Whenever I see an online argument between animal rights vegans and apostates/omnivores, they animal rights vegans claim that it's possible for anyone to be healthy as a vegan. I definitely think it's possible for many people to do veganism and I know several vegans who look and feel fine after doing veganism for several decades. But I know just as many who suffered on a vegan diet no matter what they did.
For an animal rights vegan you just have to keep trying because meat is murder and it's just not acceptable to eat even if you are sick. Whenever you present the list of things that just aren't in a plant based diet they retort that you can easily supplement those things.
Nutritionism at its finest. I respect nutrition science, but it's really in its infancy. There is so much that isn't known. Real whole foods are complex and synergistic. I'm happy there are now supplements to help those who chose to be vegan, but I refuse to accept the notion that veganism is the optimal diet that works for everyone. Maybe in the future when we know everything about nutrition and can put it in a pill, but that's not now.
Things have gotten better for vegans, but that speaks much to the juvenile status of nutrition research. Two decades ago the only supplement that was a known need was b-12, now thanks to scientific research we now know that vegans should supplement DHA as well. Who knows what the next discovery is? (ironically, all these discoveries were made at least in part by animal testing). If you are a vegan now, who really knows what you aren't getting? I think the best strategy for vegans is to supplement everything that is found in meat and that is not found in plants or that is found in lesser quality/quantity. whether or not the research is yet ironclad.
But my own goal has never been to just feel fine. I wanted to heal my illness, which I did on paleo and which was miserable on veganism. As a humanist I also wanted a diet that made me feel really good as a human. I confess I never was a animal rightist, which I feel to be a anti-humanist philosophy. As a humanist, I will always pick humans, like my grandmother who is alive because of a pig valve, over animals. Technology might someday replace the need for animals, but that's not on the radar right now.
I also would like to have truly healthy children and I think the research on prenatal nutrition and veganism is very small, but already points to serious problems. I'm going to place my bets on millions of years of human evolution rather than the tip of the iceburg we know about nutrition.
The nutrient I would like to feature today is taurine. Vegans say that the human body does a good job of synthesizing it and indeed we are able to make it ourselves. But is everyone able to make it in the correct quantities? And is the average amount we can synthesize enough? I would say definitely no on the first count and perhaps no on the second.
What is taurine? This article has a great summary. Taurine is an amino acid which is actually the most abundent intracellular amino acid in the human body. It is involved in many important and varied roles in the body from the metabolism to the blood to skeletal muscles to the heart. Here are a few:
- Taurine promotes the flow and production of bile, which is the fluid produced in the liver that is essential for digesting fats. It prevents the condition known as cholestasis where the bile flow is blocked.
- Taurine comprises 50% of the amino acids in the heart. It is important for maintaining proper blood pressure and rhythm.
- Taurine is important for brain development and neurotransmission. Recent research has shown low levels in people with seizures.
- Taurine is important in the eye's retina. People and animals with deficiencies often display retinal degeneration and lesions.
- Taurine modulates insulin activity and the metabolism of fat and glucose. Preliminary research hints that high cholesterol might be caused by taurine deficiency that reduces synthesis of cholesterol into bile acids.
- Taurine also shows activity as an antioxidant and early research shows it might play a role in male infertility, psoriasis, and depression. It has been shown to help heal colon cells and ulcers in animals.
Some scientists consider its consuming essential, other do not since healthy adults seem to be able to make it.
The average daily synthesis in adults ranges between 0.4-1.0 mmol (50-125 mg)1; under stress the synthesis capacity may be impaired; therewith some authors consider taurine as a conditionally essential amino acid, whereas for others it remains nonessential
Interestingly women synthesize it less efficiently and have higher incidences of conditions that may be caused by taurine deficiency like gallstones.
Taurine seems to be especially important for developing fetuses and infants
In the embryo, taurine deficiency has been associated with various lesions, e.g. cardiomyopathy, retinal degeneration and growth retardation. Taurine is probably an essential amino acid for neonates; due to enzymatic immaturity they have a limited capacity for its synthesis, and due to the immature kidney there is a relative inability to conserve taurine.
Other people who are probably not able to synthesize it include those with kidney and liver diseases and dysfunctions. It's not conditional for these people, it's essential. More research needs to be done on the effect of other illnesses on taurine synthesis.
What about healthy adults? This interesting study shows that even they might be affected by low taurine levels. Apparently vegetarians often have some "platelet hyperaggregability" which is a risk factor in thrombosis (dangerous blood clots), episodic vertigo, dizziness, and sudden deafness. This make sense, as platelets are rich in taurine. The authors say "Taurine is just one of a number of nutrients found almost solely in animal products – “carninutrients” – which are rational candidates for supplementation in vegans." Studies on vegans show that their taurine levels are much lower (earlier studies showed normal levels, but they made lab mistakes that messed up the data as explained here, which invalidates this study on taurine metabolism during reproduction), but I wonder if many omnivores are also too low on taurine as well.
The best sources are dark meats, with higher levels in raw meats, and seafoods like mussels and clams. Many omnivores don't eat these things. Growing up, I certainly didn't. Personally, I think it's an extreme stretch to give rights to mussels, so if you object to meat, why not eat those? Even Peter Singer admits that eating things like scallops might be OK.
Supplementation of taurine might be advisable, but there is some evidence that the supplement can exacerbate Psoriasis whereas the ingestion of taurine rich foods like turkey has not been shown to cause this problem. It shows the weakness in studies that just use isolated nutrients and also points to the fact that while suppplements can help people who want to do sub-optimal diets, there ain't nothing like the real thing...yet.
Addendum: Here is an interesting study that shows idiotic bias towards veganism. The summary reports vegan breast milk has similar (but still lower) levels of mean taurine as omnivore milk. But if you download the whole article you get a different picture. First of all, it seems they make a pretty idiotic mistake in their charts and I'm surprised it got published- the chart for breast milk claims to be in nmol/l contrasting with other papers that use nmol/ml. It makes their values basically nonsensical. Either way, the omnivore mean is 427. The vegan mean? 227, which is a statistically significant difference. Wanna bet the authors of this paper are vegan? The problem with vegan studies is there aren't many done, there aren't big populations of vegans, and the papers and studies done tend to be authored by vegans. Another major problem is that some scientists don't recognize that things like ADHD and crooked teeth are possible caused by poor prenatal or early childhood nutrition, but as science bolsters this connection perhaps we will see more interesting studies.
Another thing to think about is what the omnivore women were eating. If they were eating a standard American diet perhaps they were taurine deficient compared to women eating real foods. In this other paper, Relationship between fatty acid compositions and taurine concentration in breast milk from Chinese rural mothers, it states that breast milk concentrations of taurine in Swedish and Ethiopian mothers was 761 and 667 respectively. The Chinese rural mothers had levels lower than the vegans in that study. The same was found in rural Mexican women.
I would venture to predict that if there ever were second or third generation vegans, their breast milk would have much lower levels. There is strong evidence for transgenerational effects of taurine deficiency, which also points to the fact that vegans aren't the only ones who should be thinking of taurine.