Why what's good for your heart could also help delay dementia

Parminder Raina stepped up his workouts when he realized just how important the activity could be in preventing or forestalling dementia.

Raina now hits the gym five times a week for aerobic exercise like running and cycling, as well as strength training. 

As the scientific director of the McMaster Institute for Research on Aging at McMaster University in Hamilton, Raina works to understand why some people age in a healthy fashion and others don't.

"I have become much more prudent in my own behaviour," said Raina, who is in his early 60s. 

Researchers believe that better nutrition, physical activity and socialization that can improve heart health also tend to boost brain health and could at least delay dementia. Previous studies suggest that heart conditions may cause brain changes that increase the risk of stroke and dementia.

To understand why heart health could ease the challenges of aging, including boosting brain health, Raina and his colleagues are examining the issue from multiple perspectives.

Raina also heads up the Canadian Longitudinal Study on Aging (CLSA), a large, long-term research project on about 50,000 individuals who are between the ages of 45 and 85 when they are recruited. 

Teams of researchers follow the subjects for at least 20 years with regular questionnaires on health, finances, social aspects, lifestyle, medications and nutrition. 

The researchers will also explore whether providing people with information about better nutrition helps motivate them to improve their diet.

Some participants come in for appointments every few years to measure their blood pressure, lung function, bone density and other metrics.

Dementia is a collection of symptoms affecting brain function such as a decline in memory, planning and language, as well as physical and mood changes. Dementia is not a normal part of aging, doctors say, and Alzheimer's disease is the most common type.

For dementia, the CLSA studies will help update Canada's estimates on how common it is. In 2020, almost 477,000 Canadians aged 65 and older were living with dementia, according to the Canadian Chronic Disease Surveillance System.

A recent longitudinal study based on the U.K. Biobank of more than 356,000 participants in England and Scotland aged 40 to 69 looked at a wide range of risk factors for young onset dementia that develops before age 65, as well as other chronic diseases.

The Biobank researchers found associations between a variety of conditions, including stroke, diabetes, heart disease and depression, and an increased risk of young onset dementia.