How Many Alcoholic Drinks Does it Take to Increase Risks of Cognitive Decline? Study Says 4

Many are aware of the health risks posed by drinking alcohol. But how many drinks is too much, and how many does it take to increase the risks of cognitive decline.

A recent study analyzing more than 20,000 people in the UK found that as little as four standard alcoholic drinks in a week can be associated with brain changes linked with cognitive decline. The research is the first-ever literature correlating increased brain iron levels with moderate consumption of alcohol.

Alcohol Consumption and Brain Changes

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The recent research published in the journal PLOS Medicine, titled "Associations between moderate alcohol consumption, brain iron, and cognition in UK Biobank participants: Observational and mendelian randomization analyses," has found that as little as four alcoholic drinks a week can be associated to brain damages linked with cognitive decline. This is the first research to directly correlate increased brain iron levels with moderate consumption of alcohol.

It isn't new to suggest that alcohol negatively affects a person's health. However, how damaging it can be for a person remains unclear. Over the past few years, various studies have begun shedding light on the detrimental effects of alcohol, from raising a person's cancer risks to causing structural damage to the brain.

The recent research honed in on the effects of alcohol consumption on the brain. Following prior studies linking alcohol use to early-onset dementia, the team set out to understand how alcohol could contribute to cognitive decline.

Researchers' hypothesis arose from past studies relating high brain iron levels to neurodegenerative diseases like Parkinson's and Alzheimer's. Abnormal iron accumulation in a person's brain has been detected in the brains of heavy alcohol drinkers. Hence the study wanted to observe if the same was true for moderate alcohol drinkers.

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Analyzing the Effects of Iron and Alcohol on Cognitive Decline

Researchers analyzed more than 20,000 subjects enrolled in the UK Biobank. Self-reported alcohol consumption was linked with brain iron levels measured using MRIs. Increased levels of iron in the brain, especially in the basal ganglia, were linked with consuming more than seven units of standard alcohol per week.

The UK Biobank study also measured cognitive capabilities revealing slower executive function, slower reaction times, and lower fluid intelligence could be linked with the increased iron levels of the basal ganglia, explains Anya Topiwala, a co-author of the study. The recent findings offer potential mechanisms to connect cognitive decline with alcohol consumption, reports NewAtlas.

Topiwala adds that in the largest study to date, the team has found that drinking more than seven units of alcohol daily is associated with the accumulation of iron in the brain. Higher brain iron, in turn, is associated with poorer cognitive performance. Iron accumulation could underlie alcohol-related cognitive decline.

The study defines a unit of alcohol as ten milliliters of pure alcohol. A big glass of wine could contain about two to three units of alcohol, while regular beer cans have between 1.5 and two units of alcohol.