By David Blyweiss, M.D., Advanced Natural Wellness

December 23, 2015

• Short days of winter got you down?
• The phenomenon that rules your mood
• A happy gut means a happy brain

Next week we’ll hit the shortest day of the year. And you might be feeling the effects of it.

You see, when sunshine’s at a premium during the short days of winter, it can leave you feeling listless and blue. You can become sluggish, withdrawn and may want to sleep to your heart’s content. You might even crave sweet, starchy foods. Weight gain is also common if you suffer from winter depression, also known as seasonal affective disorder, or SAD.

Now, it’s long been believed that those long hours of darkness disrupt levels of important neurotransmitters like serotonin, acetylcholine and dopamine. All of these can play a role in your mood, emotions and behavior.

And while we’ve long known that these disruptions are somehow linked with low vitamin D levels, the reason hasn’t always been clear.

Even the Vitamin D Council says: “Vitamin D acts on the areas of your brain that are linked to depression, but exactly how vitamin D works in your brain isn’t yet fully understood.”

But I have some insights about this that may just surprise you.

It’s a phenomenon, actually a simple bidirectional pathway called the “gut-brain axis.” Our gut embryologically began as an outgrowth of our developing brain, staying connected by the vagus nerve. The bacteria in our gut (the gut microbiome) communicates directly with our brain. And with as many neurons as our spinal cord it is being recognized as a second brain.

In a nutshell, the bacteria in your gut have the ability to activate signals to your brain. This means your brain tunes into everything that’s happening in your digestive tract…and what happens in the gut doesn’t stay in the gut.

And guess what?

The vast majority of serotonin in your body is manufactured by the bacteria in your gut. So is an estimated 50% of dopamine. It’s also believed to be responsible for other brain chemicals, like GABA, norepinephrine and acetylcholine.

All of these can affect your emotions, sleep patterns and stress levels.

There’s even evidence that the bacteria in your digestive tract can influence the foods you choose to eat.

It’s easy enough to explain. They simply generate cravings for foods that enhance their fitness and overwhelm their competitors. Some prefer fats, others prefer sugars…but this could explain why you tend to crave starchy, sweet or fatty foods when you’re depressed. It’s not you. It’s your gut microbes!

What does vitamin D have to do with all of this?

Well, it turns out that your levels of vitamin D help regulate the composition of your gut microbiota. Not only do higher vitamin D levels help rid your digestive tract of unhealthy bacteria, they also increase bacterial richness and diversity.

Now, if you’re in the throes of winter depression, improving the bacterial diversity of your gut microbiome is top priority.

Boosting your vitamin D levels is your first task. Start off with a Vitamin D3 supplement in the cholecalciferol form. Just 2,000 IU daily should do the trick. But if your doctor finds that you suffer from a vitamin D deficiency (yes, you should take the simple blood test), increase that amount up to 5,000 IU/day or more depending on your numbers. Retest in about three months when levels should be stabilized.

You also want to get rid of those cravings for sweets and starches. All they do is disrupt your microbiota further, and make you feel even more depressed. But the more healthy foods you eat, the healthier your gut microbiome will become.

So zero in on fresh, organic fruits and veggies, nuts and omega-3 rich fish. Sardines are particularly good for depression. (Red meat tends to disrupt your gut bacteria, so limit it to a small portion of your diet – about 13%.) In the long-run, these choices will help wipe out those unhealthy cravings.

Adding a good probiotic to your daily routine will add further power. Look for one that contains multiple strains of lactobacillus and bifobacterium to help quench that sad mood and negative thoughts that come with it. The higher the live colony count, the better. If you’re looking for a dietary way to do the same thing, then fermented foods are the thing for you. Sauerkraut (homemade is the best), kimchi, kombucha and yogurt top the list.

Remember, a healthy gut means a happy brain…that’s a gut feeling you can live with.

Sources:
Anglin RE, Samaan Z, Walter SD, McDonald SD. Vitamin D deficiency and depression in adults: systematic review and meta-analysis. Br J Psychiatry. 2013 Feb;202:100-7.

Cantorna MT, et al. Vitamin D, immune regulation, the microbiota, and inflammatory bowel disease. Exp Biol Med (Maywood). 2014 Nov;239(11):1524-30.

Bashir M, et al. Effects of high doses of vitamin D3 on mucosa-associated gut microbiome vary between regions of the human gastrointestinal tract.Eur J Nutr. 2015 Jul 1. [Epub ahead of print]

Steenbergen L, et al. A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain Behav Immun. 2015 Aug;48:258-64.

Slyepchenko A, et al. Gut emotions – mechanisms of action of probiotics as novel therapeutic targets for depression and anxiety disorders. CNS Neurol Disord Drug Targets. 2014;13(10):1770-86.