Boozing, air pollution heighten dementia risk: Lancet study




Excessive alcohol consumption, traumatic brain injury, and air pollution are the three new modifiable risk factors for dementia as identified in the 2020 report of the Lancet Commission.

The latest report of the Lancet panel on dementia prevention, intervention and care has said that new evidence supports adding these three modifiable risk factors to its 2017 report that included nine risk factors – less education, hypertension, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes, and infrequent social contact.

According to the Lancet report, the 12 modifiable risk factors account for around 40 per cent of worldwide dementias, which consequently could theoretically be prevented or delayed.

The evidence-based study was led by Prof Gill Livingston from the University College, London. Twenty-eight other prominent medical experts, including Dr Amit Dias of the department of preventive and social medicine at the Goa Medical College and Hospital, were also part of the study.

The report has found that the three newer risk factors amount to six per cent of all dementia cases. The experts have advocated reducing exposure to air pollution and secondhand tobacco smoke. They have also advised that precautions should be taken to prevent head injuries.

Speaking to ‘The Navhind Times’, Dr Dias said the findings have shown that alcohol misuse and drinking more than 21 ‘units’ every week heightens  the risk of dementia.

The study has specified that that drinking more than 21 units per week are associated with a 17 per cent increase in dementia compared to drinking less than 14 units per week, Dr Dias explained.

“Heavy drinking is associated with brain changes, cognitive impairment, and dementia, a risk known for centuries. It is also significant to note that drinking more than 14 units were also associated with right-sided hippocampal atrophy on MRI, which is part of the brain responsible for memory,” he said.

The senior GMC doctor said the commission report’s findings have revealed that an increasing body of evidence is emerging on alcohol’s complex relationship with cognition and dementia outcomes from a variety of sources including detailed cohorts and large-scale record-based studies.

 “One unit of alcohol is 10ml or 8 gm of pure alcohol. An average adult takes one hour to process one unit of alcohol so that there is none left in the blood. Therefore we always caution people against drinking in large amounts at a time. If at all they have to drink, it should be restricted to 14 units per week and spread over time. This translates to around six pints of the average strength of beer or 10 small glasses of low strength red wine in a week. The drinking of liquor above this causes severe brain damage; and we now know that above 21 units can also lead to dementia,” he explained.

Worldwide around 50 million people live with dementia, and this number is projected to increase to 152 million by 2050.

Dr Dias said that approximately four million people affected by the particular disease are in India, adding that worldwide the disease is raising its ugly head particularly in low-income and middle-income countries where around two-thirds of people live with dementia.

He said that dementia affects individuals, their families, and the economy. Hence it is important to create awareness amongst the general public about the disease and its implications.

Taking preventive measures is the key in keeping dementia at bay, the senior doctor advised.