Don’t Think Twice About Going Vegan

2 carrots provide all the vitamin A you need for one day.

A number of readers have asked if I’d respond to the article Why You Should Think Twice About Vegetarian and Vegan Diets, by Chris Kresser. Kresser is a licensed acupuncturist who writes frequently about diet. And since I would never go around poking needles into people, I wish he would return the favor and stop giving advice about nutrition.

Kresser promotes a semi-Paleo eating pattern so it’s no surprise that he’s not a fan of vegetarian diets. But in his effort to prove that plant-based eating is unhealthy, he uses some very faulty logic. Jack addressed Kresser’s observations about vegetarian diets and longevity, so I’ll look at some of the other tired old arguments that Kresser drags out to discredit veganism.  Here are some examples (Kresser’s comments are in bold).

A common myth amongst vegetarians and vegans is that it’s possible to get B12 from plant sources like seaweed, fermented soy, spirulina and brewers yeast.

True enough. But picking at the harmful myths that circulate in the vegan community does not provide evidence that vegan diets are dangerous. It just provides evidence that being uninformed about nutrition is dangerous. Vegans who take vitamin B12 supplements do just fine, and as Jack noted, they probably are doing better in this regard than many meat-eaters.

[Plant-based diets] typically include large amounts of cereal grains (refined and unrefined) and legumes, both of which are low in bioavailable nutrients and high in anti-nutrients such as phytate […]

I’ll get to phytate in a minute. But first, do vegans and vegetarians eat more refined grains than meat-eaters? I doubt it. People eating any type of diet—omnivore, lacto-ovo vegetarian, and vegan—can make good or bad choices. It doesn’t say anything about the potential of a particular eating pattern to be adequate and healthy. Everyone—meat eaters, vegetarians and vegans—should minimize refined grains in their diets. This has absolutely nothing to do with whether or not vegetarian diets are healthy. And the evidence just doesn’t support the idea that eating moderate amounts of whole grains is harmful.

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.

Anyone claiming expertise in plant-based nutrition knows that calcium is very well-absorbed from cruciferous vegetables, which include kale. In fact, the chart Kresser links to when making his point about spinach shows the absorption rate for kale—49.3 percent—sitting right smack above the one for spinach.

We do need to eat bigger servings of most (not all) vegetables to get the same amount of calcium from a glass of milk. But who says that every serving of a calcium-rich food has to provide the same amount of calcium as a glass of milk? We get small amounts of calcium from many different foods, most of which are also good sources of other bone-building nutrients. As long as they add up to provide enough calcium, it hardly matters that you need to eat 1 ½ cups of cooked kale to get the calcium that would be provided by a glass of cow’s milk.

Vegetarians eat a similar amount of iron to omnivores, but as with calcium, the bioavailability of the iron in plant foods is much lower than in animal foods. […] This explains why vegetarians and vegans have lower iron stores than omnivores.

But Kresser doesn’t address the fact that having lower iron stores is not necessarily a bad thing. There is evidence that lower iron stores can protect against chronic disease.(1) The ideal situation might be to have lower but adequate stores.

Furthermore, the lower iron stores in vegans and vegetarians are due largely to the presence of phytate in foods. This compound binds iron and other minerals which reduces their absorption. However, phytate, long demonized as an antinutrient, is actually an antioxidant with health-promoting properties.(2) We can free iron from phytate by including vitamin C rich foods in a meal, sprouting grains and beans, or fermenting them—which is what happens when we make whole grain flour into any type of leavened bread. It’s possible that the ideal situation is a diet that includes phytate along with factors, like vitamin C-rich foods, that increase iron absorption from plants.

Freeing zinc from phytate is admittedly more difficult because zinc doesn’t seem to be affected by vitamin C in the diet. Its absorption is, however, enhanced by sprouting, leavening and fermenting.

Perhaps the biggest problem with vegetarian and vegan diets, however, is their near total lack of two fat-soluble vitamins: A and D.

Oops—it’s a common mistake to think that vitamin D is a vegan issue. We vegans get our vitamin D the same way that meat-eaters do: from sun exposure or fortified foods. Cow’s milk is fortified with vitamin D just like soymilk. Granted, you could technically get vitamin D by eating fish but you’d have to eat salmon or swordfish every day. That’s hardly a sustainable answer to meeting vitamin D needs.

While beta-carotene is converted into vitamin A in humans, the conversion is inefficient. 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 2 cups of carrots, one cup of sweet potatoes or 2 cups of kale every day.

It actually takes somewhat less than one cup per day of winter squash, carrots, kale, or spinach, or ½ cup of sweet potatoes to meet daily vitamin A needs. And the provitamin A in these foods is an antioxidant associated with lower risk of chronic disease.(3) You won’t get that benefit from liver.

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.

And why would we want to? There are no advantages to getting ten times the RDA of any nutrient. In fact, if all of this vitamin A were coming from animal foods, it would put people dangerously close to the upper limit of safety for vitamin A. If anything, this observation suggests that it’s not always ideal to look to traditional or ancestral cultures for information about how we should eat.

However, an increasing body of research has highlighted the benefits of the long-chain omega-3 fatty acids EPA & DHA. These fatty acids play a protective and therapeutic role in a wide range of diseases: cancer, asthma, depression, cardiovascular disease, ADHD, and autoimmune diseases, such as rheumatoid arthritis.

This is way overstating the evidence. Results of studies on benefits on these fats have been conflicting(4,5) and we currently have more questions than answers about their roles in healthy diets. I’m not saying that omega-3’s aren’t important. I think they may be, but I wouldn’t state their benefits in quite so definite terms. Nevertheless, there are vegan sources for those who want to supplement their diets.

From an evolutionary perspective, it is difficult to justify a diet with low levels of several nutrients critical to human function. While it may be possible to address these shortcomings through targeted supplementation (an issue that is still debated) it makes far more sense to meet nutritional needs from food.

This begs the question: If the ideal diet doesn’t require supplements, and Kresser promotes the ideal diet, then why is he selling all types of expensive supplements in his online store?

We did not evolve on a vegan diet, that’s true. But we live in a much more complex world than that faced by our Paleolithic forebears. We need to look at dietary choices in terms of our personal health but also in terms of the health of the planet and the creatures who share it with us. Fortunately, we also have the knowledge and resources that allow us to make responsible dietary choices that are a good fit to this modern world. If it takes a little bit of extra work, so be it. Eating a little extra kale and taking a vitamin B12 supplement (which I would have to do anyway since I’m over 50) don’t seem like hardships for anyone who wants to eat ethically, compassionately, and responsibly.

1.   Postmenopausal Vegetarians’ Low Serum Ferritin Level May Reduce the Risk for Metabolic Syndrome. Kim MH, Bae YJ. Biol Trace Elem Res   2012.
2.   Protection against cancer by dietary IP6 and inositol. Vucenik I, Shamsuddin AM. Nutr Cancer 2006;55:109-25.
3.    Dietary carotenoids and risk of coronary artery disease in women. Osganian SK, Stampfer MJ, Rimm E, Spiegelman D, Manson JE, Willett WC. Am J Clin Nutr 2003;77:1390-9.
4.    Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS. Jama 2012;308:1024-33.
5.    Role of n-3 fatty acids in the treatment of hypertriglyceridemia and cardiovascular disease. Jacobson TA. Am J Clin Nutr 2008;87:1981S-90S

 

41 Responses to Don’t Think Twice About Going Vegan

  1. am March 6, 2014 at 10:46 am #

    I find it amusing that having to eat a large amount of fruits and vegetables to meet RDAs is viewed as a negative aspect of a vegetarian/vegan diet type. For example, Mr. Kresser writes, “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 2 cups of carrots, one cup of sweet potatoes or 2 cups of kale every day.”

    I had a prof who always said, “fruits and veggies fill you up before they fill you out.” She never said the same about liver. :)

    • Meg March 13, 2014 at 12:47 am #

      Well said- and as a person who is newly returning to a vegan diet from a year of inhaling complete junk (along with meat) I have to add… you could get the same amount from a serving of liver a week.. but honestly, how many people would want to? Liver.. ugh.

    • danO April 4, 2014 at 10:54 am #

      yes i found the statement rather odd for its accusatory tone – who are these people who would actually abhor the idea of wanting to eat 5 cups of veggies? So much for breakfast, let’s talk about the rest of the day

  2. Molly March 6, 2014 at 11:49 am #

    Nicely written – thank you!

  3. Gabi March 6, 2014 at 12:08 pm #

    Ginny, I read that dairy is actually even worse in terms of calcium than greens, because of the high acidity of animal proteins that come with it which in fact drain the calcium from the bones instead of supplying them with calcium. Also, that osteoporosis rates are highest in countries with the highest dairy consumption, and that osteoporosis in East Asia, where people don’t traditionally consume dairy, is practically nonexistent. Any thoughts?

    • Karl March 6, 2014 at 1:57 pm #

      This is a myth. Ginny wrote about this last year:

      “Unfortunately, it’s not true. Or at the very least, the evidence in support of this relationship has fizzled over the years. I’ve written about this before, but it remains such a pervasive and potentially harmful belief that it deserves an occasional revisit.”

      Read it all here: http://www.theveganrd.com/2013/08/calcium-and-protein-and-bone-health-in-vegans.html

      • Ginny Messina March 6, 2014 at 5:08 pm #

        Thanks, Karl. And Gabi take a look at the post that Karl shared when you have a chance. The idea that protein has a negative impact on bone health is a common myth in vegan nutrition.

  4. Matt March 6, 2014 at 12:15 pm #

    “If the ideal diet doesn’t require supplements, and Kresser promotes the ideal diet, then why is he selling all types of expensive supplements in his online store?”

    ROTFL! Another huckster busted.

    • Corrin Radd March 8, 2014 at 10:48 am #

      +1,000,000

    • gk June 16, 2014 at 5:40 am #

      he is selling supplements because most ppl dont have an ideal diet?

  5. Natalie March 6, 2014 at 12:20 pm #

    I’m sorry if I cannot quote any research on this, and I am by no means a nutritionist, just trying to tread through all of the information that I find! From what I understand from recent years trends on the fish-oil bandwagon has been because ideally our omega 3 to omega 6 ratio should be 1:1. Because eating animals products are high in omega 6, and this in turn creates inflammation in the body, it then in turn created the market for omega 3 supplementation. So it’s not the amount of omega 3, but the ratio of omega 3 to omega 6. This is all in how I interpret the information that I am reading! So if you are not eating animal products, then you are not over-injesting omega 6. So if you are not eating animal products, your omega 3 to omega 6 ratios are probably at good levels. In this case, having chia/hemp/flax seeds on a daily basis is all you really need, no further supplementation is required.

    • Ginny Messina March 6, 2014 at 5:10 pm #

      Natalie, it’s really certain vegetable oils that are high in omega-6 fats. But at any rate, manipulating the ratio of omega-3 to omega-6 fats doesn’t seem to raise DHA and EPA levels enough–at least in the research. It’s still an area where we’re trying to figure out what the best advice is. But I think that some vegans may benefit from DHA/EPA supplements.

    • Theresa Anderson (NET) March 12, 2014 at 8:59 pm #

      I agree…1 TB of ground flax is great for women because of the lignans and breast cancer prevention. You cannot “wander” into any optimal diet these days, it’s important to be informed.
      Nutritional science has come a long way in the last 15-20 years with new important studies coming out all the time. I like
      NutritionFacts.org for the latest…

      Good refutation…great wording.

  6. Cyndi March 6, 2014 at 1:08 pm #

    The calcium argument–using a glass of cow’s milk as the gold standard–is so annoying. Isn’t it the case that a cow’s feed must be supplemented with calcium if she doesn’t live on grass?

  7. CR March 6, 2014 at 1:12 pm #

    Great response. One minor, minor, minor thing. (sorry, this a pet peeve on my part) “Begging the question” means something different then how you used it.
    http://en.wikipedia.org/wiki/Begging_the_question

    • Ginny Messina March 6, 2014 at 5:06 pm #

      Oh, no! I hate making mistakes like that. I just checked the Grammar Girl website (my grammar bible) and she agrees with you and wikipedia. (Merriam-Webster, on the other hand, says that my use of the phrase is okay, but Grammar Girl isn’t buying it and you probably aren’t either. :) Thanks for the info about this.

      • Dustin March 7, 2014 at 3:52 am #

        WOW! I actually LEARNED SOMETHING in a COMMENTS SECTION.

        :: Faints ::

        :-)

    • Corrin Radd March 8, 2014 at 10:52 am #

      That’s a prescriptivist point of view, and one that’s fading from favor. Ginny’s usage is widely accepted, used, and understood and that’s all that counts in language shifts.

      • VeggieMom66 March 10, 2014 at 4:09 pm #

        I was just about to say that Corrin! Language changes…I’m not in favor or poor grammar, but phrases and meanings definitely evolve.

  8. Dr Jon Maxted March 7, 2014 at 7:37 am #

    I’ve been Vegan for over 10 years, am over 50 and need no supplements – I do not suffer from B12 shortage – I am not anaemic. I don’t understand the affirmation that Vegans don’t get B12 from their diet!

    • Ginny Messina March 12, 2014 at 11:10 am #

      But if you’re a health professional, then you know that anecdotes are not science. Sometimes people who *think* they aren’t supplementing with B12 are eating just enough fortified foods to get by. The research, on the other hand, shows that vegans (and sometimes vegetarians) who don’t supplement with B12 run the risk of deficiency. So it is dangerous to imply that vegans don’t need to take supplements or use fortified foods.

      • Dr Jon Maxted March 12, 2014 at 12:03 pm #

        I’m not implying that – I’m saying that not everyone needs extra B12. It can be an expensive extra for those who are not wealthy but are healthy. All I am pointing out is that not ALL vegans need supplements!

        • Ian Thonney March 18, 2014 at 3:04 pm #

          Expensive? B12 supplementation is very cheap. Solgar 1000mcg is less than 10cents a day if taken daily, which it does not need to be at that dose. Deva B12 is a similar price. As are many other brands. If you try hard you can find expensive B12, but that would be your free choice and absolutely not a necessity.

  9. Kelly March 7, 2014 at 8:58 am #

    Ginny, I am so glad you responded to the Kresser article and I really enjoyed reading this. Sending you lots of appreciation for all of your work and the information you make available to set the vegan record straight.

  10. INVEG Josh March 7, 2014 at 2:52 pm #

    Great rebuttal. Thank you for sharing your thoughts:) We are really excited to meet you in person at the Spokane Vegfest! :)

  11. Larry March 7, 2014 at 3:12 pm #

    Great response. Thanks for your email newsletters

    Larry

  12. Lisa @The Valley Vegan March 8, 2014 at 8:47 am #

    Thanks Ginny! I get really annoyed when people assume being vegan means I eat all kinds of processed & refined foods. People project – they figure if they went vegan right now, they’d replace their meat & dairy with cereals & flour & fake meats, not taking into consideration that living the life for almost 24 years now, I might know a thing or two about my personal nutrition. I often turn it around on people and say “I know nothing about being diabetic, so I don’t give you advice on how to eat.”

    I’ve also discovered that meat eating family & friends have less of a grasp on what supplements to take, or where nutrients are coming from in their foods. They really think they get everything they need from meat. Like with parenting, often my response to unsolicited diet advice is “if I want your input, I’ll ask.”

  13. Adam March 9, 2014 at 3:38 pm #

    Great post. What is most frustrating about Chris Kresser is that he has such a large number of readers – mostly people with little scientific training that shudder at the thought of reducing their meat consumption. I wrote a similar rebuttal on my blog:
    http://www.debunkingnutrition.com/2014/02/does-plant-based-diet-lead-to-nutrient.html

  14. Kevin March 9, 2014 at 7:20 pm #

    Coming from biological anthropology to nutritional sciences, I find Kresser to be extremely frustrating.

    He relies so much on fear mongering, as if there are all of these mineral/vitamin A/D deficient veg*n individuals out there. He always fails to acknowledge the detrimental effects of his nutritional advice – his posts on liver consumption are dangerously close to hypervitaminosis A and don’t address the potentially negative effects on bone density.

    He also talks about issues that do not have nearly enough research backing them to make a complete picture. He warns against almond consumption because of PUFA oxidation, though the IOM states that as part of their reasoning for setting the upper end of the AMDR. I think Jack addressed his Vitamin K2 fear mongering already.

    I also don’t understand how pushes this pro-Paleo perspective, which I thought was inherently against dairy consumption, but then warns about oxalates. Does he really think every human on the planet needs to be getting their calcium only from salmon bones?

    His RDs responses will also make your skin crawl: https://chriskresser.com/ask-the-rd-are-seeds-healthy-and-animal-foods-for-vegetarians

  15. Louis March 10, 2014 at 11:44 am #

    First of all most meat eaters don’t eat much veggies at all, talk about not getting enough nutrients and I have been vegetarian for 22 yrs and vegan for about 6 and I am not deficient in anything and I am very healthy and look half my age, that’s what matters not what some dork writes about..proof matters not someone’s opinion or biased study

    • Rhianna March 25, 2014 at 8:18 pm #

      What do you mean that “most meat eaters don’t eat much veggies at all”? How can you assume that?

      I am a meat eater and a veggie, lentil, and fruit eater. I don’t eat grains or starches while my gut is healing (can’t handle them right now), and don’t want or need meat all the time, so I eat veggies! I may even eat more veggies than you do!

  16. Michele ramirez March 10, 2014 at 12:26 pm #

    Great article. I’m sharing this this information to friends and family that are trying to make the change to a healthy vegan diet. VEGAN POWER!!!! :D

  17. Erica March 10, 2014 at 9:20 pm #

    A facebook friend triumphantly shared that “article” as if it were the ultimate comeback for any vegan argument. I wrote my own blog refuting it and I’m going to link to this one. Thank you for keeping this blog, It’s a great resource.

  18. Offutt March 11, 2014 at 10:24 am #

    I used to work in a healthfood store and the woo Kresser is promoting makes me sick. I’ve seen my own co workers become sick and suffering from conditions of malnourishment because of foolish advice on cleansing then deciding to start eating meat because they’ve messed up their health. They then feel better, but it’s obviously an unsustainable way to eat and they could have thrived off of a plant based diet if they had not been so called cleansing all the time and eating the bare minimum of food.

  19. Dana March 17, 2014 at 5:52 pm #

    As an acupuncturist, I find this guy personally offensive. For the record, the traditional diet all across Asia is high in grains and veggies, uses meats sparingly and includes no dairy. Acupuncturists who promote paleo are just on a pop culture bandwagon. They are invariably white and privileged.

    • Dan March 21, 2014 at 7:14 am #

      What’s wrong with being white and privileged? I find the bulk of your comments to be excellent with the sole exception of the last line of text. Shall we not end trying to find divisions within our human species (homo sapiens) – end the divisive practice of “us vs. other”, regardless of whether we approve of “other” or not?

      • Dana April 23, 2014 at 12:27 pm #

        The problem with white and privileged in this context is that this guy is trying to represent the cultures of Asia, when he really has no idea what he is talking about. Going to acupuncture school does not make you an expert on Asia.

  20. Rhianna March 25, 2014 at 8:26 pm #

    Having attempted veganism for two long-term periods in my four-plus decades of life, and burned out in nutritional and hormonal depletion both times, despite having done what I could to eat a balanced, whole foods plant-based diet, I find Chris Kresser’s blogs a relief.

    Not everyone can sustain a vegan diet for the long term.

    For those who can sustain a vegan diet in sound body and mind, it must be a satisfying placefor you.

    For those who have different constitutions, or have a damaged gut and cannot digest starches, one must seek alternatives to a vegan diet.

    I feel a bit upset that even though I attempted vegan diets twice, the second attempt being educated and informed, it still didn’t work. The vegan writers claimed it would work. I lost faith.

    Now I trust my own body. I kept trying diets until I found what helped me feel my best. And it is isn’t vegan for me.

    • meg June 1, 2014 at 2:11 am #

      Couldnt agree more! I have found his articles to be very helpful to me. Reading his multi part article about GERD saved my son from what could have been a health disaster.

      I tried vegetarianism with the intent to be completely vegan. I lasted less than two weeks both times. I felt completely malnourished. Luckily I decided not to try it on my son before finding success myself. Good thing, because he was 27 weeks premature and has always has several issues, especially ones related to neurological function. I have suffered with depression for most of my life.

      Recently, after reading up on brain anatomy and function, I adopted a high fat, moderate to high protein (mostly from pastured beef and high quality fish), high veggie diet. Gluten free, only raw dairy, very low sugar and somewhat low carb (mostly from veggies). The high fat, high protien made a HUGE difference in my son’s neurological symptoms and my depression. Makes sense when you realize what our brains are made of.

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