Eat isotopes, live longer...
This is the promise of a researcher at Oxford University who says that adding natural isotopes to your steak or chicken fillet could increase your life expectancy by 10 years. In "Meat and two neutrons -- the key to a longer life," the Society of Chemical Industry explains that "scientists have shown for the first time that food enriched with natural isotopes builds bodily components that are more resistant to the processes of aging." But I have serious doubts about this claim. First, this experiment has only been done on worms which saw their life spans extended by 10% when exposed to nutrients reinforced with natural isotopes. How can this concept be adapted to us? Then, this research work has been endorsed and published by Aubrey de Grey, the very well-known but controversial gerontologist.
Let's start by looking at the facts.
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.
But can these natural isotopes be well tolerated by our organisms? In "Eat isotopes to live longer," Michael Gross answers in Chemistry World (March 22, 2007).
Heavy water (D2O) is toxic to higher organisms, but Shchepinov argues that isotopes would only be incorporated in the sites that need to be protected from oxidation. 'Ideally, they will slow down the oxidation reaction so much that they will never be released to take part in other reactions. If some of them do break free, they will only occur in small concentrations,' he said.
David Meredith, who investigates the metabolism of amino acids at the University of Oxford, warns that some of the heavy isotopes could get into general circulation. 'It would be impossible to ingest exactly the right amount and mix of amino acids that the body required for protein synthesis,' he said.
Of course, other scientists think that small amounts of deuterium would be tolerated in the body. Anyway, this research work has been published in Rejuvenation Research edited by Aubrey de Grey, under the name "Reactive Oxygen Species, Isotope Effect, Essential Nutrients, and Enhanced Longevity" (March 2007, Volume 10, Number 1, Pages 47-60). Here is a link to the abstract which is reproduced below.
A method is proposed that has the potential to lessen detrimental damages caused by reactive oxygen species (ROS) to proteins, nucleic acids, lipids, and other components in living cells. Typically, ROS oxidize substrates by a mechanism involving hydrogen abstraction in a rate-limiting step. The sites within these (bio)molecules susceptible to oxidation by ROS can thus be "protected" using heavier isotopes such as 2H (D, deuterium) and 13C (carbon-13). Ingestion of isotopically reinforced building blocks such as amino acids, lipids and components of nucleic acids and their subsequent incorporation into macromolecules would make these more stable to ROS courtesy of an isotope effect. The implications may include enhanced longevity and increased resistance to cancer and age-related diseases.
So will this method be used one day? As Nick Bostrom, director of the Future of Humanity Institute at Oxford University, said to Chemistry World, "I don't expect this method to furnish the elixir of life. Don't stop eating your vegetables just yet."
If you have any thoughts about this method, drop me a note -- my e-mail address is on the right sidebar.
Sources: Society of Chemical Industry news release, March 25, 2007; and various websites
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