In particular, in those with an aldehyde dehydrogenase 2 (ALDH2) gene mutation [79], we speculate that the long-term intake of vegetable oils causes hepatic steatosis via the accumulation of hydroxynonenal in a similar manner to the BHMT disorder related to acetaldehyde-induced ALDH2 deficiency in rats after ethanol exposure [36]. This evidence concerns the gene ALDH2 and fatty liver disease.