How carbs benefit your brain and digestion

You need carbs…

Wait, what? Is this coming from the same guy who supports ketogenic diets? The very nutrition coach who despises our apparent addiction to sweets? I mean, after all, I refuse to have cake on MY OWN birthday…Lord forbid if I should be stuck at someone else’s, fork in hand and cake on my plate – I’ll find the nearest family pet and make a new friend in a hurry. 

(I’m not rude or heartless, I’ll have a nibble of someone else’s cake but those closest to me know better than to make me one, but I digress.) 

I do whole-heartedly believe, as a society, we are entirely too free-wheeling with carbohydrates. I mentioned in our last post (Carbs for weight loss and muscle gain) that America’s obesity epidemic and the surge in carbohydrate intake from the last few decades go hand-in-hand. Until I see convincing evidence to the contrary, I don’t think it’s a large leap to stand by that claim. However…

Yep, you need carbs

Before I get into the layperson-level-nitty-gritty, I feel the need to clarify a few things. As with all things, when taken out of context, this can get ugly really quick. So let me say that: 

  • your level of insulin resistance or sensitivity MUST be considered. (again, read our last post for more)
  • your genetics play a massive role. (as in, where you originated from, not merely 2 or 3 generations back) 
  • your epigenetics may play an even bigger role. (think of epigenetics as the gene on/off switches) 
  • localized gut inflammation, aka leaky gut, should be considered as it can quickly cause systemic issues. 
  • a history of disordered eating, addictive habits, and neurochemical imbalances should also be prioritized. 

I’ve personally dealt with most of the above bullet points and let me assure you, finding a healthy balance with carbohydrates can make a world of difference. Let’s get to that nitty-gritty to answer the Why, When, and What kind. 

Disclaimer: As with anything on this site, any of our social media outlets, or the Fresh Fit Friday Newsletter (sign up for free by clicking here) I am not a medical doctor and this information is not meant to diagnose or treat any medical conditions. I’m merely speaking from personal and professional experience and an overwhelming, passionate necessity to know everything about the human body. But I do not have a Ph.D. nor do I play one on the internet.

Why do we need carbs? 

I’ll say right from the jump, it is NOT why most people think. You need carbs regardless of what your workout routine looks like. Yes, the higher the intensity of your workouts, the more carbs you can generally get away with. Yes, if you’re leaner you can be allowed more. Yes, women should increase carbs during the week of their period. 

But unfortunately, most doctors I’ve spoken with are not aware of what I’m about to tell you.

If your doc knows this stuff, they should be telling you. If they know this stuff, then you should be sticking with them because this is not the kind of thing they teach in med school. Which leads me to believe your overly informed medical professional cares about you enough to look into it in their spare time, which for most doctors typically amounts to a precious few minutes each day. 

I’ve seen it suggested time after time that we need carbs because our brains run on glucose. That without that precious blood sugar drip, we’ll simply bottom out and go into hypoglycemic shock. (Again, if you’re dealing with a serious medical condition TALK TO YOUR DOCTOR). But for the individuals not dealing with diabetes or other massive metabolic conditions, our brains can operate quite well without a constant stream of glucose. 

So why do we need carbs? Because they’re good for our brains.

Wait…but you just…WTH MAN?

There is a distinction that needs to be made here. Our brains don’t require glucose to operate well as we typically envision but they DO need a slight spike in blood sugar to help an amino acid called Tryptophan to get across something called the Blood Brain Barrier (BBB, for short).

*WARNING* We’re about to get into the weeds for a second. If you prefer to keep it surface-level, skip down to the headlineOk, carbs and serotonin, back to it...”

Getting tryptophan across the BBB is important because this is where tryptophan undergoes a conversion process. Simplifying things a bit, tryptophan converts to 5-htp, which then converts into the neurotransmitter Serotonin.

(As an aside, serotonin then becomes melatonin, which aids our internal clock and keeps us on a natural sleep/wake cycle and is also a very potent anti-oxidant for the brain) 

Serotonin is commonly known as the good mood neurotransmitter. It, in addition to GABA, allows us to relax and do well in social situations. It plays a role in your level of overall life satisfaction. This is why some people dealing with depression or anxiety are given SSRIs (selective serotonin reuptake inhibitors).

These are a class of drugs which stop or slow the brain’s process of breaking down and recycling our serotonin. Unfortunately, many of these drugs merely offer a short-term boost in mood and can increase levels of anxiety by reducing overall serotonin production.

The SSRI slows the breakdown of serotonin, our brain senses the serotonin hanging around the party a little longer and thus down-regulates the production of the happy little neuro-guys. Little-by-little, the person prescribed the SSRI becomes more and more dependent on the drug until it stops working completely. Aaaand this is where they’re usually prescribed a new drug…which is most likely another, more potent SSRI. Rinse and repeat.

Are you still with me?

Assuming you’re still reading, I think it’s important to mention I AM NOT A DOCTOR. (Deja vu much?) I’ve never been on SSRIs (or any medication for that matter, though not for lack of a doc trying to give me one when I couldn’t sleep 20 years ago) I’m simply extremely curious and passionate about the inner workings of the human mind, body, and all its systems. I think we live in an over-prescribed and over-medicated day and age. I’ve lost friends to prescription pills. I’ve watched family members fall apart at the seams and I knew I never wanted to go down that path.

Ok, carbs and serotonin, back to it…

The takeaway here is that a bit of carbs will boost blood sugar, which in turn increases insulin, in turn allowing more tryptophan across the BBB, in turn creating more serotonin and melatonin, ultimately leading to a happier and more rested you.

But wait, there’s more!

Current research tells us that approximately 90% of our serotonin is stored in our gut. But, why would a neurotransmitter that’s responsible for good moods be stored in the gut? Because it also plays a role in gut peristalsis – or the wave-like contractions that move our consumed food through our digestive system.

So, serotonin not only helps us feel happier and relaxed mentally, it helps our entire digestive system keep chugging along. This may be one very big reason as to why we feel so miserable when our digestion is out of whack. Impaired serotonin production means impaired digestion and impaired happiness.

We’ve covered the why of the post. Now let’s look at…

When and what carbs?

This is where things become even more individualized.

For example, someone like myself – who maintains relatively very low carb levels – does not enjoy eating carbs all day long. My daytime carb intake consists almost exclusively of veggies like broccoli, cauliflower, steamed cabbage and Brussel sprouts, et al.

I’ve found what works best for me are frozen berries. They are sweet enough to spike insulin a bit, yet loaded with phytonutrients and fiber to not abuse my blood sugar. And this is where things get tricky, as some experts will tell you that fructose (fruit sugar) won’t leave the liver while others will tell you that those experts are idiots. I’ve read that no cells in your body outside of the liver have receptors for fructose. And I’ve read comments from still others saying that’s complete b.s.

(I happily welcome any links to research proving things one way or the other.)

My suggestion? Until we know one way or the other, moderation. 

Personally, I measure out 2 to 3 cups of frozen berries and mix in some protein powder with unsweetened organic coconut milk. I’m actually going to be hitting that up as soon as I finish this blog, as I happen to be working late into the night. There are other benefits from this late night treat that I’m sure we’ll get into during a future post.

I think it’s wise for anyone looking to maintain a healthy bodyweight who is not a competitive athlete to keep insulin levels relatively low during the day.

This is extremely over-generalizing things, but to keep things within the scope of this post, I’ll just mention that high-intensity trainees may require more carbs (the process of increasing our body’s ability to utilize fats at higher intensities, while an extremely uncomfortable and slow experience (speaking from personal experience – but also look into Dr. Peter Attia for those curious) may prove this theory outdated).

Lastly, as I mentioned earlier and in previous videos, women do need more carbs than men. This is due to overall hormonal needs and the increased energy demands of the menstrual cycle.

If frozen berries aren’t your thing (what?!) aim for healthier options like honey or other natural sweeteners, smaller amounts of complex carbs like potatoes or grains if your digestive system and genetics play nice with them, or any other comfort carbohydrates you prefer.

Overall, just be smart.

Your serotonin production may depend on a certain level of carb intake, but that doesn’t give you a green light to eat that entire cake you’re baking for my birthday.

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