In December 2013, one of the world’s most influential medical journals, Annals of Internal Medicine, declared the multi-vitamin debate closed. In an editorial titled “Enough Is Enough: Stop Wasting Money on Mineral Supplements”, five doctors, including three professors from the prestigious Johns Hopkins University in Baltimore, examined the available evidence and concluded “their use is not justified and they should be avoided”.
The emphatic statement made headlines around the world – and apparently not a jot of difference to the rest of us.
Eighteen months on, what was meant to be the final word on the subject seems anything but, as experts continue to debate the worth – or worthlessness – of multivitamins. The website for the (also prestigious) Harvard School of Public Health in Boston, for example, calls taking a daily multivitamin “a great nutrition insurance policy” which may have added health benefits.
And as we wait for a consensus that may never come, we’re gobbling them down in ever-increasing numbers. In New Zealand, vitamin sales are closing in on $100 million a year, with multivitamins the largest sector of the market and the fastest growing, climbing at the rate of nine per cent a year to $73 million in 2013. The combined vitamin and dietary supplements market is around $275 million a year.
It’s a lucrative business, fuelled by advertising campaigns featuring the advice of sporting luminaries such as Dan Carter, Dame Susan Devoy, Bernice Mene and Barbara Kendall, who’ve all pushed natural remedies on television in recent years.
The attitudes of our own nutrition experts mirror the international conflict. At Auckland University, professor of nutrition David Cameron-Smith says he takes a multivitamin from time to time as a pragmatic response to an imperfect environment. Even with the best will in the world, he says, his diet has “ups and downs”.
“My diet is the result of my environment. I don’t swim against the tide. I’m very much part of the tide. I don’t exercise enough, I don’t de-stress, I don’t relax. I consume alcohol potentially in excess, I consume a diet that’s inadequate in some way, so I’m a pragmatist.”
Then there is Otago University’s professor of human nutrition, Murray Skeaff, who says that apart from people with known deficiencies, for example in iron, where supplementation is definitely warranted, “the evidence is overwhelming that there is very little benefit in supplements for most people.” He says the evidence is mounting that people who take dietary supplements won’t live longer, and they don’t have less heart disease or less cancer than those who don’t take supplements.
“People who take supplements in general tend to be already a bit healthier, they tend to exercise more, their diets are a bit better, they have a lower body mass index. When you look at the health of these people, it’s not the dietary supplements making them healthier, it’s that they have a slightly better lifestyle.”
Clockwise from left: Otago University professor of human nutrition Murray Skeaff. Professor Shaun Holt. Sporting heroes like Barbara Kendall have all pushed natural remedies in recent TV campaigns.
In other words, the people who take supplements the most are the ones who need them the least.
And if your diet isn’t great? “Then you need to get your diet in order. Believing if you take a supplement that it’s going to overcome a poor diet – the evidence just doesn’t show that. It just doesn’t show it. People need to accept that.”
No wonder we’re confused.
Part of the problem with nutrition research – and one of the key reasons for sometimes wildly varying results and expert advice – is the sheer difficulty of conducting the necessary long-term clinical trials.
For example, the findings on which the Johns Hopkins team based their editorial came from three studies that tracked the effect of multivitamins in cancer protection, heart health, and brain and cognitive measures. This is broad-brush stuff, and the authors accepted that “clinical trials are not well-suited to identify very small effects”. Any future attempts to study these effects, therefore, “are likely to be futile”.
Professor Shaun Holt, a doctor, pharmacist, medical researcher, adjunct professor at Victoria University and author of Natural Remedies That Really Work, agrees.
“No one knows if taking multivitamins for a generally healthy person is a good thing or not and it’s probably one of those questions we’ll never know, because the studies to prove it are in my view impossible. You’d have to get tens or even hundreds of thousands of people and control their diets for about two decades and make sure half have a multivitamin tablet every day. I’ve spent my career doing trials and you can’t even do that with 10 people for one week. It just wouldn’t succeed.”
Because of that, he says, we have to use plain old common sense based on three issues – safety, expense and health benefits.
Holt has taken a daily multivitamin, and also fish oil, for about eight years, since the publication of his book. Like Harvard and Cameron-Smith, he calls it nutritional insurance.
“Unless you are totally obsessed with your blood levels of all the vitamins and minerals – and some people are – you may be deficient in several things, even if you think you have a good diet.”
Despite some studies suggesting multivitamins may even cause harm, Holt says they’ve been “in my view horrendously badly designed, and reported [in the lay media] even worse”.
In 2011, for example, the Iowa Women’s Health Study found women aged over 55 who took multivitamins were at higher risk of dying than those who didn’t. The problem was, the study didn’t differentiate between those who were already taking vitamins when they became ill, or those who became ill and started taking vitamins then.
Multivitamins contain about 30-40 vitamins and minerals, with around 30-50 per cent of the recommended daily intake for each. “It’s small amounts and what they offer is a top-up,” says Holt, “so I just don’t think it’s biologically possible there could be a risk from taking them, because it’s a fraction of the stuff that’s in your food anyway.”
Philadelphia journalist Catherine Price thinks our faith in vitamins is actually harmful, because it encourages us to eat the very foods that are bad for us.
Neither does Cameron-Smith, but he’s far from a zealot about supplements. He’s sceptical of marketing hype and over-ambitious claims, particularly around antioxidants and vitamin “mega doses” and says synthetic vitamins are often added to nutritionally deficient foods “to give credibility to things that should not have credibility and pretending they’re somehow better for you.
“Am I an advocate for wholesale fortification and supplementation? The answer is no. No, they do not provide the magic bullet. You don’t take a multivitamin or any sort of mineral supplement and suddenly wake up in the morning with fire coursing through your veins.”
Given the choice between a daily multivitamin and a daily 30-minute walk, he’d choose the exercise every time. And, like every other nutrition expert, he stresses the need to eat more fruit, vegetables and wholegrain, while reducing the amount of highly processed food in our diets.
“Shortcuts are shortcuts; they are Band-Aids, but there does need to be a recognition that an ideal is not a reality.”
The problem for the scientists, he says, is identifying early risk. “It’s extremely difficult to identify sub-optimal concentrations of vitamins and minerals, and early signs of deficiencies. We just don’t have the sensitivity to be able to detect those things and it’s also extremely difficult to monitor someone’s diet.
“No one eats a healthy diet like they think they do – they have a very rose-tinted view, but they always fall short. If I had one message, it’s ‘Get real.’ Get real in terms of what you eat, and one of the decisions I made in terms of getting real was that the occasional consumption of a broad vitamin and mineral supplement wasn’t going to do me any harm at all and may do me some good.”
He believes everyone should think about taking a supplement as they age. Food is a price-driven commodity, he says. “It’s going to be increasingly commoditised and the things that make it do well as a commodity are the things that deplete it in vitamins and minerals.”
Skeaff, however, reckons “it’s a mythology that says there are no nutrients left in our food. There are lots of nutrients. The foods available to choose from are fine. They may not be as perfect as when they’re taken out of the ground, but there’s lots of stuff if you choose the right food.”
Our reliance on synthetic vitamins added to processed foods over a healthy diet is a theme explored at length in the new book Vitamania, by Philadelphia journalist Catherine Price, who concludes our faith in vitamins is actually causing harm, by encouraging us to eat the very foods that are bad for us.
“The primary reason food companies are willing to provide us with so many vitamin-enhanced products is simple: they’re profitable. Synthetic vitamins produce a tremendous bang for the food manufacturers’ buck, essentially conjuring value out of thin air.
If processed products were not enriched with synthetic vitamins, the nutritional emptiness of their raw ingredients would mean we’d have to eat (or take) something else to meet our micronutrient requirements. It’s possible that without synthetic vitamins, the selection of packaged foods in the middle aisles of today’s grocery stores would never have been able to grow so large.”
The book details how vitamins went from a scientific breakthrough in the 1920s to a public craze so popular that about half of all Americans report taking some sort of supplement.
Our intake is similar, according to the Otago University/Ministry of Health Adult Nutrition Survey. A Sovereign Healthy Living Survey last September (based on responses from 1655 adults, aged 25 to 74) found a slightly lower rate, with 36 per cent reporting they’d regularly taken supplements in the past 12 months, mostly multivitamins, fish oil and vitamin C.
Among women, the uptake was higher, at nearly 45 per cent. The survey also asked how healthy our participants thought they were, with the supplement users repeatedly rating themselves more highly for their lifestyle and health.
Shaun Holt’s small survey of doctors and pharmacists published last year found around two-thirds of the 50 GPs questioned said they recommended multivitamins, although only one in five took them themselves. The numbers were similar for fish oil. Pharmacists, however, seemed big fish oil proponents, with more than half the 21 chemists questioned saying they took it, and more than 70 per cent recommending it to customers.
Liggins Institute scientist Dr Ben Albert:“You wouldn’t eat a fish they gave you after two weeks, but a fish oil capsule that’s three years old looks fine and you’d still take that.”
While the science of supplements is at times both murky and contradictory, New Zealand researchers are at the forefront of international efforts to provide clear evidence for three high-profile products – vitamin D, fish oil and calcium.
Of all the vitamins, and there are just 13, the one attracting the most research interest lately is vitamin D, and not only for its traditional role in supporting bone health in the elderly. Scientists are now investigating whether vitamin D deficiency (said to be the most common medical condition in the world) is linked to our biggest killers – heart and lung disease, cancer and diabetes – and whether population screening and supplementation is warranted.
A team led by Auckland University School of Population Health epidemiologist Professor Robert Scragg has recruited more than 5000 patients for a four-year study into the effects of vitamin D on heart and respiratory health, and also whether it prevents fractures.
He says the main findings should be known in about a year. Though there have been numerous international trials – published studies of vitamin D in 2012 almost outnumbered those of A, B, C and E combined – Scragg says the Auckland work is different because it involves higher doses.
Scragg says he doesn’t take multivitamins, and couldn’t ethically take vitamin D while half the participants in his trial are on placebos.
The jury is also out on fish oil, with Auckland’s Liggins Institute making international headlines in January for its study showing only three of 32 fish oil supplements contained the labelled amount of omega 3 fatty acids, while more than half were badly oxidised, or rancid. Lead scientists on the research, Liggins director Professor Wayne Cutfield and scientist Dr Ben Albert, have more studies on fish oil – and the possible effects of that oxidation – awaiting publication.
“I think there’s a major problem with fish oil, which hasn’t been brought up much, and that’s that the omega 3 fats – the fats we are trying to take because of the suggestion they reduces heart disease risk – deteriorate very easily with oxidation,” says Albert. “And the conditions that make them oxidise are being exposed to air, light and warmth.”
With most fish oils having three-year use-by dates, and sitting on shop shelves for lengthy periods – or even displayed in bright sun outside – Albert says the researchers expected to find some had gone “off”. However he was surprised at the numbers.
The degree of oxidation was unrelated to price, use-by date or origin, meaning consumers have no real way of knowing how to get the highest-quality products. Albert says the extent of the variation could be one reason why the results of omega 3 supplements in heart disease prevention have been so mixed.
A Canadian study of 44 herbal products in 2013 found most were “of poor quality, including considerable product substitution, contamination and use of fillers”.
More fish, particularly oilier fish, in the diet is usually associated with better health outcomes, but Albert says putting the omega 3 in a capsule may not have the same effect. “You wouldn’t eat a fish they gave you after two weeks, but a fish oil capsule that’s three years old looks fine and you’d still take that.”
Statistics show we are indeed scoffing fish oil supplements in ever-increasing numbers. A Euromonitor International report last July said the fish oil market had “exploded”, growing by nearly 60 per cent – about $1 million a year – in New Zealand since 2008.
In the United States, fish oil sales are now worth $1 billion a year, so predictably, the supplements industry didn’t much like the Liggins findings. Suppliers questioned the laboratory analysis – which the institute staunchly defends – and urged it to release the results by brand, which it declined to do. The Ministry for Primary Industries and Medsafe are still investigating the results, while the other studies, looking at the effect of fish and krill oil on diabetes risk, and of oxidised fish oil in animal pregnancy, are due out later in the year.
Like the Liggins researchers, Auckland University professors Ian Reid and Mark Bolland have also found themselves on the outer with the supplements industry after their research published in the British Medical Journal in 2008 and 2011 showed that calcium supplements in women trying to prevent osteoporosis appeared to increase their risk of heart attacks by 40 per cent.
There is now significant doubt about the safety of calcium supplements, says Reid, and the evidence they prevent fractures is relatively small. “When you balance the two against each other, we no longer believe use of calcium supplements is appropriate.”
Calcium in food doesn’t appear to have the same adverse effects. “There is a safe way out – to encourage people to increase their dietary calcium intake and not to take artificial supplements which deliver a very unphysiological load of calcium instantly.”
Calcium supplement sales had been steadily accelerating from about 2000, flattened from 2008 and are now “in freefall”.
While the heavily regulated pharmaceutical industry – which makes some calcium tablets – made no comment on the research, the supplements industry went on the attack.
“What shocked me was they were saying, ‘Oh no, this is completely untrue. Everyone knows calcium is good for you.’ They didn’t actually deal with the scientific issues or shortcomings; they just provided statements that were globally reassuring. No responsible pharmaceutical company would do that, because if the passage of time proves the findings correct, you open yourself to regulatory censure.”
Reid says a small number of vociferous opponents continue to attack his team’s findings.
“I don’t entirely understand their motivation, but probably because they’ve spent their entire careers promoting calcium supplements as a cure for osteoporosis, they’re most reluctant to accept adverse data.”
In 2013, another Reid-led project – a meta-analysis of 23 studies involving 4000 people – found no statistically significant improvement in bone mineral density in healthy adults taking vitamin D, suggesting “the high use of the supplements by most healthy adults is a waste of money and resources”.
The New Zealand supplements industry – or at least the members of the organisation that represents 80 per cent of suppliers, Natural Products NZ – has criticised those conclusions as “biased and misleading”, but generally presents as more guard than attack dog.
Whenever supplement quality or efficacy is questioned, the group uses it to push for long-awaited law change, due within the next year, which will give consumers more reliable information about what the product contains and what it’s meant to do. Under current law, companies can’t make therapeutic claims that a product makes any physiological change to named conditions. It’s why labels are both hopelessly vague but also confusingly wide-ranging – products will claim to “support” and “maintain” anything from joint to immune health, but can’t say they can help osteoarthritis or colds.
“At the moment you can say things that aren’t true and you can’t say things that are true,” says Shaun Holt.
Despite the criticisms of Cameron-Smith, Skeaff and others that health claims are sometimes wildly exaggerated, Natural Products NZ executive director Alison Quesnel says she’s “comfortable” with them, although she agrees “at the moment people have to be extremely creative. You can talk about winter ills and chills, but not colds and flu.”
But as Catherine Price asks in Vitamania, “Why would you take a supplement, after all, if you didn’t think it could treat, cure or prevent something? Are there really people who would buy a product that ‘improves regularity’ without hoping it might also treat constipation?”
She says consumers don’t realise the “circular process” some companies use to produce their product labels. As one employee of the US supplement industry explained, “We use focus groups to decide what to say in claims. We hear what people want, and then we put that on the label.”
Quesnel’s confidence in the veracity of claims made in New Zealand may also be misplaced. A Health Ministry review of 263 industry websites in 2007 found nearly 80 per cent making illegal therapeutic claims. A later “compliance awareness programme”, discovered more than half the ads on websites for natural products made therapeutic claims, with a third of the websites making “high-level claims”. Low-level claims included relief from symptoms of arthritis, psoriasis, hay fever, pre-menstrual tension, gout, headaches or migraine. High-level claims included preventing or treating serious diseases, including cancer.
The Natural Health and Supplementary Products Bill, which had its second reading in 2013 but has been in the making for more than a decade, takes what the Health Ministry calls a “light-handed” regulatory approach, because the risks are low.
If it’s passed, as expected, later this year or early next, manufacturers will be able to make health claims they can back up with evidence. That evidence won’t be as rigorous as the lengthy clinical trials necessary before drugs are registered, and will include “traditional use”. Kawakawa leaves, for example, have been traditionally used by Maori to relieve upset stomachs and that claim could be made supported by a reference to such a use in Te Ara, the Encyclopedia of New Zealand.
The ministry’s chief medical officer, Dr Don Mackie, doesn’t expect companies to carry out original research but to rely on existing studies, such as the 2013 Cochrane review, which found regular vitamin C could reduce the severity and duration of colds, if not the incidence.
Quesnel says “everyone wants this bill” and the new regime will allow consumers, baby boomers in particular, to better manage their own health.
“I swallow a lot of pills. I have heart issues and I always let my doctor know what I’m taking and he’s absolutely okay with it. I take fish oil, magnesium and zinc on his advice, and vitamin D and Coenzyme Q10, which is suggested may possibly assist people taking statins.”
Well, that depends on what evidence you listen to. Last year, New Scientist magazine evaluated the evidence for CoQ10 and said while it may have promise in the clinic, for now, many health claims “are little more than CoQ and bull”.
Natural Products NZ executive director Alison Quesnel.
If legislative attitudes to natural products are relaxed internationally, we can blame US Democrat senator William Proxmire, who in 1976 sponsored the Proxmire Amendment to a proposed new law, stopping the Food and Drug Administration from limiting the potency of vitamins, or regulating them as drugs.
There is little impetus to change that approach – complementary or alternative medicines were associated with just 11 of more than 5000 adverse reactions to medicines reported here last year.
But contamination and substitution of ingredients, particularly in herbal supplements, have long been a problem overseas. A Canadian study of 44 herbal products in 2013 found most were “of poor quality, including considerable product substitution, contamination and use of fillers”. As the New York Times put it, “Many pills labelled as healing herbs are little more than powdered rice or weeds.”
In February, the New York attorney general’s office accused four of the country’s biggest stores of selling herbal products that were either contaminated, or contained none of the herbs listed on the label. Two months later, Canadian health authorities pulled from sale a number of weight-loss and workout supplements containing a chemical almost identical to amphetamine, saying the powerful stimulant was a serious health risk.
The new regulations here will be a relatively low-cost affair for companies, with products, containing permitted ingredients, being registered online. They will effectively end the disparities between the New Zealand and Australian markets, where health claims are made on natural products under the Therapeutic Goods Act.
South Auckland company Vitaco, the country’s biggest supplier of branded vitamins and supplements, including the market-leading Healtheries range, says the same glucosamine it sells here as maintaining joint health is openly marketed there as an arthritis supplement.
Vitaco, which has nearly a quarter of the domestic market share, has a Good Manufacturing Practice-licensed, Medsafe-audited plant. The GMP licence is required under the TGA in Australia, but not in New Zealand, although consumers here get the protections it affords: mainly that the product contains what it says it does. Such is the auditing and record keeping, the ingredients in the finished product can be traced back to not only the exact raw material source, but also the vat they were mixed in and when it was cleaned.
The nearly 170 products made here are sourced from more than 4000 raw materials from around the world, but supplements technical manager Amber Yates says quality issues are rare. During production, samples of capsules and tablets are tested every 30 minutes for consistency, weight, hardness and friability, among other things, and the final product is analysed against British Pharmacopoeia standards in the onsite laboratory.
Auckland University professor of nutrition David Cameron-Smith.
For Cameron-Smith, though, the biggest issue for the supplements industry is not the products themselves, but the marketing spin that surrounds them – and our sometimes misplaced faith in what they can do for us.
“There is always a kernel of truth that begins the quest towards the bottom line, and the opportunities that flow from it. It’s preying on consumers’ concerns and needs and wants. Everybody is tired, everybody’s stressed, everybody’s run down, so they target those base things.”
The biggest impact of the new law, he hopes, will be to force companies to pull back from sweeping claims. “We expect truth in advertising in our electronics. Why shouldn’t we expect it in supplements?”
Catherine Price reckons consumers themselves have to take their share of responsibility, too, for preferring the quick fix of a pill rather than following the dietary rules we already know.
“Rather than challenge the food industry status quo, we passively accept whatever new health claim or recommendation we hear. Indeed, we seem to want to do so: it’s comforting to think that even if we ourselves find nutrition confusing, there’s someone out there who knows the truth. We don’t ask where the synthetic vitamins in food come from, or why our food supply requires so much reverse engineering to begin with.
“The story of vitamins is definitely one of scientific triumph,” she says, “but it’s also a cautionary tale, a reminder that the most important issue in nutrition isn’t just what we know, it’s what we don’t.”
Words by: Donna Chisholm
Photos: Ken Downie, Adrian Malloch and Getty Images
