The ADH1B gene is responsible for breaking down alcohol. Variants on this gene (which are more common in Asian populations than Caucasians), can result in as much as 100x faster metabolism of alcohol to more toxic acetaldehyde causing more severe symptoms of toxicity such as facial flushing, nausea, and headaches, and increased oxidative damage to the body when consuming alcohol.
If you carry the CT - allele, then this could mean that you are likely to convert alcohol to acetaldehyde more rapidly. This is considered negative since acetaldehyde is far more toxic than alcohol, causing oxidative (free radical) damage to the body. If you do consume alcohol, do so in moderation and ensure adequate intake of antioxidants to offset the oxidative damage drinking is likely to cause. Support the detoxification of acetaldehyde by increasing magnesium, molybdenum, zinc and vitamins B2 and B3 - all important co-factors. Candida overgrowth will increase your levels of acetaldehyde.