Nutrigenomic 'good news' on the way

Professor of molecular and cell biology at UC's Berkeley campus, Jasper Rine, predicted consumers would be able to purchase human genomes for $100 within five years.

This would provide dietary supplements and functional foods manufacturers with a wealth of information to aid new product development and drive efficaciousness to new levels.

This area encompasses concepts such as nutrigenomics or nutragenetics which explore of the intersection between genetics and nutrition - as their name suggests.

"I'm looking for the good news in the human genome," said Professor Rine.

Writing in an online early edition of the journal, Proceedings of the National Academy of Sciences (PNAS), Rine noted how genetic differences can reduce individual enzyme efficiency and which, with the right information, can be rectified with supplementation.

Enzyme variation UC Berkeley research scientist and first author Nicholas Marini said enzymatic abnormalities such as "bad copies" were common, and were already being treated on occasion by medical professionals recommending supplementation.

"Our studies have convinced us that there is a lot of variation in the population in these enzymes, and a lot of it affects function, and a lot of it is responsive to vitamins," Marini said.

"I wouldn't be surprised if everybody is going to require a different optimal dose of vitamins based on their genetic makeup, based upon the kind of variance they are harboring in vitamin-dependent enzymes."

The study transplanted human gene variants into yeast cells and was partially funded by the Defense Advanced Research Projects Agency (DARPA) and the US Army.

"Our soldiers, like top athletes, operate under extreme conditions that may well be limited by their physiology," Rine said.

"We're now working with the defense department to identify variants of enzymes that are remediable, and ultimately hope to identify troops that have these variants and test whether performance can be enhanced by appropriate supplementation."

Rine and Marini worked with the human enzyme methylenetetrahydrofolate reductase, or MTHFR.

MTHFR requires folic acid to function optimally, and is important for synthesizing molecules used to build DNA.

Yet 30 percent of the population has one bad copy, and nine percent has two copies.

Using folic acid supplementation, full functionality was returned to the most common variant, and to all but one of the less common variants.

The researchers have subsequently located 30 other variants of the MTHFR enzyme, of which 15 have been tested.

"More than half interfere with the function of the enzyme, producing a hundred-fold range of enzyme activity.

The majority of these can be either partially or completely restored to normal activity by adding more folate.

And that is a surprise," Rine said.

Folic acid is known to protect against birth defects and seems to protect against heart disease and cancer, but broader supplementation was on the agenda.

"There are over 600 human enzymes that use vitamins or minerals as cofactors, and this study reports just what we found by studying one of them," Rine said.

"What this means is that, even if the odds of an individual having a defect in one gene is low, with 600 genes, we are all likely to have some mutations that limit one or more of our enzymes."