iron

Interesting things: female fertility, immune system, bad tests
02/05/2011 - 15:58

 A few interesting things:

 

Really great conversation between John Hawks and Kathryn Clancy, both physical anthropologists. Apparently Clancy is gluten intolerant. She also studies fertility. I suggest reading her blog. Also tantalizing is that Hawks has a grad student studying autoimmune differences between farmers and foragers.

Some great posts by Dr. Clancy:

- Iron-deficiency is not something you get just for being a lady: EXACTLY why doctors need to start reading about evolutionary medicine. Almost all doctors seem to think that iron-deficiency is part of being a woman, but that doesn't make sense evolutionarily. Turns out, it's no normal and doctors who think it is often miss the true cause, which is internal bleeding. 

When I was a freshman college I had iron issues. Just like in the post my doctor gave me iron pills, which absolutely destroyed my stomach. Finally a better doctor found out I had a GI bleed. Now why do so many people get GI bleeds? In my case it was from taking NSAIDs, which is a fairly common cause. 

-I don't have a 28-day menstrual cycle, and neither should you 

 

Great new post at Evolutionary Psychiatry about ADHD and diet. I need to post about "food allergy tests" some time, since I get so many questions about them. The unfortunate thing is that most are very inaccurate. Unethical doctors (usually naturopaths, which doesn't help their reputation) market them as accurate and I've gotten emails from people saying they are allergic to absurd combinations of food like kangaroo, banana, and cinaamon buns (just kidding). This causes people to avoid perfectly good foods. Dr. Deans mentions these tests in her post

There were a couple of interesting wrinkles. The kids were all tested for IgG antibodies to food, supposedly helping one sort out food intolerances. These tests are widely used by doctors and para-professionals alike to diagnose food allergies, but when you get down to it, there is not a lot of evidence these tests tell you much about what you might actually be allergic to. IgG antibodies simply mean that somewhere along the way your bloodstream was exposed to food allergens. To be honest, I think people with tons of positive IgG food allergies have leaky guts, that wheat and poor gut biome are reasonably likely culprits, and the foods that show up in the IgG test are a random sampling of what happened to make it through the leaky gut. In the INCA study, the kids were carefully rechallenged with their IgG + foods, and their symptoms of ADHD seemed to have nothing to do with the IgG test. So I'm right ;-) (maybe).
 

Facinating post on using infant closeness as an incubator. The fact that this had to be re-thought of speaks to the medical profession's disconnection with our evolutionary heritage. In foragers, a baby away from a female relative's body is a dead baby.

Reminds me of something I've been musing on for awhile. Evolutionary applications to modern social life sometime seem like they were invented by bros. Lots of papers on how promiscuous humans are, men are different from women, why men like attractive women blah blah blah. But what about the stuff that doesn't jive so easily with modern life? Like the importance of breastfeeding, the fact that optimal fertility occurs when a woman is relatively young, that that non-relatives don't do as good as job taking care of children as kin do? These are not ideas people want to accept because they are so against modern cultural norms. 

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Iron myths (b12 too!)
08/24/2010 - 13:01

When Pubmed and Google Scholar are available to everyone with a computer, it kind of surprises me when journalists write things that are easily proved wrong on a simple search. A good example is this article from the Atlantic food section "The Foods That Hurt Your Iron Levels," which perpetuates the myth that omnivores and veg*ans are equally at risk for iron deficiency.

Yes, some omnivores get iron deficiency and b12 deficiency. Who are these omnivores? Often they are people eating nutritionally inadequate diets of processed foods, but mostly they are elderly people. When an omnivore has such a deficiency, a responsible doctor should test for conditions that prevent people from utilizing vitamins and minerals such as increased gut permeability and celiac disease. For one of my friends, a low b12 level led to her diagnosis with celiac. The idea that healthy omnivores eating a good diet get iron deficiency is probably false.

The Atlantic article points out that some foods can also leach iron like tannins in tea or coffee. Of course then things go very wrong as the author pegs the blame on dairy and forgets to mention that grains are probably a more likely source of leaching. She doesn't cite any studies for the dairy factoid, but a quick Google turns up several studies showing dairy does not leach iron. Contrast that with phytates in grains, which as AnimalPharm points out, are well accepted as iron leachers. But if you are against people eating dairy and for a "healthy" whole grain vegan diet, then that's just inconvenient isn't it?

As far as excess iron in meat causing heart disease, most of the the studies lump in processed meats with steak and are population based, contrasting with the studies cited above that involve direct observation.

Having to take iron pills sucks. When I was a vegetarian in college I was diagnosed with anemia and given pills. I found that bacteria love free iron and I had some of the worst IBS symptoms I've ever had.

Then here is the kicker: "few realize that red meat, although it builds muscle, is not actually any better a source of iron than greens." Sorry but you only have to eat a little steak to get a lot of iron (and even less liver). By iron per calorie they might compared, but who is eating 500 calories of mustard greens? You'd have to spend a lot of time eating them and I think your stomach might be a bit upset. Besides that, the iron in vegetables is less bioavailable. The author acts like that's a good thing because iron=heart disease and you can get "too much" iron from meat. Hmmm...for women I think too much iron is the least of our problems. 

BTW did you know that the spinach=good source of iron is an urban myth? It was spread by Popeye, but it's not true.

I haven't had iron issues since going paleo and I don't have too much iron either. It's possible for some people to have too much iron on the paleo diet due to genetic variation, but the paleo diet can be done quite easily with less dietary iron.

So journalists out there...get some better sources than Dr. Linda Page's Healthy Healing. It's all at your fingertips.

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