Environment can change the way our genes work Environmental factors such as stress and diet could be affecting the genes of future generations leading to increased rates of obesity, heart disease and diabetes.A study of people suffering post-traumatic stress disorder (PTSD) after the 9/11 attacks in New York made a striking discovery. The patients included mothers who were pregnant on 9/11 and found altered levels of the stress hormone cortisol in the blood of their babies. This effect was most pronounced for mothers who were in the third trimester of pregnancy suggesting events in the womb might be responsible....