You may be familiar with the carnivore diet through Mikhaila Peterson, daughter of best-selling author and professor of psychology Jordan B. Peterson. In her听, she narrates a long history of health issues: juvenile arthritis, chronic depression, hypomania, chronic fatigue, numerous skin problems. She started eliminating foods from her diet and, through trial and error, arrived at the solution: all beef, all the time. And she reports her health has dramatically improved. And not just hers.
Her dad鈥檚 depression is under control, his gum disease went away. And her mom鈥檚 inflammatory colon disease is apparently nowhere to be seen since she joined the all-meat club.
The carnivore diet has variants. Some will eat any meat; others have eliminated everything but beef. Some add salt, while others have cut it out. But generally, it means getting rid of vegetables, fruits, grains, dairy, sweets, and processed food. Imagine eating two ribeye steaks a day. This is the keto diet on testosterone.
Some people adopt it as a way to lose weight. Others hope to be cured of their chronic affliction. It鈥檚 an act of rebellion against the medical establishment for some, a way to reassert one鈥檚 masculinity for others. For a few, it鈥檚 culinary libertarianism in the face of an alleged vegan agenda. A 鈥渄on鈥檛 tread on me鈥 flag the colour of a rare steak.
Is there any scientific evidence behind the claims of contemporary carnivory? And what are the risks associated with such a drastic dietary regimen?
Let鈥檚 first address many of the assertions made by the diet鈥檚 promoters.
Claim #1: You will lose weight
Any diet on which you burn more calories than you consume will lead to weight loss. If you consume fewer calories by eating steaks all day long, you will lose weight.
The problem is always sustainability. Losing weight initially is relatively easy, but most people on a diet will regain much if not all of the lost weight.
Extreme diets are almost always untenable: even Mikhaila鈥檚 dad, Jordan Peterson, when recently听, replied, 鈥淯nfortunately, yes. [鈥 It isn鈥檛 something I would lightly recommend. [鈥 And it鈥檚 dull as hell.鈥
Claim #2: Plant food is actually toxic
We are told that many plants have defence mechanisms and that ingesting these toxins could very well precipitate inflammation and disease. Specifically, lectins, gluten, and phytic acid are, according to some proponents of the diet, responsible for many human diseases.
鈥淲hen it comes to lectins, we know very little about them in human nutrition,鈥 says听, Ph.D. in Molecular Nutrition when I asked him about these claims of toxicity. 鈥淚t鈥檚 recommended to soak and boil beans, destroying the active lectin.鈥, a Registered Dietitian and the director of the Integrated Dietetic Internship at the University of Alberta, tells me some people can experience gas or stomach upset if they eat a lot of lectin-rich foods (like beans, bell peppers, and rice). 鈥淏ut there is no research to suggest that we should avoid all of these nutrient-rich foods.鈥
Gluten, however, is responsible for an autoimmune condition called celiac disease which affects , but its danger to the rest of us听. 鈥淭here is no evidence to suggest,鈥 Bates says, 鈥渢hat the general population needs to avoid gluten-containing foods.鈥
As for phytic acid, its affinity for minerals like iron and zinc is a theoretical concern, because it could lead to poor absorption of these minerals in the body. While this is important in developing countries where these deficiencies are more commonplace, phytic acid is not a concern in the developed world, Klatt tells me. Case in point: 鈥淰egetarians and vegans do not typically have higher rates of anemia. Phytic acid is a common bogeyman in circles trying to demonize any plant-based food.鈥
Claim #3: No constipation despite the lack of dietary fibre
Eating only meat means a drastic reduction in your fibre intake, and we鈥檝e been told that fibre is good for us. Indeed, not getting enough fibre can cause constipation鈥 but many carnivores are quick to prop up听.
However, it鈥檚 hard to simply dismiss the听听听out there,听and听that show that fibre can work to relieve constipation. But it鈥檚 not tolerated by everyone. It turns out that some constipated patients do experience distention and increased bloating on a high-fibre diet. How a patient responds to fibre seems to be associated with the type of constipation they have.
Moreover, people with active inflammatory bowel disease or Crohn鈥檚 disease may need to limit their intake of some vegetables, says Bates. And some vegetables contain FODMAPs, small sugars and alcohols that can cause bloating for certain people.
Vegetables are not to be demonized. 鈥淭here is no body of evidence that suggests that vegetables cause illness,鈥 Bates tells me. 鈥淚n fact, the opposite is true. There is an excess of evidence linking vegetable consumption to reductions in the risk for heart disease, stroke, diabetes, obesity and certain types of cancer.鈥
Claim #4: No more brain fog
Is there any evidence that an all-beef diet can increase mental clarity? 鈥淣o causal evidence,鈥 says Klatt. The best link he can imagine is that, if you have a food sensitivity or allergy that is affecting your gut, and if your carnivore diet removes the nasty trigger, you might see an improvement in mental clarity because of the crosstalk between the gut and the brain. 鈥淏ut,鈥 he points out, 鈥渨e barely understand how diet might affect mental health and clarity for the foods and nutrients we regularly eat.鈥 We commonly hear that low-carb diets give you mental clarity. 鈥淎 common claim for almost听every听diet, though,鈥 he says, 鈥渋s mental clarity.鈥
Claim #5: This diet cured Mikhaila Peterson of her juvenile arthritis
The carnivore diet is not the first dietary regimen to be linked to a miraculous remission; it鈥檚 only the latest. Mikhaila Peterson, who reports having tried drugs like naproxen, Enbrel, methotrexate, immunosuppressants, and cortisone injections for her arthritis, concludes,听. And I am happy that her symptoms have gone away and that her quality of life has improved. But before jumping to conclusions, we must zoom out of this particular testimonial and look at the bigger picture.
Juvenile arthritis has a remission rate with treatment. A听reported that the probability of achieving remission within five years of diagnosis was 50%. A听of the phenomenon looking at multiple studies calculated this remission rate to be 47% by 10 years after diagnosis. So remission from juvenile arthritis is not rare.
Even though it is tempting to link remission with our last major lifestyle change, it鈥檚 more of a manifestation of the saying that 鈥渢he brain abhors a vacuum鈥 than a legitimate explanation.
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Now that we鈥檝e addressed many of the claims surrounding the diet, let鈥檚 look at some genuine concerns.
Concern #1: Vitamin deficiency
鈥淚f you are excluding all fruits and vegetables,鈥 says听Dr. Christopher Labos, cardiologist and associate with our Office, 鈥渢his might be one of the rare circumstances where you might be deficient in certain vitamins and minerals.鈥
But some carnivores will point to the Inuit and their all-meat diet and lack of vitamin deficiency. AsPopular Science听writer Sara Chodosh highlights, however,听, which is rich in vitamin C. I suspect you won鈥檛 see many trendy carnivores shopping for whale skin at their favourite butcher, so vitamin supplements become hard to avoid.
Another counter-argument is that the amount of vitamin prescribed to us is based on diets filled with junk food. If we only eat meat, we are told, our vitamin requirements will go down dramatically. Some have even stated that, since you essentially don鈥檛 consume glucose anymore, your vitamin C requirement is very, very small.
As Klatt tells me, however, this claim comes from the observation that very high glucose levels in cells can limit the ability for these cells to uptake vitamin C. 鈥淭his does not mean that not eating carbohydrates will lead to vitamin C not being a vitamin. Even if you don't eat glucose, you'll still have glucose in your blood and you'll still need vitamin C for its vitamin properties. It's a cofactor for a number of enzymatic reactions in the body.鈥
When it comes to scurvy, however, it does take surprisingly little vitamin C to prevent the disease, about 10 mg, 鈥渕uch lower than the recommended daily allowance,鈥 says Klatt.
Concern #2: Protein and uric acid overload
鈥淓ating a lot of meat, especially organ meats, can increase your uric acid levels which can cause gout,鈥 says Dr. Labos. 鈥淎lso eating a lot of meat, and thereby a lot of protein, can potentially cause damage to your kidneys. If you are eating a lot of salted meat, that may affect your blood pressure.鈥
Concern #3: Cholesterol
I would certainly worry about cholesterol if I were tearing into a steak twice a day although, once again, bloggers are quick to point out that, actually, everything you know about cholesterol is wrong! It鈥檚 good for you!
鈥淐holesterol is most certainly not good for you,鈥 says Dr. Labos. 鈥淭here are over 25 randomized trials starting with the 4S study from the early 1990鈥檚 and, most recently, studies like the Jupiter study or the Odyssey Outcomes trial that show that lowering your cholesterol reduces cardiovascular risk. Maybe with an all-meat diet, your cholesterol won鈥檛 change too much, but that is different than saying that cholesterol has no effect on heart disease.鈥
But many carnivores are posting photos of their lab test results for cholesterol and vitamin levels showing they鈥檙e doing fine鈥 so how do we respond to that? First of all, these are risks, not certainties. Secondly, Dr. Labos says, 鈥渕ost of these risks will manifest over years, which makes them even harder to study.鈥
Concern #4: Increased cancer risk
We also know that a high consumption of meat has been linked to an increase in the risk of developing colorectal cancer. 鈥淗igh meat consumption raises your lifetime risk of colon cancer from 5% to 6%,鈥 Dr. Labos specifies. Not substantial, but these numbers are based on a diet听high听in meat, not one that is听only听meat, which might increase the risk some more.
Concern #5: Food is more than fuel
Finally, there鈥檚 what the carnivore diet will do to your mental health and social life.
Alan Levinovitz, associate professor of religion and author of the bookThe Gluten Lie, constrained himself to follow the carnivore diet for 13 days and, musing on his experience, reminds us all that there is more to food than fuel. 鈥淩educing food to physiology,鈥 he writes in听,鈥 is as shallow as reducing culture to biology. It鈥檚 hard to overstate the sociocultural importance of culinary traditions.听Breaking bread. 鈥楥omfort food.鈥 Grandma鈥檚 recipe. Potlatchs. Wedding toasts. Birthday cake. Thanksgiving dinner. You don鈥檛 have to be a foodie for food to be meaningful鈥攜ou just have to be a human being. And exponentially more than any other restrictive diet, carnivory isolates you from that meaning.鈥
Meaty testimonials
Long-term research on the carnivore diet is simply absent (and, no, that听of two men in 1930 doesn鈥檛 count).
At the end of the day, we are mainly left with anecdotes.
, one of the most commonly cited adopters of this diet, looks great for his age. But he鈥檚 just one person.
Mikhaila Peterson speaks of her meaty diet as the thing that probably got rid of her arthritis. Except look at Patrice Herbst and her piece,And Juliea Baker who, like Mikhaila, suffered from juvenile rheumatoid arthritis until she听who told her to eliminate 鈥渁ll meat, eggs, dairy, wheat, soy, and corn鈥 from her diet, and she claims her life was saved. Aftereliminatingmeat.
Whose story do you trust?
Whose anecdote is generalizable and whose is simply chance?
If you suspect you have a food trigger, I strongly recommend working with a听to follow a proper elimination diet protocol, as unsupervised elimination diets can result in nutrient deficiencies.
As for the carnivore diet, I鈥檓 awaiting better evidence to add more meat on these testimonial bones.
Take-home message:
- The carnivore diet consists of only eating meat (and, for some, only beef)
- The health claims made by its fans are either unscientific or unproven, although you can lose weight on this diet
- There are potential risks to eating only meat, like vitamin deficiencies, kidney damage and increased cholesterol, but it鈥檚 difficult to put a number on these risks
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