Nice summer weather usually means patio beers, sangria, and chilled rose. But what happens to this alcohol when we drink it? Why are some more impacted by alcohol than others? What causes the dreaded hangover that seems to get worse with each year of age? And what can we do about it?
Alcohol metabolism and detoxification depends on a variety of factors including your age, nutritional status at the time of consumption, the amount you drink, and your genetics.
Alcohol is partially absorbed by your stomach, but most of it through your small intestine. The alcohol then is converted to acetaldehyde by the enzyme alcohol dehydrogenase (ADH). For this reaction to occur, we need something called NAD to work as a cofactor as well as CYP2E1 and catalase enzymes.
Once we have this acetaldehyde, it is converted into something called acetate through aldehyde dehydrogenase (ALDH). This acetate molecule is further broken down into carbon dioxide and water.
See the image on the right for a visual of this process.
What impacts this process?
Your nutritional status at the time of drinking can impact the absorption of alcohol. If you have not eaten, you will absorb more, and therefore have more in your system. This is why we’ve all heard “don’t drink on an empty stomach.”
As a person ages, their bodies are more impacted by the toxic effects of alcohol. This is mainly due to the changes in the ALDH enzyme which becomes less efficient as well as water distribution in the body, which decrease with age. Both of these factors, combined with the interaction with several drugs many older patients are on, increase the incidence of liver disease and other toxic effects of alcohol.
Genetics also plays a major role in alcohol metabolism. The main enzymes mentioned above (ADH and ALDH) can be found in several different forms encoded by different genes; on top of that, there are different variations (called alleles) of these genes. Which ADH or ALDH alleles a person carries impacts both their alcohol consumption and risk of alcoholism. For example, ADH1B and ADH1C alleles lead to a more rapid conversion of alcohol to acetaldehyde, therefore increasing risk for alcoholism. If the alcohol is converted quickly, one would need to drink more to stay or reach in a state of intoxication.
What causes a hangover?
Acetaldehyde (the first thing alcohol is converted to) is toxic to the body. This is the main reason alcohol can generate so many symptoms like flushing, headaches, and that dreaded hangover. It isn’t the alcohol itself, but its by-product. The NAD needed for this conversion of alcohol to acetaldehyde also generates issues by throwing off the ratio of NADH to NAD+ (think high school chemistry redox reactions). When this is thrown off balance, it can lead to cell damage, cancer and disruption of hormonal and metabolic processes.
How to assist your body
Okay so we all know drinking too much is bad and we shouldn’t do it. But if you do drink, there are a few things you can use to minimize the damage caused by these byproducts of alcohol. Obviously, you should hydrate, this is the most important thing to do when trying to avoid a hangover, also have electrolytes (avoid sugary substances with lots of additives like Gatorade as this may make headaches worse). If you take 1 and 1/2 cups water, mix it with 1/8 tsp salt, 2 tbsp honey, and some lemon juice this should do the trick! Supplementing with NAC, glutathione, B vitamins, magnesium, milk thistle, curcumin, alpha lipoic acid & vitamin C are all good ideas as well. These will help mitigate some of the oxidative damage through replacing the cofactors used up in the reaction as well as through their antioxidant capacities.
Please drink responsibly!
Yours in health,
Alcohol Clin Exp Res. 2003 Jun;27(6):981-8.
Meier P, Seitz HK. Age, alcohol metabolism and liver disease. Current Opinion in Clinical Nutrition & Metabolic Care. 2008 Jan 1;11(1):21-6.