Everyone knows that winter is the flu season, and many of us also know it’s the time of seasonal affective disorder (SAD), a type of depression brought on by lack of sunlight.
Other issues aggravated by the winter months include asthma, cold sores, painful joints, cold hands and feet, and dry skin. It gets worse: Heart attacks are also more prevalent during the cold months. So are outbreaks of novovirus, an extremely infectious stomach bug.
Phew! I’m ready to book a flight to the Caribbean.
And now there’s a new worry. As if those problems weren’t bad enough, winter also blitzes our ability to think. Alarmingly, winter’s effect on cognition is so large, we could find yourself falsely diagnosed with dementia.
Keep reading for a closer look at this new issue. . .
Your Brain is Five Years Younger in the Summer
Scientists still don’t know all that much about the effects of seasonal variations on the brain.
What is recognized are its effects on mood, schizophrenia symptoms, and responses to cognitive tasks as revealed in brain scans. There is little else, and there’s been no investigation into how seasonal variations might affect seniors.
So a large group of scientists from the US, Canada and France decided to delve into this association.
They analyzed data gathered during three separate time periods covering 22 years, involving 3,353 men and women aged 60 and over living in the three countries mentioned. Over half the group had already died and a proportion suffered from cognitive decline and Alzheimer’s.
All the participants had taken a battery of neuropsychological tests, and for a proportion of them, proteins and genes known to be linked to Alzheimer’s were taken from cerebrospinal fluid or from brain regions in the course of an autopsy.
The research team also took into account many factors that could influence their findings such as age, gender, sleep duration, symptoms of depression, physical activity, education and thyroid status.
The result of their analysis was that cognitive functioning was higher in the summer and fall compared to winter and spring.
This was no small effect. Quite the opposite.
This association was described as “robust,” with mental function declining by the equivalent of 4.8 years during the winter, and the odds of being diagnosed with either mild cognitive impairment (MCI) or dementia increasing by nearly a third (31%) in the winter and spring.
This means a considerable number of people could find themselves leaving the doctor’s office and battling their way through the January snow in a state of distress, after being told by their doctors they have mild cognitive impairment — or worse.
Yet exactly the same people might have been told their brains were working just fine if they had visited their physicians in July instead.
What causes this difference? The scientists really couldn’t say, but they were willing to speculate.
Neurologist Andrew Lim from the University of Toronto, who led the study, tried to shed some light:
“Our suspicion is that changes in seasons, in light, temperature and social schedules, may see people getting less physical activity, eating more poorly or changing sleeping patterns.
“This may affect the way genes and proteins are expressed in the brain, causing the difference in how someone’s memory works. Vitamin D may also be important.
“By shedding light on the mechanisms underlying the seasonal improvement in cognition in the summer and early fall, these findings also open the door to new avenues of treatment for Alzheimer’s disease.”
Meanwhile, that Florida vacation is starting to sound mighty good. . .