An international study by scientists in the China, the UK and USA has found that people who consume little or no fish have an increased risk of dementia. 

The study of nearly 7,000 participants aged over 60 in six provinces in China reveals that people who consumed fish over the past two years have a significantly reduced risk of dementia by 27 per cent.

The consumption of fish is known to reduce risk of cardiovascular diseases including coronary heart disease and stroke. However, until now it has been uncertain whether eating fish reduces the risk of dementia, although the benefits of fish fatty acids from fish consumption have previously been proven to support brain function.

Previous studies on the association of fish consumption with dementia are predominantly from high-income countries and showed inconsistent findings. This six-province study in China, the largest low and middle income country, was conducted to find a significant link between fish consumption and dementia. In addition, scientists analysed previous studies for a comprehensive meta-analysis with a total of 3,139 dementia cases including all from high-income countries. They confirmed that consuming fish led to an approximate 20 per cent reduction in the risk of dementia and Alzheimer’s disease.

The study, published in Public Health Nutrition, is a collaboration between scientists at the University of Wolverhampton, Guangzhou and Guangdong Medical Universities, China, along with colleagues from the Universities of London and Manchester, the UK and the National Institutes of Health, USA.

Professor Ruoling Chen, the correspondent author and the guarantor for the study, is Professor of Public Health at the University of Wolverhampton. He and colleagues in China interviewed 6,981 people over 60 years old in the rural and urban communities of Guangdong, Heilongjiang, Shanghai, Shanxi, Anhui and Hubei in China to characterise their levels of fish consumption, and diagnose dementia. Professor Chen led a research team in Wolverhampton, UK, including PhD students, senior  researchers and clinical  staff to examine the large-scale health survey data of China and worldwide studies.

According to the Food and Agriculture Organisation of the United Nations, the global per capita fish consumption is on average 20 kg/year. It is much lower in lower and middle income countries than in high-income countries. Existing data shows that older people have reduced fish consumption.

Professor Chen, Lead of Global Health and Epidemiology at the University of Wolverhampton, said: “There is no known cure for dementia, and thus more efforts have been made to investigate the aetiology of dementia for prevention.  We are recommending that people, including older people increase their level of fish consumption to reduce the burden of dementia globally.”