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What's the truth about supplements?

A new study claims fish oil supplements don't protect health - Science Photo Library RF
A new study claims fish oil supplements don't protect health - Science Photo Library RF

They’re the most popular food supplement in the UK with British people spending an estimated £60 million on them each year. But are omega-3 fish oils really worth it when it comes to protecting your heart health?

Perhaps not, according to a large review by the respected Cochrane Library - a non-profit, non-government organisation formed to organise medical research - that reviewed 79 trials involving over 100,000 people and found they make “little or no difference” to protecting heart health.

Omega 3 fats are known to lower fat levels in the blood, reduce blood pressure and help prevent blood clots. They can’t be made by our bodies and therefore need to come from our diet and are found in oily fish like trout, salmon, mackerel, sardines and fresh tuna, nuts, seeds and, of course, supplements. But this new study seems to suggest that taking them in supplement form has few benefits. 

“The government has been advising people to eat oily fish once or twice a week since 1989, when our intake was very low, but the national diet has changed a lot since then and deaths from heart disease have decreased quite dramatically,” says Professor Tom Sanders, a professor of nutrition and dietetics at King’s College London. “If you follow this advice, you’ll reach the healthy threshold. If you take supplements you’ll be above that threshold but intakes above this level are unlikely to have any further benefit.  Because a small amount of an essential nutrient is needed, it does not follow that more is always better.

Supplements
Supplements

“There are also other things in oily fish that improve health, like vitamin D and selenium, which the body absorbs better in food form, and it helps with inflammation. Vegetarians or people who don’t like fish can find it in rapeseed oil, soya bean oil and walnuts. People should just eat better, not take capsules.”

Professor Sanders also points out that the study looked at people with existing heart disease: “In other words they’d already had a heart attack and obviously survived it, so they were looking at a survivor population. And there may still be a role for omega-3 fatty acids in patients with heart failure, which is still under investigation."

10 essential supplements and why you should take them
10 essential supplements and why you should take them

“My advice as a registered dietitian is that food should always come first in terms of nourishing your body,” says Helen Bond. “However, living in the heart of England, away from the sea and without a tempting fishmongers on my doorstep, even as a dietitian I sadly don’t always meet my oily fish quota. And to that end, I do take a fish oil supplement rich in EPA, DHA and  also vitamin D, which is another vitamin lacking in a lot of British people’s diet - especially in winter.

People like to focus on single nutrients or magic bullets rather than look at overall health

Professor Tom Sanders

“The UK Department of Health recommends we should eat two portions of fish a week, one of them being oily (but not more if you’re pregnancy or breastfeeding). And you’re always better off getting your omega-3s from fish rather than a pill, but with the pressures of modern life and the fact fish isn’t to everybody’s taste, many of us fail to meet those targets so supplementation does offer a convenient way to increase intakes. But it’s important to remember not all fish oils are created equally and the quality can vary, meaning it may not provide a significant dose.”

Professor Sanders says there are some cases where supplements are valid: “Pregnant women - and women planning on trying for a baby - should take folic acid. We don’t have fortification of folic acid in flour in the UK, like they do in the US and Canada, and taking a supplement in the first twelve weeks of pregnancy has been proven to reduce neural tube defects in unborn babies. In some cases, vegans may need to take a B12 supplement, and the only other supplement I’d advise is vitamin D because we fail to produce or eat enough of it, in particular the elderly and office workers who don’t see a lot of sunlight.

“But other than that, people like to focus on single nutrients, magic bullets and dietary demons: sugar is bad, this is good. But what we know is that it’s your overall diet and how much you eat is the key to good health. Aim for five portions of fruit and vegetables a day, eat fish a couple of times a week, have some dairy, limit red and processed meat, don’t smoke and drink moderately. You can’t turn a bad diet good with a handful of pills, and if your diet is good then there’s no need to take expensive supplements.”

Or as Professor Tim Chico, a professor of cardiovascular medicine and honorary consultant cardiologist at the University of Sheffield, says: “Supplements come with a significant cost, so my advice to anyone buying them in the hope that they reduce the risk of heart disease, I’d advise them to spend their money on vegetables instead.”