Eating heavy to live up to 30% longer.

In a back room of New Scientist's offices in London, I sit
down at a table with the Russian biochemist Mikhail Shchepinov. In
front of us are two teaspoons and a brown glass bottle. Shchepinov
opens the bottle, pours out a teaspoon of clear liquid and drinks it
down. He smiles. It's my turn.

I put a spoonful of the liquid in my mouth and swallow. It tastes
slightly sweet, which is a surprise. I was expecting it to be exactly
like water since that, in fact, is what it is - heavy water to be
precise, chemical formula D₂O. The D stands for deuterium,
an isotope of hydrogen with an atomic mass of 2 instead of 1. Deuterium
is what puts the heavy in heavy water. An ice cube made out of it would
sink in normal water.

http://www.newscientist.com/article/mg20026841.800-would-eating-heavy-atoms-lengthen-our-lives.html?page=1