How fish oils add years to your life (and take years off your face!) Last updated at 12:14 AM on 30th January 2010 There seems to be no end to the benefits of fish oils. Not only are they said to boost heart, brain and joint health, but they also prevent cancer, eye disease and bone problems. Last week, a new study suggested they could assist the body against premature ageing. But how do you separate the facts from the hype? PETA BEE asked the experts... Cure oil or something fishy? Fish oils contain the essential omega fatty acids, which we only get through our diet WHAT'S SO SPECIAL ABOUT FISH OILS? Fish oils are a type of polyunsaturated fat - a 'healthy' fat. Unlike saturated animal fats, they don't raise your cholesterol levels, but are known to have a positive effect on health. Polyunsaturated fats are divided into two groups of what are called Essential Fatty Acids (or EFAs) - omega-3 and omega-6. Both omegas are essential in helping to regulate blood clotting, body temperature, blood pressure and the immune system; they are also needed to make prostaglandins, important hormone-like chemicals in the body. The only way we can get them is through our diet. Omega-3 has particular benefits, producing vital substances such as DHA (docosahexaenoic acid), thought to play a key role in the development of brain and cognitive function, and EPA ( eicosapentaenoic acid), vital for brain health. The richest source of omega-3s are fish oils - salmon, mackerel, fresh tuna and herring. While most Britons consume more than enough omega-6 oils (found in most edible oils, but particularly sunflower and corn, as well as meat), they are deficient in omega-3. WILL THEY PROTECT MY HEART? There have been a number of studies suggesting fish oils boost heart health, but the most compelling evidence was a study last year published in the Journal Of The American College Of Cardiology. Led by Dr Carl Lavie, of the Ochsner Cardiology Clinic in Louisiana, the study showed omega-3 oils help to prevent blood clotting and regulate or lower blood pressure. The strongest heart-protective effect is for patients with established cardiovascular disease, the study found. Brain food? Teenagers taking exams. Fish oils help protect your brain against Alzheimer's disease but won't boost your mind power in a test 'This isn't just hype - we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years,' Dr Lavie said. Under guidelines issued by the National Institute for Health and Clinical Excellence (NICE), doctors are encouraged to prescribe supplements to patients after they have had a heart attack to prevent repeat attacks. WHAT ABOUT MY BRAIN? There has been great interest in the fish oil effect on the brain - both in preventing disease and boosting brain power. Studies have shown, for instance, that DHA can reduce the formation of plaques in the brain; these have been linked to Alzheimer's disease and dementia. Too little omega-3 has been linked to mild depression, and there is some evidence that fish oils may help here. DHA has been shown to boost foetal brain development. However, parents who feed their children fish oil supplements before exams might be wasting their money, as the evidence for fish oils boosting intelligence and exam performance is tenuous. WHAT ELSE CAN THEY DO? Eating oily fish once a week has been shown to protect against age-related macular degeneration, the most common cause of blindness in the older generation. They might also be helpful in the fight against some forms of cancer. Last year, Professor John Witte, from the University of California, suggested a high intake of omega-3s reduced men's risk of prostate cancer by about 60 per cent. There is some evidence, too, that a regular consumption of omega-3s can help prevent bowel cancer. WILL THEY HELP ME LOOK YOUNGER? Anti-ageing? One study suggests fish oils help to keep you looking youthful Last week researchers from the University of California suggested omega-3s - whether from supplements or fish - helped cells in the body live longer. When they studied heart disease patients, they found the more omega-3 the subjects ate, the slower the damage to the DNA in their cells. That, in turn, meant better protection against inflammation and the ageing process. So will fish oils help you live longer - and look younger? Heather Yuregir, a researcher at the British Nutrition Foundation, says it's possible, although more evidence is needed to confirm the anti-ageing effect. 'The study found fish oils may protect against ageing, which does indicate another possible benefit of consuming such oils in the diet. 'But it must be remembered that it is only one study; the claims need to be strengthened.' SHOULD I TAKE FISH OIL PILLS? The best food supply of omega-3s is oily fish such as salmon, tuna, mackerel and herring. Other sources include rapeseed, evening primrose and walnut oils, fresh seeds such as pumpkin and sunflower, wholemeal bread and wholegrain cereals. However, they provide omega-3s in a different chemical form which is more difficult for the body to convert into DHA and EPA, so it would be difficult to consume enough. In Britain, there are no recommended daily levels for fish oils, although the Food Standards Agency (FSA) and the British Nutrition Foundation (BNF) say eating two portions (140g each) a week of fish, including one of oily fish, will meet most people's needs - providing around 250mg of omega-3s. (Note, canned tuna does not count, as the processing reduces its omega-3 levels to those similar to white fish). However, a team of doctors reporting in the Journal Of The American College Of Cardiology last year suggested there is now 'compelling evidence' for the benefits of fish oils and recommended people try to consume 500mg of omega-3 fish oil a day, while those with heart disease or heart failure take at least 800 to 1000mg in their diet. Many experts think it is better to eat fish to provide the oil, as this ensures you also get other important nutrients and protein, and the suggestion by some researchers to take supplements instead remains controversial. 'UK guidelines suggest adults get their omega-3 intake from fish and there is no recommendation to take supplements as well,' says Bridget Benelam, of the BNF. Food or supplements? The best source of fish oils are salmon (pictured), mackerel, tuna and herring Indeed, although NICE now recommends those who've had a heart attack take a supplement, eating more oily fish is preferable, explains June Davison, a senior cardiac nurse at the British Heart Foundation. The charity recommends anyone who has suffered a heart attack eats two to three portions of oily fish a week over taking a capsule. 'For most people with or without heart disease, supplements are not generally suggested as a daily requirement,' says Davison. However, last week a survey of more than 3,000 British consumers by NutraSea found 40per cent of people never cook fish. Getting your omega-3 from other sources is preferable to getting none, says Dr Rafe Bundy, nutrition lecturer at Glasgow University. WHAT ABOUT COD LIVER OIL? Cod liver oil does contain some DHA and EPA, but not as much as the oily fish - but there are other reasons to consider it. It's a good source of vitamin D, and experts are increasingly concerned that in Britain our levels of this vitamin are low (the main source is the sun). Vitamin D deficiency is now being linked to a range of conditions, including diabetes. The vitamin is also important to prevent the bone disease rickets, which has made a comeback. Last week, the British Medical Journal revealed that spending too much time indoors, combined with poor diets, has led to a drop in vitamin D levels among children - and a rise in rickets. The fact that children are no longer being given a daily slug of cod liver oil is also thought to be contributing to the problem.