Ginny Messina: Calcium and Protein and Bone Health in Vegans
In her latest blog post, Calcium and Protein and Bone Health in Vegans, Ginny has a good reminder about the need for vegans to make sure they’re getting enough calcium and protein. Excerpt:
“The theory is that animal protein, through its acidifying action, “leaches” calcium from bones, eventually weakening them and causing bone fractures. If that’s true, it means that those of us who eat no animal protein are likely to have better bone health. And maybe even lower calcium needs.
“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.”
August 21st, 2013 at 4:28 am
Thanks, Jack. That is most helpful.
I’ve been concerned about my calcium intake since taking the leap to full veganism (from lacto-vegetarianism). However, I replaced yogurt with a cup of almond milk, which contains about 30% RDI. Here is my question – I consume that almond milk with a lot of pulverized nuts and seeds, and I am wondering about phytate intake. I also eat a lot of legumes, including, occasionally, raw lupin beans (they come semi-preserved in salt water). Would this phytate (phytic acid) load be reducing my calcium absorption?
I eat soybeans with salad for lunch and cooked chickpeas with dinner. So at every meal, I am getting either nuts or legumes. What is your take on phytates?
(I know some people soak nuts/seeds overnight and then toast them, to active phytase enzymes which degrade phytates. Is this really necessary to do? Are both parts – soaking and toasting necessary? Or can beans, seeds, and nuts just be eaten in the raw? And if a calcium-fortified food like almond milk or soy milk is consumed in the presence of beans/seeds/nuts, does this decrease absorption of the minerals and vitamins they have added to it – ie calcium, zinc, vitamin A palmitate, riboflavin, etc?)
Many thanks
Dan
August 21st, 2013 at 11:32 am
Dan,
I haven’t seen any research directly looking at the effects of phytates on calcium absorption. However, when you consider that soy has the most phytates of any plant food (that is commonly eaten, and to my knowledge), and that the calcium from soy milk is absorbed fairly well, I don’t think phytates are much to worry about. Also, the vegans in EPIC who got over 525 mg per day had the same rates of fracture as the lacto-ovo and non-vegetarians. So as long as you can boost your calcium up above 525 mg, it seems to be enough regardless of the phytates.
August 21st, 2013 at 11:42 am
Jack,
Thanks – that’s most helpful reassurance.
Re: “as long as you can boost your calcium up above 525 mg”…. I thought the RDI was 1000 mg and we should not go above 1300 mg? Am I confusing elemental calcium with calcium carbonate here? At any rate, I am sitting around 1000 mg per day, which well exceeds the 525mg mentioned.
It seems non-vegetarians are very worried about phytate loads – might be a kind of ‘paleo’ propaganda to demonize legumes/pulses/lentils/nuts/seeds. Your response has put my mind at ease.
Dan
August 21st, 2013 at 11:47 am
> Am I confusing elemental calcium with calcium carbonate here?
You are not. I recommend that people strive to get closer to the DRI of 1,000 mg just to be safe, but even vegans who got much less had the same rate of fractures.
> It seems non-vegetarians are very worried about phytate loads – might be a kind of ‘paleo’ propaganda to demonize legumes/pulses/lentils/nuts/seeds.
You nailed it.
August 21st, 2013 at 11:57 am
Jack,
Actually, the latest paleo argument I am hearing now against whole grains and legumes is that manganese in them contributes to childhood Autism. Since everything under the sun from MMR vaccines to vitamin D deficiency has been speculated to be associated with childhood Autistic disorder, I am very skeptical about this evidence, especially considering the source of it.
Wikipedia – which I’m not sure is reliable but is very widely used – cites a study about third-world consumption of phytate-rich legumes and B vitamin deficiency (I believe pellagra). Here it is:
“Phytic acid has a strong binding affinity to important minerals, such as calcium, iron, and zinc, although the binding of calcium with phytic acid is pH-dependent[18] and ascorbic acid (vitamin C) can reduce phytic acid’s effect on iron.[19] When iron and zinc bind to phytic acid they form insoluble precipitate and are far less absorbable in the intestines. This process can therefore contribute to iron and zinc deficiencies in people whose diets rely on these foods for their mineral intake, such as those in developing countries.[20][21] Contrary to that, one study correlated decreased osteoporosis risk with phytic acid consumption.[22] It also acts as an acid, chelating the vitamin niacin, the deficiency of which is known as pellagra.[23] In this regard, it is an antinutrient, despite its possible therapeutic effects (see below). For people with a particularly low intake of essential minerals, especially those in developing countries, this effect can be undesirable.”
18.^ Dendougui, Ferial; Schwedt, Georg (2004). “In vitro analysis of binding capacities of calcium to phytic acid in different food samples”. European Food Research and Technology 219 (4). doi:10.1007/s00217-004-0912-7.
19.^ Prom-U-Thai, Chanakan; Huang, Longbin; Glahn, Raymond P; Welch, Ross M; Fukai, Shu; Rerkasem, Benjavan (2006). “Iron (Fe) bioavailability and the distribution of anti-Fe nutrition biochemicals in the unpolished, polished grain and bran fraction of five rice genotypes”. Journal of the Science of Food and Agriculture 86 (8): 1209–15. doi:10.1002/jsfa.2471.
20.^ Hurrell RF (September 2003). “Influence of vegetable protein sources on trace element and mineral bioavailability”. The Journal of Nutrition 133 (9): 2973S–7S. PMID 12949395.
21.^ Committee on Food Protection, Food and Nutrition Board, National Research Council (1973). “Phytates”. Toxicants Occurring Naturally in Foods. National Academy of Sciences. pp. 363–371. ISBN 978-0-309-02117-3.
22.^ López-González AA, Grases F, Roca P, Mari B, Vicente-Herrero MT, Costa-Bauzá A (December 2008). “Phytate (myo-inositol hexaphosphate) and risk factors for osteoporosis”. Journal of Medicinal Food 11 (4): 747–52. doi:10.1089/jmf.2008.0087. PMID 19053869.
23.^ Anderson, Eugene N. (2005). Everyone eats: understanding food and culture. New York: New York University Press. pp. 47–8. ISBN 0-8147-0496-4.
I wonder if this is all just fear-mongering.
August 21st, 2013 at 12:02 pm
Dan,
Phytate inhibition of mineral absorption in countries where people do not have a wide range of, or enough, food could very well be a problem. For your typical North American vegan, I don’t think it’s anything to worry about except for people who are prone to iron deficiency.
August 21st, 2013 at 12:07 pm
Jack, that’s an excellent point. So unless someone was on a fad diet or otherwise had a very narrow range of food intake, it is doubtful that these studies from developing countries would have much relevance here (“For people with a particularly low intake of essential minerals, especially those in developing countries, this effect can be undesirable.”).
(no need to respond to this)
August 21st, 2013 at 1:50 pm
I have a calcium question. I had preventative testing done recently. mammogram showed benign breast calcifications. I read that these actually stem from too little calcium. I also had low vitamin d. the doctor prescribed both d and calcium supplements, but i’m wondering if I can get away with just d. won’t the increase in d help my body absorb the calcium I already ingest through diet? I do take b12 as well, but those are the only supplements I take.
August 21st, 2013 at 1:57 pm
Catherine,
I have never researched reducing breast calcification through calcium vs. vitamin D supplements. I am willing to do such research for hire, though, if you want to contact me through my contact form :).
For bone health, I recommend all vegans try to get the DRI for calcium of 1,000 mg for adults under 70 years, 1,200 mg for older than 70. More info here: http://veganhealth.org/articles/bones.
August 21st, 2013 at 2:33 pm
unfortunately, I am a broke animal rescuer. I will likely stick with just the d supplements and see if my calcium levels increase as well. I will then supplement, if necessary. I appreciate your good work and will continue to share your site. I did use your Amazon link to buy something the other day. Hope you get credit for that.
August 21st, 2013 at 2:38 pm
Catherine,
Thanks! I’m sure I did. And I don’t mean to bilk you out of any money, it’s just that I don’t have time to research individual people’s health issues unless I take time off other work to do it. Some people do want to pay me to research their particular problem so I just wanted to let you know in case you did. Thanks again!
August 25th, 2013 at 3:17 pm
Is it just me or does ginny sound like she fell off the wagon and is eating animal products?
Ginny didn’t mention that dairy is pasteurized and we know what happens when macronutrients are heated at high temperatures. Denatured oxidized nutrients cause further oxidation in the body.
August 25th, 2013 at 3:22 pm
Ginny is not eating animal products.
August 25th, 2013 at 3:45 pm
Jack,
Would there be any benefit to switching from 2 tablespoons of peanut butter per day (taken for the purposes of providing protein, primarily, but also some calcium and potassium) to a combination of vital wheat gluten and textured vegetable protein (or soy protein isolate)? I read there is 8 g of fat in 2 tablespoons of peanut butter – that is the no-salt, no-sugar added, no vegetable oil added variety.
Would you expect cholesterol or triglycerides to improve with a switch from 2 tbsp. of peanut butter over to wheat gluten and soy protein?
I also wonder about the downsides of eating roasted oils (which is what peanut butter and tahini are) versus the downsides of the chemicals used to extract soy protein and gluten from soybeans and wheat, respectively (which may include hexanes as well as various alcohols).
Thanks as always for your input. I realize this is somewhat tangential but it does relate to protein intake, which you have been posting on lately.
August 26th, 2013 at 2:55 pm
Dan,
> Would there be any benefit to switching from 2 tablespoons of peanut butter per day (taken for the purposes of providing protein, primarily, but also some calcium and potassium) to a combination of vital wheat gluten and textured vegetable protein (or soy protein isolate)?
I really have no idea. I’d probably be inclined to stick with the peanut butter.
August 26th, 2013 at 5:38 pm
Jack, I don’t know either. I was more concerned about the 4 g of sugar I was getting on top of the sugar in nuts and kiwi fruit, almond milk (actually there’s very little in that), and avocados. So I’ve replaced it with wheat germ and I might use hemp protein as well, if I can figure out its ALA content (should be online). I realize I’m crazy!
August 28th, 2013 at 12:44 am
Dan,
Whats wrong with natural sugar found in fruit?
Have you heard of orthorexia?