Health

12 Mar 10

Being overweight or obese increases the risk of liver cirrhosis.

Obesity and alcohol both increase the risk of liver disease, researchers from the Universities of Oxford and Glasgow show in two separate studies published in the British Medical Journal.

While alcohol is well known as a major cause of liver cirrhosis, recent evidence suggests that excess body weight may also play a role. With rates of liver disease and obesity increasing in the UK, determining this role is important.

In the first study, researchers from the University of Oxford examined the link between body mass index (BMI) and liver cirrhosis in 1.2 million middle-aged UK women as part of the Million Women Study.

‘We found that in middle-aged UK women, being overweight or obese increases the likelihood of developing liver cirrhosis compared with being a healthy weight,’ says Dr Bette Liu of the Cancer Epidemiology Unit at Oxford University, who led the study.

‘Because of the large size of the study, we were able to look at the combined effects of different levels of alcohol consumption and obesity on cirrhosis,’ she adds. ‘We estimate that almost 20% of liver cirrhosis in middle-aged UK women is due to excess weight, while almost 50% is due to alcohol consumption.’

The health of each woman was tracked for an average of 6.2 years, and risks were adjusted for factors such as age, alcohol consumption, smoking, socioeconomic status and physical activity.

The study found that over 5 years, in women who drink an average of just a third to half an alcoholic drink a day, 0.8 in 1000 of those with a healthy weight developed liver cirrhosis compared to 1 in 1000 for obese women.

For women drinking more – an average of two and a half alcoholic drinks a day – the risk of liver cirrhosis is about 2.7 in 1000 in those with a healthy weight, compared to 5 in 1000 for obese women.

‘Therefore consuming moderate amounts of alcohol and being overweight or obese are both bad for your liver’s health, and in combination they are particularly unhealthy,’ says Dr Liu.

In the second study, a research team led by the University of Glasgow investigated the joint effects of BMI and alcohol consumption on liver disease in around 9,000 middle-aged men in Scotland. Participants were tracked for an average of 29 years.

Both BMI and alcohol consumption were related to liver disease and, importantly, the combination of high BMI and alcohol consumption was greater than the additive effect of the two separate factors.

The two studies suggest that public health strategies to reduce both excessive alcohol consumption and obesity should lead to a reduction in the incidence of liver disease. Preventive efforts are also needed to limit the affordability and availability of alcohol and to increase physical activity, the research groups say.