January 12, 2013 in Health, Lifestyle

Feeling SAD

seasons-tree-300x300As winter settles in for those of us in the Northern Hemisphere, many people will find themselves in the rut of the winter blues: Seasonal Affective Disorder (SAD). SAD is a complex issue, being a mix of environmental and lifestyle elements that create the potential for deep and lasting depression.

That’s the bad news. The good news is that SAD’s effects can be largely mitigated by carefully attending to some very basic lifestyle tweaks. I’ll outline them here:

Diurnal Cycle

This is the biggie. Many people in modern times forgo the mantra of “early to bed, early to rise” and time-shift their daily routine such that they go to sleep many hours after sunset and rise a similar number of hours after sunrise. This time shift puts the body into a state of perpetual jet lag, where our exposure to the earth’s day/night rhythm is disrupted and out of sync.

The solution is to put our diurnal cycle back in order. Our task is to be awake and exposed to natural light for as many hours as there is daylight. And in order to alleviate the cultural time shifting imparted by Daylight Saving Time, your best bet is to fix your rise time to match the dawn of the longest day of the year. Where I live, for example, summer’s peak has sunrise at 4:25 a.m. and sunset at 7:01 p.m. As such, my optimal wake up time is 4 a.m., with bedtime correspondingly coming at 8 p.m.

In winter, holding to this schedule has my morning starting off in the quiet of night. Sunrise doesn’t come until 6:47 a.m. on the morning of the solstice. It’s a short day, too, with sunset coming at a mere 4:32 p.m. With such a short day, it’s important to optimize our exposure to natural light. But how to do that?

The Sun at Zenith

The second aspect of dealing with SAD is to ensure that you get adequate exposure to natural sunlight. This means not only getting outside often during daylight hours, but timing that excursion to be at the best possible time of day. Our serotonin/melatonin hormonal cycle depends on this optimal exposure. We produce serotonin by having correct daylight exposure, which then promotes adequate melatonin production during our peak sleep hours (between 11 p.m. and 1 a.m. at night).

When is this peak daylight exposure? When the sun is at zenith (at its highest point in the sky, also known as its “transit time”). The transit time is fairly stagnant. That is, for a particular region, the transit time will be within about 10 minutes (ignoring DST) between the shortest day and longest day. Where I am, transit time for the sun on the winter solstice was 11:39 a.m. At the summer solstice, the transit time was 11:43 a.m.; a mere 4 minutes difference.

Our serotonin production peaks when our UVA and UVB exposure is in optimized ratios. UVB exposure is highest when the sun is at zenith. UVA exposure stays mostly the same throughout the daylight hours. UVB is the ultraviolet wavelength that is associated with causing our body to utilize cholesterol to produce Vitamin D3. It also triggers an anti-inflammatory response via stimulation of the hippocampus via the optic nerve. Conversely, UVA triggers an inflammatory response. As such, we want, as much as possible, to optimize our sunlight exposure to those peak hours when the sun is high in the sky.

We grew up under the canopy of the trees. The canopy filters out most direct sunlight until the sun is directly overhead. Because of that, it makes sense that we should forgo the “common sense” wisdom of avoiding sunlight during peak hours. We evolved to expect and require the opposite! Tickle your orbs with sunlight during midday and you’ll enjoy a better mood and improved health.


The last ingredient in your recipe for winter health is exercise. Exercise promotes all manner of hormonal release in the body that benefits both physical and mental health! Moderate exercise that makes you perspire will induce production of serotonin, dopamine, endorphins and estrogen, as well as various growth factors. Exercise sufficient to cause perspiration will also encourage the body to express toxins.

Light Box Therapy and Tanning Beds

For severe SAD episodes, you might wish to purchase a light box. There are any number of them on the market, but I have some thoughts on those that may be better than others. The first rule for an effective light box is one that optimizes UVB output. Feel free to get one that promotes Vitamin D production and even tanning.

As with tanning beds, light boxes should not use magnetic ballasts, which are implicated in melanomas and other cancers. Only light boxes and tanning solutions that implement electronic ballasts should be considered. Choose wisely.Your light box should use full-spectrum bulbs, optimized for UVB output ratios. As close to natural sunlight at zenith as possible is ideal.

When using a light box or tanning bed, consider using them only during peak sunlight hours. The reason is that we want to stimulate our skin and our eyes to mimic that of natural sunlight. (In a tanning bed/booth DO use eye protection!) The idea is to get the right amount of light at the right time. Artificial lighting can do wonders, but at the wrong time of the day, it will be detrimental to your health.

Vitamin D3

Finally, consider supplementing your diet and lifestyle with Vitamin D3. The human body needs anywhere from 4,000-8,000 i.u. of D3 per day in order to be healthy and have optimal immune function and appropriate inflammatory response. Whatever we’re not creating naturally by virtue of skin exposure to the sun, we need to supplement. Food for thought.

I hope this helps shed some “light” on the subject of Seasonal Affective Disorder. Get outside and enjoy the sun. Sleep with your mask on and blackout drapes. Eat well. Exercise. Don’t be SAD, be happy!

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