Is sunshine a natural anti-depressant?
This summer's delightful weather has brought a smile to people's faces. Yes, some have complained about the grass being dry, crops parched and possible risk to the economy, but on the whole people seem to be thriving on the unusual warmth. A healthy glow, a spring in the step and a jaunty look seem to be the order of the day.
And no, I'm not imagining this. Sunshine really does help mood. A number of possible explanations for this present themselves. During the warm weather, people are out and about more than usual - perhaps at the beach, in street-side coffee shops and tending to their gardens.
People chat to their neighbours over the fences or when they're walking in the evenings, or after work for an outdoor drink. It always seems so civilised to drink any beverage out of doors.
Social encounters with neighbours, acquaintances and friends are hugely important to the social fabric of community living. And intermingling with others wards off loneliness and gives us a feeling of belonging and of being cared about. Human contact is one of the essential aspects of emotionally healthy living.
Few of us are cut out to be hermits. Those at greatest risk of mood disorders are people who are lonely or who lack social supports.
Our connectedness inevitably increases during the summer months and especially when this is assisted by long, warm summer days and evenings.
And exercise, as we know, is good for one's mental health. The release of endorphins in the brain during and after exercise is like a shot of opiate. It induces a feeling of well-being. And whether the activity is at the beach or in the garden, the effect is similarly positive. The late evening walkers will experience the endorphin-surge as much as the tennis players or the bee keepers. All have a heightened sense of well-being after their chosen exercise.
One probable element likely to be significant is vitamin D. This is also known as the 'sunshine vitamin' because sun it is the most important source of this. It may seem difficult to believe that nature rather than diet is the creator of this vital nutrient, but in the presence of the sun, the ultra-violet rays hit the skin and induce a reaction that produces large amounts of vitamin D3.
Around 10 minutes, with the skin unprotected, is sufficient. And most is made when large areas such as the back are exposed. This can be done without fear of fatal damage.
One of the factors affecting the amount of vitamin D that your skin produces is the time of year. Summer sun is superior to that seen in winter. So you'll create more vitamin D sitting in the sun compared to skiing. Another factor is the type of skin.
For fair complexioned skin, the time to producing large quantities of vitamin D is much shorter, in the order of minutes, while for dark-skinned complexions it may be hours.
This is nature's inbuilt protection for those most at risk of skin cancer. Those closest to the equator, not surprisingly, also produce more of this vitamin than those farthest removed.
Diet is a source, but less important. It is found in fatty fish like salmon and mackerel, as well as shellfish and beef liver. And, of course, some foods are fortified with it.
So how does vitamin D influence depression? The current theory is that it boosts the production on mono-amines. These include neurotransmitters such as serotonin, dopamine and nor-adrenaline and all have been linked to mood disorders. In other words, it may act like an antidepressant.
It also has a role in reducing inflammation. There are two competing theories about the genesis of depression - the first is that it is due to imbalance in neurotransmitters; the second, newer one, is that it is an inflammatory condition.
Vitamin D receptors have been identified in the regions of the brain linked to depression and it is involved in many genes that regulate the brain's serotonin pathway. Several large studies have linked vitamin D deficiency to clinical depression.
Despite this, there is still uncertainty if supplements help treat depression. It is also unclear if the low levels of vitamin D associated with depression were the result of being withdrawn and not exposing oneself to sun or the cause.
There is also the question as to whether vitamin D influences "normal" low mood as distinct from the psychiatric disorder called major depression.
The answers to these questions are imponderable but it is beyond doubt that the sun is helpful to your health, in moderation. Thinking of the sun as a nutrient puts a completely new perspective on the banality of weather.
Health & Living