Aldehyde dehydrogenase enzymes employ the sulfur chemistry of cysteine. Taking n-acetyl cysteine before you drink helps your body to synthesize the ALDH. Glutamate (easily available from monosodium glutamate) is required, along with water, for the enzyme to process aldehydes into carboxylic acids. The reaction is powered by NAD+/NADH, so adequate niacin and tryptophan in your diet would help you have enough of that, but that system also powers the alcohol dehydrogenase that is producing the aldehydes.
Whether you get hangovers or not largely depends on the relative efficiency of your ADH versus your ALDH enzymes. If you clear aldehyde faster than you can metabolize the alcohol, you never get hangovers unless you have some odd sulfur-based chemistry happening in your body. If you clear aldehyde slower than you metabolize alcohol, you get hangover effects. If you have an ALDH defect, or are taking a drug that antagonizes it, you might experience "Asian blush", with immediate unpleasant reactions to drinking alcohol.
Dehydration has its own unpleasant symptoms, and since alcohol is a diuretic, it can dehydrate you. Drinking water or electrolyte rehydration solutions will help with that. You can be fully hydrated and still have a hangover, but at least you won't have a hangover and be dehydrated too.
I have never had a hangover, but the chemistry suggests that if you get them routinely, supplementing your diet with NAC might help. Eating tofu and shiitake (high in tryptophan/niacin) with MSG as you drink or after you drink might also help. It's mostly your genetics, though. If you get bad hangovers, there's no easy cure for it other than to drink less alcohol.