How many alcoholic drinks did you have yesterday? The day before? How many per day, on average, in the past month or so? Your answers matter—a lot. Drinking too much alcohol is a risk factor for numerous health problems, including diabetes, liver disease, cancer and more. So it’s logical to expect that people who drink a lot also are more likely to someday require an operation to treat a health problem.

And unfortunately for them, the very same risk factor (the booze) that increases their odds of needing surgery also increases their odds of developing complications or even dying after that surgery. Just how big are those surgery-related risks—and just how much (or how little!) does a person need to drink to fall into that danger zone? A huge new study provides some surprising answers.


The new research was a meta-analysis that combined the results from 55 different studies—involving a total of more than 1.2 million patients—examining the association between alcohol consumption and the risk for complications or death after surgery. All of the studies included in the analysis used 30 days after surgery as the cutoff in defining the postoperative period.

When it came to defining levels of alcohol use, the studies were not as consistent. Some studies broke down alcohol use into low-to-moderate versus high-consumption categories, while others compared nondrinkers to high-consumption drinkers. In general, though, drinking levels were defined as…

Low-to-moderate consumption. This refers to drinking some alcohol, but less than the equivalent of 24 grams (for women) or 36 grams (for men) of pure alcohol per day. For reference, a five-ounce glass of wine, 12-ounce beer and 1.5-ounce 80-proof drink each contain 14 grams of pure alcohol. Thus the upper limit for this category would be about one-and-a-half drinks per day for a woman or two-and-a-half drinks per day for a man.

High consumption. This category encompasses anything in excess of the low-to-moderate level.


Low-to-moderate drinkers got some good news out of this study—this level of consumption was not associated with any increased risk for postoperative complications.

But there was bad news for people who drink more. Comparing the well-defined high-consumption drinkers with nondrinkers, the researchers found that high alcohol consumption was associated with…

  • Nearly triple the risk of dying within 30 days after an operation.
  • More than double the risk for infection or pulmonary complications.
  • 58% higher risk for wound complications.


Which types of surgeries were most likely to involve complications for high-consumption drinkers? Abdominal surgery primarily led to higher rates of wound complications…thoracic (chest) surgery was mostly linked to higher mortality, infections and pulmonary complications.

This analysis didn’t address why high alcohol consumption endangers surgery patients. However, other studies have shown that excessive drinking interferes with the immune system, increasing vulnerability to infection…puts the endocrine system’s stress response into overdrive, exacerbating existing health problems…and reduces blood coagulation, boosting the risk for bleeding and slowing down wound healing.

What if you take a break from drinking before an operation?A few studies looked at what happened after surgery when patients had stopped drinking in the month or so before their operations—and those studies found a significant reduction in the risk for postsurgical complications. Of course, not all people who need surgery have the benefit of advance notice…which is yet another reason why it’s beneficial to always stay below the high-consumption threshold.

If you need help cutting back: The government-sponsored Web site Rethinking Drinking has some excellent resources, including calculators that show just how much alcohol is in various drinks…and links to programs that can assist people who want to reduce their alcohol consumption.