I had a great question from Christie posted on my other blog as I apparently had the comments on this blog a little more restricted that I had thought. I think I have fixed that. So this week's post will be based on the question. It's a good thing too otherwise it would be on the validation and calibration of semiquantitative Food Frequency Questionnaires. Just kidding, I don't think I could actually write a whole post on that. That is just what my week's article was on that I read for some continuing credits.
I will post Christie's question here again so I make sure I answer it:
"Do you know anything about soaking whole grains before baking them? I like to make my own granola and have found several sources that advise soaking the oats in whatever liquid the recipe calls for, plus an acid medium (vinegar, lemon juice, buttermilk) before baking them. allegedly it breaks down the antinutrients and makes them more easily digestible. but it's kind of a pain because I have to start the process 24 hours in advance to allow adequate "soaking" time. just wondering if you recommend this or if it's worth the extra time. "
Okay, so I wasn't super familiar with the soaking of whole grains (I'm somewhat familiar with sprouting) but after doing some researching and brushing up on my phytic acid knowledge here is the low down.
So the "antinutrients" that Christie refers to in whole grains is mainly just phytic acid (side-note: Christie, I thought you were totally making up that word; turns out that it is an actual word
http://en.wikipedia.org/wiki/Antinutrient. I was familiar with the concept just not that term).
Whole grains (as well as legumes, seeds and nuts) have phytic acid in them, which is how plants store phosphorus. Unfortunately, this phytic acid binds with some of the desirable minerals in whole grains (iron and zinc mostly, with calcium and magnesium being affected to a lesser extent). This binding makes these minerals
nonabsorbable by our bodies.
Is this a problem? Only if you are concerned you are not getting enough of those minerals in other places in your diet. This is the case for those in developing countries who live on diets that are composed mostly of whole grains. It might be the case for those following vegetarian diets if they are counting on the whole grains, legumes, nuts or seeds to be the source of their iron and zinc.
Another thing to know about phytic acid is that
it is not all bad. It appears to have some antioxidant and anticancer effects. It isn't fully understood either (you'll notice this a lot when you are in the nutrition world). You would think if it binds minerals that those who eat a lot of phytic acid wouldn't get the calcium they need and would have more cases of osteoporosis. But one study found just the opposite, that those who ate more phytate had less osteoporosis (1). Interesting, huh?
However, if you are concerned about phytic acid there are ways to reduce it in your foods. Just
cooking the grains will decrease the amount some.
Soaking them (especially if you use an acid medium) will reduce the levels even more and increase the amount your body absorbs. Also, if you make sure you get some foods with
vitamin C in them at the same time this helps your body absorb iron and to some extent zinc in plant foods such as whole grains.
For more on how to soak whole grains, try this website:
http://www.passionatehomemaking.com/2008/04/whole-grains-grinding-soaking.html
For more on iron:
http://ods.od.nih.gov/factsheets/iron/
For more on zinc:
http://www.nlm.nih.gov/medlineplus/ency/article/002416.htm
My
overall take on phytic acid is that you only need to be concerned about it if you are a
pretty strict vegetarian (don't eat any meat or dairy*) and you aren't getting iron and zinc from other sources (i.e. a multivitamin).
Whether you want to get into soaking grains and sprouting legumes, I'll leave that up to you. If it was me I'd just make sure I got a good variety of food in a variety of preparations (some cooked, some raw, etc) and include fruits and vegetables with my whole grains to give me the acids to help my body absorb those minerals. I'd probably try some soaking on the occasion but not as an every day thing. But if it was me I wouldn't be a vegetarian, because I like eating me some meats - although I do try to follow the Word of Wisdom's counsel to keep that more to a rarity.
Doctrine & Covenants 89:12
"Yea, a also of b and of the fowls of the air, I, the Lord, have ordained for the use of man with thanksgiving; nevertheless they are to be used c;"
Oh, also, as far as granola goes I don't think the whole soaking thing would work as it would make it all mushy, right? Soaking works for oatmeal or if you are cooking the oats in like a bread or something, as far as I understand. I can't imagine using soaked oats in my granola recipe but I could be wrong.
I'd like to apply that last statement to anything I say - because I know you are thinking I am always right (ha!), but just ask Ammón - I'm not. For instance I always get Encyclopedia Brown stories wrong, although my answers could totally work too. Ammón however, always seems to get them right, darn him.
*Post edit: I took eggs out here as they really aren't a good source of iron or zinc, I'm not sure why I included it in the first place. Also, just for your reference:
1 slice of whole wheat bread has 0.54 mg of zinc (this doesn't tell us how much your body might actually absorb considering the presence of phytic acid)
8 oz of low-fat vanilla yogurt has 1.88 mg of zinc
3 oz hamburger patty has about 5.5 mg of zinc
References:
1. Phytate and risk factors for osteoporosis. J Med Food. 2008 Dec;11(4):747-52.
2. http://en.wikipedia.org/wiki/Phytic_acid
3. Roberta Duyff. Complete Food and Nutrition Guide. 2nd ed. Hoboken, New Jersey: John Wiley & Sons, Inc.; 2002 (p. 133).
4. Position of the American Dietetic Association: Vegetarian diets. J Am Diet Assoc. 2009;109:1266-1282.