A method of using isotopes to make bonds in the body more resistant to free radical damage could lengthen human lives by 10% or about 10 years. It does not reverse free radical damage, so it would be less helpful to older people.
A team led by Mikhail Shchepinov, formerly of Oxford University, fed nematode worms nutrients reinforced with natural isotopes (naturally occurring atomic variations of elements). In initial experiments, worms' life spans were extended by 10%, which, with humans expected to routinely coast close to the centenary, could add a further 10 years to human life.
Food enhanced with isotopes is thought to produce bodily constituents and DNA more resistant to detrimental processes, like free radical attack. The isotopes replace atoms in susceptible bonds making these bonds stronger. 'Because these bonds are so much more stable, it should be possible to slow down the process of oxidation and ageing,' Shchepinov says.
The isotopes could be used in animal feed so that humans could get the "age-defying" isotopes indirectly in steaks or chicken fillets, for example, rather than eating chemically enhanced products themselves. Shchepinov says an occasional top-up would be sufficient to have a beneficial effect.
Ageing experts are impressed with the isotopic approach. Aubrey de Grey, the Cambridge-based gerontologist, says it could be very relevant to the rates of several chemical and enzymatic processes relevant to ageing 'It is a highly novel idea,' he says. 'But it remains to be seen whether it can be the source of practicable therapies, but it is a prospect that certainly cannot be ruled out.'
Doctors have rejuvenated post-heart attack patients by injecting them with stem cells. Hare and his team injected intravenously 53 patients within 10 days of a heart attack. They randomly assigned patients different doses (0.5 million 1.6 million or 5.0 million cells per kilogram) and compared the dosages with a placebo.
Over six months, the patients receiving the stem-cell treatment had better heart and lung function with fewer arrhythmias.
Echocardiography also showed better heart function, especially in patients with greater heart damage.