Phytates Revisited – What are Phytates?

phytates-revisitedIn the Paleosphere, there’s a lot of negative talk about phytates. Found in grains, legumes, nuts and seeds, we classify them as anti-nutrients because they decrease the bioavailability of minerals such as magnesium, zinc, iron and calcium and they’re known to cause mineral deficiencies and accompanying deficiency diseases in cultures that rely heavily on grains as dietary staples. When eaten excessively, phytates may impede the function of pancreatic enzymes and interfere with digestion, contribute to bacterial overgrowth and increase gut permeability, aka leaky gut. However, there are two sides to every story and in this post we’ll discuss how phytates can be a good thing for your health!

What are Phytates?

Phytates are actually molecules of phytic acid bound to a mineral (phytic acid + mineral = phytate) yet we refer to phytates and phytic acid interchangeably. Phytate molecules are present in all plants as the storage form of phosphorus, which is important to plant metabolism. Phytates also prevent oxidative stress to the developing seed (yup, they’re antioxidants!) and contribute to structural activities such as cell membrane formation.  Present in all parts of plants including leaves and stems phytates are highly concentrated in the hull and bran of grains, and the outer layers of nuts, seeds and legumes.

piles-of-chocolateAre you wondering how many phytates there are in the foods you commonly eat? Phytate charts can be difficult to decipher and Chris Kresser has put together a simple comparative list in this post. Within the framework of the Paleo diet nuts, seeds and chocolate (Chocolate? Who knew!) have the potential for providing the greatest sources of phytates.

Aren’t phytates indigestible? Phytates require phytase for digestion into absorbable components and humans produce only a small amount of this enzyme (rats, for instance produce about 30 times more than we do.) However, there’s evidence that adaptation occurs over time whereby the more phytate you eat, the more phytase the healthy microbiota in your intestines produce.

The Potential Benefits of Phytates

iron-vector-smHeart Disease: Heart disease is characterized by atherosclerosis, the thickening and hardening of arteries. When dietary iron is consumed in excess it can contribute to atherosclerosis by acting as a powerful oxidant, creating inflammation and damaging arterial cells. Men, post-menopausal women and people with hemochromatosis are most susceptible to excess iron absorption and may benefit from phytate’s binding capacity which effectively neutralizes iron’s oxidative and atherosclerotic effects.

Cancer: Phytates have many anti-cancer functions, which may be why high fiber foods are often associated with reduced risk of malignancies such as colon cancer. It’s likely that phytate’s antioxidant effect plays an anti-inflammatory role however, phytates have also been observed to reduce cell proliferation of malignant cells, increase the activity of natural killer cells, increase cell differentiation (when cancer cells behave more like normal cells and are less aggressive), and act as a cancer preventive in general. Furthermore, phytates have been shown to act synergistically to increase the efficacy of chemotherapy without damaging any healthy cells in the process.

spineOsteoporosis: Phytate consumption is known to have a protective effect against osteoporosis possibly by inhibiting osteoclasts, cells that break down bones.

Kidney Stones: Increased urinary excretion of phytates is associated with decreased calcium oxalate kidney stone development. When phytate consumption is higher, excretion rates are higher which appears to prevent the crystallazition of calcium salts and the formation of kidney stones.

Diabetes: Phytates, again much like fiber, may slow carbohydrate digestion and result in a lowered glucose response.

Heavy Metals Chelation: Phytates not only bind to essential minerals but to minerals we don’t want to absorb such as the toxic heavy metals cadmium and lead, preventing their aborption.

Do the Benefits of Phytate Consumption Outweigh the Risks?

Clearly, there are benefits to phytate consumption but what about the risks? Nutrient density is lacking in standard Western diets and iron deficiency anemia and osteoporosis are nearly endemic to certain populations. Add to this the rise of gut-related health issues including autoimmunity and it begs the question, do the benefits of phytate consumption outweigh the risks? The answer is maybe. If you’re a healthy person eating from a nutrient rich Paleo template and you’re not eating excessive amounts of nuts and seeds, your phytate consumption should be a non-issue. If you tend to eat a lot of high phytate foods and you suspect they are negatively affecting your health, you can take steps to minimize the amount of phytate in your diet and influence they have on dietary minerals by employing various strategies:

  • soaked-almondsSoak, dehydrate and even sprout nuts and seeds.
  • Increase your intake of mineral rich animal foods including organ meats while reducing high phytate foods.  To boost iron absorption, add sources of vitamin C to meals such as fruit and vegetables.
  • Practice meal timing. Minerals are susecptable to phytates only when mixed together in the gut at the same time. Eat small amounts of high phytate foods such as almonds and chocolate between meals as snacks instead of with meals.

What’s been your experience with phytates? Do you take steps to decrease your intake?  Please let us know in the comments!

In health,

Sally

Selected References

http://www.ncbi.nlm.nih.gov/pubmed/4111248

http://www.ncbi.nlm.nih.gov/pubmed/19774556

http://www.ncbi.nlm.nih.gov/pubmed/23551617

http://www.ncbi.nlm.nih.gov/pubmed/19267950

http://www.ncbi.nlm.nih.gov/pubmed/2182395

http://jn.nutrition.org/content/133/11/3778S.full,

http://www.webmd.com/heart-disease/news/20001025/too-much-iron-may-lead-to-heart-attack

http://www.ncbi.nlm.nih.gov/pubmed/22614760

http://www.ncbi.nlm.nih.gov/pubmed/19053869

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0043187

http://www.ncbi.nlm.nih.gov/pubmed/10961468

http://ajcn.nutrition.org/content/46/3/467.long

 

Comments

  1. Good article Sally! I think the benefits from eating these foods outweigh the risks by a considerable margin for most people.

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