Camilla Jessen
Dementia risk not reduced by light alcohol use, study says.
For years, light alcohol consumption has been linked to possible health benefits, including claims that it might protect the brain. But new research is challenging that belief and prompting fresh warnings from medical experts.
A large 2024 study suggests that even so-called moderate drinking does not reduce dementia risk, and may offer no protection at all.
Long-held belief
Some earlier research pointed to a so-called “J-shaped” relationship between alcohol and dementia. Under that theory, non-drinkers and heavy drinkers appeared to face higher risks, while light to moderate drinkers seemed better protected.
In the UK, moderate drinking is defined as up to 14 units of alcohol per week. In the US, the Centers for Disease Control and Prevention defines it as up to one drink per day for women and two for men.
These ideas were often linked to claims that small amounts of alcohol, such as red wine, could improve heart health and cholesterol levels.
What the study found
The 2024 study analysed data from the UK Biobank, examining 313,958 white British adults who drank alcohol and were free from dementia between 2006 and 2010.
Researchers then tracked whether participants developed dementia by 2021. According to the study, earlier findings may have been distorted by “abstainer bias”.
This occurs when former drinkers who stopped due to health problems are grouped together with lifelong non-drinkers, making moderate drinkers appear healthier by comparison.
“Our findings suggested that there was no safe level of alcohol consumption for dementia,” the study concluded.
Brain health concerns
Following the study, doctors warned that alcohol can directly harm the brain. Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, said alcohol’s effects are especially concerning for cognitive health.
“Alcohol is a central nervous system depressant drug which causes brain atrophy. Patients with dementia have baseline suppressed nervous system function with atrophy,” he told Medical News Today.
Damage over time
Psychiatrist Ozan Toy added that alcohol can affect key memory areas of the brain.
“Alcohol can negatively impact the brain’s memory center known as the hippocampus by causing cell atrophy and by inhibiting the growth of new neurons via a process called neurogenesis,” he said.
He also warned that long-term drinking can reduce levels of thiamine, a vitamin essential for memory and cognition.
“We also know that chronic alcohol use can lead to depletion of an important B-vitamin, thiamine, which is also really important for memory and cognition,” Toy said.
The study adds to growing evidence that alcohol may not offer the protective effects once suggested, even at low levels. Researchers and doctors say the findings should encourage people to rethink assumptions about “safe” or “beneficial” drinking.
Sources: UK Biobank study (2024), Medical News Today
