Cod Liver Oil, the Remedy that Changed the World

Suffering from an ear infection? Stress? Malfunctioning ticker? Turn, then, to the cloying amber fluid detested by children through the years. And yesterday it emerged it can defeat arthritis. Michael McCarthy reports: They're not yet saying it can enable you to stop a bullet or leap tall buildings but it's not far short of that.

Yet another medical triumph for cod liver oil was announced yesterday (accompanied by the rather forward claim that the later life of the Queen Mother would have been quite different, had she only imbibed a daily spoonful as a girl).

Yes, you name it - ear infections, impaired cardiovascular functions, insulin resistance, high cholesterol levels, allergies, learning disorders, stress, manic depression - cod liver oil can help, various studies show.

No one seems to have mentioned ingrown toenails but it can only be a matter of time. The latest success for the viscous amber fluid from deep in a fish's insides is with osteoarthritis, that most cripplingly painful of degenerative diseases.

Scientists released data yesterday showing it really is effective in slowing the destruction of joint cartilage in osteoarthritis sufferers. Cartilage is the "gristle" that cushions bones and prevents them from grinding against each other and it is the loss of it which brings osteoarthritis on; it is a condition that caused more than two million people in the UK to visit their GP in the last year and is the main reason for joint replacement surgery.

The groundbreaking clinical study, led by Professor Bruce Caterson and Professor John Harwood of Cardiff University, and Professor Colin Dent, orthopaedic consultant at the University of Wales College of Medicine, looked at the effect of taking - and not taking - the oil on 31 patients on an NHS waiting list.

Half of the patients, who were recruited 10 to 12 weeks prior to total knee-joint replacement surgery, were given two daily capsules containing 1000mg extra high strength cod liver oil, and half (poor them!) were given placebo capsules. At the time of surgery, samples of cartilage and joint tissue were taken from the knee joints and subjected to analysis.

The trial showed, the scientists said, that 86 per cent of the patients who took cod liver oil capsules daily had absent or significantly reduced levels of the enzymes that cause cartilage damage, compared with 26 per cent of those given the placebo oil capsules. In addition, the result showed a marked reduction in some of the enzymes that cause joint pain, in those patients taking the real stuff.

Well there you are. The researchers suggested yesterday that the findings could hold the key to reducing the number of knee and hip replacements carried out in the UK each year, thereby shortening NHS waiting lists for joint replacement surgery. The estimated direct cost of arthritis to the health and social services is approximately £5.5bn a year.

"Patients resort to joint replacement surgery when the symptoms and pain of their arthritis becomes unbearable," said Professor Dent. "Cod liver oil can counteract these symptoms and if you can switch off the cartilage destruction and pain, then surgery may not be necessary."

Professor Caterson said the findings represented a "hugely significant" breakthrough. "The data suggests cod liver oil has a dual mode of action, potentially slowing down the cartilage degeneration inherent in osteoarthritis, and also reducing factors that cause pain and inflammation," he said.

"By taking cod liver oil, people are more likely to delay the onset of osteoarthritis and less likely to require multiple joint replacements later in life." And he added: "To put this into perspective, it is highly likely that if the Queen Mother had taken cod liver oil as a young adult, she may have needed her first hip replacement much later on in life."

Perhaps. But what certainly seems to be true is that the gooey stuff that mothers used to force down the unwilling throats of their offspring - "because it will do you good, so take it!" - is an old wives' tale come true.

Research is showing that it is genuinely effective in treating a whole range of ailments. Children used to hold their noses when they swallowed it and be unaware of any real benefits but perhaps because it prevented rather than cured.

By the mid-19th century it had certainly been found to be an efficacious treatment for rickets, a childhood disease of weak and softening bones caused by the sufferer not getting enough vitamin D.

Cod liver oil has bags of vitamin D, and even more vitamin A - more of the latter per unit weight than any other common food, more than three times as much, for example, as the next richest source, beef liver - and it is also a huge source of omega-3 fatty acids. It seems to work on a variety of maladies.

One, for example, is otitis media, the infected "runny ear" so often suffered by children. In a study at the New York Eye and Ear Infirmary, investigators found that youngsters prone to otitis media had lower than normal levels of EPA (an anti-inflammatory omega-3 fatty acid), vitamin A, and selenium. When they gave the youngsters cod liver oil, a multivitamin, and selenium, they found the children suffered fewer ear infections.

Other studies have shown that the elongated omega-3 fatty acids in cod liver oil improve brain function, stress response, allergies, memory and learning and many behavioural disorders. It is counselled in everything from digestive troubles to sleeping problems. Yet it has had the odd piece of bad publicity of its own.

On more than one occasion, tests have shown high levels of potentially cancer-causing chemicals, such dioxins and polychlorinated biphenyls (PCBs), to be present in unacceptable levels in cod liver oil being sold.

Two years ago, such levels were found in cod liver oil sold by Superdrug and the health food chain Holland & Barret, - the Food Standards Agency (FSA) asked both firms to remove the oil from sale.

The FSA said the oil concerned contained more than twice the recommended daily intake of the chemicals, which were not considered to be harmful to health immediately, but were a matter of concern over potential damage from long-term exposure.

The FSA tested 33 samples of branded fish oil supplement on sale across the UK. Most of the dioxin levels found were low, apart from the two recommended for withdrawal.

Dr Jon Bell, the FSA's deputy chief executive and head of food safety, said at the time: "While there have been measurable improvements in dioxin levels in fish oil supplements, there is scope for additional action by the industry to reduce levels still further. The agency has initiated discussions with retailers and industry about ways to continue to reduce levels of potentially harmful dioxins."

The chemicals are in the oil because the chemicals are in the sea and can eventually accumulate and become concentrated in marine organisms. (It has been estimated one third of all the PCBs ever produced are now in the oceans.) But in totting up a balance, the benefits of taking a daily spoonful seem

Cod liver oil probably works in two different ways in preventing arthritis. It is a rich source of vitamin D and of n-3 fatty acids - these substances modify immune reactions in the body and help to prevent the body being attacked by itself in what is called an autoimmune reaction.

Arthritis is one of several diseases that have been found to occur as a result of deficiency of vitamin D. Some vitamin D is obtained from eggs, butter, and meat and, for those who eat it, oily fish, but we obtain 90 per cent of our vitamin D from the sun.