Make the most of natural light in winter

 
 Winter Sunlight  Seasonal Affective Disorder .

by Denise Martin, Specialist Occupational Therapist 2018

It’s that time of year again.  The nights are drawing in, the days are shorter, the weather has changed.  Time to dive under the duvet and hibernate.

It can be a challenge to do the activities that are important to us when sunlight is in such short supply at this time of year; especially when we know how vital sunlight can be in so many ways.

Exposure to sunlight primarily helps the body boost its supply of vitamin D. 

Vitamin D is essential for healthy bones and muscles.  It also plays an important role in immune function and can, when in short supply, impact on levels of fatigue.  Vitamin D helps us heal and we can’t always get enough vitamin D from diet alone. 

We also know that sun exposure sets our circadian rhythm. 

Put basically, sunlight can help activate the day / night cycle which enables us to engage in social and vocational activities.  A good circadian rhythm is important for the regulation of sleep wake cycles, hormone release, body temperature and other bodily functions. Getting enough light increases night time melatonin levels (the hormone that helps induce sleep).  This ‘kick starts’ our sleep cycle at night.  (Ref: ‘Less exposure to daily ambient light in winter increases sensitivity of melatonin to light suppression’ Higuchi S, Motohashi Y, Ishabashi K, Maeda T.)

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Winter can be a difficult time to get enough daylight, especially if we are struggling to be awake in the morning. We may also rely on artificial light and electronic screens late into the evening.

Conversely, by avoiding bright light before bedtime we promote melatonin production to help us sleep.

Back-lit screens and devices such as many smart phones, TVs or laptops contain a large amount of blue light. We also often have hand held devices close to our eyes. This kind of light is the strongest for suppressing melatonin production and keeping us awake. Try avoiding electrical screens for 30-60 minutes before bedtime.   

Sunlight deficiency

Sun exposure can also make you happier; combatting depression and Seasonal Affective Disorder.

Sunlight increases levels of Serotonin (boosting our body’s ‘feel good factor’).  Higher Serotonin levels can lead to a better mood and a calm, focused outlook on life (‘Effect of sunlight and season on Serotonin turnover in the brain’ Dr. GW Lambert PhD published in the Lancet, December 2002).  Sunlight also increases levels of Dopamine; some studies have shown that exposure to bright light increased blood flow in dopamine-rich areas of the brain (‘Dopamine and light: dissecting effects on mood and motivational states’ Elizabeth Cawley, MSc, in the Journal of Psychiatry and Neuroscience, Nov 2013)

 Sunlight deficiency

Sunlight can increase alertness and potentially help us focus on the tasks we need to do. 

Researchers tell us that there are several Vitamin D receptors found in the brain parts that are involved in complex planning, processing and memory formation. 

Sunlight increases beta-endorphins in the skin and relaxes the nervous system and can make us feel calmer.

So, another impact of sunlight is that it could have pain killing properties.  Endorphins are our natural ‘feel good factors’ and often sunlight can help decrease stress and pain which means less reliance on pharmacological interventions. 

The impact of sunlight is huge.

At this time of year, we are less at risk of sunburn and we may certainly have to be patient at times to view that yellow orb in the sky.

How can we optimise our exposure to light for vitality?

We should aim to get natural daylight when it’s time to be awake, particularly in the morning. Even on a cloudy winter day. Professor Russell Foster of Oxford University Circadian Neuroscience Department recommends 20 minutes of daylight, ideally at around 10am to help us feel more awake, alert and ready for the day. Being outside in the morning may be the aim, but we must start at our own pace. If light sensitivity is an issue try graded exposure to window light, opening the curtains gradually to increase tolerance over several days. Try working on tolerance to the weaker winter afternoon sunlight, and then working on morning - midday sunlight tolerance. If able to sit outside, wrap up warmly, perhaps take a mug of tea and try a few minutes to begin with. Take it from there in manageable steps over time.

However, I for one, am certainly going to prioritise a short walk or an opportunity to stand on the back-doorstep now that I know the multitude of benefits even short exposure to sunlight can give.

 
Rachel FullerSAD