For decades it was believed that genes determined destiny: if you’ve inherited genes that predispose you to heart disease, for example, you will develop cardiovascular disease. More recently, we’ve learned that genes have on/oﬀ switches: the potential may be there for your heart attack, but your diet and lifestyle may help you keep that switch turned oﬀ, by “down-regulating” the gene. Scientists at the University of Kuopio studied gene expression in 47 middle-aged adults who ate either an oat/wheat bread/potato diet or a rye/pasta diet for 12 weeks. They found 71 down-regulated genes with the rye/pasta group, including some involved with impaired insulin signaling, in contrast to 62 up-regulated genes in the oat/wheat/potato group, including genes that related to stress and over-action of the immune system, even in the absence of weight loss.
American Journal of Clinical Nutrition. May 2007; 85(5): 1169-70.