Dementia, an umbrella term for a range of neurodegenerative diseases characterised by progressive memory loss and other cognitive impairments, affects approximately 50 million people worldwide, according to the World Health Organization (WHO).
The results of this study, which was led by Helena Hörder, were published yesterday in the journal Neurology.
For the purpose of the study, the researchers worked with 191 women, aged 50, on average. The participants’ cardiovascular fitness, or their ability to sustain physical effort over a prolonged period, was assessed through a bicycle exercise test.
Hörder and team asked the women to participate in the exercise until they felt physically exhausted; this allowed the researchers to establish what each participant’s peak cardiovascular capacity was.
In specialty literature, this peak capacity is defined as “the maximum ability of the cardiovascular system to deliver oxygen to exercising skeletal muscle and of the exercising muscle to extract oxygen from the blood.”
The researchers behind this new study measured average peak workload at 103 watts.
Following these assessments, 40 women qualified as highly physically fit (120 watts or higher peak workload), 92 women exhibited medium fitness, and 59 women had low fitness levels (80 watts or lower peak workload).
Some of the women in the latter category had to interrupt exercise participation due to hypertension, chest pain, or other cardiovascular symptoms.
The participants were then followed-up over a period of 44 years, during which time they were assessed for dementia six times. During that time, 44 of the participants developed the condition.
Of the women who has scored as highly fit, only 5% were diagnosed with dementia in that 44-year interval. In contrast, 25% of the moderately fit participants and 32% of the women with low physical fitness levels developed the disease.
In other words, the women who were highly fit in middle age had an 88% lower risk of dementia than their moderately fit counterparts.
‘Exciting findings’ may speak to prevention
Another notable finding is that among the women who had been forced to cease exercise participation due to cardiovascular problems, 45% went on to develop dementia.
“This indicates,” says Hörder, “that negative cardiovascular processes may be happening in midlife that could increase the risk of dementia much later in life.”
“These findings are exciting because it’s possible that improving people’s cardiovascular fitness in middle age could delay or even prevent them from developing dementia,” added Hörder.
At the same time, however, she warns that “this study does not show cause and effect between cardiovascular fitness and dementia, it only shows an association.”
She continues, saying, “More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important.”
Source: Medical News Today