Should I worry about anti-nutrients?

Q: I recently heard someone talking about anti-nutrients. What are they and where are they found? Thanks, Susan.

Foods don’t just contain nutrients; some foods also contain what are often referred to as antinutrients when eaten in excessive amounts. Anything consumed in excess can be harmful. Some common anti-nutrients are phytic acid, oxalates and lectins. Alcohol and caffeine also have antinutrient properties. Let’s look at phytic acid, lectins and oxalates.

A: PHYTIC ACID

Phytic acid or phytates perform many important functions for plants. Phytic acid is found in wholegrains, nuts, seeds and beans and are considered to be anti-nutrients because they represent a potential absorptive roadblock. Phytic acid is the principal storage form of the mineral phosphorus in many plant tissues, especially the bran portion of grains and other seeds.

For humans, the phosphorus in this molecule is not readily

available. Components of the phytic acid molecule also bind with other minerals – such as calcium, magnesium, iron and zinc – sowe are unable to absorb them. Soaking wholegrains, beans, nuts and seeds overnight is one of the most effective ways to reduce their phytic acid content.

LECTINS

with other minerals such as calcium, which under certain conditions form a salt known as an oxalate. Oxalic acid interferes with the absorption of calcium and iron, making it unusable by the body. Some individuals are more prone to problems with oxalates than others.

While some plant foods contain these anti-nutrients, the benefits of the vitamins, minerals, antioxidants, and beneficial phytochemicals that they also contain far outweigh any potential negatives. It’s the dose that is important – ifwe consumed huge quantities of one particular food, anti-nutrients may be of concern, but so would nutrient deficiencies.

When we eat a wide range of nutritious foods, there’s no need to worry about anti-nutrients.

Dr Libby is a nutritional biochemist, best-selling author and speaker. The advice contained in this column is not intended to be a substitute for direct, personalised advice from a health professional. See drlibby.com.