A conversation with Elizabeth K. Farkouh, MD, MS, Resident Physician at Brigham & Women's Hospital.
Alcohol use is often part of social routines, but growing research shows it can have lasting effects on brain health, including an increased risk of dementia. From how alcohol affects memory and decision-making to its role in long-term cognitive decline, understanding these impacts is key to making informed choices.
To help break down the science and what it means for everyday life, we spoke with Elizabeth K. Farkouh, MD, MS, a resident physician at Brigham & Women’s Hospital. In this expert interview, she shares evidence-based insights on how alcohol affects the brain, common misconceptions, and what people should know about reducing their risk.
Can you explain the relationship between alcohol consumption and overall brain health?
Alcohol has short- and long-term impacts on the brain because it easily crosses the blood-brain barrier. In the short term, alcohol can lead to disinhibition, loss of coordination, and slower reaction times. Heavy alcohol use, it can even lead to loss of consciousness. But when we’re talking about long-term impact, alcohol (or ethanol, a neurotoxin), damages the cells in the brain.
Certain areas of the brain are particularly affected by this, such as the prefrontal cortex, which is responsible for planning, decision-making, and judgment. Another area of the brain that's particularly affected is the hippocampus, which is responsible for memory. This is one reason why alcohol use can contribute to increased dementia risk. Alcohol use can also disrupt REM sleep, which helps with the consolidation of memory and promotes brain development.
Research shows that alcohol’s neurotoxic effects can lead to shrinkage of the brain over time. Even low to moderate alcohol consumption can still negatively impact the brain.
Does the type of alcoholic beverage matter?
Generally speaking, the more alcohol one consumes, the higher their risk.
Although spirit consumption tends to be associated with riskier patterns of binge drinking, it is ultimately the amount of pure ethanol consumed that matters. My general advice to people: all alcohol should really be treated the same. You may see studies that say wine is associated with better outcomes compared to spirits—but this data is highly confounded by socioeconomic status and drinking patterns. So, at this point, we don’t have compelling data to show a significant risk difference by drink type.
What role does age play in how alcohol affects the brain and cognitive function?
Everyone should be thinking about alcohol and its impact on health. Being young doesn't exclude you from the negative impacts of alcohol. In fact, the adolescent brain is particularly vulnerable to the effects of alcohol use because the brain continues to develop into one's twenties. Binge drinking during that period can also damage the hippocampus, which is responsible for memory.
One study out of Sweden found that binge drinking during adolescence was associated with a significantly increased risk of early-onset dementia. While older adults are particularly vulnerable to alcohol from a neurologic perspective, everybody, no matter the age, should be considering this.
Can reducing or eliminating alcohol later in life meaningfully lower health or dementia risk, or is damage already done?
While there’s more work that needs to be done to fully answer this question, there are data for some health outcomes. For example, we know that even one month of abstinence from alcohol can lead to significant reductions in blood pressure. Eliminating alcohol use among patients with liver disease can also be beneficial to their liver.
The International Agency for Research on Cancer recently released a report that showed evidence to suggest reducing or eliminating alcohol use can decrease the risk of oral and esophageal cancers. It may also reduce your risk of other cancers like colorectal or breast cancer.
Does binge drinking carry different risks than consistent moderate drinking?
Alcohol use can be harmful to the brain and overall health regardless of the pattern of consumption. Moderate drinking still has negative health impacts. That being said, there's substantial evidence that binge drinking* is very harmful across multiple health conditions, including cancer, liver disease, and cardiovascular disease.
This is also true for brain health. One study, for example, found that moderate drinkers who reported losing consciousness due to binge drinking, even just once in the past year, had an increased risk of developing dementia compared to moderate drinkers who had never lost consciousness.
*Please note that binge drinking is defined as four or more drinks per occasion for females—and five or more for males.
Does the risk differ between men and women?
Generally speaking, women tend to be more vulnerable to the health impacts of alcohol. While past studies have shown men tend to engage in more binge drinking, that's changed recently, and research is showing women are binge drinking at similar rates, which is very concerning.
Are some types of alcohol (wine, beer, spirits) considered lower risk, or is ethanol itself the primary concern?
This is a question we get a lot. The way that I frame it is that alcohol, or ethanol, is the component that's present in all types of alcoholic beverages. That includes wine, beer, and spirits. When we think about a standard drink—such as a 5-ounce glass of wine or a 1 1/2 ounce a shot of liquor—the amount of ethanol is the same across beverages.
Are there still health risks associated with non-alcoholic beverages?
I think it's important for folks to be aware that non-alcoholic beverages may still contain some amounts of ethanol. When you're comparing a non-alcoholic drink to a standard drink, of course, it's substantially better for health in terms of the ethanol risk.
Particularly, individuals who are pregnant should consider that we don't really have data to tell us if non-alcoholic beverages still contain trace levels of alcohol. We don't have the data to say that it’s completely safe in pregnancy—and the same goes for liver disease. On the flip side, non-alcoholic beverages can help someone reduce their alcohol use.
Read the ingredients because certain beverages that are labeled alcohol-free or non-alcoholic can still contain traces.
How does alcohol interact with other dementia risk factors like high blood pressure, poor sleep, diabetes, or depression?
Data suggests that alcohol's impact on the brain is amplified among those with high blood pressure or diabetes. With depression, there’s a bi-directional relationship. That’s because alcohol can exacerbate symptoms for those who struggle with depression. Alternatively, people with depression are very vulnerable to alcohol use and to the negative impacts of alcohol. With so many intersecting factors, alcohol is that much more important to consider for those with a comorbidity that increases their dementia risk.
Can you talk more about alcohol use and cancer risk?
Since 1988, alcohol has been classified as a group 1 carcinogen, meaning it's known to cause cancer in humans. But public education remains low. With the carcinogenic impact of alcohol, these conditions are definitively related to alcohol use:
- breast cancer
- colorectal cancer
- liver cancer
- esophageal cancer
- head and neck cancers
Emerging data is showing that alcohol use is also related to an increased risk of pancreatic and prostate cancer.
Breast cancer is one of the most important alcohol-related cancers, which is actually a surprise to most people. That’s because alcohol impacts estrogen levels. One study found that 16% (1 in 6) of US breast cancer cases are linked to alcohol consumption. So, if we were to eliminate alcohol consumption at the population level, we could prevent 16% of breast cancer cases.
Learn more from Brigham and Women's Hospital.
