Malnutrition during childhood can weaken brain function during old age, according to a new study.

The find could have implications for many poor, developing nations and suggests that fighting childhood hunger could have other advantages too.

"For example, fighting childhood hunger can reduce future medical expenditures. It's very expensive for families and society to take care of people who suffer from dementia or cognitive impairment," said Zhenmei Zhang, MSU assistant professor of sociology and lead researcher on the project.

The study revealed that women were 35 per cent more likely to have cognitive impairment at age 65 or older, while men, a 29 per cent higher chance.

"Many of China's surviving older individuals suffered from severe hunger and devastating wars in their childhood. Before 1949, for example, life expectancy in China was 35 years," Zhang said.

The study appears in the journal Social Science & Medicine .