Because the reproduction of the serum levels observed in human patients with Alzheimer’s disease via the administration of synthetic hydroxynonenal induced severe liver injury in all four monkeys studied, it is likely that hydroxynonenal resulting from vegetable oil peroxidation, if generated in excess, especially in elderly people and those with an ALDH2 deficiency [78,79], will produce similar adverse effects in humans. This evidence concerns the gene ALDH2 and Alzheimer disease.