Everyday compounds like caffeine and paracetamol extend life expectancy. At least, they do if you're a nematode. Paracetamol in particular is an effective life extender, discovered researchers at Mount Sinai School of Medicine. The painkiller extended the lifespan of the tiny lab animal Caenorhabditis elegans by 66 percent.
In all rich and almost-rich countries scientists are searching for substances that can help us to live longer and keep us fit and healthy too. Five years ago the Howard Hughes Medical Institute, after screening 80,000 compounds for life-extending properties, published on the longevity-effect of substances such as mianserin, which boosts the concentration of serotonin in the brain. [Nature. 2007 Nov 22;450(7169):553-6.] The substances extend the lifespan of nematodes by about twenty percent. The researchers also found compounds that extended the lifespan of the nematodes by sixty percent, but they maintained a stony silence about these.
Studies similar to those done by the Howard Hughes Medical Institute show that there is a relationship between brain cells and life span. The researchers at Mount Sinai base their work on these. For thirty compounds which inhibited in vitro the aging of brain cells as a result of glucose, they examined which ones had a life-extending effect on nematodes. It was already known that nematodes live less long if you give them glucose. [Cell Metab. 2009 Nov;10(5):379-91.]
The researchers scored a hit with six of the substances: caffeine [in the figure below 3], paracetamol , tannic acid , the anti-fungal ciclopirox-olamine, the antibiotic bacitracin and the flavone baicalein all helped the nematodes to live longer. The first three substances are ones that most people consume regularly. Tannic acid is a compound that the food industry uses often. Baicalein is available on the market in Japan as a liver-protection supplement.
The researchers mixed the compounds into the food substrate that the nematodes received, and then recorded how long the animals lived. The nematodes in the vehicle group were not given any compounds. Paracetamol was the most effective.
The researchers tested the compounds on normal nematodes [N2] and genetically modified nematodes in which a few crucial molecules had been deactivated.
In the nematodes in which the Crebs-binding protein molecule had been deactivated [cbp-1 (RNAi)] paracetamol no longer worked. This was the case with all of the life-extending compounds. That's probably not a coincidence, the researchers think. They believe that substances that activate Crebs may be effective life-extenders.
PLoS One. 2011;6(11):e27762.