Foundation Diet and Health

The best perspective for your health

The best perspective for your health

The best perspective for your health

The best perspective for your health

Cashews (cashew nuts, kernels)

Cashews (cashew nuts, cashew kernels) sold at the grocery store are seldom raw. Heat is used to remove the toxic cardol oil they contain.
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Cashews sold at the grocery store are seldom raw. Read more to find out why. The cardol oil in cashews is toxic and can only be removed by applying high heat. The term “raw” therefore misleads consumers. This video about the production of cashews shows the complex manufacturing process that is carried out almost completely by hand.

Culinary uses:

Cashews (cashew nuts, cashew kernels) have a sweet, nutty flavor and are available commercially “raw,” roasted, or roasted and salted. In this case, “raw” simply means not roasted. Cashews are a common snack food. They are also used in muesli or toasted in a skillet and then added to salads or other dishes. Finely ground, they are also used to make vegan cheese and many other products. Although they are unhealthy, cashews are particularly popular in the vegan scene and among raw foodists (who haven’t informed themselves). See the link below.

Not only vegans or vegetarians should read this:
A Vegan Diet Can Be Unhealthy. Nutrition Mistakes.

Nutritional information:

Cashews contain high amounts of the essential amino acid tryptophan, which is important for the production of the neurotransmitter serotonin. Together with vitamin B6 (e.g., in brewer’s yeast and potatoes), consuming tryptophan can alleviate depression in cases where the depression is caused by a lack of this amino acid. And cashews also naturally contain a wide range of minerals such as magnesium and iron. Cashews have a buttery, slightly sweet flavor that cause us to tend to eat too many.

Unfortunately, cashews contain a high level of omega-6 fatty acids (linoleic acid, LA, 7.8 g/100 g) and very little omega-3 fatty acids (alpha-linolenic acid, ALA). — even those that are sold as “raw.” The ratio of LA to ALA is at least 48:1 and can be up to 130:1. People who eat a Western diet usually consume a ratio of about 10:1 instead of the desired 2:1; health authorities are therefore trying to bring this ratio down to at least 5:1. And vegans and vegetarians can show a ratio of 17:1 to 24:1 — to a large extent because they eat more cashews — a nut that promotes all kinds of inflammatory processes in the long term. The receptors for linoleic acid alpha-linolenic acid are the same, although the first promotes inflammation and the latter helps reduce it.

At 160:1, peanuts have an even worse LA:ALA ratio, but they still play an important role in most vegan and vegetarian diets.

Health aspects — effects — all we can do is to give a warning:

Incorrectly or uninformed vegans and vegetarians generally have a poorer diet than “normal eaters” — there will surely soon be a study that will show the incontrovertible evidence. (for more info, see the link in the box above). This would then stop the vegan hype — which is so important for animal welfare and the environment — and discredit this lifestyle. This has been our fear since 2014! Read here about something similar that happened with the raw food movement (The Giessen Raw Food Study).

Recommendations made by Switzerland’s Federal Commission for Nutrition (FCN) in 2006:

At the request of Switzerland’s Federal Office of Public Health (FOPH), the FCN was commissioned in 2003 to adapt the recommendations from 1992 regarding fats and oils to be in line with the latest scientific findings. Under the ingredient olive oil, we have described these in detail. Here we will just provide an overview of the key points.

Polyunsaturated fatty acids are essential and are divided into two main groups (there are also others): linoleic acid and its derivatives as a group of the n-6 or omega-6 fatty acids (LA) and α-linolenic acid or alpha-linolenic acid — which is often just called linolenic acid or ALA (omega-3 or n-3) — and its derivatives. Vegetable oils7 are the main source of inflammatory LA, but nuts and seeds also contain significant amounts! The main sources of healthy anti-inflammatory omega-3 (ALA) include canola oil, flaxseeds, walnuts, and leafy vegetables.7

Health-conscious people get omega-3 from flaxseed, chia seeds, walnuts, macadamia nuts, and leafy vegetables because these have a particularly good LA:ALA ratio. You can click on an ingredient in the ingredient list for any recipe and then scroll down to the end of the text. There you will find detailed nutrient tables for the ingredient (with only a few exceptions). The recipes also include detailed nutritional information in table form. For example, Erb Muesli has an ideal combination of ingredients that yield a LA to ALA of 1:1.

Direct statement from the FCN: Excessive consumption of n-6 fatty acids can promote thrombosis and inflammation. It is therefore a good idea to focus on reducing the ratio from n-6:n-3 to a maximum of 5:1. Today, most people consume these fatty acids in a ratio of approx. 10:1. There is evidence that lowering this ratio can reduce the risk of atherosclerosis and prevent or slow inflammatory processes.7


If you ever have access to a cashew tree, you must resist the temptation of picking and eating the cashews straight from the tree (Anacardium occidentale)! Its shell contains the toxic oil cardol that has to be deactivated by roasting or steaming. If the oil comes into contact with the mucous membranes, it can cause severe burns. The oil has serious irritating effects on the skin. The hard shells can only be opened by applying high heat.

Some people are allergic to cashews, but this allergy is much rarer than in the case of other species of nuts. All of the nuts in the Anacardiaceae family contain high amouts of essential oil and sometimes resins, acids, and phenols (cardol). 5

We need to critically examine not only the consumption of cashews but also the manufacturing process as it takes place under precarious health conditions.

The production of cashews:

Cashew trees grow exclusively in tropical areas. The main growing areas for cashews are Vietnam, the Philippines, Indonesia, and many African countries. According to Wikipedia, the majority of exported cashews come from Africa: in 2016, it was 51.6 %. However, the nuts are processed primarily in Vietnam. This has a major impact on the environment, especially since it involves transporting raw cashews, which weigh five times as much as the shelled version.2

There are many small companies that harvest cashews and get them ready for trading (e.g., Peace Corps). This practice helps prevent an exodus from rural areas as it provides jobs for locals. However, consumers aren’t aware of the conditions under which production takes place. When buying cashews, please make sure to always buy organic and to look for labels such as FairTrade.

Cashews go through elaborate processing steps before they can be eaten. In addition to the time-consuming manual work, which requires a lot of tact and skill, the production processes can also be harmful to the workers’ health.

The entire cashew (shell and kernel) is harvested. The cashew apple, actually a thickened fruit stalk on which the nut hangs, is very sensitive to pressure and cannot be stored. If it is to be further processed into cashew juice or jam, this must be done immediately after harvesting. Harvest residues such as sand and stones have to be removed. The cashew kernels we know are actually the seed of the fruit that is contained in the rock-hard shell that hangs under the cashew apple. The unpeeled nut accounts for about 20 % of the total weight of the entire fruit. Before the roasting process, the cashews have to be soaked in water for a few hours so that they don’t glow when heated. The moisture content of the nut should be at least 9 %.4

The shell is very difficult to open without heating. There are a few traditional methods (e.g., in Sri Lanka), where they are opened individually by hammering them on stones. Direct contact of the toxic oil cardol with the mucous membranes can cause burns, which is why workers have to wear gloves. However, the rubber dissolves very easily upon contact with the corrosive oil. Workers often rub their hands with cooking oil, clay, wood ash, or potash to avoid direct contact with the skin.3

For larger quantities and especially for export, processes with high heat are used. Under high temperatures, the shell cracks relatively quickly and the cashews can be removed. To do this, the cashews are boiled, steamed, or roasted in large vats. However, this process is also associated with health risks. During the heating process (approx. 190 °C), the cardol found in cashews produces black smoke with corrosive vapors.

After a 24-hour drying phase in the shade, the outer shell can sometimes be opened by hand. In practice, a special device, resembling a nutcracker, is used that is operated with a foot pedal. To do this, the nut is placed between the sharp blades of the device and the shell is then split. There are also mechanical processes, but the risk of breakage is much greater. Here, too, there is still a risk of residual corrosive oil.

For protection, many workers use the natural means listed above instead of expensive gloves. Since the demand for white cashews is greatest, a further processing step is required to remove the thin dark skin (testa) around the edible cashew kernel. To facilitate this process, the cashew kernels are dried an additional time. Traditionally, they were placed in the sun or dried over an open fire at approx. 55–60 °C. However, increasingly large quantities have to be dried using mechanical processes (e.g., in drawers heated to approx. 70 °C). This process serves as protection against fungal attack and reduces the moisture to approx. 3 %. In this state, the cashews are particularly sensitive, which is why the shells are most often removed by hand. Mechanical processes result in about 30 % more breakage, which greatly reduces the quality.

In order to get a good price, after the cashews are shelled they need to be sorted manually. This is because machine sorting causes too much breakage – only large, whole cashews have the highest quality level. Before packing, the moisture content has to be brought back to about 5 % so that a greater stability can be guaranteed. At high humidity, this happens by itself and no further steps have to be taken. The cashews are packed in air-tight containers, the oxygen is extracted, and the nut are also fumigated with CO2 to prevent colonization by harmful fungi and bacteria.

General information:

Cashews (Anacardium occidentale) originated in South and Central America; often Brazil and Mexico are listed as the origin. Cashews get their name from the Indian word Kaju, but various tribes have also called them Merei or Marañon. They also extracted the nuts by roasting, and they often used the oil for medical purposes (e.g., casts). Indigenous peoples made juice or wine from the cashew apples.5 Botanically speaking, cashews are not a nut, but rather the seed of a pseudofruit.

The tree is now cultivated in all tropical countries, especially in Africa and in many areas between India and Vietnam. Cashews didn’t become a major commodity until an industrial roasting process that removed the toxic oil was developed.6 The hard shell actually consists of two shells and the toxic oil is found in the chambers between the shells.

The toxic oil is called cashew nut shell liquid (CNSL) and is usually removed through a roasting process. The oil consists of anacaric acid (70 %), cardol (18 %), cardanol (5 %), and other substances. It is processed, for example, into synthetic resins, brake pads, clutch discs, and paints.6 It is also used for medical purposes.

From Wikipedia: Cashew fruits are sometimes also called elephant louse. They also contain the nuts that we call cashews. Cashews are small, greenish to brownish in color, kidney-shaped or boxer- glove-shaped nuts that hang down from a fleshy, thicker fruit stalk. This 5-10 cm long, pear- or bell-pepper-shaped fruit stalk is known as the cashew apple. It is a pseudofruit since the cashew apple is only the thickened fruit stalk and not the actual, reproductive fruit of the cashew tree. Cashew apples are yellowish orange to red when ripe and are often used to make cashew juice and marmelade.

Go to the following link to read more about the ingredient dry-roasted cashews, unsalted.


  1. Video: Cashew Nut Processing — Peace Corps
  2. “Transport um die halbe Welt, der Irrsinn mit den Cashewnüssen” (Transport halfway around the world, the insanity of the cashew industry).
  3. Azam Ali SH, Judge EC. Small-scale cashew nut processing. FAO. 2001
  4. International Finance Corporation IFC. Prospects of Cambodia’s Cashew Sub-Sector. 2010
  5. Brücher H. “Tropische Nutzpflanzen: Ursprung, Evolution und Domestikation” (Tropical crops: origin, evolution, and domestication). Berlin: Springer-Verlag. 1977
  6. Rehm S, Espig G. “Die Kulturpflanzen der Tropen und Subtropen: Anbau, wirtschaftliche Bedeutung, Verwertung” (The cultivated plants of the tropics and subtropics: cultivation, economic importance, and recycling). Stuttgart: Eugen Ulmer Verlag. 1976
  7. EEK_Report _Fats_in_the _Nutrition_ 2006_EN.pdf

Ingredient with nutrient tables

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