Does Meat Really Heal? Show me the Evidence for the Carnivore Diet

Over the past year, many anecdotal reports have been released claiming that the carnivore diet – which basically consists of eating a diet restricted to meat (usually red fatty meat)–has alleviated the symptoms of autoimmune disease, depression and caused weight loss and improved health. Internet leaders that have promoted the meat diet include renowned psychologist Dr Jordan Peterson and his daughter Mikaila Peterson both of whom suffer from autoimmune conditions. Dr Peterson and Mikaila claim their autoimmune flare-ups have resolved, their cognition and mood have improved and their bodies feel more fit and better than ever as a result of the meat diet. Orthopedic surgeon Dr Shawn Baker, another advocate of the diet, and whose book about the diet is set for release in 2019, claims his 52 year old body is stronger and more muscular because of his high consumption of meats. 

Despite these anecdotal accounts that the all meat diet can decrease systemic inflammation associated with autoimmune disease, clear cognitive fog and depression, and promote weight loss, is there any scientific evidence to support the claims?

Does the Carnivore Diet cause weight loss?

Yes. The carnivore diet restricts your intake of processed carbohydrates and simple sugars, the leading culprits of weight gain. The carnivore diet is essentially a modified version of the ketogenic diet, a diet that involves eating primarily fats and protein with little carbohydrates. The ketogenic diet forces your body to use fat as energy rather than sugars, which will quickly burn off any excess fat on ones body.

Does the Carnivore Diet Cure Autoimmune Disease?

The meat diet calls for severe restriction of intake of carbohydrates and sugars. Studies have shown that excess intake of sugary foods and processed carbohydrates increases systemic levels of inflammation in the body, which can increase the risk for cancer and autoimmune diseases. Eliminating sugar intake through the meat diet can therefore theoretically decrease levels of inflammation in the body.

But does the meat diet directly decrease levels of inflammation in the body? As I mentioned before, the meat diet is essentially another version of the ketogenic diet, a diet that involves high intake of fat and protein and very low intake of carbohydrates. There is evidence that shows that the ketogenic diet is anti-inflammatory. The ketogenic diet sends the body into a metabolic state called ‘ketosis,’ which essentially means that the cells in the body are using fat and ketones for energy rather than glucose. Compared glucose metabolism which produces large amounts of free oxygen radicals (and thus contributes to inflammation), ketotic metabolism has been shown to produce fewer free radicals. In fact studies have shown that the ketogenic diet decreases inflammationand reactive radicals in animal models of multiple sclerosis, an autoimmune condition that affects the brain. Other studies show that the ketogenic diet decreases markers of liver inflammation in people with non-alcoholic fatty liver disease. The ketogenic diet has also been shown to produce anti-inflammatory effects by directly inhibiting pro-inflammatory immune pathways in the body. Thus the ketogenic diet, and likely by proxy the carnivore diet (which seems to be a modified version of the ketogenic diet), can in fact guard against inflammation and ameliorate symptoms of autoimmune disease.

Does the Carnivore Diet Offer Cancer-Fighting Properties?

Emerging evidence suggests that the ketogenic diet may decrease the risk of cancer through its anti-inflammatory properties. Carcinogenesis (the development of cancer) has been related to hyperinsulinemia, hyperglycemia, and chronic inflammation. The ketogenic diet is hypothesized to decrease risk of cancer by decreasing levels of insulin and glucose in the body and also by decreasing systemic levels of inflammation. 

Does the carnivore diet have the same effect? Perhaps, but there is no definitive evidence of this, mainly because of the newness and consequent lack of research studies on the diet. However, because of its similarities with the ketogenic diet, the carnivore may hold similar cancer-fighting properties.

But what of the studies that show a correlation between red meat and cancer? There is one major flaw in the way these studies are interpreted.  These studies are epidemiologic. This means that causal effects cannot be implied. In other words, just because there is a correlation between meat consumption and cancer does not mean that meat consumption itself causes cancer. Epidiomologic studies are problematic (especially to those who are not familiar with science and statistics) are because often causality is implied when it is not appropriate. There are many factors that may have contributed to cancer development in people eating meat that were not addressed in the studies. Those eating meat could have also consumed high amounts of sugar and processed carbohydrates (i.e., eating lots of hamburgers –unhealthy buns included— and fries at their local burger joint). They could have partaken in other unhealthy activities, such as smoking or a sedentary lifestyle, thus contributing to an increased risk of cancer.  The only type of research that can suggest a causal effect is the randomized control trial, and I haven’t seen one that found that meat consumption causes cancer. Until I see that, I’ll remain skeptical. 

Can the Carnivore diet Improve Cognitive Functioning?

Although there is limited evidence on the neuroprotective effects of the carnivore diet specifically, there is much evidence on the neuroprotective of the ketogenic diet, which the carnivore diet closely resembles. Data suggests that the ketogenic diet has anti-inflammatory effects on the brain and holds neuro-protective benefits. In fact, we use this diet in my area of expertise. We start the ketogenic diet on children with very severe seizures that do not respond to antiseizure medications. Studies show that as many as half of patients that are started on the ketogenic diet have fewer seizures after starting the diet. In children with specific genetic epilepsies or epilepsy syndromes, studies have shown up to 90% of patients achieve seizure freedom on the ketogenic diet. Moreover, several studies show that the ketogenic diet may be effective as adjunctive treatment for people with life-threatening seizures in the critical care unit who don’t respond to first line medicines. Because inflammation is thought to play an important role in epilepsy and seizures, the ketogenic diet may decrease seizure occurrence through its anti-inflammatory effects. The anti-inflammatory mechanisms of the ketogenic diet involve reduced mitochondrial production of pro-inflammatory molecules and reduced production of excess excitatory neurotransmitter glutamate, which can cause neuronal damage (a.k.a “glutamate excitotoxicity”).

Inflammation is thought to play a role in the development of other neurological diseases such as autism (increasingly associated with maternal inflammation), Alzheimer’s Disease, and Parkinson’s Disease, as well as cognitive dysfunction in people with diabetes and obesity. Thus, decreasing inflammation, potentially through the ketogenic diet, may improve symptoms related to neurological dysfunction associated with inflammatory processes.

Can the Carnivore Diet Improve Depression?

The ketogenic diet has shown neurological and psychological effects beyond the treatment of seizures and chronic pain. Several studies of adults who partook in the ketogenic diet reported benefits such as increased alertness, energy, mood and concentration.

Moreover, inflammation can contribute to depression, and depression itself can promote inflammation. The ketogenic diet may improve mood and ameliorate depression symptoms through its anti-inflammatory properties.

 

What are the Long term Effects of the Carnivore Diet?

We do not understand the long-term effects of the all-meat diet and the ketogenic diet and we do not know whether the body can gain the necessary micronutrients through fat and meats alone. Of course, simple and processed carbohydrates hold no nutritional value and so technically there is no need for humans to consume those food sources. But are leafy greens and veggies, and perhaps complex carbohydrates necessary for a human to obtain all the necessary nutrients to be healthy? Studies do show that meat, especially organ meat and red meat have high levels of micronutrients such as B vitamins and iron, which are more easily absorbed by our gut from meat than similar nutrients found in plants. However, other nutrients, such as vitamin C (a powerful antioxidant that is important for maintenance of connective tissue) are not found in sufficient amounts in most cooked meats. A few studies show that sufficient amounts of vitamin C are present in raw fish eggs and raw liver – two meats that are probably not the most popular among carnivore diet consumers. Moreover, most antioxidants and phytochemicals important to bodily functions are found exclusively in vegetables (i.e., carotenoids, lycopenes, bioflavenoids, phytic acid, etc).

My experience with the Carnivore Diet

Both my husband and I started the meat diet about a year ago because we heard about it from leaders like Dr Shawn Baker. I lost about 3 pounds, but I wasn’t doing it to lose weight. What I found more impressive was that my body fat decreased and muscle definition improved (please note that I lift weights and do yoga regularly and did not change my exercise regimen). I also noticed I was physically stronger, and able to lift objects like 5 gallon water jugs with ease, when I had struggled in the past. Moreover, I noticed my hair grew thicker. During the stressful years of residency, my hair thinned significantly, but it all grew back a few months into starting the carnivore diet.

I also noticed that my cognition improved. The brain fog that Jordan Peterson speaks of that lifted with the meat diet also lifted with me and I found that I did not need more than 1-1.5 cups of coffee, whereas in the past I required at least two cups a day to stay alert. Despite drinking less coffee, the afternoon sleepiness I used to get pre-carnivore diet disappeared.

I found that I could not just eat meat however, that I needed some veggies to appease my palate. I also realized that complete lack of carbohydrate intake affected my sleep – I woke up often during the night without at least one serving of complex carbohydrates in the evening. I therefore adjusted my diet to allow for one to two servings of complex, non-processed carbohydrates (rice, quinoa, or potatoes) limited to the evening with dinner. This allows for a mild insulin spike, promoting sleep and keeping me asleep through the night.

It’s important to note that there is not a ‘one-size-fit all’  when it comes to diet. Every one has a different body, genetics, digestive system and immune system (all of these play a role in the body’s reaction to food) is different. However, one fact is certain - people should avoid sugary and processed carbohydrate foods because these are known to cause weight gain, pro-inflammatory states, and health problems.