With people living longer today, the number of new dementia cases is rising worldwide, however a new report states that there is some good news, as many people appear to be developing the condition at a later age.

Over 35 million people worldwide are affected by dementia, including more than 40,000 people in Ireland.

However, US experts anaylsyed several studies on this topic and found that some people who were born in the later part of the last century developed dementia at a later age. This was particularly true of those older people who were most likely to develop dementia, including Alzheimer's disease.

"Of course, people are tending to live longer, with worldwide populations ageing, so there are many new cases of dementia. But some seem to be developing it at later ages and we're optimistic about this lengthening of the time that people can live without dementia," commented one of the report's authors, Dr Eric Larson, of the Group Health Research Institute in Seattle.

Studies from the US and Europe have suggested that this may be due to better education, improved income and improvements in lifestyle and healthcare, such as better prevention and treatment of heart disease risk factors like cholesterol and high blood pressure.

The report stated that it is imperative that these trends continue, given the massive impact dementia can have on patients, their families and the healthcare system.

"This is a fascinating example of personal health changes earlier in life having an impact on personal and public health in late life. Still, we need to be aware that recent increases in obesity and diabetes threaten to reverse these gains, because of the impact these conditions can have on the ageing brain," commented another of the report's authors, Prof Kristine Yaffe of the University of California, San Francisco.

She emphasised that while the obesity and diabetes epidemic ‘are not affecting age groups most at risk for dementia yet', it is only a matter of time before they do.

"To help more people avoid dementia, we'll need to find better ways of preventing obesity and avoiding obesity-linked health risks, including diabetes and dementia.

"As luck would have it, preventing obesity and diabetes jibes with preventing dementia. In other words, we must focus on exercise, diet, education, treating hypertension (high blood pressure) and quitting smoking," Dr Larson added.

The experts' report was published in the New England Journal of Medicine.

For more information on dementia, see our Alzheimer's Clinic here