Experience a heavy sensation in your stomach after eating nuts? Have you noticed the next day that the nuts are in your stool? Even if you don’t show obvious symptoms, many argue, you may be compromising nutritional uptake by eating improperly prepared nuts or seeds.
Phytic acid is the storage form of phosphorus found in many plants, especially in the bran or hull of grains and in nuts and seeds. Although herbivores like cows and sheep can digest phytic acid, humans cannot. This is bad news because phytic acid binds to minerals (i.e., iron and zinc) in food and prevents us from absorbing them[i][ii][iii]. Nuts also contain lectins and enzyme inhibitors, notorious little “anti-nutrients” that put some people’s stomachs through the ringer.
Here are some basic cooking techniques to increase the bioavailability of nuts and seeds:
- Buy a few cups of raw, organic nuts or seeds for the week or so to prepare (as this process can be a little time-consuming).
- Ideally soak nuts for 18-24 hours with sea salt (the salt neutralizes the enzymes).
- Right after they’re done soaking, it is crucial to thoroughly dry them. The best ways to ensure they will dry all the way through is to lay them out in a single, sparse layer in the sun or in a warm oven (lowest possible setting—ideally not more than 120 degrees). If you have a dehydrator or don’t mind investing in one, that’s a good route to go as well.
- Dehydrate for 12-24 hours or until crisp.
- ENJOY! Not only does this maximize the nutrients, but it also enhances the flavor in the walnuts, almonds, pumpkin seeds, pecans, or whatever nut/seed you choose!
- Please NOTE: Cashews, macadamia nuts, pine nuts, and hazelnuts should be soaked for no more than 6 hours and roasted quickly.
A handful of nuts (1-2 ounces, depending on your hand) properly prepared each day should be fine for most people in the context of a mineral rich diet. Ancient cultures across the world knew better when it came to eating these foods and always practiced these techniques before consumption. Once again, never underestimate traditional wisdom!
[i] Zhou JR, Erdman JW. Phytic acid in health and disease. Crit Rev Food Sci Nutr. 1995;35(6):495-508.
[ii] Macfarlane BJ, Bezwoda WR, Bothwell TH, et al. Inhibitory effect of nuts on iron absorption. Am J Clin Nutr. 1988;47(2):270-4.
[iii] Torre M, Rodriguez AR, Saura-calixto F. Effects of dietary fiber and phytic acid on mineral availability. Crit Rev Food Sci Nutr. 1991;30(1):1-22.
Lindsey Mueller, BSBA, CCN is a clinical nutritionist living in San Diego. You may find out more about her and her services by visiting her at eat-ology.