In past newsletters, we’ve explored how fruit and vegetable consumption can help protect your DNA by protecting it against free radical damage. Now, new research is demonstrating how key nutrients actually support DNA repair.Among these, vitamin B6 is emerging as an “A” player on the DNA maintenance team. Provided abundantly by bananas, red bell peppers (see featured superfood, below, and recipe, right), fish, walnuts and Russet potatoes (and destroyed, incidentally, by excessive alcohol consumption), B6 is used to convert folate — another B vitamin — into thymine, a component of DNA.
Think of thymine molecules as those little bulbs on strings of Christmas tree lights. When one thymine/bulb winks out, your body reaches in the B6 box for another bulb. But when you’re running low on B6, you’re out of replacement thymine/bulbs. The DNA reaches for something that kinda looks like thymine, but isn’t — think of it like sticking endives into your string of lights. They don’t work!
If too many such mistakes occur, the repair-enzyme mechanisms can become overwhelmed. The result: DNA strand breaks, which cumulatively leads to negative effects of aging and development of disease.
In fact, after just one month in a Washington State University study, participants on a low B6 diet exhibited 75% more DNA-strand breaks than when they started. Once recommended intake levels of B6 were restored, the rate of DNA breakage returned to normal range. It’s therefore not a surprise that in larger scale epidemiological studies, people with higher intakes of B6 were found to have a lower incidence of colon, prostate, lung, gastric and pancreatic cancers.
In addition to supporting DNA repair, B6 also helps with protein metabolism, red blood cell formation, nervous and immune system function, the conversion of tryptophan (an amino acid) to niacin (a vitamin) and the conversion of glycogen (stored carbohydrate) to glucose to maintain normal blood sugar levels.
How can you make sure you’re getting enough B6? Here’s the checklist:
– Watch alcohol intake and don’t smoke — both booze and butts deplete the body’s B6 levels.
– And in addition to the excellent sources of B6 listed above, add these good sources to your plate: broccoli, Brussels sprouts, sweet potatoes, butternut squash, cauliflower and green peas to meet your 2mg-a-day requirement.
– Don’t reach for the supplement shelf! Not only are B6 pills less effective in protecting DNA, excessive supplementation can lead to nerve damage in the arms and legs.
Published April 4, 2005