Phytates and Health: Separating Myth from Science
Phytates and Health: Separating Myth from Science
Long vilified by paleo pundits as "anti-nutrients", phytates are getting a second look... and it's long overdue.
You might have heard of phytates as vaguely problematic plant compounds lurking in beans and grains. To this day, critics say they block nutrient absorption, hijack essential minerals to create nutrient deficiencies, and wreak havoc on the gut. But like many controversies in the world of nutrition, the story isn't so black and white.
Read on to see why phytates might actually be wrongfully accused of being nutrient thieves, and who should still avoid them anyway.
In this article, we’ll look at:
- What phytates are and how they work
- The foods that contain the most phytates
- Their surprising health benefits
- Who may want to limit them and how
What Are Phytates?
Phytates are the molecular storage form for phosphorus in plants, and their ability to attach to minerals (aka chelation) is what makes them so useful to living things. They're also the compound behind the term phytic acid, which is the version of phytate before it binds to a mineral.
In nature, phytates are crucial for protecting seeds and supporting their growth in early stages. In our bodies, however, they've earned a somewhat less positive reputation. Because humans lack the enzyme phytase, our digestive systems can't break down phytates very well. This means that when we eat them alongside mineral-rich foods, some of those precious minerals get tied up and pass through unabsorbed.
In a nutshell, the core of the phytate controversy is their (very real) chelating power. But do phytates actually cause nutrient deficiencies in the real world? The impact might not be as dire as you think.
What Do They Do in the Body?
Since phytates effectively bind to minerals in the digestive tract, particularly calcium, magnesium, iron, and zinc, it's true that absorption can be significantly reduced. However, it's only true of the minerals present at that specific meal, and not equally for everyone. Factors like cooking method and smart food pairings (to be outlined below), as well as vitamin D status and overall gut health, all affect how much of an actual issue phytates will be for any one individual.
Vegetarians, who eat the most of them, should take heart in knowing that over time, the body can even adapt to heavy phytate consumption. One 8-week randomized controlled trial found that 14 people who ate a high-phytate diet actually increased their iron absorption by 41 per cent compared to the initial baseline. The body is smarter and more adaptive than we tend to give it credit for. That's probably why, in general, vegetarians aren't deficient in minerals like zinc, copper, or iron.
What Foods Are Highest in Phytates?
The list of high-phytate foods is easy to remember, and you might notice that these are some of the very foods we're always being told to eat more of:
- Legumes: ie. soybeans, black beans, lentils, kidney beans
- Whole grains: ie, brown rice, oats, wheat bran, whole wheat
- Nuts & Seeds: ie, sesame, almonds, sunflower, walnuts
The Surprising Health Benefits of Phytates
It's not just that phytate-rich foods are healthy despite their phytate content. In fact, it's partly because of phytates that these foods are as healthy as they are.
So what do phytates actually do for us? As it turns out, quite a bit.
Antioxidant & Anti-Cancer
Phytates are antioxidants, an important role they play in protecting the life of plants that produce them, and they protect against DNA damage. They also appear to inhibit the growth of various cancers, prevent tumour proliferation, and can even cause malignant cells to revert to normal, non-cancerous cells.
If that wasn't enough, phytates can enhance the activity of natural killer cells - the immune system's cancer assassins.
Neuroprotective
Sometimes chelation of minerals can be a very good thing, like when phytates chelate toxic heavy metals, such as lead and cadmium, associated with cognitive decline. Scientists have suggested that the potential ability of phytates to slow pathology of neurodegenerative diseases like Parkinson's and Alzheimer's more than makes up for any possible downside to consuming them.
Mouse studies have even shown that direct administration of phytic acid can protect against Alzheimer's development by modulating autophagy (controlled cellular recycling) and reducing amyloid plaque formation in the brain.
Bone Health
Since they bind to minerals like calcium, osteoporosis is sometimes named as a specific concern for heavy phytate consumers. In fact, the opposite seems to be true. Diets high in phytic acids actually inhibit bone resorption and protect against skeletal mineral depletion.
Studies have directly connected high-phytate diets to reductions in loss of bone mass and lower fracture rates in high-risk, postmenopausal populations. It has even been suggested that eating lots of phytates can even rival osteoporosis drugs, with no side effects.
Kidney Stone Prevention
Multiple studies have demonstrated that phytates are powerful allies in stopping the aggregation of painful kidney stones by inhibiting calcium salt crystallization. The DASH and Mediterranean Diets, both positively loaded with phytates, have been shown to significantly reduce the risk of kidney stone development. Phytates are now even being explored as a therapeutic agent for those with existing stones and those at high risk.
Metabolic Support
Phytates can minimize acute spikes in blood sugar, and generally keep blood glucose at a lower level. They may also reduce cholesterol and regulate insulin. Some researchers have speculated that phytates are part of why legumes are so protective against metabolic syndrome. Once again, a theme emerges: famously healthy foods like nuts, seeds, and legumes, might not be healthy despite phytic acid content, but (at least partly) because of it.
Who Should Avoid Phytates and How to Reduce Them
Despite all the aforementioned benefits, there are some people who may want to be mindful of their intake. A few groups who might want to pay closer attention include:
- People with habitual iron-deficiency anemia, or other chronic mineral deficiency
- Those with gut-related malabsorption syndromes (e.g., celiac, IBD)
- Anyone relying heavily on legumes and grains without much other food variety
But even for these groups, the best solution probably won't be cutting phytates out entirely, but eating them strategically. Phytates can be reduced by soaking, sprouting, fermenting, pressure-cooking, or even just boiling the foods that contain them. Anyone concerned with iron absorption in particular can make use of vitamin C rich food pairings to help overcome the phytate effect.
In Summary
Phytates, or phytic acid, are found naturally in nearly every plant seed. They've been called "anti-nutrients" because they bind to essential minerals like iron, calcium, and zinc, thereby making them harder for the body to absorb.
But this so-called drawback also seems to come with impressive benefits, including cancer prevention, protection against osteoporosis and kidney stones, and improved overall metabolic health.
The fact of the matter is that, when all is said and done, it's pretty unusual for anyone to get a nutrient deficiency from eating beans, nuts or seeds. In a well-balanced diet, the downsides are negligible- and can be further cancelled out by how foods are cooked and combined.
The benefits, however, are very real.
Phytate FAQs
Q: Should I avoid phytates if I'm low in iron or calcium? Not necessarily. But it may be helpful to avoid combining mineral supplements with high-phytate meals. Making liberal use of tried-and-true food prep strategies like soaking, fermenting, or pressure-cooking can also be greatly beneficial.
Q: Do phytates cause mineral deficiency? Generally, they do not. It's only in cases of extreme, monotonous diets like unvaried grain-based subsistence. For anyone eating a diverse and balanced diet, it's essentially a non-issue.
Q: What's the best way to reduce phytates in my meals? Sprouting, soaking, fermenting, pressure-cooking, and boiling all work. Pairing with vitamin C-rich foods (even a squeeze of lemon juice) is a great way to boost mineral absorption for overcoming the phytate chelation effect.
Q: Are phytates bad for digestion? For most people, most of the time, no. In fact, the prebiotic-rich foods they're found in (beans, whole grains) can be great for building a healthy gut microbiome.
If you liked this article, check out The Ultimate Guide to Raising Low Iron Levels.
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