Experts have pin-pointed three key time periods in life when the harmful effects of alcohol on the brain are likely to be at their greatest.

While drinking booze can harm the brain at any point in your life, researchers in Australia and the UK suggest there are three periods of brain changes that may be particularly sensitive to the effects of alcohol. These are: gestation (from conception to birth), later adolescence (15-19 years), and older adulthood (over 65 years). 

In the British Medical Journal (BMJ), they warned that these key periods “could increase sensitivity to the effects of environmental exposures such as alcohol” and called for a focus on harm prevention policies.

Conception to birth

Obviously we’re not talking about booze-swigging babies here. Globally, around 10% of pregnant women consume alcohol, with rates considerably higher in European countries than the global average, researchers said.

The Chief Medical Officers for the UK recommend that if someone is pregnant or planning to become pregnant, the safest approach is not to drink alcohol at all. This is because drinking alcohol, especially in the first three months of pregnancy, has been linked to an increased risk of miscarriage, premature birth and the baby having a low birthweight. Drinking after the first three months of pregnancy could affect the baby after they’re born.

Heavy alcohol use during pregnancy can cause foetal alcohol spectrum disorder, which can result in poor growth and learning and behavioural problems. Even low or moderate alcohol consumption during pregnancy is significantly associated with poorer psychological and behavioural outcomes in offspring, data suggests.

Late teens

More than 20% of 15-19 year olds in European and other high income countries report at least occasional binge drinking – defined as consuming 60g of alcohol on a single occasion. 

Studies indicate that the transition to binge drinking in adolescence is associated with reduced brain volume, poorer white matter development (which is critical for efficient brain functioning), and small to moderate deficits in a range of cognitive functions, researchers said.

65 and over

In older people, alcohol-use disorders were recently shown to be one of the strongest modifiable risk factors for all types of dementia – particularly early onset dementia – compared with other established risk factors such as high blood pressure and smoking.

Although alcohol-use disorders are relatively rare in older adults, the authors said even moderate drinking has been shown to be linked to a small but significant loss of brain volume in midlife. Further studies are needed, though, to test whether these changes translate into actual impairment.

So, what does this mean?

When asked whether pregnant people, adolescents and those aged 65 and over should take even greater care than the rest of the population, Tony Rao, a researcher in alcohol and dementia at King’s College London, said yes. “The evidence does point to these three key times during the lifespan, when the brain is at most risk from the damaging effects of alcohol,” he tells HuffPost UK.

“This would mean that extra vigilance is required during these stages of life and increased investment needed to provide harm reduction interventions. It also means that extra care should be taken with alcohol intake at these stages. 

“We know the safest measure is not drink at all during pregnancy and that lower risk limits for older people may need to be lower than for the general population.”

The researchers of the study in the BMJ called for an integrated approach to reduce harm from drinking alcohol at all ages, especially as surveys have suggested people drank more alcohol during the first Covid-19 lockdown. 

The Global Drug Survey, conducted during April and May, also revealed more than half of people have drank more – but also that excessive drinking left many of us feeling worse, exacerbating underlying mental and physical health issues.

The researchers recommended guidelines on low-risk drinking, alcohol pricing policies, and lower drink driving limits, as well as training that considers risk to the human brain throughout life.

Dr Richard Piper, chief executive of Alcohol Research UK, tells HuffPost UK: “We all know that alcohol affects the brain in the short term when we feel tipsy or drunk. But research such as this new study is shedding light on the complex ways that alcohol affects our brains in the long-term too, and as we learn more our policy makers must respond.

“Evidence shows that there are effective, workable measures that can reduce the harm caused by alcohol – for example setting a minimum price for a unit of alcohol, a measure already in place in Scotland and Wales while England lags behind. There is an ever-growing list of reasons why change is vital, and urgent.”

If you want to keep your brain healthy and your risk of dementia low, Alcohol Change UK advises people to stick to the Chief Medical Officers’ low-risk drinking guidelines. This means drinking no more than 14 units of alcohol per week (about six pints of lager or one and a half bottles of wine) and spreading intake over three days or more. You can also reduce your dementia risk by keeping physically active, eating healthily and avoiding smoking.