The three conditions are among the leading causes of mortality and disability in the older population, with global costs estimated to be 2% of the annual world gross domestic product.
“Usually we hear about heart disease and about cancer but for some reason there is less focus on these diseases,” said lead researcher Kamran Ikram, associate professor of neurology and epidemiology at Erasmus Medical Center in Rotterdam, Netherlands.
The study observed 12,102 individuals from Rotterdam over 26 years, carrying out full medical checks every four years. Over the course of the study, starting in 1990 and ending in 2016, a total of 1,489 people were diagnosed with dementia, 1,285 with stroke and 263 with Parkinson’s. Four hundred thirty-eight people were diagnosed with multiple diseases.
“These numbers are alarmingly high,” Ikram said.
The team found that 48.2% of women and 36.2% of men developed one of the three conditions.
Women had a higher risk of developing dementia and stroke, with a 31.4% chance of developing dementia after the age of 45, compared with an 18.6% chance among men. Women had a 21.6% chance of developing stroke compared to 19.3% of men, according to the study published Tuesday in the Journal of Neurology Neurosurgery, and Psychiatry.
Ikram suggested that longer life expectancies for females was the underlying reason for the different rates women and men face.
The risk of developing Parkinson’s disease was near equal for both genders, with women having a 4.3% risk and men a 4.9% risk of developing the disease.
“From a societal point of view, it is important to have these numbers in terms of planning for health care providers,” said Ikram, citing the lack of therapies addressing the root causes of the three brain diseases. “We do have symptomatic treatments, but we need to focus more research efforts to find durable treatments for these diseases.”
Previous studies have shown that neurological diseases such as dementia and stroke received less research funding in the UK than diseases such as cancer — with 64% of the UK’s charity and government funding going to cancer research compared to 11% being assigned to dementia research and 7% to stroke.
Between the ages of 45 and 65, women have a 2.6% chance and men a 3.2% chance of developing one of the three conditions. The risk rises as people age – beyond age 45, women have a more than 48% risk of developing one of these conditions during their lifetimes, and men have more than a 36% risk.
Taking proactive measures
Patients diagnosed with these neurological diseases were also more likely to have a higher prevalence of other health issues at the beginning of the study, such as type 2 diabetes, hypertension, and atrial fibrillation — an irregular heartbeat.
James Pickett, head researcher at the Alzheimer’s Society in the UK, said: “This study further highlights the well-established fact that women are at a greater risk of dementia than men, but shows how taking proactive healthy lifestyle measures can significantly lessen that dementia risk, regardless of age.”
“As researchers found that people who had dementia were more likely to have had high blood pressure or type 2 diabetes, what we can take from this is that healthy lifestyle choices such as eating a Mediterranean-style diet, exercising regularly and not smoking can make a real impact on reducing dementia risk, and it’s never too late to start. We need more research to better understand the link between heart and brain health.”
A recent study suggested that a Mediterranean diet can reduce risks of developing dementia.
Ikram’s findings highlight that if diagnoses of any of the three diseases are delayed by one, two or three years, the potential risk of developing the disease drops by 20% to 50%.
Dr Claudia Cooper, professor at UCL Psychiatry and consultant old age psychiatrist, said, “If we look at key factor of dementia, like lifestyle factors such as diets, exercise, less social isolation and not smoking, and if we address these factors, then there is a likelihood that we delay or prevented a third of dementia cases,” she said.
“We are realising more and more that if we can prevent or delay these diseases in old age we can have a very important impact on wellbeing for the older population.”