With so much information around nutrition, it can be challenging to cut through the noise. Now, with increasing conversation about anti-nutrients, eating well just reached a new level of difficulty.
But what exactly are anti-nutrients – and do we really need to worry about them? We asked the experts to find out more.
What are anti-nutrients?
We know that plant foods are a staple in a healthy diet – great for supporting our gut health and overall wellbeing. But, what’s not often discussed is that certain plant foods also contain compounds known as anti-nutrients.
“These are part of a plant’s chemical defence mechanism,” explains Priya Tew, a specialist dietitian with Dietitian UK. “They’re designed to protect the plant from being eaten by insects, bacteria, or animals.”
While these compounds aren’t inherently bad, they can interfere with how well our bodies absorb certain nutrients. In rare cases, they can even affect our levels of iron, calcium and zinc.
Which foods do you find anti-nutrients in?
As Nichola Ludlam-Raine, a dietitian and author of How Not To Eat Ultra-Processed, explains, we find anti-nutrients in surprising places – including kitchen staples.
“They’re most commonly found in things like legumes (including lentils and beans), whole grains, nuts, seeds and some vegetables such as spinach and kale,” she says.
Anti-nutrient compounds can be broken down into separate groups, depending on the foods they’re found in:
- Phytates: whole grains, beans and pulses
- Oxalates: spinach, nuts and rhubarb
- Lectins: nuts, cereals and legumes
- Tannins: tea and berries
- Glucosinolates: cruciferous vegetables such as broccoli, cabbage, kale and cauliflower
“These compounds can bind to certain vitamins and minerals in the digestive tract, preventing your body from absorbing them as well,” explains Priya.
An example of this is the oxalates in spinach. While spinach is rich in calcium, our body struggles to absorb it due to the oxalic acid in spinach binding to the calcium. It’s generally not an issue for many of us, but in rare cases it can causes health issues such as kidney stones. Plus, it means we’re not getting the most out of our food.
Another example of anti-nutrients are foods that contain phytates. These compounds are known to interfere with zinc and iron absorption – key minerals for our skin, bone and immune health.
“Phytates are essentially stealing those minerals from the body,” says Priya.
So, how much do we need to worry about this?
Anti-nutrients and our health
The likelihood of anti-nutrients causing health problems is quite low. This is because we rarely eat these foods in their raw state – they typically taste better after they’ve been soaked, boiled or steamed, which helps to reduce anti-nutrient compounds.
Plus, we can’t overlook the benefits that these plant foods bring.
“Foods that contain anti-nutrients also contain fibre, vitamins and antioxidants,” Priya says. “These vastly outweigh the small reduction in mineral absorption. If you eat a varied diet, the body is very good at compensating.”
However, there are special cases. Vegans and vegetarians should take care when it comes to iron – plant-based sources can be more difficult to absorb. Plus, for those with anaemia, certain food combinations should be avoided. This includes drinking tea (tannins) at the same time as eating an iron-rich lunch as this can affect iron absorption.
As Priya explains, anti-nutrients are unlikely to cause health problems for the vast majority of us.
“The primary risk is mineral deficiency but that will only happen if we’re eating a lot of these foods raw, or if someone is relying on these foods too heavily,” she says. “And, of course, if they have a specific medical condition that might affect it.”
Do anti-nutrients offer any health benefits?
The short answer is yes.
Many compounds classed as ‘anti-nutrients’ are also ‘phytonutrients’. This means they are powerful antioxidants and may help to lower our risk of chronic diseases, like cancer and heart disease.
Priya says that phytates have been linked to a reduced risk of kidney stones, while tannins are good for our heart health. Lectins slow down carbohydrate digestion, helping to keep our blood sugar levels more stable.
“We don’t need to avoid these nutrient-dense foods,” says nutritionist, Thalia Pellegrini. “We just need to be aware of how to prepare them to get the benefits without the downsides.”
