Finding the perfect temperature is important for more than just being comfortable at home. It turns out that setting your thermostat correctly could be key to preventing dementia in the future.
After tracking dozens of people ages 65 and older for a year, Harvard researchers found that a temperature between 68 degrees Fahrenheit and 75 degrees Fahrenheit (20 C to 24 C) was best for maintaining brain health.
Outside this range, the likelihood of experiencing attention difficulties doubled with a 7-degree Fahrenheit change in either direction.
They said older adults whose homes were in the ideal range were less likely to report difficulty concentrating than those whose homes were hotter or colder.
The researchers said their results could prove especially significant as the climate changes.
They said: ‘Our results suggest that, even in the current climate, a considerable proportion of older adults find indoor temperatures detrimental to their cognitive abilities.
‘Climate change may exacerbate this problem, particularly among low-income and underserved older adults. Addressing this issue in public health and housing policies is essential to building climate resilience in this vulnerable population.”
Researchers found that a temperature between 68 degrees Fahrenheit and 75 degrees Fahrenheit was ideal for brain function (file image)
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In a cold home, the scientists said, lower temperatures cause blood vessels to constrict, limiting blood flow to the brain, something that can increase the risk of dementia, which currently affects about 8 million Americans.
Colder temperatures can also cause the body’s cells to work harder as they try to maintain their temperature. Over time, cells become less efficient, meaning there is less energy available to brain cells.
In hot homes, the team suggested, the heat could cause excessive sweating and dehydration, which can damage the brain and therefore increase the risk of dementia.
Other experts have suggested that a hot home could also disrupt sleep, and poor sleep is known to be a major risk factor for dementia.
However, the researchers acknowledged that the study was observational and they could not definitively prove whether changes in home temperature were directly causing cognitive decline.
Another limitation of the research was that cognitive impairment was self-reported by participants or reported to researchers, and was not confirmed by clinical testing.
For the study, researchers at Harvard’s Hinda and Arthur Marcus Institute for Aging Research tracked 47 adults in Boston, Massachusetts.
Each had a sensor installed in the room of their house where they spent most of their time to monitor the home’s temperature over the course of a year.
Participants were also asked to fill out questionnaires several times a week about whether they had trouble concentrating.
The adults recruited had an average age of 79 years and the vast majority (80 percent) were women, who have a higher incidence of dementia.
The study began in October 2021 and ended in March 2023.
Their findings build on previous research that sleep is most efficient (an important factor in preventing dementia) for older adults when temperatures range between 68 and 77 degrees Fahrenheit.
Dr Amir Baniassadi, brain health expert and lead author of the study, said: “Our findings underscore the importance of how environmental factors, such as indoor temperature, affect cognitive health in aging populations.”
“This research highlights the need for public health interventions and housing policies that prioritize the climate resilience of older adults.”
He added: “As global temperatures rise, ensuring access to temperature-controlled environments will be crucial to protecting their cognitive well-being.”
In the United States, about 514,000 people are diagnosed with dementia each year, but researchers estimate that this number could increase to 1 million people per year by 2060 due to the increasing aging of the American population.
A recent study found that this amounted to nearly one in two Americans developing dementia at some point in their lives.