At Christmas time, walnuts are often on the plate – even if only as a delicious biscuit garnish. And that’s a good thing, because the nuts are full of valuable ingredients. But how many walnuts are healthy and what should you look out for when buying?
Many people especially like to eat walnuts in the wintertime, along with tangerines and oranges. The nuts are said to provide us with valuable fats and minerals, and at the same time they are considered fattening. We looked at what actually makes walnuts healthy, how many of them you should eat, and what to look out for when shopping.
How healthy are walnuts?
Walnut trees grow all over the world, in Germany walnuts are harvested in autumn and are often served in the cold season. Once the nuts have been cracked and the two halves of the kernel removed from the shell, there is almost nothing standing in the way of healthy nibbling. But not all walnuts are the same: In our test of around 20 walnuts, not all products were convincing: Some walnut kernels tasted like packaging, and we also found mineral oil and a plasticizer.
Basically, walnuts provide us with many valuable ingredients:
Omega-3 fatty acids: Walnuts have the highest content of alpha-linolenic acid, an omega-3 fatty acid, of all types of nuts. This has an anti-inflammatory effect and can improve cholesterol levels
The minerals potassium, magnesium, calcium, zinc and iron
Beta carotene, which is important for the heart
Folic acid, a B vitamin that helps form blood cells
Vitamins, especially vitamin E (protects the cells), vitamin C and vitamin B6 (important for the metabolism)
Walnuts consist mainly of fats and proteins. The unsaturated fatty acids, which are also found in walnut oil and other vegetable oils, have a positive effect on the cardiovascular system. The German Society for Nutrition (DGE) explains that we can reduce the risk of cardiovascular disease if we consume more unsaturated fatty acids instead of saturated ones.
The protein in nuts, on the other hand, contains a lot of serotonin. People who are sensitive to the hormone could experience headaches from high walnut consumption.
Walnuts have as many antioxidants as polyphenols, which protect the tissue from free radicals, for example.
Small calorie bombs: do walnuts make you fat?
We had just praised the valuable polyunsaturated fatty acids in walnuts. The high fat content of over 60 percent also means a lot of calories. 100 grams of walnuts have over 600 kilocalories (kcal).
However, the DGE gives the all-clear: Vegetable oils and nuts are high in calories, but they are also valuable suppliers of nutrients and should therefore be on our menu in small quantities every day.
And it gets even better, because eating some nuts can even help you lose weight. Thanks to their high fiber and protein content, walnuts keep you full for a long time and can prevent cravings.
However, you shouldn’t eat more than a handful of walnuts a day, otherwise you’ll be consuming too many calories. The guideline is eight whole walnuts per day.
Are there mold toxins in walnuts?
Last year, the Federal Office for Consumer Protection and Food Safety (BVL) warned of mold in walnuts. The reason for this: Nuts are repeatedly attacked by the mold species Aspergillus flavus and ochraceus. These two molds form the mold toxins aflatoxin and ochratoxin A, preferably in a warm and humid environment. This sometimes happens during harvesting and transport, but often only during storage.
Unlike some other pollutants, mold is not destroyed by high temperatures during cooking, roasting, or baking. The BVL warned that mold can lead to various diseases in humans, promote the development of cancer, damage the kidneys and liver, impair the immune system or cause diarrhea and vomiting.
At least in our walnut test, we were able to give the all-clear: the commissioned laboratory did not find mold toxins in any of the products examined.
Buy walnuts – you can pay attention to that
You can buy walnuts loose, which saves a lot on packaging. All you have to do is crack the nuts yourself.
Starting in autumn, you will find walnuts from the region or at least from Europe at weekly markets, in supermarkets most walnuts come from the USA or China.
After buying nuts, the following applies: store walnuts in a dry, cool and preferably dark place. This prevents the formation of mold toxins. Nuts in shell can be kept for up to a year if stored correctly.
Tip for Christmas baking: It is better to buy whole walnut kernels and crush or grind them yourself. Walnut kernels are less susceptible to mold than more crushed nuts.