Our progress in understanding human genes has been amazing and humbling. About 150 years ago, Gregor Mendel used pea plants to establish some rules of inheritance, and about 50 years ago, Watson and Crick described the double helix of DNA. In 2003, the entire human genome was sequenced, something I have done a few years ago.
The humbling part was, when the number of genes in human cells were counted and compared to other organisms, our genome was considerably smaller than that of many other species. For example, humans have about 25,000 genes in each cell, while the tiny water flea has over 30,000. Scientists had assumed that due to our advanced abilities and organ structure, we'd have over 100,000 genes.
While we don't have that many genes, scientists have very recently discovered ways to impact the modest number we have, in an exciting new field called epigenetics. It explains how changes in gene activity can occur without changing our actual DNA.
One way that we can influence gene activity is through the foods we eat. Food can be used as a genetic on and off switch to alter our weight, blood pressure, blood cholesterol, cancer growth, and even our chances of healthy aging.The impact of nutrition on our genes is often called nutrigenomics.
To date, most of the elegant studies on nutrigenomics have been performed with a plant based, low-fat menu—specifically the Ornish Diet. Let’s look at some of these experiments: