In a new study led by researchers at Uppsala University, scientists have investigated the genes for the two key enzymes that are needed to produce Omega-3 and Omega-6 fatty acids from vegetable oils. They have found that humans have a unique genetic variant that leads to increased production of these acids. According to Adam Ameur, a bioinformatician at the Department of Immunology, Genetics and Pathology, during humans' earlier development, when there was a general energy deficit, this variant made it possible for us to satisfy the great need for polyunsaturated fatty acids required for our unique brain capacity. Today, with a surplus of nourishment, this genetic adaptation contributes instead to a greater risk of developing disorders like cardiovascular disease. This is an example of a 'thrifty gene,' a genetic adaptation that contributed to enhanced survival in an earlier stage of human development, but can now be a risk factor for lifestyle diseases.