"Chocolate is poisonous for dogs, as it contains theobromine and caffeine, two stimulants that dogs cannot efficiently metabolise, so ingesting even a small amount can make them quite unwell.

Source: https://www.dailypost.co.uk/news/uk-world-news/april-warning-dog-owners-millions-26606818

The alcohol flush reaction is also primarily “due to inherited variations in genes of certain enzymes” – found among people of East Asian ancestry – that cause them “to metabolise alcohol less efficiently”.

Source: https://www.independent.co.uk/life-style/dry-january-benefits-drinking-break-alcohol-b2463316.html