Low Carb Diets High Fat Ketogenic Diets Bad for Gut Health & Thyroid Health

Created: July 29, 2019 Written By Salvatore Crapanzano C.C.Ir., B.A.Sc., M.A.Sc.

What You Need to Be Aware of With Low Carb Diets, aka Ketogenic

Following a low-carbohydrate diet such as the Ketogenic diet to gain better health can backfire on you.

To be clear, a low carb or very low-carb diet does not imply a high-fat diet such as the Ketogenic. Although it is important to note the Ketogenic diet is a low carbohydrate diet by definition (ultra low-carb), a low carbohydrate diet can have health consequences even when dietary fat is not a high percentage of calories.

So, why are low-carb and/or high-fat diets able to degrade health?

There are at least 2 reasons in the scientific literature I will give you:

Repercussion #1: Thyroid Health and Adrenal Output

1. Your Thyroid can reduce its hormone output, and you can, therefore, lose your ability to make enough energy to run your day.

This may seem like a scary thought to you if you want to lose weight or keep slim in the long-term. And in the end, you know that thyroid imbalance will rule your metabolism.

You might think this does not apply to me, but we are all biochemically unique. If this were not true then there would not be any reference ranges on blood tests to account for this.

And even those "medically" justified reference ranges can get us stuck in disease if we hold rigidly to what medical science believes ought to be true about hypothyroidism!

I've recently seen a client follow a zero-carb diet for too long and then suppress thyroid hormones, and also eventually produce adrenal dysfunction (fatigue) as well.

Here's what precisionnutrition.com says drastically restricting your carb intake long-term can cause: (1)

  • decreased thyroid output
  • increased cortisol output
  • decreased testosterone
  • impairs mood and cognitive function
  • muscle catabolism
  • suppressed immune function

All bad.

So, your Adrenal stress hormones get raised (cortisol), and you are unable to build muscle so easily. It then feels like you are under more chronic stress when carbs are restricted.

What happens when your Adrenal glands are disturbed and weakened?:

You get some Adrenal symptoms like:

  • Poor blood sugar control or hypoglycemia after eating
  • Getting dizzy or lightheaded, temporary darkening of vision, when you stand up quickly
  • Faintness and fainting
  • Intolerance to stress
  • Nervousness and irritability
  • Excessive fatigue
  • Difficulty getting started in the morning (difficulty getting out of bed too)

Ok. So that was the effect of a low-carb diet on your glands, particularly the thyroid and adrenals.

If you are a woman, you may asking, what effect that has on your reproductive hormones. Plenty! Because all the hormones work in concert!

We will have something more to write for you hopefully soon in another newsletter about female hormone balance.

But now for repercussion #2. Gut Health!

2. Your gut health could worsen when it is already impaired to begin with.

When you have great gut health, you will prevent many diseases!

Gut health is so important for healthy hormone production, and neurotransmitter production as well (like our happy serotonin hormone to avoid depression).

Gut health is intricately connected to thyroid health as well. So much so that cases of hypothyroidism will not resolve without improvement in gut health.

When gut health is a source of inflammation and toxins get into the bloodstream, you can achieve an autoimmune Hashimoto's hypothyroidism. The most common type.

And it can start as early as your 20's with poor food choices, in as little as one meal!

So what we are also asking out loud here is: If you've been wanting to do a Ketogenic diet, is it going to improve gut health?

It may depend on whether you had great gut health, to begin with, but the diet we adopt has complex effects on our intestines, gut bacterial composition, and overall health.

The Negative Side of A Low-Carbohydrate, High-Fat Ketogenic Diet

In the scientific Paper: "Dysbiosis and metabolic endotoxemia induced by high-fat diet" several Brazilian researchers concluded that high-fat diets are associated with a reduction in intestinal bacterial diversity, changes in membrane integrity, inducing increased permeability and increased lipopolysaccharide (LPS), changes in the immune system, and generation of low-intensity systemic inflammation.

All bad events.

That last thing you want to do with any high-fat diet is to increase inflammation, especially when you have leaky gut.

Part of the increased inflammation comes from these bad LPS molecules (given off from bacteria in your gut) crossing into your bloodstream.

Increased gut inflammation can trigger disease.

Here's an important example: First take antibiotics for an infection. This wipes out a lot of good gut microbes. Third, a "dysbiotic" balance is created which can affect neurotransmitter hormones, as well as many other hormones.

The result can start an episode of depression, and anxiety that lasts until the gut microbes get back in balance.

Sadly, some people take years to figure this out after getting worse with many medications. And other's are already on anti-depressants when the gut problems a few years ago

The particular takeaways here:

  1. Use mono-unsaturated fats (MUFAs), like olive oil, avocado oil, and good fish fats
  2. Avoid saturated fats (even vegetable sources like coconut oil)
  3. Treat the leaky gut first, in other words, get the gut bacteria back into balance

So, stay away from saturated fats until the gut is sealed tight.

An Example of Ketogenic Diet Gone Bad

Dr. Ruscio a functional medicine doctor recently produced an article about low-carbohydrate keto diets not being bad for gut health.

In other words, he posits that they are OK for gut health! But...

It may look like Dr. Ruscio, missed at least one particularly important point about the Ketogenic diet's affect on gut health!

Here's what someone said as a comment on that web page:

I did a 30-day keto experiment, testing my microbiome before, after 30 days on keto (monitoring macros, getting greens daily, small amounts of berries, salmon, grass-fed meats/dairy, organic coconut oil, low-carb veg), then again 30 days later (back on my normal higher carb diet). Before keto, my mood and general health were great, my F. prausnitzii and Akkermansia levels were fantastic, my butyrate production was good, as were my GABA and serotonin production. By the end of 30 days of keto, I was experiencing depression, anxiety, moodiness, fatigue, and felt generally crappy. My gut tests were abysmal after keto - my Akkermansia levels dropped to 0.32%, my butyrate production dropped significantly, as did my GABA and serotonin levels (not surprising, as how I felt perfectly reflected this). My test results at 30-days back on my regular diet were much better - my gut was recovering - but it still another month or two until I felt back to normal. I have to wonder how many people are unknowingly harming their microbiomes on low carb or keto (or carnivore for that matter). Some people just don't tolerate low carb. It seems to me that regularly monitoring the microbiome would make sense for anyone doing low carb. Just because the effect on the microbiome hasn't been extensively researched doesn't mean there isn't reason to proceed with caution. Sandi.

Here's a highlighted quote from above: “By the end of 30 days of keto, I was experiencing depression, anxiety, moodiness, fatigue, and felt generally crappy.”

Sandi mentions that F. prausnitzii and Akkermansia levels were reduced. These are two specialized bacteria in the gut that are next-generation. So obviously important!

"Akkermansia (muciniphila) population in the gut is inversely associated with obesity, diabetes, cardiometabolic diseases and, low-grade inflammation." (2)

This next-generation microbiome starts turning your fat-burning genes on when you fast intermittently, and kick starts metabolism!

When it comes to general health, we need to have great gut health!

This means having a diversity of microbiome in your gut, as well as avoiding intestinal hyperpermeability, or leaky gut.

Remember, when it comes to medicine, you can always take matters in your own hands and get healthier.

What Gut Health Means

Gut health means a diverse range of healthy gut microbiota (healthy gut bacteria/microbes) in the intestines doing their job to assist you in your health.

Our gut flora assists in maintaining metabolism, digesting our food, and creating nutrients. 90% of our happy hormones (serotonin) comes from the gut.

Women's hormones are swayed either positively or negatively by your gut microbiota.

Gut health also means low inflammation in the gut, and also a solid intestinal mucosal barrier.

No increased intestinal hyper-permeability. In other words, no leaky gut.

A leaky gut allows particles not meant to in the bloodstream get through. The difficulty with a dysbiotic gut and intestinal hyperpermeability is the LPS molecules get into our bloodstream and can start body-wide inflammation. The beginning of disease.

Even a single poor quality meal can cause increased intestinal permeability.

Diseases Prevented By a Healthy Gut

There are a few diseases that come to mind that you would want to avoid as you age.

  1. Diabetes & Insulin Resistance (Pre-Diabetes)
  2. Heart Disease
  3. Weight gain and Obesity
  4. IBS

These all have a cause in your gut bacteria. And although your gut microbiome can be quite stable over time, there is variability at the extremes of age and among different persons.

For women, whether you sail through menopause depends on your gut health, and your adrenal health as well.

What Can Create/Increase Leaky Gut

There are a few things we need to avoid to keep intestinal permeability from increasing.

  1. Antibiotics
  2. Excessive Alcohol
  3. Smoking
  4. Stress
  5. Lack of Sleep
  6. Intense exercise
  7. Artificial sweeteners
  8. Sugar
  9. Saturated fats
  10. Glyphosate

Dysbiosis is when there is a disruption of the balance of normal gut bacteria. An overgrowth of the pathogenic bacteria microbes in the gut occurs. The usual culprit is excess sugar or antibiotics.

Excessive stress can change the bugs in your gut into bad bugs, and increase the permeability, letting through protein molecules, and LPS molecules into the bloodstream.

Stress reduction is a necessity in any kind of infection, including the candida fungal infection.

And intense exercise is another stress to your body besides psychological or emotional stress.

Avoid Low-Intensity Gut Inflammation

What we are trying to avoid in the gut is inflammation. Even low-grade inflammation.

We want to lower the set-point of inflammation in the gut for better long-term health.

Because low-grade or sub-clinical inflammation is related to the manifestation of several chronic diseases: obesity, diabetes, insulin resistance.

At the same time, a reduction in some species of "good" bacteria in the gut microbiome is thought to negatively affect host-microbiome interactions causing disease (3).

You know, I'm saying these good gut microbes are our friends. They try to keep us healthy, but most of us don't know how to keep them happy! We don't even know when they are unhappy.

And when we are stressed out for a long time we created more nasty gut bacteria.

Recommendation For Healthy Gut Health

When healing Leaky Gut, we recommend using probiotics to reseed.

It is also recommended to avoid a saturated fat diet for 2-3 months.

This includes Coconut oil. (as well as the usual cheese, and high saturated fat meats).

Omega-3 fats or oils are beneficial while healing the Leaky Gut.

Cooking with avocado oil is recommended, rather than coconut oil.

Look at hs-CRP in Blood Tests for an Inflammation Marker

Have you looked at your hs-CRP (high sensitivity C-Reactive Protein) marker in your blood work recently? To see if you have any low-grade inflammation?

Your doctor can order this test easily.

CRP shows if you have body wide inflammation. Check it before and after nutritional changes.

Know Your Gut Healthy Foods to Stay Healthy: Viome Microbiome Testing

Advances in lab testing have been made to find out what foods you think are healthy is available.

And what the balance of the microbiota is in your gut.

The testing involves testing your microbiome to find out what is particular to you.

Viome Science

Short Term Low-Carb Ketogenic Diet vs Long-Term Ketogenic Diet studies

To add further twists on the low-carb ketogenic diet health craze, there are no good studies showing a potentially long-term negative affect on mortality.

In other words, they do not prolong your life.

Several articles published by Medical News Today in August 2018 showed recommendations from lead researchers are to avoid the animal based low-carbohydrate diets in the long-term.

Why a low-carb diet may not be so good for you Medical News, 20 August 2018

Related Paper: Lower Carbohydrate diets and All-Cause and Cause-Specific Mortality: a population-based cohort study and pooling of prospective studies., European Heart Journal, 2019 Apr 19, Mazidi, Mohsen & Katsiki, Niki & P Mikhailidis, Dimitri & Sattar, Naveed & Banach, Maciej &, ILEP (International Lipid Expert Panel) & Group, LBPMC (Lipid and Blood Pressure Meta-analysis collaboration) (2019)

Low-carb diets 'are unsafe and should be avoided', Medical News Today, 28 August 2018

Nutrient Deficiencies Possible in the Ketogenic Diet

Let me say, I'm not an expert on the Keto Diet by any means.

Research shows that the Keto Diet has many benefits, but research also shows it can negatively impact gut health.

Upon examination of Health Lines's Keto diet Foods to Avoid food, you will find Root vegetables and tubers, and grains are on the list.

Silica is a mineral that is most abundant in natural oats, millet, barley, wheat , and potatoes. Gluten-free as well? You won't get it from some of these previous sources.

Other sources of Silicon (the original mineral Silica is made from) include breakfast cereals, rice, teas, and waters, and even beer. (4)

So, the one nutrient that you will miss from these foods is Silica, an essential mineral. You will probably not know you are deficient in this nutrient, because it won't show up on a blood test.

It's just that some kind of skin cut may not heal that quickly.

Silica is known as the forgotten Nutrient, by Klaus Kaufmann.

It turns out that Silica is an important nutrient in the production of collagen, calcium management, bone formation, and connective tissue formation (Eidon)

Silica is often known as the beautiful hair, skin, and nails nutrient. There several diverse silica supplements available. A good collagen supplement may also be in order as you age.


LPS: What are Lipopolysaccharide molecules (LPS)?

Mani V, et al. Nutrition & Metabolism. 2013;10:6, Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia

Nutrition, oxidative stress and intestinal dysbiosis: Influence of diet on gut microbiota in inflammatory bowel diseases. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2016, Dec. 160(4):461-466

[Discusses the role of diet on IBD (Inflammatory Bowel Disease) Mediterranean and vegetarian diets that includes abundant fruits, vegetables, olive oil, and oily fish are known for their anti-inflammatory effects and could prevent dysbiosis and subsequent IBD.]

Dysbiosis and metabolic endotoxemia induced by high-fat diet, Candida et al, Nutricion Hospitalaria, 2018; 35(6): 1432-1440

Next-Generation Beneficial Microbes: The Case of Akkermansia muciniphila, Frontiers in Microbiology, Patrice Cani, Willem M. de Vos, 2017; 8: 1765

Insider: Ways The Ketogenic Diet Can Affect Your Gut and Digestion