Very small and very large babies have the worst hearing, vision and mental ability in adulthood, a British study says.

Being too light or heavy at birth can increase the risk of poorer hearing, vision and mental ability in middle age, a study has shown.

Researchers came to the conclusion after analysing data on 433,390 UK adults.

They found that people near the top of the weight table at birth had the best outcomes in adulthood, as did those who grew at a healthy rate as children.

Very small and very large babies turned out to have the worst hearing, vision and cognitive function.

Dr Piers Dawes, from the University of Manchester's School of Psychological Sciences, who led the study, said: "Sensory problems and illness such as dementia are an increasing problem but these findings suggest that issues begin to develop right from early life.

"While interventions in adulthood may only have a small effect, concentrating on making small improvements to birth size and child development could have a much greater impact on numbers of people with hearing, vision and cognitive impairment."

The data were taken from the UK Biobank, which contains detailed information on UK adults aged between 40 and 69 during the years 2006 to 2010.

Statistical adjustments were made to correct for other sources of impairment such as smoking, economic deprivation and ill-health.

Poor nutrition may affect the development of the brain and sensory systems, said the researchers whose findings are reported in the online journal Public Library of Science ONE.

Alternatively, growth hormones and genetic regulation may be influenced by early life experiences.