New research out of UC Berkeley (go bears!) may bring some legitimacy to the “once-a-day” vitamin market. With affordable rapid genome sequencing to be available to the general public within the next 5-10 years, scientists are looking at what useful information we can actually extract from all of that DNA.
UC Berkeley scientists are looking at specific vitamin-dependent enzymes in the human genome. Many dysfunctional variants can be corrected with specific vitamins such as Folate for methylenetetrahydrofolate reductase (MTHFR). Here is some more info from the press release:
Using DNA samples from 564 individuals of many races and ethnicities, colleagues at Applied Biosystems of Foster City, Calif., sequenced for each person the two alleles that code for the MTHFR enzyme. Consistent with earlier studies, they found three common variants of the enzyme, but also 11 uncommon variants, each of the latter accounting for less than one percent of the sample.
They then synthesized the gene for each variant of the enzyme, and Marini, Rine and their UC Berkeley colleagues inserted these genes into separate yeast cells in order to judge the activity of each variant. Yeast use many of the same enzymes and cofactor vitamins and minerals as humans and are an excellent model for human metabolism, Rine said.
The researchers found that four different mutations affected the functioning of the human enzyme in yeast. One of these mutations is well known: Nearly 30 percent of the population has one copy, and nine percent has two copies.
The researchers were able to supplement the diet of the cultured yeast with folate, however, and restore full functionality to the most common variant, and to all but one of the less common variants.
Since this experiment, the researchers have found 30 other variants of the MTHFR enzyme and tested about 15 of them, “and 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.
Most scientists think that harmful mutations are disfavored by evolution, but Rine pointed out that this applies only to mutations that affect reproductive fitness. Mutations that affect our health in later years are not efficiently removed by evolution and may remain in our genome forever.
Read the full story here…