Here’s your chance to get in on the ground floor – at least, the ground floor of a pitch you probably haven’t heard before. The chemists and biologists in the crowd will be familiar with how isotopic enrichment takes place in biological systems. Bonds between heavier atoms are slightly harder to break, making the rate constants of those reactions a bit slower than otherwise. The deuterium isotope effect (versus plain hydrogen) can be large enough to take advantage of therapeutically, if a key C-H bond involved in metabolic clearance of the drug is replaced by a C-D. That’s as big an isotope effects as you can get, since deuterium is twice as heavy as hydrogen, but heavier isotopes (whose differences get smaller and smaller) can be partitioned as well. The radio of carbon-12 to carbon-13 can provide a lot of information, such as whether the testosterone in your Tour-de-France-winning body came from your own enzymatic production or from a pill bottle, where it was produced from plant sources. An environment that constantly makes and breaks small-molecule bonds in organic molecules – the inside of a living cell – will tend to gradually shift isotopes around like this, and skewed isotopic ratios in the lighter elements (compared to the local abiotic background) are considered good candidates for detection of extraterrestrial life.
Even surprisingly heavy isotopes can show subtle variations in biological systems. I didn’t realize it, but there have been several reports of varying zinc-64/zinc-66 ratios. It seems that various organs actually do differ in their zinc isotope content, with hair at one end of the scale and blood at the other. Overall, the ratios seen don’t really go much outside the range seen in geological samples – we don’t enrich things that far, because that’s really not much of an atomic weight difference – but the variations do seem to be real, and make some sense according to the various bonding environments of zinc atoms in biomolecules.
So where’s this pitch I was speaking of? Well, a reader sent news that a small Florida company (“Vector Vitale”) seems to have picked up on this research, and is claiming that isotopic ratios vary between younger and older bodily tissues, as well as healthy and diseased samples. That’s certainly possible, although they provide no data, but they’re also (you saw this coming) saying that the key to health is getting your isotopic ratios back in balance. And guess what! They’re preparing to sell you stuff to do just that!
The level of scientific thinking behind all this is illustrated by the company’s statement that “In accordance to modern science, one would never expect any deviation from natural distribution of isotopes for a given chemical element.” That is exactly wrong – in accordance with modern science, you would expect isotopic distributions to constantly vary in subtle ways, and these effects have been studied for many decades in fields as different as biology (as above), geology, astronomy, and more. Of course, these folks go on to say, after touting their own research into zinc isotope distribution, that “Isotope selectivity is obviously common and naturally done. It has never been studied in biological organisms under the current scientific paradigm“, and that’s also completely ridiculous, as ten seconds looking at the biological literature will tell you.
They claim to be developing potassium and zinc preparations enriched in the lighter isotopes, potassium-39 and zinc-64. (The first report I can find of potassium isotope distributions in biological samples, by the way, dates from 1948). I particularly like the part where they say:
From the time of Adam and Eve, we ignore the importance of isotope selectivity in food and medicine, and every single day we consume a poison-antidote mixture to be lucky enough to stay alive for a while.
Human cells are well equipped to distinguish between complex macromolecules; different ions of chemical elements but for some reasons lack mass-spectrometry functions, as it requires strong magnets or centrifuges.
Read up on the kinetic isotope effect, guys; it’s great stuff, taught in college chemistry courses wherever competent instructors are to be found, because it’s been appreciated and studied since the 1930s. But once you do the reading, you will understand why the isotopic differences in heavier elements like potassium and zinc are highly unlikely to have much to do with disease and aging. It would be a Nobel-worthy discovery if they did, but that discovery is unlikely to come from people who act as if isotopes in biology have never even been looked at before. . .