Along with the clocks going back last weekend, the onset of winter often brings with it claims from many people that their mood changes for the worse at this time of year. Sluggishness, tiredness and feeling more down-beat than usual are all symptomatic of the dreaded “winter blues”.
The well-documented cause for this annual mood swing is “seasonal affective disorder”, perhaps aptly known as SAD. Sufferers of it report negative changes to their mood and energy levels during winter.
It is thought that SAD is caused by the way in which the body responds to daylight. Melatonin, the hormone that helps regulate our sleep, is released by the pineal gland in the brain into the bloodstream. Because this gland is activated by darkness, in shorter daylight hours in the winter higher levels of melatonin are produced, causing lethargy and feelings of low energy.
Production of serotonin, a hormone responsible for maintaining mood balance, can also be decreased because of a lack of sunlight, which can lead to feelings of depression and can also affect our sleep and appetite.
So, it seems that the seasons can have a physical impact on our brain. But to what extent is our cognitive function and performance level affected by winter?
Opinions on this differ. Some studies are thought to indicate that we have reduced brain activity in the winter months, and this has been interpreted as a plausible reason for why we feel sluggish.
If this is the case, shorter day length may be a key factor contributing to this reduction in cognitive activity. Our body’s instinct is to conserve energy in challenging times – think of slowed heartbeats during extremely cold weather. Research has shown that during winter our brains allocate fewer resources to maintaining attention when the days are shortest. Conversely, our ability to sustain attention has been shown to increase in the summer months when the days are longer.
However, studies have also shown that whilst our brain activity is down, our performance levels remain the same in winter, leading some to suggest that our brains operate more efficiently – consuming fewer resources for the same performance.
Whether or not our brains actually change in winter, there is no escaping from the fact that it makes many of us feel lower and more lethargic. Understanding the science that keeps our brains performing well can combat this, and get the best out of our brains at this notoriously busy time of year at work. Here are some practical suggestions for how you might improve your mental resilience and productivity as the nights draw in during the build up to Christmas:
Getting a good night’s sleep will help you to combat feelings of sluggish-ness during the day.
To improve your sleep quality try to:
- Turn off all digital media completely an hour before you go to bed. The blue light and information from the screen keeps your brain active by inhibiting melatonin secretion and affects your ability to fall asleep.
- Start your morning using a light alarm clock, which can emulate natural light when it is still dark in the mornings and signal to your pineal gland that it is time to wake up.
- Whilst lie ins or taking to bed early in the cold and dark can be tempting, try to maintain consistent sleep and wake times that are no longer than in the summer, and within 7-9 hours per night.
- Keep your extremities warm, e.g. by wearing socks in bed, so that your body doesn’t waste resources on trying to heat them.
Don’t waste your cognitive resource during the shorter days.
Do this by sticking to a regular and simple morning routine, including picking out your clothes the night before.
The brain uses 20-30% of your daily energy intake, so eating for your brain is important.
Whilst winter can make us crave stodgy, carb-heavy food, making sure you are properly fueled and hydrated boosts your brain’s executive functions such as emotional regulation, solving complex problems and thinking flexibly. Try a higher protein diet, with brain-friendly foods like salmon and oily fish, eggs, coconut oil and nuts and seeds.
Fresh air and sunlight from outdoor exercise provide us with an increased oxygen supply and Vitamin D, a mineral regulator which keeps bones and muscles healthy.
Exercising outside in winter will help you to feel more energised, and regular exercise can have the same effect on the brain as a low dose of anti-depressants. Vitamin D is more challenging, as your limbs or torso need to be exposed to sunlight, however using Vitamin D supplements can help alleviate this problem.
There is a positive relationship between social engagement and your mood.
The social bonding hormone oxytocin (released into the blood via the pituitary gland during times of love and bonding) makes the region of the brain associated with social interaction become more active. So no matter how tempting hibernation might be, get out to spend time with friends and family as much as you can.
About the author
Tara Swart is a medical doctor, neuroscientist, award winning author and the CEO of The Unlimited Mind. She also lectures at MIT Sloan in the USA and does a bit of advisory work for businesses in the wellbeing space. She travels a lot and always tries to take in some art, fashion and exotic cuisine as a reward for all the hard work!
Find out more about Tara here.