Even though winter usually has a lot going for it – woolly hats, hot chocolate, curling up with a good book, cosy socks and other things ‘hygge’ – there is something important missing: light.
At this time of year, you’d normally go to work before sunrise and come home after sunset, with very little exposure to natural light in between. This lack of light over months on end causes serious problems for many people. And with the current lockdown restrictions in place, many people aren’t getting out at all, or only for a limited amount of time.
According to BUPA, nearly 1 in 30 people in the UK suffer from seasonal affective disorder (SAD). Symptoms include low mood, feeling teary and emotional, listlessness, low concentration, an increased need for sleep and cravings for sweets and carbohydrates – and therefore weight gain. It affects women more often than men, and particularly people who may already be struggling on the verge of depression.
What are the causes of SAD?
The exact causes of SAD are not yet properly understood, but it is thought that an imbalance of neurotransmitters is involved. These are chemical messengers in the brain needed for mental and physical performance, mood and sleep - serotonin and melatonin, among others.
Melatonin – the sleep hormone – is made in the body from serotonin – the happy hormone. The lack of the neurotransmitter serotonin due to low levels of light can tip sensitive people over the edge.
Serotonin is a brain chemical required to make you feel happy and content, for motivation and activity. Many common anti-depressants work by increasing serotonin levels in the brain.
While serotonin production requires light, melatonin requires darkness. During the dark days and long nights of winter, more serotonin is converted into melatonin, further reducing the levels of our happy hormone. Melatonin is required for sleep, but too much of it may make you feel sleepy during the day, and tiredness is a common symptom of SAD.
Check your vitamin D levels
Low vitamin D levels also affect mood. This vitamin is the only one your body can produce - it's actually a hormone rather than a vitamin. It is made when your skin is exposed to direct sunlight. During the winter we're bundled up in coats, scarves, hats and gloves so of course we make less of it. So it’s not surprising that many people feel low at this time of year.
Boosting your vitamin D levels during the winter months usually requires supplementation as it is difficult to get enough from food. The best sources are oily fish (salmon, sardines, fresh tuna, trout, halibut, mackerel, et.), high-quality cod liver oil, egg yolks and liver. Mushrooms contain a form of vitamin D called D2 (ergocalciferol).
Research shows that D2 is less effective at raising levels of vitamin D in the blood. What your body needs is D3 (cholecalciferol). Plenty of processed foods are fortified with vitamin D (like cereals, margarine and some yoghurts) but they contain contain D2, and often a synthetic one.
The NHS recommends that every one supplements with vitamin D between October and March, but it’s helpful to know your starting point. It doesn’t cost much to get your vitamin D levels checked, and if yours are low, then you need to start supplementing.
Reset your circadian rhythm
The reduced level of sunlight in winter may disrupt your body's circadian rhythm (your internal clock) and lead to feelings of depression.
Many sufferers of SAD respond well to using a full-spectrum lightbox. About 70% report a considerable improvement. To get the benefit, it is necessary to spend 30 minutes each day in front of a full-spectrum lightbox or six hours with artificial full-spectrum lighting in the house. 98% of light enters your body through the eyes, only 2% through the skin.
Looking out of a window isn’t enough, as glass blocks the ultraviolet light, as do sunglasses. Ideally leave off your sunglasses when you are out during the winter and the sun is not directly in your face.
What you eat can always play a role in helping you feel better and healthier.
Tryptophan is one of eight essential amino acids that our body needs to build protein – that means we have to eat it, as our body cannot make it – and it is a precursor for serotonin – the happy hormone.
Good sources of tryptophan include poultry, eggs, dairy, red meat, fish, dark chocolate, oats, dried dates, chickpeas, almonds, sunflower and pumpkin seeds and bananas.
Tryptophan needs carbohydrates to be able to reach the brain and create serotonin. So it’s important to combine your tryptophan-rich foods with complex carbohydrates such as brown rice, brown pasta, wholegrain bread or oats.
Get outside and get moving
Exercise has been found to be effective in combating depression, so one of the best ways to combat SAD is to exercise, especially outdoors. When your body feels better, so does the mind. It doesn’t really matter what you do as long as you are active.
And it doesn’t have to be anything too vigorous, if that’s not your thing. Even a 10-minute walk during your lunch break, walking to the shops instead of driving, taking the stairs instead of the escalators or lift, is better than nothing.
Ideally, get out in nature and visit your local park or forest. Even a gentle stroll, observing the colours and shapes around you can help. Studies have shown that exposure to fractals in nature – those repeating, mesmerising endless patterns on leaves, flowers and snowflakes – can be very soothing and help lower stress levels.
Try and incorporate small changes like these and you may soon find that you are able to do more, walk further, or climb faster, which is a great incentive to keep going.