Again and again, it is said that nuts have to be soaked and germinated before consumption so that they are digestible and harmless to health. Is it really true that you have to soak nuts?
Should you soak nuts or not?
Nuts are often advised to soak in water for several hours (8 to 24 hours) before eating. The nuts have to be “activated”, it is said. Otherwise, so-called antinutrients are included, which would lead to health problems in the long term. Soaked nuts are also easier to digest.
All of this applies to cereals and legumes. The antinutrients in these two food groups can be significantly reduced by soaking them, depending on how long they have been soaked. But what about nuts and almonds?
Do you really have to soak and “activate” nuts before eating them? Can soaking actually eliminate the antinutrients? Or are the antinutrients perhaps not antinutrients at all, but valuable substances that can benefit health? Can you save yourself the effort of soaking?
First, the commonly recommended guide to properly soaking/“activating” nuts and almonds so you know what the specifics are:
How soaking nuts and almonds works
Depending on the type of nut, different soaking times are given. On average, however, it is 10 hours. Cashew nuts should only be soaked for 3 to 6 hours, otherwise, they will become slimy.
- Put the nuts in a bowl and add enough salted water to cover the nuts well (approx. ½ to 1 teaspoon of salt per 0.5 liters of water).
- Now let the nuts soak for 8 to 12 hours.
- Pour off the water using a sieve and rinse the nuts under running water.
- You can now eat the nuts immediately or process them further. But if you don’t need them immediately, they have to be dried again so that they don’t start to get moldy.
- Put the nuts in a dehydrator or the oven and dry them there at 50 degrees for 12 to 24 hours (until they are well dry, the larger the nut, the longer the drying process). Leave the oven door slightly open to allow moisture to escape. Move the nuts occasionally so they can dry well on all sides.
It is therefore a rather lengthy and energy-intensive process, which is generally accepted if it can reduce the anti-nutrients that are always said to be so harmful.
What are anti-nutrients?
Antinutrients usually mean lectins, phytic acid, so-called enzyme inhibitors (protease and amylase inhibitors), oxalic acid, or tannins. Since usually only the first three are discussed, we will only deal with them below. Let’s start with the enzyme inhibitors:
Nuts and other seeds (cereals, legumes, oilseeds) contain enzyme inhibitors to inhibit the digestive enzymes of their predators (insects).
In this way, the plant may be able to protect its fruit from excessive(!) insect damage. However, a complete insect repellent is not possible. Of course, in the course of evolution, insects have also come up with strategies that they can use to eat plants and fruits that contain enzyme inhibitors.
In humans, it is even more obvious that the enzyme inhibitors do not necessarily have an effect. Although there are people who find nuts difficult to stomach, others can easily eat nuts without developing any symptoms.
In this case, humans are most likely not part of the target group of the plant’s own protective measures. After all, what use is it to the plant if people don’t even notice and happily eat one nut after the other?
Soaking in salt water is said to activate enzymes, which in turn deactivate the enzyme inhibitors. The nuts are said to be “activated” which means they are “brought to life” by initiating the germination process. This would make the nutrients and minerals contained in the nut more usable for humans and the nut itself easier to digest.
However, as explained below, soaking nuts alone will most likely not result in the germination process and therefore no “activation”. This also does not necessarily make the nuts easier to digest – see also below.
Lectins are also part of the plant’s own protective mechanisms against herbivores. Each plant has its own species-specific lectin, which means that there is not just one lectin, but many different lectins.
Lectins – so it is said – would promote inflammation and damage nerves and cells. Due to their binding properties, they too could – like the phytic acid described below – bind minerals and contribute to a corresponding deficiency.
Lectins would also attach themselves to the intestinal mucosa and damage it. The intestinal wall becomes permeable, the so-called leaky gut syndrome can develop.
As a result, along with many other harmful substances, the lectins can migrate from the gut into the bloodstream. Once in the blood, they bind to blood cells and encourage them to clump together, which in turn promotes cardiovascular problems.
The lectins would also trigger immune reactions, leading to chronic inflammation and even contributing to the development of autoimmune diseases in some people.
But if you soak the nut, the lectins would be broken down and could no longer do any harm.
Can you remove lectins from nuts by soaking them?
The number of lectins can be reduced by cooking or fermenting – depending on the cooking time and temperature when cooking (in the case of core beans, the lectin activity is zero after 10 minutes at 100 degrees), and depending on the fermentation time when fermenting. Normally, however, nuts are neither boiled nor fermented.
Even soaking cannot completely remove lectins. Lectins were found in the soaking water of some core beans, but the amount was minimal, so the number of lectins in the beans themselves was almost unchanged. There is no known study on nuts.
Phytic acid is a phosphorus compound that stores the energy for the coming germination process in the nut (or the respective seed). In autumn and winter, the nut of unfinished business lies on the ground, hidden in the leaves. As soon as the temperatures rise in spring and the nut is in a favorable and moist place, the germination process begins.
Now an enzyme called phytase is produced in the nut. It breaks down the phytic acid, and the phosphorus contained in it is released and now helps the newly emerging nut tree to grow and thrive in the first days of life.
In the human digestive system, phytic acid is said to have a tendency to bind minerals and trace elements, so that people can no longer use these vital substances. Instead, bound to phytic acid, they are excreted in the stool. In the long term, this should lead to a mineral deficiency.
However, if you soak the nut a few hours before eating it, the germination process is initiated and the phytic acid is broken down, according to thousands and thousands of blogs and websites.
Can you remove phytic acid from nuts and almonds by soaking them?
First of all, the phytic acid content in nuts varies enormously, so in some cases, it is not relevant at all, which of course you do not see in the nuts or almonds.
Almonds, for example, can contain between 0.35 and 9.42 g of phytic acid per 100 g, walnuts between 0.2 and 6.69 g, and cashews between 0.19 and 4.98 g (1). (For comparison cereals: oats contain 0.42 to 1.16 g per 100 g.)
Phytic acid is not a problem with a balanced diet
That excess of phytic acid in the body can lead to a mineral deficiency (especially iron and zinc), Dr. Ulrich Schlemmer, a scientist at the Max Rubner Institute in Karlsruhe, concluded in his 2009 study.
However, he writes in it that this applies in particular to developing countries, where the diet is one-sided and therefore poor in iron and zinc. There it could make sense to reduce the phytic acid content of the food or – the other way around – to supplement the minerals.
With a balanced diet, however, phytic acid is not a problem. On the contrary, precisely where civilization diseases are commonplace, says Dr. Schlemmer, could it be helpful? Finally, phytic acid has positive properties, e.g. For example, it has antioxidant and anti-cancer effects, balances blood sugar and blood lipid levels, and can even inhibit kidney stone formation.
Phytic acid is not an antinutrient!
Schlemmer, therefore, advocates no longer dismissing phytic acid as an “antinutrient”. On the contrary, if you break down foods containing phytic acid before consuming them, you are missing out on their beneficial and disease-protective effects, so it may make more sense NOT to soak the foods in question, and instead to have the mineral supply – if it is should a deficiency occur at all – to be optimized with the help of other foods or dietary supplements.
Schlemmer showed in detail that the phytic acid in cereals and legumes could actually be largely or almost completely broken down by long soaking times of around 20 to 48 hours. Not so with nuts and almonds!
Soaking does not change the phytic acid content in nuts and almonds
For a master’s thesis from 2017, the author investigated how soaking hazelnuts and almonds affects their phytic acid and mineral content. The nuts were chopped on the one hand and whole on the other
- 12 hours in salt water,
- 4 hours in salt water and
- Soaked for 12 hours without salt.
Soaking whole nuts and almonds did not appear to change the phytic acid and mineral levels compared to the original levels. The phytic acid content of the chopped hazelnuts was reduced by 10 percent. However, a significant decrease in the mineral content (calcium, iron, magnesium, potassium, zinc, phosphorus) could also be observed here.
Finally, the author stated that there was still no evidence that soaking nuts and almonds could provide benefits in terms of phytic acid content or better mineral bioavailability.
Soaking can actually increase phytic acid in almonds
A 2018 study even showed that soaking—in the case of almonds—increased phytate levels. The 76 participants received 30 g of almonds in different shapes and preparations: whole/unsoaked, whole/soaked, chopped/unsoaked, or chopped/soaked, daily for 12 days.
Compared to the whole, unsoaked almonds (531 mg phytate per 100 g), the phytate concentration of the whole, soaked almonds was 563 mg per 100 g.
Soaking does not improve the digestibility of almonds
Because the participants experienced more bloating with the soaked almonds than with the unsoaked almonds, the researchers concluded that, contrary to what the lay press has said, soaking does not appear to improve tolerance—at least not in the case of almonds.
A year earlier, researchers from Singapore came to similar conclusions. In their study, almonds (whole kernels) were soaked in water for 15 hours at different temperatures and different pH values: 25 degrees + pH 5.0, 25 degrees + pH 7.0, 40 degrees + pH 5.0 and 40 degrees + pH 7.0.
The phytic acid content increased at temperatures of 40 degrees. At 25 degrees, i.e. room temperature, there was no noticeable change in terms of phytic acid.
Even raw cashew nuts do not need to be soaked
In a 2016 study, soaking raw almonds, walnuts, and cashews (in lightly salted water at 25 degrees) for up to 15 hours did not change the phytic acid content in the nuts, nor did their antioxidant potential.
Do nuts sprout when soaked?
Almost everywhere that soaking and “activating” nuts are promoted, one reads that the breakdown of the antinutrients e.g. through the incipient germination process.
Cereal grains, legumes such as chickpeas and lentils, and oilseeds such as sunflower seeds generally germinate very quickly – within 24 hours, depending on the temperature. But not nuts.
On the contrary, the local nuts – walnuts and hazelnuts – are even so-called cold germs. They first need a cold period of several weeks, preferably with frost, and should ideally lie in moist soil before they are even able to germinate.
Shelled walnuts and hazelnuts are also commercially available. When peeling, however, they are often damaged, so that which also impairs germination. It should be clear that walnut HALFTEN no longer germinate.
Cashew nuts are usually heated in stores and therefore do not germinate either. And macadamia nuts – so it is said – apparently need certain substances that (in the tropics) are released in the root area of other trees, so that they will certainly not germinate in a Central European kitchen bowl. The nuts just soak up water, so not much else happens during soaking.
Conclusion: to soak nuts and almonds or not?
With nuts and almonds, you can save yourself the effort of soaking, at least if you have the reduction of antinutrients in mind. If it is necessary for the recipe, you can of course do it.
If you have found out for yourself that you tolerate soaked nuts better, you should of course soak them. Everyone has an individual tolerance here, so you simply test what is best for you.
In any case, one should refrain from evaluating the so-called antinutrients as negative. In the context of an overall varied diet, they are by no means so, but only if you z. B. would have to live exclusively on porridge.
In reality, these are high-quality plant compounds that can certainly have health benefits if you don’t look at them separately and in isolation, but as completely natural and self-evident components of healthy foods; Constituents that have always been contained in these foods and with which humans have come to terms in the course of evolution.