Two substances found naturally in the body could reverse the ageing process when taken as supplements. Anne Woodham explains the research

Can health supplements acetyl-L-carnitine and alpha-lipoic acid do to humans what they did to ageing rats? Californian researchers were amazed when they fed these dietary supplements that can be bought in high street health shops to laboratory animals.

'With the two supplements together, these old rats got up and did the macarena,' said Bruce N. Ames, Professor of Molecular and Cell Biology at the University of California, Berkeley. 'The brain looks better, they are full of energy - everything we looked at looks more like a young animal.'

Within hours of news of Ames' results appearing in the media in February, a Richmond health store had sold out of the supplements. A spokesperson for health shop chain Holland & Barrett reported a nationwide run on stocks.

According to Professor Ames, evidence suggests that the deterioration of mitochondria, our cells' energy power packs, is as an important cause of ageing. Destructive molecules called free radicals that are produced during normal metabolism (chemical processes that convert nutrients into energy and keep us alive) are thought to cause this deterioration.

Acetyl-L-carnitine and alpha-lipoic acid are chemicals found naturally in body cells. Alpha-lipoic acid is an antioxidant that destroys free radicals. Acetyl-L-carnitine is a protein that boosts the action of an enzyme (carnitine acetyltransferase) that fuels mitochondria and becomes less active with age.

Professor Ames and his team reckoned that combining the two as supplements would deliver a two-pronged punch to ageing cells. Their studies, published in the US science journal Proceedings of the National Academy of Sciences in February 2002, showed they were right. 'Each chemical solves a different problem,' said Ames. 'The two together are better than either one alone.'

From old age to middle age
After a month on the supplements, elderly and lethargic rats had more energy, did better on memory tests and their mitochondria worked better. The decline in overall activity typical of aged rats was reversed to that of a middle-aged to young adult rat seven to ten months of age. This is equivalent to making a 75- to 80-year-old person act middle-aged.

'The animals seem to have much more vigour and are much more active than animals not on this diet, signalling massive improvement to these animals' health and well-being,' said Dr. Tory Hagen, a colleague of Ames who is now at the Linus Pauling Institute at Oregon State University.

Professor Ames and Dr. Hagen have formed a company, Juvenon, to patent the combination and are currently carrying out human clinical trials of the treatment. But their experiments with rats are only the first step and other scientists warn against rushing into health shops and self-dosing on the supplements before they have been shown to work in humans or the proper dose is established.

Alpha-lipoic acid
The mitochondria in the cells normally make enough of this chemical compound for energy production purposes. It is only when in excess and circulating in a 'free' state in our cells that alpha-lipoic acid acts as an antioxidant, and the only way to achieve an excess is through supplementation. Most foods, apart from liver and yeast, contain only tiny amounts of the compound.

As an antioxidant, it switches off many fat- and water-soluble free radicals in the body and seems to protect our genetic material, DNA. It also re-processes vitamins C and E and other antioxidants to make them more effective.

Research indicates that it will prove a very special and powerful antioxidant but there is still little known about it. What there is suggests that supplements can help keep nerves healthy and prevent or treat age-related diseases such as heart disease, cataracts and diabetes. Because it is made in the cells by the mitochondria, it is particularly well placed to prevent and even reverse ageing. It appears to be safe, but nobody knows what amounts should be used. If it is so potent, it may also be possible to overdose. Anyone who is on medication for heart disease or diabetes should talk to a doctor before taking it.

Acetyl-L-carnitine
This molecule occurs naturally in the liver, brain and kidney and is similar in form to the amino acid L-carnitine, which carries fatty acids into the mitochondria where they are converted to energy. Acetyl-L-carnitine is involved in the production of a key neurotransmitter acetylcholine, important for cognitive function. Some studies suggest that it may delay the progression of Alzheimer's disease, protect nerve cells from deterioration, increase mental energy and help relieve depression.

The body normally converts L-carnitine, which is made in the liver, into acetyl-L-carnitine. Levels may decrease after the age of 40, but it is not normally considered an essential nutrient because the body can manufacture all it needs. Most research involving acetyl-L-carnitine uses 500mg three times a day. It appears to be safe, although body odour, nausea, vomiting, agitation, skin rash and increased appetite are reported side effects. Because some medications may interact with it, discuss any supplementation with your doctor or pharmacist.