The Longing For More

Photo: Cauliflower, green and red cucumber, carrots

Permanent diet to prolong life:
theoretically yes, practically no;
© SXC

Can life be stretched like chewing gum? Since the 1950s, a huge group of researchers considers ageing primarily as the sum of damages occurring in an organism in the course of time meaning that the ageing process could in fact be delayed or at least be slowed down if damages could be prevented.

Already in 1936, it was shown for the first time: when rats were put on a strict diet with 30 to 50 percent less calories, their lifetime extended by 20 to 30 percent in laboratory tests. This also worked with mice and worms in later experiments. If these results can be applied on humans – what again is not proven so far - this implies: „The ones starting a permanent diet with 50, will feel like 70 at the age of 80“, Andreas Simm, gerontologist and research director in the University Clinic and Polyclinic for Cardiac and Thoracic Surgery in Halle, explains.

The explanation for such an effect: Converted food to energy in the body gives rise to a by-product, the so-called free radicals. These radicals would in turn attack the genes and, thus, be responsible for the ageing process. This permits the reverse conclusion that the consumption of less food would result in less free radicals and therefore would slow down the ageing process.

Contradictory results

This has been observed in mice: Rodents with a defective DNA whose repair mechanism did not function any more did grow old faster. „The damage to the genes seemed to be linked to the ageing process. Everybody was happy, the damage theory seemed to be correct“, Simm explains. However, when the amount of free radicals was measured in these mice the researchers observed something surprising: the levels were not raised.

„A few years ago, scientists found out that an organism uses energy more efficiently with a reduced calorie intake: Mitochondria which convert food to energy increase their activity during a diet,“ explains Michael Ristow, Professor for nutritional medicine in Jena. This means that a cell needs to become used to a reduced calorie supply in order to diminishes mitochondria activity again. Before this happens, more free radicals are produced instead of less.

Most recent research results, therefore, contradict the original theory of free radicals. „Free radicals should not be as vilified as they once were“, Ristow reasons. „Chronically high amounts of free radicals are certainly harmful. But short-term increased radical production has a positive effect.“

Worms put on diet

Ristow used worms with a life expectancy of about one month in order to test his theory. He assumed that a „hormesis effect“ may take place. „Hormesis“ refers to the converse, positive effect that small amounts of harmful or toxic substances can have on an organism. And indeed: Whenever the amount of radicals was increased in the worms, protective enzymes were increasingly produced. Therefore, Ristow is convinced that the reduced food intake increases the short-term activaty of mitochondria - more radicals are being produced. These radicals not only damage the genotype, but also activate protective enzymes which in turn improve the body’s defences. „The balance is positive“, according to Ristow. He believes this to be the reason why organisms live longer when they eat less.

The conclusion for us: Eat crispbread and cucumbers only and become 100? The answer for Simm is No. "This would be a dangerous conclusion." In the end, the experiment so far only works with animals under laboratory conditions, far away from the real world. In the wild, a starving mouse would surely die quicker being too slow and an easy prey. „Most people would not be able to keep up a permanent diet anyway, and if, then they would get a psychological problem: they would think of food all the time“, Simm adds. And there is another small side effect: a continuous diet makes infertile.

Anke Barth
MEDICA.de