Chemical Structure of Phytic Acid, An Antinutrient
Chemical Structure of Phytic Acid, An Antinutrient

What if I told you there is a substance most South Asian families are unknowingly consuming on a daily basis that may increase the risk of osteoporosis in adults, possibly reduce growth potential in kids, and cause essential vitamin and mineral deficiencies linked to a whole host of chronic health conditions?  Unfortunately there is such a substance and it’s called phytic acid.  It affects South Asians from all dietary backgrounds, but its deleterious effects are particularly pronounced in vegetarian adults and children.

Phytic Acid and Malnutrition

Malnutrition isn’t just about the healthy foods you don’t eat, but also refers to some of the substances we consume which may block absorption of essential vitamins and minerals in the foods we do eat.  We refer to these nutrient blockers as “antinutrients” and today I’ll focus on a very common one in South Asian diets called phytic acid.  Phytic acid is a chemical used by plants to store phosphorus in its seeds.  The property of phytic acid you should be concerned about is its function as a “chelator,” a substance that can bind to vitamins and minerals like iron, zinc, calcium, vitamin D, and magnesium, preventing your body from absorbing and utilizing these essential nutrients.   In other words, consuming a healthy nutrient-dense diet in the presence of too much phytic acid means your actual net intake of key nutrients is significantly less.  Phytic acid is essentially a nutrient thief!

Which Foods Have Phytic Acid?

It may surprise you to discover that some of the foods you consider healthiest are major sources of phytic acid such as grains, legumes, nuts and seeds.  I’m not suggesting you ban these foods from your diet, but if these are the bulk of your daily eating plan, they may be lowering your overall nutrient intake.  For example, a typical Indian vegetarian consumes a combination of flat breads (wheat chapatis) and beans/lentils in the absence of adequate protein sources and minimal vegetables in the form of 1-2 overcooked Indian vegetable curries (“sabjis”).   The abundance of carbohydrates in this type of eating plan not only leads to excessive body fat storage and increased cholesterol, particularly triglycerides, but the phytic acid also leads to vitamin and mineral deficiencies that  perpetuate chronic health conditions such as insulin resistance.

Phytic Acid and Growth Issues in Children

Growing children are most susceptible to the potentially growth stunting effects of a diet high in phytic acid in addition to highly processed foods and minimal vegetables and fruits.  A young vegetarian child who is already not eating much protein and whose calories are mostly wheat chapatis, lentils, and rice may not be meeting his or her growth potential.  Proper calcium and vitamin D absorption, which is impaired by excess phytic acid,  is essential for bone development and growth.  In fact, a scientific study in the prestigious journal Lancet back in 1972 observed nutritional rickets (vitamin D deficiency) and osteomalacia (bone weakening) in Indian immigrants consuming a primarily wheat-based diet.  The study authors stated the following:

The high dietary phytic acid among the chapati-eating Asian immigrants may be sufficient to impair calcium absorption and account for the nutritional rickets and osteomalacia in this population group.”

Osteoporosis Risk

Even the well recognized national osteoporosis foundation (NOF) has put in a disclaimer on their website about beans, stating that:

While beans contain calcium, magnesium, fiber and other nutrients, they are also high in substances called phytates.  Phytates interfere with your body’s ability to absorb the calcium that is contained in beans…”

A typical Indian meal of whole wheat chapatis and kidney bean curry (rajma) with lentils may be depleting your body’s calcium and vitamin D stores.  Add on top of that the fact that most Indians are vitamin D deficient (due to skin color and limited sun exposure) and inactive (prevents healthy bone building) and you have a recipe for the development of osteoporosis, especially in women.  This study highlights the combination of high phytic acid, low dietary calcium intake, and low vitamin D as being contributors to the high incidence of poor bone health in Asian Indians.

How to Reduce Phytic Acid In Your Diet

I’m not suggesting you eliminate staple foods such as grains, legumes, nuts/seeds from your eating plan.  You need to instead make special efforts to increase your consumption of protein, healthy fats, high quality dairy, and at least 6-8 servings of fresh vegetables and fruit.  In other words, shift the balance of your meals and snacks so they are not so phytic acid dominant and pay special attention to the nutrient and growth depleting effects of staple South Asian foods on your child’s diet.  This has become such a crisis in the diet of today’s South Asian child, that I had my wife, pediatrician Shally Sinha, help me write an extensive chapter on Children’s Health in my book.  If you can hold onto eggs as some vegetarians are open to, please do so.  Eggs are one of the most perfect foods on earth and do not worry about the so-called cholesterol raising effects of eggs as I discuss here.  In addition, keep in mind that the traditional practice of soaking, sprouting and fermenting grains, legumes, nuts and seeds may reduce some of the anti-nutrient content of these foods.   In the end, if you strive towards maximizing nutrient dense foods and minimizing nutrient depleting foods, you improve the growth and development of your children, and overall health at every stage of life.