What makes people prone to quacks

People long for eternal youth - as far back as we can look back - and they have always fallen for charlatans and quacks who sell pills and juices for sale against old age. But there has always been a serious search for rejuvenating agents. Gold in particular was considered an elixir for a long life in the Middle Ages.

Recently, however, the offerings of so-called anti-aging medicine have become questionable, and young and old are taking advantage of the most tempting promises of fitness en masse. A now almost unmistakable range of allegedly scientifically based cures and remedies of all kinds is entering the market, with the Internet making customer contact even easier for profitable providers.

We are watching this development with concern. That is why we have decided, together with a large number of our colleagues from aging research, to publish a warning statement. People should know that, according to all scientific findings, not a single one of the measures marketed today is suitable for slowing down, stopping or even reversing natural aging. Some of the advertised methods can even be dangerous. Many biologists who intentionally research the causes of aging hope to actually find ways and means that delay the aging process. As a result, frailty would set in later in old age and a good quality of life would be maintained for longer. However, anyone who claims today that they have such products ready is either wrong or they are deliberately lying. In the essay printed here, we three authors present our own point of view.

The term "aging" is not used consistently. By this we understand that over the years, random damage accumulates in the building blocks of life, especially in the genetic material, proteins, carbohydrates and lipids. This happens from youth on, but at some point the self-repair mechanisms of the organism can no longer cope with the defects. Gradually, this impairs the functions of cells, tissues, organs and organ systems, which on the one hand makes the organism more susceptible to disease, on the other hand it causes the typical aging phenomena and loss of performance. These manifest themselves, among other things, in the loss of muscle and bone mass, in a decline in the speed of reaction, as well as in vision and hearing, and in reduced skin elasticity.

The causes for the defects in the biological molecules are diverse. In a tricky way, the life-sustaining processes of energy generation also apparently play a part in this. During regular cell respiration, highly aggressive oxygen radicals are created in the cells' power stations, the mitochondria. For the most part, the cells repair the damage caused by these so-called free radicals - just not always. Biologists suspect that the oxygen radicals gradually irreparably impair the genetic make-up of the mitochondria and thus cell respiration. After all, the cells can no longer maintain the regular interaction of countless molecules for important body functions. In addition to the mitochondria, the free radicals are also likely to attack other locations in the cells.

Aging and old age diseases are two different things

It is true that aging, understood in this sense, makes people more susceptible to certain diseases, such as certain heart conditions, Alzheimer's disease, stroke or cancer. However, these diseases are only side effects that must not be equated with the aging process itself. Because even if the typical diseases of old age - which are the leading causes of death in industrialized countries today - were to be prevented one day, the process of aging would not have disappeared. The current illnesses of the elderly would be replaced by others. And due to aging, physiological functions, such as the circulatory system, would definitely break down. The biological truth is that the machinery of life, once started, inevitably lays the seeds for its own destruction.

The fact that we are living much longer in industrialized countries than ever in human history does not change that. In earlier centuries people lived on average only about 25 years old. Today, however, life expectancy for men in industrialized nations is around 75 years and for women 80 years, and it is likely to increase further in the future. We owe much of this to the containment and control of infectious diseases with vaccinations, better hygiene and antibiotics.

We live longer today not because we age differently, but because we live differently. Although the process is inevitable, there is no genetic program for aging. The mechanisms of evolution would not even allow a selection of special genes for physiological degradation according to a precise time schedule. There are also no genes that determine lifespan.

Genes create the prerequisites for their being passed on to the next generation by ensuring that the fertilized egg cell becomes an individual that reproduces. Any genetic variant that prevented this would of course do its own thing. In contrast, the evolutionary mechanisms are to a certain extent blind to gene effects after the fertile one

Lifetime, completely irrelevant whether these harm or benefit the organism or are simply irrelevant. That is why genes or gene variants that have a devastating effect on the organism after the end of the reproductive phase of life can quite often be represented in the population - but only if they fulfill an important function at a younger age. For example, some genes involved in cancer are involved in growth and development processes in the young organism.

Of course, a lot of hereditary factors influence aging, but this happens indirectly. To a certain extent, aging is a marginal phenomenon of the processes that ensure growth and development, the maintenance of health and vitality. And because there is no genetic program for aging and dying, the aging process does not offer medicine any clear areas of attack in order to be able to act against it as against a disease. Even with a single genetic intervention, for example, it would hardly be possible to achieve a victory against aging in an organism as complex as humans. Too many genes and biological processes play a role, each of which makes the tiniest, often unpredictable, contributions.

Beware of false prophets

Nonetheless, some scientists believe that they could someday succeed in slowing down the aging of humans. If successful, many would live longer as a result than under today's conditions. Individuals could even break the current age record of 122 years. But this goal should not be a priority in the research. It is not the life itself that needs to be extended, but the phase of healthy life. If aging was postponed, frailty and old-age diseases would set in later - people actually stayed young longer.

What is the basis of our claim that none of the currently advertised treatments has been scientifically proven to have the desired effect? In order to determine whether a measure influences a biological process, one must first be able to measure the process itself somehow. But aging, the degree of aging, has not yet been able to be measured due to the lack of an indicator. Neither in animals nor in humans has found anything that turned out to be suitable, no single sequence and no interlinked processes. Without such a reference, statements about treatment success are simply not possible.

Some people who care about staying young or feeling fresher again may well recognize this shortcoming. But if you think that you can't lose anything by trying one or the other anti-aging procedure anyway, you should think twice about it. For example, when it comes to the popular dietary supplements that are readily available in many places, the US Food and Drug Administration does not require the same stringent safety and efficacy tests as it does for drugs. The products therefore guarantee neither purity nor active ingredient content, the dosage does not follow tried and tested guidelines, and there are often no indications of drug interactions. In Germany, at least the criteria for classification as a dietary supplement are stricter.

Antioxidants are one of the most popular anti-aging substances. These compounds are also found naturally in the body and in plant-based foods. It is believed that they neutralize free radicals. Proponents recommend adding antioxidants because, given in sufficient quantities, they are designed to scavenge the aggressive compounds and thus supposedly slow down or prevent aging. Only - if all free radicals were fished out, we would die. They are indispensable for intermediate steps in biochemical reactions in cell communication and immune defense, among other things. In addition, epidemiological studies have shown that vitamins E and C, which are touted as antioxidants, can reduce the risk of cancer if they are taken from food. The same was found for some other diseases, such as macular degeneration, a retinal breakdown phenomenon that is common in old age. However, it has not yet been proven whether vitamin supplements can do something similar, whether they delay aging and limit damage caused by free radicals.

There is also much demand for hormone replacement, which is also based on entirely plausible considerations. In the early 20th century, attempts were made to transfer goat or monkey testicles or to administer testicular extracts to maintain virility. Today, as for other indications, pure hormones are available for this. In principle, hormone substitution in the elderly may seem reasonable. The blood levels of most of these substances, such as melatonin, growth hormone, testosterone, and dehydroepiandrosterone (DHEA), tend to decrease with age. It has been proven, for example, that the administration of growth hormone has beneficial effects in the short term in older men in various ways, particularly on muscle mass and skin elasticity.

Hormone replacement cannot stop aging

But added hormones can also have serious side effects. If melatonin is administered to mice, this increases their risk of cancer. If you get them to produce a lot of growth hormone, kidney damage and early heart and lung failure occur. The rodents die prematurely. Some people who were given growth hormone as adults had external parts of their body that grew, a phenomenon called acromegaly, or they had carpal tunnel syndrome, in which the forearm nerve in the wrist becomes too squeezed. Estrogen replacement after menopause can definitely improve the well-being of some women. However, this measure is also controversial because it increases the risk of breast cancer and thrombosis, for example. Hormone replacement may be appropriate to treat certain age-related disorders. However, there is no evidence that the hormone administration is delaying aging.

But what about a healthy diet and regular exercise? The health organizations strongly recommend both. But is there a natural fountain of youth hidden here? What is certain is that exercise and a sensible diet reduce the risk of many diseases and thus help many people to live longer and healthier lives. Still, we have to disappoint our readers: there is no evidence that such behavior itself postpones aging.

It seems absurd to us that especially at this time when aging research is making significant progress, the market for dubious anti-aging products is booming. Researchers succeeded in genetically manipulating yeast cells, roundworms, fruit flies and mice so that the organisms lived longer. However, an important characteristic of the aging phenomenon is that the risk of death in a population increases exponentially depending on the time after puberty. However, the genetic interventions had no influence on this, so it is not certain whether they really changed the aging process. However, further studies on the genes concerned could reveal the background to longevity and thus open up opportunities to postpone frailty and old-age diseases.

A real delay in aging could come from research into a highly reduced calorie diet. Scientists have been testing the method on animals for decades. In all tested species, including monkeys, the animals die later and stay healthy longer on average if they receive at least a third fewer calories than they would eat on their own - provided they get the nutrients they need for bodily functions. One can assume that such a diet would also have a similar effect on human life. But hardly anyone will want to restrict their meals so strictly. That is why biologists are now investigating the metabolic mechanisms on which the effect is based. The researchers want to imitate these so that people can benefit from the effects without having to go hungry.

Many scientists are optimistic about current developments in aging research. In their view, one day it will actually be possible to slow down the process. They also expect to repair and rejuvenate tissue with stem cells that are still unspecialized. But not all researchers share this confidence. In their view, because of its complexity, the aging process will oppose all antiaging therapies forever.

Only one thing is certain: the number of old people is growing worldwide, and many people are looking to enrich themselves with products against aging. When we and nearly fifty colleagues signed the statement for the Scientific American website, we put small disagreements aside in the interests of the matter. Not all of us can agree to every formulation of the text, but this is secondary. We want to wake up the public. Everyone should know that the alleged anti-aging agents and treatments have not been scientifically proven to be effective. On the other hand, such products can be very harmful. It may be that research on aging will one day enable treatments to slow the inexorable decline in old age. But that day is not yet in sight.

From: Spektrum der Wissenschaft 8/2002, page 68
© Spektrum der Wissenschaft Verlagsgesellschaft mbH

This article is included in Spectrum of Science 8/2002