It took me a long time to write this post, and here’s why: There is no greater debate in the nutrition world than that between meat eaters and vegetarians/vegans on which diet is healthier. I’ve been on both sides of the fence. I have, at times, considered vegetarianism to be the healthiest diet, but then when I saw it adversely affect my own health, I changed my tune (read about that here).

I then went on to vigorously defend (organic, sustainable) meat eating and recommended vegans and vegetarians become omnivores because that’s how we evolved to eat, after all. Meat provides us with a fuller spectrum of nutrients we can’t get from a vegetarian diet, and there’s even a study that says vegetarians aren’t as healthy as meat eaters.

Meat eaters swear we evolved as omnivores, while vegetarians point out that they live longer and suffer fewer chronic health problems than their meat eating counterparts. Who’s right?

Well, it’s not that simple. I understand this conundrum intimately, having been a vegetarian for 13 years before reverting back to eating meat, at which point I became convinced that an omnivorous diet provides humans with all the essential nutrients often deficient in vegetarians and vegans: iron, B12, zinc, essential fatty acids. I recommended that most, if not all, of my vegetarian clients include some animal protein in their diets, because I’ve seen first-hand how vegetarian and vegan diets can aggravate or even cause health issues and deficiencies, especially if the meatless diet is poorly designed. This can be true in the case of depression, mood disorders, deficiencies, and digestive issues or bacterial overgrowth where a person may not be able to tolerate large amounts of grains, legumes, and fibers/starches in a plant-based diet. Or if the person is consuming a large amount of soy or processed soy, he/she is at risk of getting too much estrogen which can cause a host of health problems.

But it’s hard to ignore the research that says red meat and processed meats contribute to cancer, heart, disease, and inflammation.

So now I’m reevaluating my stance on vegetarianism again. Nutrition is an ever-evolving field (just look at the war on saturated fat, which has finally been exonerated), and as such, I am constantly evaluating and reconsidering my recommendations. I’ve always maintained that the best diet for human health is plant-based, meaning the bulk of our diets should be vegetables of all types with whatever amount of protein (usually organic meat, eggs, fish) is right for you based on age, activity level, genetics, and gender. But I’ve also always said there is never a one size fits all approach to this stuff: No one diet is right for everyone. Furthermore, your current diet may not be right for you long term. Your diet should change according to stress levels, age, activity level, illness, pregnancy, etc.

Vegetarian and Vegan Diets: Are They Healthy?

You’ve probably seen the barrage of headlines in the past few years correlating red meat to cancer. This of course is mostly true with poor quality processed meats and conventionally farmed meats as part of an otherwise unhealthy diet. But there is so much we are just learning: that red meat may influence your gut bacteria to make compounds that increase plaque formation (read the study here). That processed meats (bacon, sausage, bologna, hot dogs) are a direct cause of cancer because of carcinogenic substances formed during processing, and that red meat breaks down into compounds in the body that damage the gut lining, leading to free radical production and the DNA damage over time that sparks cancer development. (source) That cooking or grilling meat at high temperatures creates chemicals in the meat that may contribute to cancer. That people who eat the most processed meat have around a 17 per cent higher risk of developing bowel cancer. (source) Processed meats are now considered a group 1 carcinogen, same as alcohol and smoking.

Of course, much of the evidence is observational/epidemiological in nature, rather than from randomized trials. This means that causation is hard to pin down. We know that human studies are difficult to carry out accurately due to inconsistencies in the subjects’ reporting (wait, what did I have for breakfast?); food quality (were they eating McDonald’s at every meal?); and other lifestyle factors (smoking, drinking, being stressed). You can’t keep a human in a cage and in a perfectly controlled environment, and lab rats may not give us entirely accurate transferable-to-humans results.

Add to that that some scientists theorize that those who have a diet high in processed meats aren’t as health conscious overall and tend to drink or smoke more, for example. We also know that vegetarians tend to lead healthier lifestyles overall and take better care of themselves. People seem to assume health conscious individuals are vegetarian: When people find out I’m a nutritionist, they usually assume I’m vegetarian. (I love telling them I’m not).

BUT a small study of health conscious vegetarians and omnivores together showed that both groups lived longer than the general population, indicating that as long as you engage in heathy activities and have a healthy diet, meat or not, you’ll have a longer lifespan (source).

That is probably the answer to this debate right there: If you get plenty of disease-fighting antioxidants (highest in fruits and vegetables), eliminate processed food and reduce sugar, and engage in healthy behaviors, it doesn’t matter if you eat meat. I’m wagering the omnivores in this study are eating organic animal products also. Also, a new study is showing vegetarianism won’t help you live longer. (source) Eating meat doesn’t matter as much as eating quality food.

BOTTOM LINE: it’s hard to use human subjects for diet studies. Vegetarians are more likely to take better care of themselves in all areas of their lives, while those who eat a lot of processed meats are likely to be eating more “junk” food overall, and are more likely to smoke and drink more than their vegetarian counterparts, and this has probably affected the outcome of diet studies on human subjects (“healthy user bias”). Above all, eating a healthy diet and engaging in healthy lifestyle habits increases your lifespan, meat or not.

Most of us are probably aware that a processed meat-centric diet with too few plants will not provide us with the diverse array of antioxidants (which are found in the highest concentrations in brightly colored fruits and vegetables) we need to prevent cancer. But one confusing issue about the health of meat is how it’s raised. Unless you’re eating perfectly grass fed and organic every time you chow a burger, you’re getting a healthy dose of hormones, antibiotics, and other toxins stored in the fat tissues of animals. The antibiotics that are fed to animals to prevent disease in deplorable factory farming conditions destroy our gut flora (where the majority of our immune system lives, changing our immune response), and the hormones cause estrogen dominance, putting us at higher risk for hormonal cancers (like breast cancer). We know that certain animal proteins contribute to inflammation, but we don’t have any human studies on this when subjects are consuming only organic animal protein. So we theorize that non-organic, conventionally raised protein that is higher in the inflammatory omega 6 fatty acids and contains all the other junk might be a contributing factor to disease. But we don’t know for sure.

What we do know is eating more plants will reduce your disease risk. Eating fewer processed foods and less sugar slashes disease risk. But in some cases, including animal protein may actually contribute to reversing chronic health conditions. This is especially true in the case of autoimmune diseases, brain or thyroid dysfunction, for example. Adding meat provides you with healing nutrients you can’t find in plant foods or can only find in micro doses: CoQ10, zinc, B vitamins, choline, certain amino acids. These nutrients are vital for healthy metabolism and immune health.

So where does that leave us? Here is what we know about what we should eat:

• Your diet should be plant-based for optimal health. The majority of your plate should be vegetables of all types, both leafy and starchy, at each meal. Plants contain fibers that nourish your microbiome, the base of your immune system. They’re rich in disease-fighting antioxidants.
• You probably need to include animal protein if you have autoimmune disease, digestive issues such as SIBO or IBS, or deficiencies (in iron, B vitamins, zinc, for example).
• You may want to limit your red meat consumption and keep it to fatty fish (like salmon, sardines) and seafood if you’re suffering with any inflammatory condition: cancer, heart disease, arthritis, high blood pressure, diabetes. Include anti-inflammatory foods (like certain fish) and absolutely avoid processed meats and conventionally raised meats. Reduce or eliminate red meat altogether.
• If you’ve had a heart attack, you may fare well on a vegetarian or vegan diet, which has been proven to reverse heart disease. However, the subjects in this study also used stress reduction and exercise, so it’s hard to tell which factor had the most dramatic effect.
• Cutting down or eliminating processed meats can slash your risk of bowel cancer.
• If you do eat meat, strive for organic and grass fed meats, and make meat a condiment rather than the bulk of your plate. The conventionally raised meats contribute to inflammation, which is a cause of nearly every major disease. Click here to read how to build the ideal plate.

BOTTOM LINE: eating more plants will make you healthier. But certain chronic conditions may improve with the inclusion of organic animal protein, while other diseases (heart disease and cancer in particular) are possibly completely reversible on a vegetarian or vegan diet.

Many of my colleagues and mentors have been recently vocal about cutting down on animal protein. I personally have never been a big red meat fan. I eat grass fed beef once, maybe twice a month. My diet has always been mostly plant-based, including legumes (which I love), and lighter proteins such as seafood and poultry. I get house made sausages from my local butcher (no preservatives or nitrates) and really don’t eat a lot of bacon. I do feel better when I include some animal protein, and it helps to keep blood sugar levels stable. But I’ll often go a day or more per week with no animal protein. I use pea protein in smoothies, lentils/legumes, and quinoa as my main plant proteins. I avoid soy and tofu. You really can’t go wrong increasing your intake of veggies, unless you have SIBO or carbohydrate intolerance.

That said, there are times when I absolutely need more protein, if my stress or activity levels increase. I tend to crave red meat when I need it, so I’ll eat it. Tune into your body’s needs.

Most importantly, however, I am no longer a staunch defender of meat-eating only. There was a time when I thought anyone with health challenges needed animal protein, and I encouraged my vegetarian clients to include at least some animal products. Now I’m changing my tune. I see great improvements in people with metabolic and inflammatory issues when they cut down on or eliminate meat: energy levels and blood work markers improve.

I continue to review the research with a critical eye, but I never make blanket recommendations. It’s certainly possible to be an unhealthy vegetarian, just as it is an unhealthy meat eater. Hey, you can be a vegan and subsist on oreos (yes, they’re vegan) and coke. But I believe in our culture we are too meat-focused and not enough vegetable-focused. And my vegetarian clients may have been getting into trouble because they just weren’t designing their diets properly. With a few adjustments, they’d probably be fine continuing as vegetarians.

BOTTOM LINE: I no longer think the health of every vegetarian and vegan can be improved by including (organic) animal protein (in most cases; there are always exceptions!). It’s certainly possible to be healthy as a vegetarian, though I believe vegans need B vitamin and fatty acid supplementation. Meat eaters can be just as healthy choosing organic proteins and making their diets plant-based.

It can be hard to know what you should eat (which is why I have a job), but keep these 2 factors in mind: no one diet is right for you throughout the course of your life, and your needs are different than anyone else’s. You’ll need to tweak your diet depending on your unique physiology and health status and be mindful about how what you’re eating makes you feel.

Finally, I do have to say that factory farming and the conditions under which we raise animals for food in this country are heartbreaking. This alone is why I became a vegetarian at age 15. I have a deep love for animals and often still feel guilty about eating them. I am fortunate enough to live in California where it’s easy for me to buy meat that has been raised humanely, but you can’t be certain about that when you eat at restaurants or don’t have access to local, small scale farming operations. The factory farming industry is cruel to animals and is also ruining human health (see documentaries like Food Inc and Cowspiracy). So please, if you do choose to eat meat, do your best to purchase humanely raised meat. Whole Foods, for example, is good about disclosing where they source meat.

BOTTOM LINE? In the words of Michael Pollan, “Eat food. Not too much. Mostly plants.”

Read more:

Dr Hyman on the pegan diet (which is basically what I follow)
My original meat vs vegetarian article

Mary Vance, NC

Mary Vance is a Certified Nutrition Consultant and author specializing in digestive health. She combines a science-based approach with natural therapies to rebalance the body. In addition to her 1:1 coaching, she offers courses to help you heal your gut and improve your health. Mary lives in San Francisco and Lake Tahoe in Northern California. Read more about her coaching practice here and her background here.

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