Colette's Blog

Low-Carb Diet = Depression??? Not So Fast!

November 17, 2014

I’ve noticed a few blogs on the internet recently and posts within our Community from people asking about the effects of Atkins on their sleep or whether doing Atkins would increase their risk of depression. I’ve addressed this topic before, but I thought it would be a great time to revisit it.

One study that was well publicized in the past followed a group of adults who were separated into two weight-loss groups: a very low-carb plan and a restricted-calorie, moderately high-carb plan. Both groups lost about the same amount of weight over a year—30 pounds. But, according to the researchers, the low-carb group reported higher levels of anger, depression and confusion vs. the higher-carb group. The researchers suggested a link to better serotonin (a neurotransmitter involved in mood) synthesis with the higher-carb group while the low-carb group had lower levels of serotonin. Concluding that higher carbohydrate intake can increase serotonin concentrations in the brain, while fat and protein reduce concentrations.

But it’s just not that simple. Even the researchers suggest that more studies need to be done to support this theory.

Let’s start with this indisputable fact: The body needs tryptophan to make serotonin. No one denies this—tryptophan is an essential amino acid, and we need it for all sorts of things, including making serotonin. Tryptophan is a good guy.

But no one knows just how much is needed; nor does anyone know exactly how much serotonin we need to make in order to “not be depressed”.

What we do know: Depression is a function of an Internet-like maze of interrelationships between serotonin, dopamine, beta-endorphins and other neurotransmitters like norepinephrine and epinephrine. The making of any of these chemical messengers can be influenced by dozens of variables including the availability of amino acids (which are found in protein, by the way, not carbohydrates) and the presence of vitamins, which are needed to convert them.

The making of these compounds is also influenced by a dozen other things that have absolutely nothing to do with food, like sunshine, making love, watching a football game and petting a dog!

So how did we get the idea that a low-carb diet “causes” depression?

To understand this theory—and remember that it is completely theoretical at this point—we have to look at tryptophan.

Think of tryptophan and the other amino acids as passengers on a train to the brain. The other amino acids are big, strong guys and push everyone else out of the way to get to the seats first, leaving most of the runty little tryptophan molecules to stand around waiting for the next train. Insulin comes along and thins the crowd. It removes some tryptophan, but it removes more of the big strong guys than it does the tryptophan. The result of this action is that there’s more tryptophan on line relative to the big guys. So tryptophan has a better chance of getting on the train to the brain where it can be made into serotonin

Here’s the thinking: High-carb meals raise insulin. Insulin “thins the crowd”. Thus:more tryptophane on line for the train to the brain. The theory is that because low-carb meals don’t produce as much insulin, there’s no “crowd thinning” effect and therefore lesstryptophan can get on the train to the brain.

But who cares? Some studies did indeed show that after high-carb meals, insulin “thinned the line for the train to the brain”, leaving less tryptophan waiting for passage upstairs. Fine.

Here’s the problem:

It may not matter. There may be more than enough tryptophan in the blood to get the job done, even if there is a bit less of it waiting on line.

See, we have no idea exactly how much tryptophan is needed to make adequate levels of serotonin to prevent depression. The amount that’s there waiting on line in the first place—especially when you’re eating a lot of protein, which is where tryptophan is found – may be more than enough even without the “line thinning” effect of insulin.

And, in fact, in real life studies that didn’t just measure the amount of tryptophan in the blood but looked at how people actually felt, people eating low-carb diets felt great! The famous study by Eric Westman at Duke University, which actually had people on the low levels of carb intake that are typical of the Phase One Atkins Induction diet, reported that 85% had increases in energy and 51% had improvement in their mood! Doesn’t sound very much like depression, does it?

So high-carb meals produce more available tryptophan in the blood. So what? Low-carb meals may produce more than enough tryptophan to get the job done! And without the dangers of high-carbohydrate, high-glycemic meals with big spikes of insulin.

Let’s look at what else high-carb, high-glycemic meals with their high levels of insulin produce besides a (possibly meaningless) increase in available tryptophan in the blood:

  • High levels of triglycerides
  • Increased risk of some cancers
  • Worsened LDL particle size
  • Increased risk factors for syndrome X, heart disease, diabetes and obesity

And, it’s worth noting that diabetes doubles the risk for depression.

This is really a case where the “cure”—extremely high-carbohydrate meals—is worse than the disease. Especially since it’s curing a theoretical problem, not a real one!

It’s important that we understand that there is, in some people, an adaptive period of about a week when they first switch from a high-carb diet to Atkins Phase One Induction. During this week the body is switching from primarily burning carbohydrates to primarily burning fat (and ketones). Some people, during that short adaptive period, experience a temporary drop in energy. Virtually everyone who sticks it out finds that after a week that feeling is gone. It is important not to confuse that temporary adaptation with depression. It’s not.

On the other hand, let’s be practical. We are biochemically as unique as our fingerprints, and no one of us would ever claim that there is one diet that is perfect for every human on the planet. It’s entirely possible that there are some metabolic or biochemical types whose bodies are so sensitive to changes in tryptophan concentrations, or whose bodies have such a high threshold for serotonin production, that the slightly reduced availability of tryptophan on a lower carb diet might be a problem for them. Perhaps those people need to not be on an Induction Phase diet. It’s not for everyone. Such people might do better by adding back some carbs or starting with the ongoing weight loss—Phase Two.

For everyone else, we have a minor change in blood levels of an amino acid. And that change may ultimately make absolutely no practical difference when it comes to mood. What does this mean to you? Our bodies are complicated machines. Managing and/or decreasing your carb consumption is not a prescription for depression, and research that proves otherwise has not fully evaluated all the potential factors that may cause depression. Most likely, following Atkins will offer benefits that far outweigh even the initial adjustment that happens during Induction. Need proof? Just talk to the countless folks within our Community who have discovered that Atkins has changed their lives.

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