Phytic acid: contrary to everything you have heard before

Surprise @ SIphotography

Surprise @ SIphotography

“Health authorities from all over the world universally recommend increasing consumption of whole grains and legumes [beans, split peas, chickpeas, and lentils] for health promotion.” But, what about the phytates?

“Phytate…is a naturally-occurring compound found in all [plant] seeds.” So, botanically, that means all beans, grains, nuts, and seeds. Over the decades, “phytate has been badly maligned” as a mineral-absorption inhibitor. That’s why, for example, you hear advice to roast, sprout, or soak your nuts—to get rid of phytates, so we can absorb more minerals, like calcium.

The concern about phytates and bone health arose from a series of laboratory experiments performed on puppies, published in 1949, suggesting high-phytate diets have a bone-softening and anti-calcifying effect. Subsequent studies on rats, in which they fed them the equivalent of ten loaves of bread a day, confirmed phytate’s status as a so-called “anti-nutrient.” But more recently, in light of actual human data, phytate’s image has undergone a makeover.

If you put people on a high-phytate diet and measure their calcium balance, their bodies appear to become accustomed to the extra phytate over time, and it all worked out. But, this study was done on only three people. So I was glad to see this study published, which asked the simple question, do people who avoid high-phytate foods—legumes, nuts, and whole grains—have better bone mineral density? No. In fact, quite the opposite. Those that consumed more high-phytate foods had stronger bones, as measured in the heel, spine, and hip. The researchers conclude “that dietary phytate consumption had protective effects against osteoporosis and that low phytate consumption [may instead be] considered an osteoporosis risk factor.” This is consistent with reports that phytate can inhibit the dissolution of bone, similar to anti-osteoporosis drugs like Fosamax.

A follow-up study found the same thing—improved bone density in those that consumed the most phytates. But, this is the most convincing study to date, actually measuring phytate levels flowing through women’s bodies, and following their bone mass over time. And, women with the highest phytate levels had the lowest levels of bone loss in their spine, and their hip. And, so, no surprise that those who ate the most phytates were estimated to have significantly lower risk of major fracture, and lower risk of hip fracture, specifically.

This is thought to be, in part, because phytates help block the formation of bone-eating cells, and their bone-eating activity. You can see how much more bone is eaten away in the non-phytate group on the left.

Now, the drug Fosamax can have a similar beneficial effect. But phytates don’t have the side effects associated with this class of bisphosphonate drugs—side effects like osteonecrosis.

There’s a rare side effect associated with this class of drugs, called osteonecrosis of the jaw. The whole reason people take these drugs is to protect their bones, but by doing so, may also risk rotting them away.

This article has been reprinted from the website with permission from the NutritionFacts team. This article has been exclusively first published on – a strictly non-commercial, science-based public service providing free updates on the latest in nutrition research.

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