I just read about a study of twins that shows that our environment, more than our heredity, plays the starring role in determining the state of our immune system, the body’s primary defense against disease. This is especially true as we age, the study indicates.When the human genome was first sequenced, the expectations were high that this would be the key to curing many diseases. More and more studies since have shown however, that less is determined by our genes than we thought. I see this as a very positive discovery, that we don’t need to be fatalistic about our chances to disease, and can take an active role in influencing our internal and external environment. Not only with physical factors as which food we choose and which chemicals we use (body care products etc.), but also in life style choices to limit stress, get enough exercise and sleep!