Keeping your mind busy doing complex mental tasks while maintaining a high degree of social interaction could help protect against some facets of Alzheimer’s disease caused by bad diet, a new study suggests.

It turns out that while eating a “Western” diet, which includes high levels of red meat, processed food, and sugary meals, is associated with an increase in cognitive decline, this effect can be reversed somewhat by having a more mentally stimulating career and lifestyle. The jobs that offset the negative influences of a poor diet the most include lawyers, teachers, and engineers, while those jobs that afforded the least protection were those such as laborers, cashiers, and machine operators.

“People who regularly challenge their brains through education, work and leisure activities tend to have lower rates of dementia in later life,” explains Dr Doug Brown, the Director of Research and Development at Alzheimer’s Society, who was not involved in the research. “This study broadens out our understanding to suggest these activities could help to protect the brain by compensating against the negative impact of an unhealthy diet.”

The research has been presented at the Alzheimer’s Association International Conference in Toronto by a team of scientists working out of the Wisconsin Alzheimer’s Disease Research Center. Not only did they find that over a three-year period the consumption of a Western diet may increase one's risk of cognitive decline, but that those who have attained a higher education, conduct mentally stimulating work, and have high social engagement are much more protected against it.

The researchers assessed the risk of developing the disease by tracking what are known as white matter hyperintensities – regions of high intensity on brain scans that have been associated with Alzheimer’s – in 284 people thought to be at high risk. Those with occupations involving work with people, rather than data or “things”, showed fewer signs of being affected by brain damage indicated by these white matter hyperintensities. In essence, a stimulating lifestyle protected against the risk factors associated with a poor Western diet.

“This shouldn’t become an excuse to continue eating stodgy and sugary foods, though,” warns Dr Brown. “Getting a healthy balanced diet that’s low in red meat and high in fruit and veg is still one of the best ways to reduce your risk of dementia throughout life.” It is now thought highly likely that there is a range of factors – including behavioral, environmental, and genetic – that contribute to the development of the disease, and that understating these and how they interact could help prevent its onset.