Using supplements? You need to keep these things in mind.

By Claudine Ryan, Tegan Osborne and Dr Jocelyn Lowinger.

It might be echinacea for a cold, fish oil for your heart, or St John’s Wort for your mood. Chances are, at some point, you have taken supplements.

More than half of us take a supplement or other complementary medicine each year, and some experts say it could be up to 80 per cent of us. In 2014, the complementary medicines industry as a whole generated $3.5 billion in revenue, and profits are rising.

Yet the reality is that most of us take supplements on trust. We often don’t know what ingredients they contain, where they come from or whether they are even effective for our condition.

At worst, supplements can be dangerous. But for most, there’s little reliable evidence they work for much at all — and they are not as closely regulated for safety and effectiveness as you might think.

It truly is a case of buyer beware. So what are some of the things you need to keep in mind before you buy and use supplements and complementary medicines?

They can be dangerous.

It’s tempting to think that supplements are ‘safe’ because they are ‘natural’. But ‘natural’ does not equal ‘safe’.

This week, Four Corners airs an investigation by the New York Times and PBS Frontline program into the hidden dangers in vitamins and supplements. The program identified a number of supplements that had been linked to liver injury, with one weight loss supplement linked to more than 70 cases of liver injury and at least one death.

But this isn’t just an issue in the United States. The potential dangers of using dietary supplements made headlines in Australia earlier this year with the case of Western Australian man Matthew Whitby, who lost his liver — most likely as a result of taking a protein powder with green tea extract.

Since then it has emerged that herbal supplements have been linked to at least six Australian organ transplants since 2011, and many commonly used dietary supplements have been linked to kidney damage.

While these cases sound horrifying, clinical pharmacologist Professor Ric Day, from St Vincent’s Hospital, Sydney, said cases like Mr Whitby’s are unusual and could happen with prescribed medications as well.

In his view, the risks of taking supplements are quite low as they have been given “a wide level of exposure in the population”.

Supplements are not regulated like other medicines.

Complementary medicines and supplements don’t receive the same level of testing and regulation as prescription drugs before they can be sold.

Australia has a two-tiered system for the regulation of medicines, which is overseen using a risk-based approach by the Therapeutic Goods Administration (TGA).

Medicines with what the TGA considers low-risk ingredients — including most complementary medicines — receive less checking than higher risk products, and are listed as “Aust-L”.

In explaining the checks in place for Aust-L products — which can be identified by an Aust-L number on the packaging — the TGA website states:

“For products containing low-risk ingredients, regulation centres on the safety of the product and the consistency of the manufacturing process; less emphasis is placed on assessing the evidence for the claims being made.”
For Aust-L products, the manufacturer must certify that they have only used pre-approved ingredients and that the product has been made according to good manufacturing practice standards. But the TGA relies on the honesty of the manufacturer when it comes to ingredient quality and the manufacturing process. And more significantly — they do not need to provide proof to the TGA that their products work.

Higher risk drugs, like prescription medicines, are checked more rigorously and are registered as “Aust-R”. For these drugs, the TGA checks that the products meet safety and quality criteria — but also that they have been demonstrated to have the claimed effect.

What this all means is that even if the supplement or complementary medicine you are taking is regulated by the TGA, you can never be 100 per cent sure that it contains what is on the label, or that it will work.

You should also take care with supplements sold as teas, as these can may fall outside the TGA’s regulation altogether, because they are classified as a food.

Products bought online can be dodgy.

Online supplement stores are a “minefield” of dangers, said Dr Joanna Harnett, an associate lecturer who teaches evidence-based complementary medicine through the University of Sydney’s Pharmacy faculty.

Buying supplements online, particularly from overseas, is a very risky activity, as indeed is buying any medication, as the chances of receiving forged products are significant.

Supplements sold on the internet are unlikely to have been evaluated by the TGA, which means there is even less surety that the product contains what it says it does, whether it contains unlisted, illegal or dangerous ingredients, or whether it is contaminated with toxic heavy metals such as lead, mercury or arsenic.

Currently there are a number of TGA safety alerts for weight loss and other products that are contaminated with illegal ingredients that have been linked to health issues such as heart disease and cancer.

In recent years, for example, the online sale of supplements containing green tea catechins has become common.

“We know that the consumption of green tea appears to have a good antioxidant affect and there’s been some large epidemiological studies [indicating] a decreased risk of certain cancers,” Dr Harnett said. “So the supplemental industry have isolated some of these green tea catechins.”

But if the supplements are made the wrong way, the impact can be devastating — even deadly.

“The green tea catechins can in fact have a toxic affect and cause liver damage if they’re made in a particular way, and in these very high doses that are sold over the internet,” she said.

They have side effects and interact with medications.

Dr Lynn Weekes CEO of NPS MedicineWise said some people faced a higher risk from the side effects of supplements and complementary medicines. Those most at risk include pregnant and breastfeeding women, children, people who are about to have or are recovering from surgery, those undergoing cancer treatment, those with compromised immune systems and those taking other medications.

“People who are on anti-coagulant medicines for example, like warfarin or the newer anticoagulants, they shouldn’t be taking a herbal medicine,” Dr Weekes said. “If you take ginko with that you’re more likely to have a bleed.”

Dr Weekes said all of us, not just those taking regular medication, should talk to our doctors before taking supplements.

“Sometimes people don’t feel that they need to tell their doctor, or they are a bit embarrassed to tell their doctor, but we really encourage them to. Because then, if there is the likelihood of a problem, we are likely to pick it up.”

For those undergoing cancer treatments – such as chemotherapy and radiotherapy – these conversations are vital, said Dr Harnett.

“Unfortunately the literature would tell us that people don’t [speak with their doctor] for numerous reason and they’re not always asked either about their use,” she said.

Some supplements and herbs can reduce the effectiveness or increase the toxicity of chemotherapy drugs.

They usually don’t work.

Despite their wide-spread use and popularity, there’s not a lot of good evidence to show that supplements and complementary medicines work.

“Overall there’s not really strong efficacy for most products, with a few exceptions,” Dr Weekes said.

“Even in those areas where there has been quite a lot of research done, such as around fish oil, the data are quite contradictory at times.”

Fish oil has been more extensively studied for conditions such as heart disease, depression and arthritis.

Evidence suggests it may have some role in the treatment of arthritis and possibly alongside other treatments for depression.

But the evidence for heart disease is not as strong as was once believed, with one recent trial finding fish oil supplements weren’t as helpful as once thought in preventing worsening of heart disease in people who had previously had a heart attack. In response, the Heart Foundation has now modified their recommendations for fish oil supplements.

You probably don’t need them.

If your doctor diagnoses you with a nutritional deficiency, for example anaemia, then obviously you should take the prescribed supplement.

But the vast majority of us who take supplements do so without any diagnoses, in a bid to improve our health and wellbeing, and fight off disease.

If you’re taking supplements — especially nutritional supplements — to improve your health, Associate Professor in Nutrition Tim Crowe said you would be better off spending your money on improving your diet.

“It is always going to be better to get the nutrients from your food,” he said.

“If you are relying on supplements to meet your nutritional needs rather than your diet, you are missing out on a lot of beneficial things in food that are going to be better for your health.

For those who choose to take nutritional supplements, Association Professor Crowe recommended choosing a good multi-vitamin as this reduces the chances you will ‘overdose’ on a specific nutrient.

“There is a small amount of everything, and not too much of anything, in those multivitamins.”

“As with anything, too much of any food, too much of any supplement can be harmful.”

They will not cure cancer (or any other major disease).

There is very little evidence that supplements can prevent, fight or cure cancer.

Dr Harnett said any supplement claiming to cure cancer should raise a “red flag” for consumers.

“There are no vitamins, minerals or herbal medicines that have undergone rigorous trials, and demonstrated they will cure cancer.”

Some supplements claim to aid cancer prevention. Antioxidant supplements, such as vitamins A, C and E and beta-carotene supplements, are often used because people believe they may help to prevent chronic diseases, including cancer.

But studies have actually shown certain supplements can do more harm than good.

“Increasing the intake of vitamins, minerals and plant nutrients from increasing fruit and vegetable intake, there’s clear evidence that this is playing a role in the prevention of chronic disease, including cancer,” Dr Harnett said.

“However when we take them and isolate them in forms of supplements, we can either see no difference or an increased risk of certain cancers.”

In one well-know study from the 1990s smokers were given supplemental beta-carotene (a substance concerted to vitamin A in the body), and this had to be discontinued after a notable increase in the number of participants who developed cancer.

“From what was predicted, it had an opposite outcome,” Dr Harnett said.

This post originally appeared on ABC News.

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