Older people now run a lower risk of dementia than older people ten years ago, according to a worldwide study co-conducted by Erasmus MC in Rotterdam. Someone who was 70 years old in 2010 was 13 percent more likely to have dementia than someone who is now 70 years old.

The researchers followed more than 49,000 people aged 65 and older in Europe and the United States, including residents of the Rotterdam neighborhood of Ommoord. More than 4,200 of the people followed developed dementia. That equates to a share of almost 9 percent.

The results show that the risk of dementia has decreased by 13 percent in every decade over the past 30 years. The results show that dementia can be influenced, says lead researcher and physician-epidemiologist Frank Wolters.

According to Wolters, the decline is related to better healthcare. "In both Europe and the United States, doctors and researchers have tackled cardiovascular disease by identifying and treating patients with high blood pressure and high levels of bad cholesterol and cutting down on smoking." As a result, the brain also suffers less damage with age, says Wolters.

'Brains can possibly build up a reserve against wear and tear'

A higher level of education can be another cause. "Several studies show that people with a higher education are less likely to develop dementia," says Wolters. "It could be that these people live healthier lives and that this has an effect. But it could also be that higher education protects, that learning develops your brain better. That your brain builds up a reserve against wear and tear later in life."

With the results of this research, there is a glimmer of light at the end of the tunnel, says Wolters. "Interest groups and researchers have been warning of an Alzheimer's tsunami for years."

Dementia is a collective term for symptoms caused by more than ten brain diseases, the best known of which is Alzheimer's disease. About 280,000 Dutch people have the disease. Dementia is the second most common cause of death in the Netherlands after cardiovascular disease.

The Rotterdam hospital carried out the research together with the Harvard School of Public Health and published the result in the journal Neurology .