamins A, C, E, beta carotene) could increase bladder cancer risk by 50 per cent.
And a US study last year found vitamin E supplements (dose of 150 iu) increased the risk of prostate cancer by 17 per cent, with the risk of death increasing as the dose got larger.
And yet, despite such findings, the sale of supplements generally continues to rise, with the biggest boost seen in individual supplements, for example, vitamin C capsules. Concerns about antioxidant supplements are highlighted in a new book, The Health Delusion, written by Aidan Goggins, a pharmacist, and Glen Matten, both of whom have masters degrees in nutritional medicine.
As the authors explain: “Millions of people are misled into ritualistically ingesting these substances in the belief that they are enhancing their general health and well-being.”
In fact, they say, these pills can be positively unhealthy.
They are particularly critical of the manufacturers: “Maybe it’s a genuine lack of comprehension of the science, or a stubbornness to expunge former beliefs, or worse, a blatant attempt to cash in while there’s still money to be made. Whatever it is, [the supplement manufacturers] are putting your health in jeopardy and it’s high time it stopped.
“It is clear that it is no longer science but market forces that are driving the macabre antioxidant industry.”
It’s a controversial view, but Goggins and Matten point out that supplements are based on a flawed understanding of how antioxidants work.
They say the original studies which switched the world on to the health-giving properties of antioxidants were based on diets rich in these compounds in their natural state — i.e. as found in fruit and vegetables.
What is the antioxidant theory?
It was first proposed by US scientist Denham Harman in the 1950s. He suggested that the ageing process and its related diseases were the consequence of free-radical activity, and showed that free-radical inhibitors (antioxidants) were able to extend the lifespan of mice.
Over subsequent decades, these findings were backed up by mounting evidence from laboratory studies that showed ‘diets containing antioxidants’ stopped free radicals in their tracks, reducing the incidence of heart disease, strokes and cancers.
“Free radicals quickly became public enemy number one, and antioxidants our saviours,” write Goggins and Matten. By the late 1970s, antioxidant supplements were flying off the shelves, with manufacturers packing larger and larger doses into each pill. Vitamins swiftly became a global mega-business.
The industry backed studies which supported a growing belief that vitamin pills could be just as effective as vitamins ingested in their natural form. But as Goggins and Matten point out, the studies extolling the virtues of vitamin pills were largely ‘observational’. This means they reported what appeared to happen to groups of people taking vitamins.
However, subsequent ‘intervention studies’ (that is, more rigorous clinical trials involving placebo groups) have failed to show such dramatic results.
“Not only did the intervention studies show no positive effects from antioxidant supplementation, but also a worrying trend of increased harmful effects was emerging,” they say. “The omens weren’t good. Cancer, heart disease and mortality — the very things antioxidants were supposed to protect us against — were increased in those who supplemented their diet.”
Meanwhile, scientists began to realise that free radicals could actually be important to our health.
They perform a host of vital functions in the body, including helping the immune system fight infection. Significantly, studies now show they actually stop the growth and cause the death of cancer cells.
The emerging science indicates that free radicals only turn ‘bad’ when the body’s coping abilities are overwhelmed - a term known as ‘oxidative stress’.
“We are left with a delicate balancing act,” explain Goggins and Matten. “Both too many and too few free radicals spell trouble.”
And, it seems, large doses of vitamin pills can upset that delicate balance.
When vitamin companies started to put large doses in their capsules, the implication was that you could use supplements as you might a drug - in other words, like a preventative medicine.
“We thought we could become masters of this dynamic, complex, finely tuned, self-regulating system simply by consuming large doses of antioxidants in the form of a pill,” say Goggins and Matten.
“But high-dose supplements are very different from the levels of antioxidants found in fruits and vegetables. By taking high-dose antioxidant pills, we end up overwhelming our body and putting this fragile balance out of whack.”
Can taking supplements lead to an overdose?
The recommended daily allowance (RDA) for vitamin E, for instance, is 22 iu, but your average vitamin E pill contains 18 times that. Similarly, a diet rich in fruit and vegetables provides around 200mg vitamin C per day, yet supplement doses of 1000mg (1g) are routinely taken.
At best, this could be money wasted. A meta-analysis of trials published in 2008 found that dietary vitamin C (from food such as oranges and red peppers) can offer protection against heart disease, and even reduce the risk of breast cancer in women with a family history of the disease.
But the same trials found these reductions in risk did not exist in those taking vitamin C supplements, reported the European Journal of Cardiovascular Prevention and Rehabilitation.
(And while many people think that if you take too much vitamin C any excess is simply excreted by the body, in high doses, some of the excess will still be absorbed.)
Furthermore, an excessive intake of some nutrients (in pill form) can actually diminish the effect of other nutrients, causing real health problems.
For instance, vitamin E is found in eight different forms in the body but most supplements contain only one (alpha tocopherol). Studies show that when we ingest high levels of one type of vitamin E, our bodies kick out the other types to make room for it.
This upsets a delicate balance, negating any potential disease-fighting properties and rendering the body more vulnerable to disease at a cellular level, write Goggins and Matten.
“Taking a high dose of one nutrient without regard to the others is a bit like playing Russian roulette with your health,” say Goggins and Matten. “You should still strive to get antioxidants, but they should come the way nature intended - via food.”
But do the same concerns apply to ordinary multivitamin and mineral supplements?
The authors say that a low-dose capsule which provides the recommended daily amounts of nutrients is unlikely to be harmful.
In fact, they accept that for women who are pregnant or breastfeeding, or for those who are following a strict vegetarian diet, there is a very legitimate need for use of a broader range of nutrients to meet the additional needs of the body. But, for the rest of us, it’s just money wasted.
“If your diet is terrible, then a multivitamin may be of some benefit,” says Matten. “But we cannot over-emphasise how much of a “poor man’s alternative” it is to an optimal diet.
“The notion that we can replace the synergy of literally hundreds of nutrients found in food with isolated nutrients in a pill form is absurd.”
Adapted from The Health Delusion by Glen Matten and Aidan Goggins.
