Questioner: Hi, Sundari.
I hope you’re well and enjoying your social distancing retreat! I enjoyed reading your newsletter. We think along the same lines.
I just have a couple of comments. I think you might be mistaken in saying:
“there are vital nutrients found in animals not found in other sources,” and
“we need certain animal nutrients to survive.”
I’ve been studying diet and nutrition for a couple of years now, hundreds of hours.
I have not seen or heard, from a source I consider to be reputable (i.e. research scientists not working for the meat and dairy industries) that it is necessary to eat animal food in order to be healthy.
I know there are certain nutrients that are not as available in plant foods as in animal foods, but I don’t think the research shows that higher amounts are necessary.
Apparently vitamin B12 is made by a soil bacteria, and the reason animal food is a source of B12 is that the animals eat unwashed plants.
Maybe you were referring to some particular nutrients that I don’t know about, that may have been newly discovered?
I would like to know your thinking, if you’d care to share.
Sundari: Thank you for your email.
In mithya, there is no absolute truth about anything. However, even relative truth has a basis for veracity. And it is this: Does what you hold to be “true” stand independent of your beliefs or is it based on confirmation bias?
My statement about vitamin B12 is not my belief. It is based on impersonal science. I am not invested one way or the other. Because veganism has become an ideology based on emotions, often confirmation bias is operating in people who adhere to it. They are not open to anything that contradicts what they want to hear.
Vitamin B12
Obviously, we are not going to eat dirt or drink “dirty” water to get our vitamin B12, if that were even possible, which it is not. It is true that most people, both vegans and meat-eaters, are not getting enough B12. In my article, I stress that the only meat products that are not only morally defensible but healthy to eat are those from organically farmed sources because healthy animals do not need to be fed supplements or antibiotics. The animals are healthy, whereas industrially farmed animals are sick. The vitamin B12 they make themselves is destroyed by antibiotics. In addition, if the person has a bad diet, whether vegan or meat-eater, they are going to have a very unhealthy gut.
Absorption of vitamin B12 requires an intact and functioning stomach, pancreas, sufficient quantities of intrinsic factor and, most importantly, healthy small-bowel function. Problems with any one of these organs make a vitamin B12 deficiency possible. For people who have problems absorbing B12 through their digestive system, which is more prevalent as we age, supplemental injections can be given. The problem with fanatical vegans is that most vitamin B12 supplements are made from animal sources, so they won’t take them.
Although vitamin B12 is found in some plants, it is not in the form that the body can use or it requires certain other co-factors to be present to be useful to the body. Vitamin B12 stored in your liver will be completely exhausted after three to seven years, at which point you may start to experience serious neurodegenerative diseases. There are many documented cases of blindness from B12 deficiency, as well as other neurological disorders. Vitamin B12 works together with folate in the synthesis of DNA and red blood cells. It’s also involved in the production of the myelin sheath around the nerves and the conduction of nerve impulses.
In the peer-reviewed published research, the only plant food that has been tested for improving B12 status in humans using the gold standard of lowering methylmalonic acid (MMA) levels is nori, which, contrary to what many want to believe, does not improve vitamin B12 status. A number of foods, arguably, warrant further attention but unless these foods are shown consistently to correct B12 deficiency, vegans should not rely on them for vitamin B12. A common myth amongst vegetarians and vegans is that it’s possible to get B12 from plant sources like seaweed, fermented soy, spirulina and brewer’s yeast. But plant foods said to contain B12 actually contain B12 analogues called cobamides that not only block the intake of but also increase the need for true B12.
Omega-3
Vegans believe they will convert short-chain omega-3 fats into the long-chain omega-3 fats. They absolutely and positively cannot. Our brain is about 70 per cent fat; 50 per cent of that fat is DHA. There are beautiful longitudinal studies showing people with the highest omega-3 index have the largest brains as they age, and the largest areas of memory in the hippocampus. People with the lowest levels of omega-3 index have the most shrunken brains and the smallest areas of memory.
Research confirms that, to optimize health, seafood is one of the healthiest foods on the planet, primarily because of its docosahexaenoic acid (DHA) content – a 22-carbon omega-3 fat that is absolutely essential for your health, as it’s a structural component of your cell membranes. If you have low DHA levels, it’s almost physiologically impossible to be healthy, because it’s such an important part of energy generation at the molecular level. You need DHA, which is only found in fatty fish and certain other marine animals like krill. Granted, water pollution is a major concern today, so you must eat really low on the food chain. Anchovies, sardines, herring, wild Alaskan salmon, fish roe and krill are all good choices, as they’re high in omega-3s while being low in mercury and other pollutants.
Like It or Not, You Need Marine-Based DHA
If you exclude these foods, you’re just not going to be healthy. And contrary to popular belief, you simply cannot obtain all the DHA you need from plant sources. Plant-based omega-3 (alpha-linolenic acid, or ALA) has 18 carbons, whereas marine-based omega-3s (DHA and eicosapentaenoic acid or EPA) have 22 and 20 respectively. The difference in the length of the carbon chain makes a significant difference in terms of functionality. ALA functions as a source of fuel (food), whereas EPA and DHA are structural elements. More than 90 per cent of the omega-3 fat found in your brain tissue is DHA, which suggests how important it is for healthy neurological function, for example. The problem is that, although your body can convert some of the ALA found in plants to the DHA found in marine oils, it is very rare for it to be more than five per cent – the typical conversion rate is one to three per cent or even less. This simply isn’t enough to have any significant benefit.
What is as important is the proportion of omega-3 and omega-6 ingested. In excess omega-6s cause widespread inflammation. The perfect one-to-one proportion of omega-3s and omega-6s is optimal for health. In many plant sources, the ratio between omega-3s and omega-6s is out of proportion.
Fat-Soluble Vitamins A and D
Perhaps the biggest problem with vegetarian and vegan diets is their near total lack of two fat-soluble vitamins: A and D. Fat-soluble vitamins play numerous and critical roles in human health. Vitamin A promotes healthy immune function, fertility, eyesight, normal cell division, bone remodelling, the formation of enamel on teeth during their development in childhood and skin health. Vitamin D regulates calcium metabolism, regulates immune function, reduces inflammation and protects against some forms of cancer.
These important fat-soluble vitamins are concentrated, and in some cases found almost exclusively in animal foods, primarily seafood, organ meats, eggs and dairy products. Some obscure species of mushrooms can provide large amounts of vitamin D, but these mushrooms are rarely consumed and often difficult to obtain. (This explains why vitamin D levels are 58% lower in vegetarians and 74% lower in vegans than in omnivores.)
The idea that plant foods contain vitamin A is a common misconception. Plants contain beta-carotene, the precursor to active vitamin A (retinol). While beta-carotene is converted into vitamin A in humans, the conversion is inefficient. Even healthy adults can’t do this efficiently, and the young and the old may not be able to do it at all. For example, a single serving of liver per week would meet the RDA of 3,000 IU. To get the same amount from plant foods, you’d have to eat two cups of carrots, one cup of sweet potatoes or two cups of kale every day. Moreover, traditional cultures consumed up to 10 times the RDA for vitamin A. It would be nearly impossible to get this amount of vitamin A from plant foods without juicing or taking supplements.
Essential Amino Acids/Proteins
While animal protein has traditionally been regarded as higher-quality and superior to plant-based protein, plant protein has been getting a major reputation boost recently, both as isolated products (hemp protein, pea protein, brown rice protein and so on), and in whole-food form (ever see the “broccoli has more protein than beef” meme that occasionally pops up on Facebook?). This has led some people to believe that plants are just as good as animals (if not better!) when it comes to supplying protein. When we look at the evidence though, it becomes clear that plants are great sources of plenty of important things, but protein isn’t one of them. Plant protein takes a back seat to animal protein in terms of quality, digestibility and density. Here’s why:
Understanding Protein
Protein is made of long chains of amino acids (organic compounds that contain a carboxyl and amino group). Even though we’ve identified about 500 different amino acids, only 20 are used to build the proteins in our bodies, and only nine of those are considered essential (meaning we can’t synthesize them from other amino acids and have to get them from food). The essential amino acids are:
- tryptophan
- threonine
- isoleucine
- leucine
- lysine
- methionine
- phenylalanine
- valine
- nistidine
When we talk about a food being a “complete protein,” it means that the food contains an adequate proportion of all nine of the essential amino acids. In general, animal foods supply complete protein, whereas plant foods tend to be low in at least one essential amino acid. That’s why we see advice for vegetarian foods to be paired together (or at least eaten within the same day) to fill in each other’s gaps (such as the classic combination of rice and beans: beans are low in methionine but high in lysine, whereas rice is low in lysine but high in methionine).
The small number of plant foods that contain all or most of the essential amino acids necessary to build complete proteins are notably spirulina, chlorella, moringa, quinoa, buckwheat, hempseeds, chia seeds, pumpkin seeds, cashew nuts, among a few others. However, seeds like chia must be soaked first for the nutrients to be bio-available, and quinoa contains saponins, which are lectins (like gluten), making quinoa very problematic to digest for many. To obtain the full complement of amino acids, vegans and vegetarians need to eat a variety of plants, soak, ferment and combine plants intelligently, which takes knowledge, diligence and effort.
But even the idea of complete protein can be misleading. Some amino acids become essential during times of illness or stress (arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline and serine). And even non-essential amino acids are important to consume in our diet, both because the process of synthesizing them can be inefficient and because many of them play roles in the body that go beyond protein synthesis. Carnosine, carnitine, taurine, conjugated linoleic acid are all lacking in vegetarian and especially vegan diets, which may lead to mitochondrial dysfunction.
Sadly, the vegetarian myth that plant protein is superior to animal protein is untrue. How well a protein is absorbed is determined by its amino acid profile. Animal proteins are much more digestible than those of plant sources because animal-based proteins are more similar to our proteins than plant proteins, and are thus assimilated more readily. Some animal proteins have around 90% to 99% digestibility, whereas plants have at best a digestibility range from 70% to 90%.
Calcium
On paper, calcium intake is similar in vegetarians and omnivores (probably because both eat dairy products), but is much lower in vegans, who are often deficient. We know of many ex-vegans who suffered serious, sometimes permanent, skeletal problems due to calcium deficiency. Calcium bioavailability from plant foods is affected by their levels of oxalate and phytate, which are inhibitors of calcium absorption, and thus decrease the amount of calcium the body can extract from plant foods. So while leafy greens like spinach and kale have a relatively high calcium content, the calcium is not efficiently absorbed during digestion. One study suggests that it would take 16 servings of spinach to get the same amount of absorbable calcium as an 8-ounce glass of milk. That would be 33 cups of baby spinach or around five to six cups of cooked spinach. There are a few vegetables listed in this paper that have higher levels of bioavailable calcium, but it’s important to note that all the vegetables tested required multiple servings to achieve the same amount of usable calcium as one single serving of milk, cheese or yogurt. This suggests that trying to meet your daily calcium needs from plant foods alone (rather than dairy products or bone-in fish) might not be a great strategy. Many people are moving away from dairy products, for various reasons, so getting enough can be a problem.
Iron
Vegetarians and omnivores have similar levels of serum iron, but levels of ferritin – the long-term storage form of iron – are lower in vegetarians/vegans than in omnivores. This is significant because ferritin depletion is the first stage of iron deficiency. Moreover, although vegetarians often have similar iron intakes to omnivores on paper, it is more common for vegetarians (and particularly vegans) to be iron-deficient. For example, this study of 75 vegan women in Germany found that 40% of them were iron-deficient, despite average iron intakes that were above the recommended daily allowance. Why would this be? As with calcium, the bioavailability of the iron in plant foods is much lower than in animal foods. Other commonly consumed substances also inhibit plant-based forms of iron, such as coffee, tea, dairy products, supplemental fibre and supplemental calcium. This explains why vegetarian diets have been shown to reduce non-heme iron absorption by 70% and total iron absorption by 85%.
Zinc
Overt zinc-deficiency is not often seen in Western vegetarians, but their intake often falls below recommendations. This is another case where bioavailability is important; many plant foods that contain zinc also contain phytate, which inhibits zinc absorption. Vegetarian diets tend to reduce zinc absorption by about 35% compared with the omnivorous diet. Thus even when the diet meets or exceeds the RDA for zinc, deficiency may still occur. One study suggested that vegetarians may require up to 50% more zinc than omnivores for this reason.
Glycation and Insulin Resistance
Many vegetarians and vegans are addicted to sweets, and because their diets rely so heavily on carbs, the likelihood of insulin-leptin resistance is great. Glycation is the binding of protein by glucose molecules, making it unavailable for absorption.
Hyperglycemia
This is literally too much sugar in the blood, causing extreme tiredness, constant hunger, urinating and thirst that “pure” vegans typically suffer, not to mention widespread inflammation and degenerative joint disease as a result of diets too reliant on carbohydrates.
~ Om, Sundari
