I commonly recommend an autoimmune Paleo diet to my patients with Graves’ disease and Hashimoto’s, but I’d like to dedicate a few blog posts to some of the other common diets, and to determine if they might also be a good fit in some people with thyroid and autoimmune thyroid conditions. In this blog post I’ll be discussing the ketogenic diet, as it is one of the most well known diets. And while many people use a ketogenic diet as a way of losing weight, I’m going to discuss some of the other health benefits of this diet, as well as if it’s a diet that should be considered for those with hyperthyroidism/Graves’ disease and hypothyroidism/Hashimoto’s.
What is a Ketogenic Diet?
A ketogenic diet is essentially a high fat, low carbohydrate diet. When following such a diet the person will typically consume 20 to 50 grams of carbohydrates per day. It usually consists of 70% fat, 20% protein, and 10% carbohydrates, although there is also a variation called the “high-protein ketogenic diet”, where the ratio is around 60% fat and 30-35% protein. Following a ketogenic diet will cause the glucose reserves to decrease, and ketones are used as an alternative source of energy, and this is referred to as ketosis. The two main types of ketones are acetoacetate and β-hydroxybutyrate. These are produced in the liver through the process of ketogenesis. It’s worth mentioning that a lot of this takes place in the mitochondria of liver cells.
Why Do People Follow a Ketogenic Diet?
Most people who follow a ketogenic diet do so because it can be very effective in helping them to lose weight. While losing weight is probably the number one reason why most people choose to follow a ketogenic diet, it was originally used to help in cases of pediatric epilepsy. However, the ketogenic diet became less popular once antiepileptic agents were developed. As I’ll discuss below, the ketogenic diet can help with numerous health conditions.
Unfortunately people who follow a ketogenic diet don’t always pay attention to the quality of the food they eat. So while it is very possible to follow a healthy ketogenic diet, it’s also possible to eat an unhealthy ketogenic diet. But this is the case with just about any other diet, as for example, many vegans and vegetarians don’t eat good quality foods. Similarly, while the Paleo diet is considered to be healthy, it’s possible to eat an unhealthy Paleo diet (i.e. eating fast food burgers without the bun instead of organic grass fed beef). The same is true with an autoimmune Paleo (AIP) diet, as while I’d like to think that most people who follow this diet are paying attention to the quality of the food they eat, this isn’t always the case.
On a side note, I’m not suggesting that someone has to eat a 100% organic diet for it to be considered healthy. Whatever diet you follow, the number one goal should be to eat whole, healthy foods, while avoiding refined foods and sugars, unhealthy oils, etc. But I would try to eat organic whenever possible, especially when it comes to vegetables, fruits, and meat/poultry.
What Does The Research Show?
There is a lot of research on the ketogenic diet, and here are some of the health conditions it can potentially help with:
- Might lower cardiovascular disease risk
- Improves lipid panel markers
- Can benefit those with cancer
- Can help with obesity
- Can benefit those with type 1 and type 2 diabetes
- Can help with fatty liver
- Has neuroprotective effects
- May help with obstructive sleep apnea
So you can see that it’s not just about weight loss, although obesity does go hand in hand with some of these other conditions. On the list above it mentions how following a ketogenic diet can improve lipid panel markers, although I will say that in some people, eating higher amounts of saturated fats can cause elevations in total cholesterol and LDL. This includes healthier saturated fats such as coconut oil. This is especially true when someone has the APOE4 genotype (1) (2).
Regarding neuroprotective effects, multiple sclerosis is an autoimmune condition that involves neurodegeneration, and there is evidence that the ketogenic diet can help people with progressive multiple sclerosis (3). This may be due to the ketone bodies, as apparently they play a neuroprotective role in animal models of neurodegeneration (4) (5). This also may be the reason why the ketogenic diet can benefit people with Alzheimer’s disease (6) (7).
Is the Ketogenic Diet Safe To Follow For Those with Thyroid and Autoimmune Thyroid Conditions?
A few studies have shown that a ketogenic diet can result in lower thyroid hormone levels (T3 and T4). One study involved 120 patients who followed a ketogenic diet for an entire year (8). The results of the study showed that the ketogenic diet causes thyroid malfunction and L-thyroxine treatment may be required. Another study looked at the effects of a modified Atkins diet on thyroid function, and the results showed that after 12 weeks on the diet there was a significant reduction in total T3 and free T3 levels, but oddly a significant increase in free T4 levels (9).
Based on these studies, those with hypothyroidism/Hashimoto’s might want to be cautious about following a ketogenic diet. On the other hand, it would be interesting to see if following a ketogenic diet would benefit people with hyperthyroidism/Graves’ disease. In other words, would following a ketogenic diet help to lower thyroid hormone levels in people with hyperthyroidism? One of the dilemmas is that many people with hyperthyroidism lose a lot of weight, and a ketogenic diet might contribute to this. For example, when I dealt with Graves’ disease I lost 42 pounds, and so I’m not sure if a ketogenic diet would have been a good option for me. On the other hand, some people with hyperthyroidism struggle to lose weight, and in this situation a ketogenic might be an option to consider. This is especially true if they prefer not to take antithyroid medication.
Does a Ketogenic Diet Negatively Affect The Gut Microbiome?
A few different studies have looked at the effect of the ketogenic diet on the gut microbiome. The concern is that in order to have a diverse microbiome you need plenty of dietary fibers, and many people who follow a ketogenic diet don’t eat as many foods rich in dietary fiber since these are a source of carbohydrates. One way to get around this is to supplement with prebiotics, including inulin, fructooligosaccharides, and galactooligosaccharides.
But is supplementing with prebiotics absolutely necessary? Well, one study looked at the effects of a ketogenic diet on the gut microbiome in people with multiple sclerosis (10). This was a very small study, as ten patients followed a ketogenic diet for 6 months, and in the short term, bacterial concentrations and diversity decreased, but then they started to increase at week 12 and after 23-24 weeks actually exceeded the baseline values.
Another small study looked at the short-term impact of the ketogenic diet on the gut microbiota (11). The results of the study showed that there were no statistically significant differences at 3 months in Firmicutes and Bacteroidetes. However, there was a statistically significant increase in a bacterial group that has been linked to increasing inflammation.
Yet another study looked at the impact of low-FODMAPs, gluten-free, and ketogenic diets on the gut microbiota (12). The authors concluded that the low-FODMAP and gluten free diet might have a greater impact on the diversity of the microbiome, and with the ketogenic diet the picture isn’t entirely clear. I think that more research needs to be done, and for those who choose to follow a ketogenic diet, just to play it safe I would consider supplementing with prebiotics.
How Long Should One Follow a Ketogenic Diet For?
A ketogenic diet will usually be followed for at least a few weeks, and while some will follow the diet for 6 to 12 months, many find it difficult to stick with the diet past 6 months. But of course this is also the case with other restrictive diets. I don’t look at a ketogenic diet as being a long-term diet, just as I don’t look at the autoimmune Paleo diet to be a long term diet. That being said, including components of the ketogenic diet into your regular diet routine is probably a good idea. For example, while you might choose to eat more than 50 grams of carbohydrates per day, it probably isn’t a good idea to exceed more than 200 grams per day on a regular basis, which many people do. It’s also wise to eat a good amount of healthy fats.
Have You Followed a Ketogenic Diet?
If you have followed a ketogenic diet I’d love to hear from you! If you have hypothyroidism/Hashimoto’s and followed a ketogenic diet please let me know! Or if you followed it while dealing with hyperthyroidism please let me know. And even if you followed it before developing a thyroid condition let me know! Thank you for sharing your experience with everyone.