by Zeenat Farooq
Walnuts are round, single-seeded stone fruits that grow from the walnut tree. Walnut trees are conventionally native to eastern North America but are now commonly grown in other parts of the world as well like China and Iran. Kashmir valley also has a rich share of the production of the world’s finest walnuts. Beneath the husk of the walnut fruit is a wrinkly, globe-shaped nut. The walnut is split into two flat segments to be sold commercially.
Walnuts are available both raw or roasted and salted or unsalted. According to the U.S. Department of Agriculture National Nutrient Database, approximately 1 ounce of raw walnuts (28.35 grams) contains 185 calories and following amounts of other nutrients
|Nutrient||Percentage (per ounce)|
Nuts generally have a reputation for being a high calorie and high-fat food. However, walnuts are also rich in good nutrients and provide heart-healthy fats. Walnuts have a high percentage of monounsaturated (MUFA) and polyunsaturated (PUFA) fats and are a good source of protein. The combination of healthy fats, protein, and fibre in walnuts increase satisfaction and fullness, which makes them a great snack compared to simple carbohydrate foods like chips or crackers.
Consuming plant-based foods of all kinds has long been associated with a reduced risk of many lifestyle-related health conditions like obesity and diabetes. Many studies suggest that eating more plant-based foods like walnuts also decrease the risk of heart disease and overall mortality. Eating such foods also promote a healthy complexion and hair, increase energy consumption, and overall have a weight lowering effect.
The monounsaturated and polyunsaturated fatty acids found in walnuts have been shown to decrease low-density lipoproteins (LDL) or bad cholesterol and triglyceride levels which in turn reduce the risk of cardiovascular disease. A study published in the “British Journal of Nutrition” showed that the risk of coronary heart disease is 37% lower for those consuming nuts more than four times per week compared to those who never or rarely consumed nuts. In another study, it has also been found that regularly eating walnuts could reduce the risk of coronary heart disease. In fact, the U.S. Food and Drug Administration (FDA) have approved the claim for food labels that “eating 1.5 ounces per day of most nuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease.”
Walnuts have a weight neutral or weight lowering effect which makes them a good choice snack for people who are overweight. According to research published in the “Asia Pacific Journal of Clinical Nutrition”, “routine nut consumption is associated with elevated resting energy expenditure”. That is, to say, burning of calories in the resting stage increases with regular nut consumption. In some trial experiments also, diets that included nuts resulted in significant weight loss. A study published in the “American Journal of Clinical Nutrition” also found that over a study period of eight years, women who rarely ate nuts had a greater incidence of weight gain.
According to a study published in the “American Journal of Clinical Nutrition”, frequent nut consumption is associated with a reduced risk of cholecystectomy (a surgical procedure to remove the gallbladder). In another statistical study conducted for over 20 years that included over a million people, it was reported that women who consumed more than 5 ounces of nuts a week had a significantly lower risk of cholecystectomy.
Walnuts are a good source of the mineral copper whose deficiency is associated with lower bone mineral density and an increased risk of osteoporosis (a medical condition in which bones become thinner and less dense, making them easier to fracture and break). Copper also plays an important role in the maintenance of collagen (a substance that makes up the building blocks for bone) and elastin and without sufficient copper, the body cannot replace damaged collagen. This condition can lead to a range of other issues including joint dysfunction. Walnuts also contain manganese that has been shown to prevent osteoporosis in combination with the minerals calcium and copper. Magnesium, another mineral in walnuts, is important for bone formation as it aids in the absorption of calcium into the bone.
Walnuts and Epilepsy
Walnuts are a good source of the mineral manganese whose deficiency has been shown to be associated with epilepsy. Rats with manganese deficiency tend to be more susceptible to seizures. People with epilepsy have also been shown to have lower whole blood manganese levels than those without epilepsy.
Word of caution
Walnuts are dense in calories and therefore should be consumed in moderation. Like any other dietary component with potential health benefits, it is the total quantity consumed and overall eating pattern that is most important in disease prevention and achieving good health. In order to enjoy the health benefits of any diet, it is better to eat a diet with a variety of constituents than to concentrate on limited foods.
(The author is a Research Scholar at Department of Biotechnology, University of Kashmir)