L-Cysteine is available from raw eggs. Ever heard the saying "Here's egg in your beer"? Trouble is the egg does not float in beer, you have to guzzle the entire thing to get to the egg.
If you want to avoid a hangover consume some raw eggs and orange juice BEFORE drinking. Vitamin C is another component needed to manufacture Acetaldehyde-dehydrogenase.
Life Extensions is a great compendium of anti-aging focused biological studies. Much of it regarding antioxidants. 50 years ago.