At first glance, the appearance of walnut may seem very strange. They are shriveled, oddly shaped and resemble small brains; But if you can get past their weird appearance, walnuts are worth a try. Walnuts are very nutritious and crunchy. These nutritious nuts are rich in healthy fats, antioxidants, vitamins and minerals.
What is a walnut
Botanically, a walnut is not actually a nut, but a type of fruit that contains an edible seed.
According to a scientific review conducted in the International Journal of Molecular Sciences (IJMS), walnuts are the product of the tree of the same name. This tree has fleshy fruits with a green and leathery outer layer called walnut shell. When the fruit ripens, the green skin splits open to reveal the hard brown skin (known as the seed) that contains the seed. This part is the part we eat. Other parts of the nut, such as the shell, are usually discarded or used for industrial purposes such as energy production.
While there are many different types of walnuts, in the United States, the most common type is the English walnut (also known as the common walnut or Persian walnut).
Nutrient value of walnuts
Walnuts have high nutritional value due to their high amounts of polyunsaturated fatty acids (PUFA), often referred to as “good” fats. Walnuts also contain fiber, vitamin E, potassium, iron, zinc, magnesium and antioxidants such as polyphenols.
According to the United States Department of Agriculture, the nutrients in 28 grams of walnuts (7 whole walnuts or 1/4 cup) are as follows:
- 185 calories
- 4 grams of protein
- 19 grams of fat
- 4 grams of carbohydrates
- 2 grams of fiber
- <1 gram of sugar
Roasted walnuts or other processed forms of walnuts (such as walnut milk, walnut flour) may have different nutritional profiles. According to the Cleveland Clinic, in general, nuts that are raw, roasted, or unsalted contain less fat and sodium than salt-roasted ones. Walnut oil has almost the properties of walnuts.
Health benefits of walnuts
remove disease with walnuts
Research has linked free radicals to countless chronic diseases, but the antioxidants in walnuts can keep these free radicals in check. According to nutritionist Tracy Frimpong, these antioxidants include compounds such as polyphenols, vitamin E, and catechins (which are also found in green tea).
Free radicals are unstable molecules that can cause cellular damage or oxidative stress, which over time can lead to heart disease and cancer.
Antioxidants help reduce and eliminate free radicals by changing their molecular structure. These antioxidants protect cells from damage and ultimately prevent chronic diseases.
controlling blood sugar with walnuts
According to the Annals of Medicine, walnuts contain soluble fiber, which is one of the best nutrients for controlling blood sugar. Soluble fiber dissolves in the gut and forms a gel-like substance that slows glucose absorption and lowers blood sugar, explains Jonathan Portell, a nutritionist at Lenox Hill Hospital. This feature helps control blood sugar, which in turn prevents high blood sugar and can reduce the risk of type 2 diabetes.
But soluble fiber is not the only nutrient responsible for lowering blood sugar in walnuts. Magnesium and ALA help increase insulin sensitivity, Portell adds. According to the National Center for Biotechnology Information, insulin sensitivity refers to how well your body responds to insulin (the hormone that moves glucose into cells). Increasing insulin sensitivity controls blood sugar and prevents type 2 diabetes.
Improve heart function with walnuts
Thanks to their impressive amounts of ALA, walnuts are very good for your heart. According to a study in the Journal of the American Heart Association, ALA (which is a beneficial fatty acid) can lower LDL cholesterol (bad cholesterol). Also, research shows that ALA has antioxidant effects that protect the body against LDL oxidation. The process of LDL oxidation occurs when LDL cholesterol reacts with free radicals in the body. This process plays a role in plaque formation, which can lead to heart disease.
In addition, according to Portal, ALA can also create compounds that cause blood vessels to dilate, thereby reducing high blood pressure and the associated risk of heart disease. Similarly, potassium adds to the health value of walnuts by dilating blood vessels, better controlling blood pressure and preventing cardiovascular problems, Portal explains.
Supporting brain health from the properties of walnuts
In addition to resembling small brains, walnuts can actually be very beneficial for the brain. We mentioned that walnuts have significant properties for heart health, and brain health, however, relies on proper blood flow, which is controlled by the heart. Factors such as high blood pressure and cholesterol can disrupt blood flow to the brain and lead to cognitive impairment; But since the heart-friendly nutrients in walnuts (ALA and potassium) control these factors, they can also protect the brain. According to Frimpong, ALA also helps the body produce anti-inflammatory molecules that prevent inflammation and damage to blood vessels — which in turn can reduce the risk of neurological disorders like Alzheimer’s disease.
The antioxidant properties of walnuts also help the brain. Frimpong explains that when the brain is under oxidative stress, it can lead to cognitive decline. This happens because over time, oxidative stress destroys brain cells; But according to a scientific review published in the journal Nutrients, walnut antioxidants can reduce this oxidative damage and ultimately delay the progression of cognitive decline.
Regulating sleep from the properties of walnuts
Walnuts contain melatonin, which can help you sleep well. According to an article published in the journal Cells, melatonin is a hormone that regulates the circadian rhythm of the body or the body’s internal clock. Your body’s melatonin levels naturally drop in the morning, and this is what makes you wake up. In the afternoon, your melatonin levels rise, making you sleepy and tired.
The pineal gland (a gland located in the brain) can make melatonin on its own, but you’ll also be able to get melatonin from foods like walnuts, Portell says. In simple language, eating walnuts helps to increase the level of melatonin in your body, which in turn causes you to have a restful and comfortable sleep.
Possible harms of walnuts
According to the American College of Allergy, Asthma and Immunology (ACAAI), walnuts are one of the most common food allergens. Possible symptoms of a food allergy include hives, cough, stomach cramps, difficulty breathing, and swelling of the tongue or mouth.
In severe cases, food allergies can cause a life-threatening reaction called anaphylactic shock, which inhibits breathing, Frimpong adds. So, if you have a history of allergy to other tree nuts such as almonds, hazelnuts, and cashews, it is better to be careful when consuming walnuts. If you are new to walnuts and have a history of food allergies, be sure to consult an allergist before eating them.
How to store walnuts
Walnuts are different in terms of preparation (raw / dry roasted / roasted in oil), seasoning (unsalted / salted / spiced) and shape (whole / halved / chopped).
According to the Academy of Dietetics, nuts are easily affected by heat due to their high content of unsaturated fats. So, be careful when buying shelled walnuts and remember to store them properly to prevent premature spoilage.
According to the California Walnut Board, the best way to store walnuts is to refrigerate them. With this method, you can store walnuts for a month or more. However, prepackaged walnuts can be stored at room temperature until unopened. But after opening, it is better to store them in a closed container (for example, a glass container) in the refrigerator. If you put walnuts in the freezer, you can keep them for two years or more.
Identification of fresh walnuts
One of the clear and obvious signs of walnut is visible mold residue on the surface of the walnut. Also, according to the report of the Walnut Board of California, the smell and color of the walnut kernel is one of the important characteristics to recognize the freshness of the product. Leftover walnuts have an unpleasant smell and are more oily than fresh walnuts, so eating 2 to 3 of them will cause acne.