A large U.S. study has found that adults with higher concentrations of serum alpha-carotene in their blood were likely to live longer than those who had lower levels. "These findings support increasing fruit and vegetable consumption as a means of preventing premature death," the researchers noted. For fuller details see the full Scientific Americain article at: http://www.scientificamerican.com/blog/post.cfm?id=alpha-carotene-from-veggies-linked-2010-12-30

Ray reckons that by 2045 humans will be able to merge with machines and live forever. His current regime has given him better health indicator results at age 62 than when he was 37. It is a regime, however, involving exercise, meditation, lots of sleep, calorific restriction, 150 daily supplements plus weekly intravenous infusions. And he’s looking forward to technical developments that will add to this regime. See ‘Taking the measure of Ray’, New Scientist, 25 December 2010, pp38/39) hide this.

Scientists claim to be a step closer to reversing the ageing process after rejuvenating worn out organs in elderly mice. The experimental treatment developed by researchers at the Dana-Farber Cancer Institute, Harvard Medical School, turned weak and feeble old mice into healthy animals by regenerating their aged bodies.

The surprise recovery of the animals has raised hopes among scientists that it may be possible to achieve a similar feat in humans – or at least to slow down the ageing process.

An anti-ageing therapy could have a dramatic impact on public health by reducing the burden of age-related health problems, such as dementia, stroke and heart disease, and prolonging the quality of life for an increasingly aged population.

"What we saw in these animals was not a slowing down or stabilisation of the ageing process. We saw a dramatic reversal – and that was unexpected," said Ronald DePinho who led the study, published in Nature.

"This could lead to strategies that enhance the regenerative potential of organs as individuals age and so increase their quality of life. Whether it serves to increase longevity is a question we are not yet in a position to answer."

The ageing process is poorly understood, but scientists know it is caused by many factors. Highly reactive particles called free radicals are made naturally in the body and cause damage to cells, while smoking, ultraviolet light and other environmental factors contribute to ageing.

The Harvard group focused on a process called telomere shortening. Most cells in the body contain 23 pairs of chromosomes, which carry our DNA. At the ends of each chromosome is a protective cap called a telomere. Each time a cell divides, the telomeres are snipped shorter, until eventually they stop working and the cell dies or goes into a suspended state called "senescence". The process is behind much of the wear and tear associated with ageing.

At Harvard, they bred genetically manipulated mice that lacked an enzyme called telomerase that stops telomeres getting shorter. Without the enzyme, the mice aged prematurely and suffered ailments, including a poor sense of smell, smaller brain size, infertility and damaged intestines and spleens. But when DePinho gave the mice injections to reactivate the enzyme, it repaired the damaged tissues and reversed the signs of ageing.

"These were severely aged animals, but after a month of treatment they showed a substantial restoration, including the growth of new neurons in their brains," said DePinho.

Repeating the trick in humans will be more difficult. Mice make telomerase throughout their lives, but the enzyme is switched off in adult humans, an evolutionary compromise that stops cells growing out of control and turning into cancer. Raising levels of telomerase in people might slow the ageing process, but it makes the risk of cancer soar.

DePinho said the treatment might be safe in humans if it were given periodically and only to younger people who do not have tiny clumps of cancer cells already living, unnoticed, in their bodies.

David Kipling, who studies ageing at Cardiff University, said: "The goal for human tissue 'rejuvenation' would be to remove senescent cells, or else compensate for the deleterious effects they have on tissues and organs. Although this is a fascinating study, it must be remembered that mice are not little men, particularly with regard to their telomeres, and it remains unclear whether a similar telomerase reactivation in adult humans would lead to the removal of senescent cells."

Lynne Cox, a biochemist at Oxford University, said the study was "extremely important" and "provides proof of principle that short-term treatment to restore telomerase in adults already showing age-related tissue degeneration can rejuvenate aged tissues and restore physiological function."

DePinho said none of Harvard's mice developed cancer after the treatment. The team is now investigating whether it extends the lifespan of mice or enables them to live healthier lives into old age.

Tom Kirkwood, director of the Institute for Ageing and Health at Newcastle University, said: "The key question is what might this mean for human therapies against age-related diseases? While there is some evidence that telomere erosion contributes to age-associated human pathology, it is surely not the only, or even dominant, cause, as it appears to be in mice engineered to lack telomerase. Furthermore, there is the ever-present anxiety that telomerase reactivation is a hallmark of most human cancers."

(See ‘The Guardian’, November 2010) hide this.

Heavy hydrogen (Deuterium) based organic molecules appear to withstand oxidative/free-radical damage associated with ageing (albeit only in yeast cells so far). Further work on other cells is planned. (See ‘Heavy hydrogen keeps yeast looking good’, New Scientist, 30 October 2010, p14) hide this.

This book, ‘Selling the Fountain: How the anti-aging industry made a disease of getting old – and made billions’ by Arlene Weintraub, outs the sellers of anti-ageing ‘medicine’, food for thought for anyone tempted by promises to turn back the clock. (See ‘A youthful racket’, New Scientist, 18 September 2010, p47) hide this.

The Quest for Immortality and the Youth Pill

‘Long for This World: The strange science of immortality’, by Jonathan Weiner, is a story of longevity science that centres on the enthusiastic Aubrey de Grey. ‘The Youth Pill: Scientists at the brink of an anti-ageing revolution’, by David Stipp, brings together the historical work of early immortalists with that of modern science with Harvard biologist David Sinclair as the central character. (See ‘The three ring circus of eternal life’, New Scientist, 10 July 2010, p42)

Genetic Indication of Longevity Prospects?

There are single genetic letter code variations that are more likely to be found in centenarians according to research by Boston University But these variations don’t tally with a similar Icelandic study. The jury’s therefore still out. (See ‘Live long and prosper, if your genes will let you’, New Scientist, 10 July 2010, p11)

Live Longer with an Ovarian Transplant

If you’re a mouse, female and past the menopause you can live 40% longer with an ovarian transplant. It is, however, too early to know if the few women who have had ovarian transplants will live longer. (See ‘Transplanted Youth’, New Scientist, 3 July 2010, p5) hide this.

For centuries scientists have been attempting to come up with an elixir of youth. Now remarkable discoveries are suggesting that ageing is something flexible that can ultimately be manipulated. Horizon met the scientists who are attempting to piece together why we age and more vitally for all of us, what we can do to prevent it. But which theory will prevail? Does the 95-year-old woman who smokes two packets of cigarettes a day hold the clue? Do blueberries really delay signs of ageing or is it more a question of attitude? Does the real key to controlling how we age lie with a five-year-old boy with an extraordinary ageing disease or with a self-experimenting Harvard professor? Could one of these breakthroughs really see our lives extend past 120 years?

1. Why do we Age?

This field of study is relatively new and each of us has a different opinion of what is old; will there be an answer, or even a cure, for the ageing process?

2. Diet

A couple are experimenting to see if a calorie restricted diet can help them live longer; an experiment that has worked on mice for over eighty years.

3. Anti-Oxidants

Two different professors are trying to prove that oxidative stress can cause people to age. However, their findings were not what they, or the anti-oxidant businesses, hoped for.

4. Stopping the Ageing Process

Dr Bill Andrews has worked all his life to see if it is possible to stop the ageing process. He may be one step closer after finding out what he believes to be the cause of ageing.

5. Progeria

Josiah is 5 years old and he suffers from a premature ageing disease which may prove Bill Andrews’ theory correct, although other experts don’t agree.

6. Genes vs Lifestyle

Studies of a certain group of long-living people examine how much the age of someone has to do with their genes, and how much it has to do with their lifestyle.

7. Thinking Yourself Young

Professor Ellen Langer tried to determine if age was a case of mind over matter by taking a group of over 75s and forcing them to live as if it was 20 years previous to see if they acted younger.

8. Conclusions

Is there a way to cheat the ageing process? Or does it simply come down to your genetic make-up? hide this.

Eat Your Vegetables, and Raw

Italian researchers have found that eating as little as one cup of raw vegetables daily can add two years to your life. Why raw? Cooking can deplete up to 30 percent of the antioxidants in vegetables. That said, sautéing, steaming, or blanching them is far better than not eating them at all. If you consume more than five servings of fruits and vegetables per day, you have a 26 percent lower risk of stroke than people who eat fewer than three servings, according to one British study. Try to eat as many different colors of vegetables as you can, and keep in mind that darker greens tend to contain the most vitamins and nutrients. Spinach, Swiss chard, kale, and collard greens are all excellent choices. When making salads, experiment with flavorful greens that you're not too familiar with -- watercress, for instance, which has a peppery kick. A study from the American Journal of Clinical Nutrition found that eating three ounces of watercress every day increases levels of the cancer-fighting antioxidants lutein and betacarotene by 100 and 33 percent, respectively. Just go easy on the salad dressings, which tend to be high in calories and sodium. For a healthy, easy-to-make DIY dressing, mix two parts extra-virgin olive oil with one part balsamic vinegar, and then add salt and pepper to taste.

Crack Some Shells

When Loma Linda University researchers tracked the lifestyle habits of 34,000 Seventh-Day Adventists -- a population famous for its longevity -- they discovered that those who munched nuts five days a week earned an extra 2.9 years on the planet. Not surprisingly, nuts are one of the healthiest snacks you can have. High in monounsaturated fats and protein, they help keep your arteries clean and your stomach feeling full. Eat two handfuls a day as snacks betweens meals. Almonds are especially good for their high doses of vitamin E and magnesium, but walnuts are a good alternative because they contain more heart-healthy omega-3s and pack half as much protein as chicken. Or you can opt for Planters NUT-rition Heart Healthy Mix, which contains six key nuts, including almonds and walnuts. Just remember to always opt for raw, unsalted nuts. Smoking and salting increases the sodium content, which can have a negative impact on your blood pressure. Be especially wary of macadamia nuts. Though a great source of monounsaturated fats, they're often covered in salt.

Check Your Belly

The fat you carry today could kill you tomorrow. University of Alabama researchers discovered that maintaining a body-mass index of 25 to 35 can shorten your life by up to three years. BMI is a simple calculation of a person's weight-to-height ratio that doctors often use to determine a person's health risk. According to the National Institute of Health, a BMI of 19-24.9 is normal, 25-29.9 is overweight, and 30 or greater is obese. Excess body fat raises your risk of diabetes, heart disease, stroke, and colon cancer and, unfortunately, the bad news doesn't even end there. As a man's waist size goes up, his testosterone goes down. In one landmark 2007 study, men with a 5-point increase in BMI -- about 30 extra pounds on a 5'10" guy -- had testosterone levels comparable to men who were a full decade older. Women need to watch their BMI, too. A study published in the International Journal of Obesity found that nearly a third of young women with a normal BMI still carry excessive body fat. Research also suggests that gaining more than 20 pounds from age 18 to midlife doubles the risk of post-menopausal breast cancer. Calculate your BMI using an online calculator. To improve your score, try circuit training-a conditioning technique that combines the best aspects of strength training and cardio into a single activity by having you move from one weightlifting station to the next without rest. Then persuade your significant other to join. A Duke University study showed that sedentary people are 50 percent more likely to work out three times a week if their partners participate.

Invite Your Friends Over

Chronic stress weakens the immune system and ages cells more quickly -- ultimately shortening life-spans -- but friendships can act as a buffer against stresses of everyday life. When Australian researchers looked at seventy-somethings, for instance, they found that those with the largest network of friends had the longest lease on life. For the average person, this could add up to seven additional years. But acquaintances aren't friends: You need people you can openly confide in. In a survey conducted jointly by Duke University and the University of Arizona, sociologists learned that women today report having an average of only two close confidants, down from three in 1985; nearly a quarter of the women surveyed reported having no one at all in whom they could confide. So say "hello" to the neighbor you've never met, invite your closest friends over for game night, and then maintain rituals, whether it's a simple weekly Sunday night phone call or a yearly stay in a beach villa.

Find a Happy Place

In a Yale University study of older adults, people with a positive outlook on the aging process lived more than seven years longer than those who felt doomed to deteriorating mental and physical health. If you're outlook has some room for improvement, give back to your community by volunteering or mentoring-selfless actions that distract from unhealthy obsessing, according to studies. In addition to helping others, don't forget to care for yourself. Make yourself happy by doing the activities you enjoy most-whether it's going to the spa for a facial, drinking green tea (which is loaded with antioxidants in the evening), or hitting the links. Golf even has a life-extending effect, according to a Scandinavian study, because it engages people in a stress-reducing social activity, gets them outside for several hours, and makes them walk the equivalent of four miles. hide this.

Avoiding life-shortening ‘environmental’ factors is one thing but, as we get older and survive these, genes become the key and the prospects for understanding what sets one set of genes apart from another are brightening. (See ‘Lessons in longevity’, New Scientist, 5 September 2009, pp42/45) hide this.

Restricting calorie intake has now been demonstrated to increase lifespan in worms, flies, mice and now primates. So it is likely to work for humans too. (See ‘Anti-ageing diet works in monkeys’, New Scientist, 18 July 2009, p16) hide this.

Maintaining vitamin D levels has to be the easiest and cheapest way to improve your health and increase your life expectancy.

Life expectancy can be increased by just hanging out with your friends and family.

Improve your life expectancy with a commitment to daily exercise.

The fact that flossing daily can extend life expectancy falls in the weird-but-true category.

Your life expectancy may be increased through having more sex.

Life expectancy can be linked to three factors that vegetarians excel at: fewer bad fats, more antioxidants and lower weight. What we mean is the person who is eating lots of vegetables prepared in healthy fats (such as olive oil) while limiting animal products, such as cheese and cream.

Learn to relax through destressing techniques or meditation to keep your life expectancy up where it should be.

Preventing diseases (or catching them early) is probably the single best way to add years to your life expectancy.

Watching TV makes you inactive. TV makes you eat more junk food. TV makes you antisocial. TV is stressful. TV keeps you from doing other things.

Life expectancy can be protected by making sure that you don't take any unnecessary risks. hide this.

It’s a bit like a scene from a movie: the elderly scientist, working late in the lab, takes a sip of potion from a bubbling flask and undergoes a miraculous transformation as his body regains its youth and vigour. Pure fantasy? Maybe not – because that’s pretty much what happened to elderly laboratory rats when they were fed two dietary supplements in a recent landmark study. According to the professor in charge of the study, ‘the old rats became so full of energy, they got up and did the Macarena’!

Over the last 18 months, scientific interest in alpha lipoic acid (ALA) and acetyl L-carnitine (ALC), the two supplements used in the studies, has exploded and a large number of studies are now under way with humans. Initial results look encouraging, but what are the implications for athletes – and can these nutrients be harnessed to improve performance?

Some readers may be familiar with the amino acid carnitine, which carries fatty acids into the mitochondria (the cellular furnaces), where they are ‘oxidised’ for energy. As its name suggests, acetyl L-carnitine (ALC) is very similar, consisting of the same basic amino acid structure, with an acetyl group attached. In the body, acetyl L-carnitine is synthesised from L-carnitine by the enzyme carnitine acetyltransferase. Although levels tend to decrease after the age of 40, acetyl L-carnitine (ALC) is not normally considered an ‘essential nutrient’ because the body can manufacture all it needs.

One of the main roles of acetyl L-carnitine (ALC) is to carry fatty acids from the cytosol (the main body of the cell) into the mitochondria (the energy-producing furnaces within cells) so that these fats can be oxidised for energy. Although L-carnitine carries out this role too, acetyl L-carnitine (ALC) also provides acetyl groups, from which acetyl-coenzyme A (a key metabolic intermediate) can be regenerated, thereby facilitating the transport of metabolic energy and boosting mitochondrial activity.

The addition of the acetyl group also endows acetyl L-carnitine (ALC) with a greater solubility in water, which enables it not only to diffuse easily across the inner wall of the mitochondria and into the cell cytosol, but also cross cell membranes in general more easily. In plain English, acetyl L-carnitine (ALC) reaches parts of the body that L-carnitine just can’t reach! In addition to its role in mitochondrial activity, acetyl L-carnitine (ALC) is involved in the production of the key brain neurotransmitter acetylcholine and is also able to donate its acetyl group in a number of other biochemical reactions.

Alpha lipoic acid (ALA) is a sulphur-containing antioxidant, which occurs naturally, in small amounts, in such foods as spinach, broccoli, beef, yeast, kidney, and heart. alpha lipoic acid (ALA) is readily soluble in water and fat, enabling it to exert an antioxidant effect in almost any part of the body, including the brain. In the mitochondria, alpha lipoic acid (ALA) can act both as an antioxidant, capable of recycling other antioxidant nutrients such as vitamin C and vitamin E, and as a coenzyme for key metabolic enzymes involved in energy production. In addition to its role as an antioxidant, alpha lipoic acid (ALA) also raises the levels within cells of a substance called glutathione, which is critical for neural function, and aids in glycolysis, the first stages of breaking down carbohydrates for energy.

The initial excitement about ALC/alpha lipoic acid (ALA) supplementation began when a team of researchers in California fed elderly rats both nutrients for a period of seven weeks and then compared them with young rats. They were testing the theory that mitochondrial decline is caused by freeradical damage (see panel opposite). There was already evidence that supplementation with acetyl L-carnitine (ALC) could reverse the age-related decline in mitochondrial activity in rats, increase fatty acid oxidation and boost general metabolic activity. However the down side to this increased mitochondrial function was that more oxidative damage occurred, so the researchers decided to add the powerful mitochondrial antioxidant alpha lipoic acid (ALA) to the mix to see if they could get the best of both worlds: increased mitochondrial energy output, with reduced mitochondrial damage.

This two-pronged ‘punch’ to ageing cells seemed to work, with the two supplements together producing better results than either one alone. After a month on the supplements, elderly (24-month-old) and lethargic rats had more energy and did better on memory tests, while their mitochondria worked better. The decline in overall activity typical of aged rats was reversed to the level of young-to-middle-aged adult rats, aged 7-10 months. The researchers likened this result to a group of 80-year-old humans throwing away their walking sticks and starting to act 35 years younger!

The implications for human health

These studies on rats caused a huge stir within the scientific community. Here was evidence that some of the processes of ageing could be slowed or even reversed, and the implications for human health and performance were enormous. In the months that followed, a number of human studies were started, many of which are still under way.

However, the question of whether the benefits observed in rats might also apply to humans will not be easy to determine. For one thing, the ageing process in humans is much slower than in rats, so the seven-week supplementation period used in the rat studies would equate to around five years of supplementation in humans! Secondly, the amounts of acetyl L-carnitine (ALC)/alpha lipoic acid (ALA) used in the rat studies were very high – equivalent to 50g per day of acetyl L-carnitine (ALC) and 5g of alpha lipoic acid (ALA) for an 11-stone adult. That’s around 50 times more than is typically available in acetyl L-carnitine (ALC)/ALA supplements found on the shelves of most health food stores!

One of the earliest studies examining the effect of acetyl L-carnitine (ALC) and alpha lipoic acid (ALA) in humans was carried out at San Francisco State University in 2001. In a double-blind, placebo-controlled study lasting 17 weeks, 18 healthy sedentary men aged 60-71 were randomised to one of two treatment régimes: a placebo tablet twice a day or 1,000mgs of acetyl L-carnitine (ALC) and 400mgs of alpha lipoic acid (ALA) in two divided doses. Both groups were then asked to perform a demanding sequence of exercises, after which blood was drawn and analysed for signs of exercise-induced oxidative stress (a potentially damaging by-product of energy production). To measure oxidative stress, the study evaluated nine different biomarkers: ammonia, beta-carotene, glutamine, glutathione, malondialdehyde, total antioxidant status (TAS), vitamin C, vitamin E-alpha tocopherol, and vitamin E-gamma tocopherol. For eight of these nine biomarkers, a majority of subjects in the treatment group recorded values indicating that levels of oxidative stress had fallen. By contrast, no such benefits were reported in the placebo group.

If an acetyl L-carnitine (ALC)/alpha lipoic acid (ALA) combination can reduce exercise-induced oxidative stress, that would be good news for athletes, who are particularly vulnerable to such stress. However, because the small scale of this study made it difficult to reach statistically significant conclusions, the results were not submitted for scientific publication, which means they should be interpreted with caution.

Other human studies are also currently under way, but so far there are no published human studies available, although positive studies in animals continue to proliferate. Last year, for example, American researchers demonstrated that alpha lipoic acid (ALA) supplementation in older racehorses reduced the oxidative stress burden even under light training loads, while a number of other animal studies have shown that acetyl L-carnitine (ALC)/ALA supplementation reduces oxidative stress and improves mitochondrial function in a number of tissues, including brain, muscle and heart.

In one of these studies, researchers examined the effects of acetyl L-carnitine (ALC)/alpha lipoic acid (ALA) therapy on ageing and hearing in rats, and found that it reduced the normal age-associated deterioration in auditory sensitivity and improved inner ear function. They concluded that these improvements were related to the acetyl L-carnitine (ALC)/ALA combination’s ability to protect and repair age-induced mitochondrial DNA damage, thereby boosting mitochondrial function and improving energy turnover. However, while the initial evidence from animal studies looks extremely promising, the jury is still out as far as humans are concerned.

THE THEORY OF MITOCHONDRIAL DECLINE AND AGEING

The free radical theory of ageing is based on the idea that our cells and DNA (the latter containing the code for proper cell division and replication) eventually become irreversibly damaged by the onslaught of highly-reactive chemical species called ‘free radicals’. These transient species are generated unavoidably as a by-product of aerobic (oxygen) metabolism. In other words, while oxygen provides us with the energy for life, it’s also responsible for generating highly damaging chemical species that cause biochemical havoc within the cells of our bodies. The mitochondrial decline theory of ageing takes this process one step further. Mitochondria are the energy-producing furnaces in the body, whose job is to make adenosine triphosphate (ATP), the energy currency of life, by burning fuel in the presence of oxygen. But this process inevitably leaves the mitochondria themselves subject to very high levels of damaging free radical attack by reactive oxygen species. Mitochondria lack many of the defence systems found in other parts of the body, so they decline in number and efficiency with age, leading to a corresponding decline in ATP production. Reduced ATP means less energy to fuel the vital life-sustaining processes of the body, which can result in the onset of a number of disease states and processes.

For athletes in hard training, the prospect of preventing or even reversing some of the age-related decline in physical performance is enticing, holding out the promise of longer careers, including more sustained levels of peak performance. However, as is so often the case with new and unfolding nutritional research, it is difficult to make hard and fast recommendations about the benefits of supplementation.

The first thing to point out is that dietary manipulation to boost these nutrients is not an option. Although alpha lipoic acid (ALA) and acetyl L-carnitine (ALC) are present in some foods, the amounts are very small by comparison with those used in human studies. To boost these nutrients, therefore, it is necessary to take supplements.

Secondly, it’s important to realise that even if the ALA/ALC combination is eventually proven to slow down or reverse mitochondrial decline, the evidence suggests this will not lead to sudden and dramatic improvements in performance. Like the antioxidant phytochemicals in fruit and vegetables and the antioxidant vitamins and minerals, alpha lipoic acid (ALA)/acetyl L-carnitine (ALC) is most likely to offer a long-term investment for your health.

If you are tempted to ‘jump the scientific gun’ and supplement these nutrients anyway, the good news is that they appear to be relatively non-toxic, even at very high doses. The only caveat is that alpha lipoic acid (ALA) in high doses is known to enhance sensitivity to insulin, which could lead to a drop in blood sugar. For this reason, it should be taken with food.

The bad news is that alpha lipoic acid (ALA) and acetyl L-carnitine (ALC) are not particularly cheap, and athletes need to ask themselves whether that expenditure could be more effectively allocated to improving the basic quality of their diet. As yet, there is no clear guidance on what the optimum or most cost-effective intake of alpha lipoic acid (ALA)/acetyl L-carnitine (ALC) might be. The altitude sickness study used 600mgs of alpha lipoic acid (ALA) per day, while studies showing that acetyl L-carnitine (ALC) improves brain function in Alzheimer’s patients have used between 1,500 and 3,000mgs per day. However, the human study carried out in San Francisco, which used 400mgs of alpha lipoic acid (ALA) and 1,000mgs of acetyl L-carnitine (ALC) per day, was overseen by the same team that carried out the initial rat studies, so that might be a good place to start.

One final point: don’t confuse acetyl L-carnitine (ALC) with L-carnitine. While it is considerably cheaper, L-carnitine does not have the same bioavailability as acetyl L-carnitine (ALC) and has not been used in studies on mitochondrial decline. And while L-carnitine has often been promoted as a popular ‘fat burning’ and endurance supplement, there is actually very little evidence for this in the scientific literature. But that’s another story! hide this.

Scientists have rejuvenated ageing rats by giving them a cocktail of dietary supplements. The breakthrough raises hopes that it might one day be possible to develop an anti-ageing drug for humans. The researchers gave a combination of two natural chemicals available in health food stores to the animals - which were in the rat equivalent of their seventies. Lead researcher Dr Bruce Ames, of the University of California at Berkeley, said the results were astonishing. He said: "With the two supplements together, these old rats got up and did the Macarena. The brain looks better, they are full of energy - everything we looked at looks more like a young animal." The animals' memories were also significantly improved. The researchers estimate that the effect on the rats was the equivalent making a 75 to 80-year-old person act middle-aged.

Found in the body

The chemicals used in the experiment were acetyl-L-carnitine and alpha-lipoic acid, both of which are normally found in the body's cells. Acetyl-L-carnitine is sold as an energy-booster and alpha-lipoic acid as an antioxidant with anti-ageing effects. The combination of the two chemicals has now been patented by the University of California. A company set up to exploit the patent, Juvenon, is already conducting human clinical trials. Three research papers on different animal studies of the chemicals have been published in the journal Proceedings of the National Academy of Sciences. The studies probed the biochemical action of the supplements, compared the behaviour of old and young rats, and tested the memory of animals fed the compounds.

Cell power house

The researchers found that the two chemicals in combination have a positive impact on mini-organs within the body's cells called mitochondria. Mitochondria generate energy within the cells, and research has suggested that their deterioration is an important cause of ageing. The problem seems to be that the very process of creating energy generates molecules called free radicals, which have a deeply destructive effect on the way cells work. The supplement combination was found to mop up the free radicals in mitochondria. It also boosts the activity of an enzyme fundamental to the energy-creating process. The research also showed that mitochondria in brain cells important to memory were less damaged by radicals in animals fed the supplements.

Important research

Caroline Bradley, of the charity Research into Ageing, told BBC News Online that the study was clearly important. She said: "The big step forward is that they have found a way of getting anti-oxidant into the mitochondria itself. Getting past the mitochondrial membrane has been the main challenge.” She added that it was early days for the research but that it was the first step towards improving human health in later life. However, Professor David Colquhoun, an expert in pharmacology at University College London, said "Before rushing out to the local health food shop, perhaps people should bear in mind that this treatment has not yet been shown to be effective in humans, and neither has it been shown to be safe. The fact that the substances are naturally occurring does not guarantee their safety when they are given in unnatural doses. Even on the rats that they tested, any effects on memory are relatively small, though results in the water maze test might be interpreted as meaning that old rats can see or swim or cope with stress better after treatment. There is also no real reason to think that the two compounds work better together that separately on these tests. This may be an interesting lead, but only time will tell if it really works.” hide this.