Antinutrients – Should You Be Avoiding Them?

Should You Be Avoiding Antinutrients?

The discussion around antinutrients is just as polarized as the nutrition world (vegan vs. carnivore), because antinutrients are present only in plant sources.  The animal-based camps highlight the downsides of antinutrients, while the plant-based camps claim that antinutrients have beneficial effects that outweigh their potential harm.

Who’s right?  How does one handle the various claims on antinutrients?  Are there foods we should avoid?  Or is it just certain food combinations?  Are antinutrients even relevant?

I don’t have all the answers, but it’s clear that antinutrients are relevant.  After all, what’s the point of nutrition?  To provide essential nutrients to our bodies.

If there are compounds that interfere with our bodies obtaining nutrients, then there is clearly a tug-of-war at play.  Understanding how nutrients interact with one another may be more relevant than anyone appreciates, especially considering that nutrient deficiencies are still present in the developed countries despite the amount of enriched and fortified food products.


Nutrient deficiencies

There are numerous syndromes caused by vitamin deficiencies and nutrient deficiencies.  Nutrient requirements change throughout one’s lifetime.  For example: as we age, we need more vitamin D, but less iron.

In the developing world, nutrient deficiencies remain prevalent, especially iron, vitamin A, zinc, iodine, and folate (ref).  They contribute to increased infections, illness, and death.  In developed countries, common micronutrient deficiencies include calcium, iron, magnesium, potassium, vitamin A, vitamin C, and vitamin D.

Benefits of Antinutrients?

Supporters of plants argue that, despite the downside of impairing nutrient absorption, there are other health benefits to antinutrients.  There are reported benefits to some antinutrients, specifically some antioxidant properties or the ability to bind to heavy metals.

For most people, however, large amounts of antinutrients may have negative effects.  There is a general consensus advising against consuming large amounts of these antinutrients at one time, due to their potential toxic effects.  There may be individuals who are particularly susceptible to the effects of antinutrients, as well.

The jury’s out

Antinutrients are generally not consumed in isolation, but rather with a mix of other food compounds.  There may be complex interactions between these different compounds, ultimately resulting in some antinutrients being rendered inactive and some perhaps being amplified.

The general advice is to limit the amount of antinutrients consumed, eat a wider variety of foods, and to prepare foods with various techniques that allegedly reduce the quantity or activity of these antinutrients, such as soaking/sprouting/fermenting seeds.



Who should avoid antinutrients?

As is typical in the world of nutrition, there are no absolutes, as human physiology is infinitely complex and cannot be studied in a vacuum.  Thus, we must rely on the best data available and make educated guesses about what is best for our health, while acknowledging how little we understand about the complex interplay of many factors.

Given what we know about antinutrients, individuals with the following conditions may want to be mindful of their consumption of antinutrients.

Iron deficiency

Iron deficiency is the most prevalent nutritional deficiency worldwide, with young children and menstruating women being at the highest risk.

Avoid: tannins, phytates

Low calcium; Osteopenia/Osteoporosis

Bone health is typically considered a problem of calcium, however protein is just as important.  Note that Vitamin D is important for increasing the absorption of calcium from the gut.

Avoid: phytates, oxalates

Thyroid disease

Iodine is critical for proper thyroid function.  There is also evidence that glucosinolate intake is correlated with thyroid cancer risk in women.  If taking thyroid medication (e.g. levothyroxine, liothyronine, desiccated thyroid extract), avoid consuming calcium or iron for a few hours before and after each dose.

Avoid: goitrogens/glucosinolates.

Kidney Stones

Calcium oxalate is responsible for an estimated 75% of all kidney stones.

Avoid: oxalates

Infertility; Low testosterone; Estrogen-sensitive cancers

Infants fed soy formula vs. cow milk formula demonstrated increased uterine size and changes to the vaginal cells.  There is mixed data on phytoestrogens and cancer.  Phytoestrogens do, however, appear to increase estrogen and lower testosterone.

Avoid: phytoestrogens

Micronutrient deficiency; Gastrointestinal malabsorption

Anyone with borderline nutritional status should be focused on obtaining the highest quality and most bioavailable nutrients.  Many illnesses put individuals at risk of decreased nutrient absorption, including celiac disease, inflammatory bowel disease, history of bariatric surgery, etc.

Avoid: all antinutrients

The dose makes the poison

Just as antinutrients are usually not consumed in large enough amounts to cause noticeable toxic effects, so too are they not consumed in large enough amounts to exert noticeable beneficial effects.  The amount required for a beneficial effect is often not discussed and may well be much greater than the amount that causes harm.

For example, vegetarians may consume 100 mg per day of saponins (from legumes), an amount that may inhibit iron status in individuals who have relatively low iron intake.  That amount, however, is likely not enough to cause any beneficial effects.  It’s argued that saponins have a cholesterol-lowering effect, however intakes up to 500 mg per day have not had significant effects on cholesterol levels (ref).

Thus, the alleged benefits of antinutrients may be outweighed by their negative effects, depending on the individual.

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