Is the Keto Diet Good or Bad for Brain Health?

Is the Keto Diet Good or Bad for Brain Health?

You may think the ketogenic diet, or keto diet, is simply the latest trend in weight loss. But did you know that this diet has been used since the 1920s in treatment-resistant epilepsy? Research shows that it cuts seizure frequency in children by more than 50%.

But that isn’t the only positive brain benefit it provides. A review of studies on the diet show improved symptoms related to depression, anxiety, ADD/ADHD, and schizophrenia. Its effects on bipolar disorder and autism spectrum disorder, however, have been mixed.

One of my patients who had a severe case of premenstrual dysphoric disorder (PMDD) noticed her moods were significantly better on the diet. Her brain showed severe overactivity right before her period, which lessened considerably on the diet.

Keto Basics

The keto diet can be challenging to maintain, but when it works it can be powerfully effective. The main idea is for you to get more calories from protein and fat and significantly fewer calories from carbohydrates. Basically, you cut back on carbs that are easy to digest, such as sugar, soda, pastries, and white bread—something you should do anyway.

When you eat less than 50 grams of carbohydrates a day, your body runs out of blood sugars and eventually (usually after 3-4 days) starts to break down protein and fat for energy. This is called ketosis. People use this diet most often to lose weight because it takes more calories to convert fat into energy than carbohydrates and helps you feel fuller longer, but it has also been shown to help seizures, diabetes, acne, and even some forms of cancer.

The keto diet isn’t right for everyone and there can be a few downsides.

3 Potential Keto Problems for Mental Health

1. The Keto-Gut Bacteria Dilemma

The traditional keto diet is low in dietary fiber, which can negatively impact gut bacteria. Fiber-rich foods are necessary to feed the good bugs, or friendly bacteria, in our gut. Without enough fiber, their numbers can decrease, allowing the population of bad bugs to proliferate. This can mean trouble because the gut coordinates with the brain in the synthesis of neurotransmitters, which are important for healthy moods. Gut imbalances are associated with increased risk of feeling anxious, stressed, depressed, and tired.

2. For Women Only—Hormonal Hazards

Because most of the research on the keto diet has been done on men (and quite a few lab rats), some of its effects on women remain unclear. In some women, consuming a keto-friendly diet may cause hormonal imbalances, which can interfere with healthy neurotransmitter production and contribute to mood issues, anxiety, and irritability.

3. The Thyroid Effect

Research on the keto diet’s effect on thyroid function is mixed. Some research, such as a 2017 study on children with epilepsy on a keto diet, suggests that following a ketogenic eating plan may cause thyroid dysfunction. Other studies have reported that thyroid levels have changed in people on a keto diet while others found no changes in thyroid function.

This is important because the thyroid is a neurohormone, and if it is either underactive or overactive, it can contribute to symptoms associated with “mental illness.” When the thyroid is underactive (hypothyroidism), it can lead to symptoms of depression, attention problems, memory problems, and psychosis. An overactive thyroid is associated with anxiety, racing thoughts, difficulty concentrating, mania, and more.

Considering that the jury is still out on keto and thyroid function, it is advisable for people with thyroid issues to consult with a healthcare professional before starting a keto plan.

In my book, The End of Mental Illness, I explore the many ways the foods you eat affect your mental well-being. And I make food insanely simple with a handy chart that shows you what to eat and what to skip to reduce your risk factors for psychological and cognitive problems.

The End of Mental Illness is written by psychiatrist, neuroscientist, and brain health expert Dr. Daniel Amen and relies on the latest neuroscience and leading-edge brain imaging to show that mental health is really brain health. The book reveals that “mental illnesses” are really “brain health issues” that steal your mind, and it shows how minimizing your biological, psychological, social, and spiritual risk factors can help alleviate “psychiatric” symptoms. Order your copy here.

If you want to join the tens of thousands of people who have already enhanced their brain health and overcome their symptoms at Amen Clinics, speak to a specialist today at 888-288-9834. If all our specialists are busy helping others, you can also schedule a time to talk.


  1. This is falsehood. One third of the Keto daily intake is vegetables, which if I am not mistaken are high in fiber. What have you been reading?

    Comment by pat purtell — January 7, 2020 @ 7:22 AM

  2. 7-10 cups of greens a day =a lot of healthy fiber on the Keto diet .

    Comment by Heidi Slay — January 8, 2020 @ 3:31 AM

  3. I eat plenty of vegetables and fermented foods on keto for gut health. I also allow myself to eat more fiber-based foods with higher carb grams the week before my period for hormone building. Dr. Mindy Pelz teaches how to go around the issues mentioned above in the article very easily to adapt keto for women and gut and brain health.

    Comment by Agnis J Pena-Toro — January 8, 2020 @ 4:31 AM

  4. Pat, This is true if you are doing healthy keto- which I do. Unfortunately, I know of many, many people who don’t do keto this way. They eat bacon, eggs, fatty steak, hard cheese, etc. but almost no vegetables, nuts, etc. And that will put you in ketosis, but I can see where it would cause a fiber problem.

    Comment by Felicia H Robichaud — January 8, 2020 @ 4:32 AM

  5. I’m sorry to see you twisting information and not reporting fact incorrectly in order to discourage its use The ketogenic diet is very very effective and has over 50 clinical trials to stand behind to show its effectiveness.

    Comment by Fay Krapf — January 8, 2020 @ 4:32 AM

  6. Pat, Keto includes veggies but as low as one third of my diet would cause constipation. So yes Keto has veggies but for some not enough to keep gut health, healthy.

    Comment by Barbie McQuay — January 8, 2020 @ 5:51 AM

  7. Yes of course I knew that’s how the Keto diet started. I also have heard that the reason why it works for epilepsy is that it turns down brain electrical activity. I don’t think that’s something that I am interested in. Keto came out as one of the worst diets in the recent study. I’m not surprised it is not a healthy diet and it should not be continued more than one month if one is going to do it.
    People on this diet cut out fruits and vegetables that are high in carbs. Every healthy diet tells you to eat more fruits and vegetables. High fat diet’s are also known to clog arteries. There are no long-term studies for this diet because it is so new. I’m afraid what we will be hearing in 10 years from all the people who stay on it when they shouldn’t.

    Comment by Suzan — January 8, 2020 @ 9:02 AM

  8. Thank you.

    Comment by Yvonne Forsman — January 8, 2020 @ 9:31 AM

  9. Pat Purtell – Completely agreed!

    This article started out strong, but crashed and burned by the last paragraph – as so many articles about keto tend to do. Keto is not difficult to maintain if there is commitment. This is true of any lifestyle change, diet or otherwise. Additionally, the carbohydrates on keto are primarily dark leafy greens and cruciferous vegetables. Low fiber? I don’t think so!

    Gut imbalance that may be experienced on keto is readily addressed through probiotics and fermented foods, which are also keto friendly. Keto is very healing for the gut since sugars, starches and other gut-damaging foods are eliminated.

    Removing simple carbohydrates from the diet also nourishes hormone health, in both females and males. That is the main reason for the term Keto Babies. Couples who have experienced chronic infertility, women who have PCOS, etc., often see a quick reversal of these issues as their bodies heal through keto.

    There is so much strong research and medical documentation that validates the health of keto, and not just for weight loss. This includes psychiatric improvement.

    It is disappointing to find a post like this on Dr. Amen’s site.

    Comment by McDonna — January 8, 2020 @ 10:28 AM

  10. I am not sure about the Keto Diet causing issues with gut bacteria since dairy is on the yes list, so is yogurt, and other things with good bacteria such as sauerkraut. Frankly I don’t think enough studies have been done on that diet for long term effects.

    Comment by Andrea — January 8, 2020 @ 11:55 AM

  11. I believe you miss understand what is being said. Vegetables are part of Keto diet just stop sugars and starches. I believe fasting will have better benefits to brain health along with a healthy Mediterranean diet

    Comment by Margaret — January 8, 2020 @ 12:29 PM

  12. Everyone does the keto diet different. The amount of vegetables is different depending on who you listen to or what you prefer or what feels good for your body. Some people don’t eat vegetables at all on the far side of the spectrum but are still doing a keto diet.

    Comment by Barbara Galloway — January 8, 2020 @ 1:30 PM

  13. i call your search pat… manure…

    Comment by pam — January 8, 2020 @ 4:27 PM

  14. There are many variations of a “keto” diet. The classical keto diet which I believe was developed at Johns Hopkins for treatment-resistant epilepsy was not only very low carb but also very low fiber (yes, fiber is a carb but doesn’t convert to glucose like non-fiber carbs). But I agree, what many people understand now is that most anyone can achieve nutritional ketosis and still consume plenty of healthy fiber from green leafy veggies and cruciferous veggies like cauliflower and broccoli. And depending on your activity level, you can even maintain ketosis with relatively high carb intake (100 grams or more a day). Two books by Volek and Phinney (pioneers in the modern keto era) “The Art And Scince of Low Carb Living” and “The Art and Science of Low Carb Performance ” are great resources.

    Comment by Gregg Kellogg — January 8, 2020 @ 4:48 PM

  15. Dr. Amen, thanks for your encouraging comments on Keto. However, you did not mention Beta-hydroxybutyrate. I’m taking Avordart and Metformin under the direction of my doctor but a friend suggested I try this product. I will see my doctor before taking it but I would value yours.

    Comment by Roger Bourne — January 8, 2020 @ 7:23 PM

  16. Suzan, I think you have not done enough homework. I don’t know about epilepsy, but if it is caused by excess brain electrical activity, turning it down is good. The main problem keto helps with is impaired glucose metabolism which tends to get more common with age, and is a primary contributor to cognitive impairment. The cells that cant metabolize glucose for energy adequately can use ketones w/o problem to compensate. There is at least one sturdy that examined a large cohort of epilepsy patients in their late 20s/early 30s who had been in ketosis for 20+ years. They were all in good health and had normal labs, so you can’t just say it is unhealthy.
    You don’t “cut out veg” on a keto diet – just high starch, high glycemic veg. As for fruit the common nutritionist advice to eat more fruit can be a very bad idea. Fructose is a very strongly inflammatory sugar, and high fructose diets are very unhealthy, causing chronic systemic inflammation. I was diagnosed a few years ago with osteo-arthritis after following advice to eat more fruit. Cutting out 80% of my fructose intake eliminated the problem. Chronic low level inflammation is another major contributor to cognitive impairment.
    Also there is no undisputed evidence that high fat diets clog arteries. The type of fat is critical, and “high” needs to be quantified. New science is demonstrating that even saturated fats are healthy in moderation. People with low cholesterol are as likely to develop atherosclerosis as people with high cholesterol. The real issues are the lipid make-up of the cholesterol and the presence or absence of inflammation in the arteries – neither of which is simply dependent on dietary fat.
    Maybe you don’t want to go full keto, but if you want to experience healthy aging cut out the refined carbs, the high glycemic veg and the high fructose fruit.

    Comment by Murray — January 9, 2020 @ 9:30 AM

  17. All you folks who don’t buy the fiber issue are probably young. At my age, on less than 50 grams of good carbs/day and a low caloric diet you definitely need additional fiber. Otherwise constipation becomes a problem and can be very severe. I have been hospitalized with it. Several months of good probiotics and regular psyllium husk fiber intake has restored my gut health completely – still on a low carb, low cal diet. The supplementary fiber, if the right kind, (gel-forming) is recognized by your digestive system as food, not as some foreign matter and is really important. Low carb diets tend to be low fiber diets. As someone has noted above, the indigestible fiber does not count as carbs, so does not have any negative effect on ketosis, but is really vital for continued good digestive health.

    Comment by Murray Duffin — January 9, 2020 @ 9:41 AM

  18. Very interesting. What about apples who have seizures??? Seems like if it’s good for children then it should also be good for Adults…

    Comment by Betty — February 3, 2020 @ 3:20 AM

  19. I’ve been on a very low carb way of eating which is to say low fibre. My bowel function has improved in regularity and ease.

    Comment by Heather — February 3, 2020 @ 5:50 AM

  20. Hi,! I read your article it is really amazing I’ll share it with my friends and I think a ketogenic diet is good for brain health.

    Comment by Elsa gray — February 19, 2020 @ 8:42 AM

  21. As a certified nutritionist, i would recommend 1tsp of chia seeds along with 250ml of water, after a meal which leads to constipation. it is generally because your diet is lacking in Magnesium, and Chia seeds are rich in it. Other options where you can also supplement yourself with Milk of Magnesia Oral solution. Using the above mentioned options will further help you to create more healthy and efficient Gut Microbiome.

    Comment by Fahad Khan — April 22, 2020 @ 6:38 PM

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