Leading an "intellectually, socially and physically active lifestyle" may help protect against dementia and other cognitive decline, a new study suggests.

This could include continuing education or taking part in hobbies.

The new study, published in the journal Neurology, examined various factors which could lead to cognitive decline.

It involved some 1,184 participants, all of whom were born in the UK in 1946.

Researchers examined each participant's childhood cognition when they were eight years old, their "educational attainment" by the time they reached 26, their engagement in leisure activities when they were 43, and their occupation up to the age of 53.

Participants' reading ability was also assessed at 53 as well as an exam on their cognitive abilities at 69.

This test had a maximum score of 100 and the average score among participants was 92.

Researchers found that those who performed best in the cognition test for 69-year-olds were more likely to have had higher scores in assessments taken earlier in life - the childhood cognitive skills, the "cognitive reserve index" and reading ability tests.

Those with a degree performed better than those who had no formal education.

But the team of academics found that continuing to learn over a lifetime may help protect the brain.

Participants who engaged in six or more leisure activities, such as adult education classes, clubs, volunteer work, social activities and gardening, scored higher than people who engaged in up to four leisure activities.

Study author Dr Dorina Cadar, from Brighton and Sussex Medical School, said: "These results are exciting because they indicate that cognitive ability is subject to factors throughout our lifetime, and taking part in an intellectually, socially and physically active lifestyle may help ward off cognitive decline and dementia.

"It's heartening to find that building up one's cognitive reserve may offset the negative influence of low childhood cognition for people who might not have benefited from an enriching childhood, and offer stronger mental resilience until later in life."

The authors also found that people who had "professional" careers performed better in cognition tests when they were 69 compared with people who had "unskilled" jobs.

Dr Michal Schnaider Beeri, from the Icahn School of Medicine at Mount Sinai in New York, who wrote an editorial accompanying the study, said: "From a public health and societal perspective, there may be broad, long-term benefits in investing in high education, widening opportunities for leisure activities, and providing cognitive challenging activities for people, especially those working in less skilled occupations."

Commenting on the study, Katherine Gray, research communications manager at the Alzheimer's Society, said: "This long-term Alzheimer's Society-funded study adds to a popular theory that the more you regularly challenge your brain, the less likely you are to experience memory and thinking problems in your later years.

"From childhood to adulthood, participants who kept their brain active, whether it's in education, their career or by taking part in complex hobbies, had better thinking abilities by the age of 69.

"It's estimated that the number of people with dementia in the UK is set to rise to 1.6 million by 2040. While there are many risk factors related to developing dementia, it is hopeful to know that engaging in mentally stimulating activities and finding ways to regularly challenge your brain can help reduce the development of memory and thinking problems in the future."

It comes as a new study presented to the Alzheimer's Association International Conference in San Diego concluded that high blood pressure during pregnancy is linked to an increased risk of dementia.

Women who have high blood pressure when pregnant have a higher chance of being diagnosed with vascular dementia in later life, researchers said.

Commenting on the findings, Dr Rosa Sancho, head of research from Alzheimer's Research UK, said: "High blood pressure is a risk factor for poor heart health, which has a knock-on effect on our brain health. This new research highlights the impact that high blood pressure and related disorders during pregnancy can have on women's risk of developing dementia later in life."