Walnuts are edible seeds that grow on the trees in the genus Juglans. Botanically, walnut is a drupe, not a nut, since it takes the form of a fruit enclosed by a fleshy outer layer with a seed inside. As walnuts age on the tree, the outer shell dries and pulls away, leaving the shell and seed behind. The fruit inside is edible that resembles the brain.
There are two common varieties of walnuts: English walnut and black walnut. The English walnut originated in Persia, while the black walnut is native to eastern North America.
They’re both have a crunchy texture and have similar nutritional content. Both the black and the English walnuts are packed with nutrients like omega 3 fatty acids, protein, fibre, antioxidants, as well as minerals such as folate, thiamin, magnesium, potassium, manganese and copper. However, the black walnut has slightly more protein and less fat.
Health Benefits of Walnuts
1. Reduce cancer risk
Walnuts may help reduce the risk of prostate cancer, breast cancer as well as lung cancer. According to preliminary research presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, walnuts provide protection from lung cancer. A type of vitamin E known as gamma tocopherol has been found to provide significant protection against lung cancer.
In one study, mice that ate the human equivalent of 2.4 ounces of whole walnuts for 18 weeks had significantly smaller and slower-growing prostate tumors compared to the control group that consumed the same amount of fat but from other sources.
2. Prevent diabetes
According to studies, women who consumed 28 grams of walnuts twice a week, were 24% less likely to develop type 2 diabetes. Walnuts are uniquely high in omega-3 and omega-6 fatty acids, which play a vital role in the prevention of type 2 diabetes.
Women who reported eating one ounce (30 g) of nuts at least five times per week reduced their risk of type 2 diabetes by almost 30% compared to those who rarely or never ate nuts, say researchers at the Harvard School of Public Health. The mono and polyunsaturated fats in nuts are good for insulin sensitivity.
3. Maintain brain Health
Walnuts are the top nut for brain health. They are a rich source of omega-3 fatty acid, which plays a major role in the optimum functioning of the brain cells, making you smarter. Walnuts also contain high levels of B-vitamin folate, which improves neural health, and reduces the risk of cognitive diseases.
Many research suggests that walnut consumption may support brain health, including increasing inferential reasoning in young adults.
4. Cardiovascular benefits
Walnuts contain the amino acid l-arginine, which offers protection against heart disease. Walnuts also contain the plant-based omega-3 fat alpha-linolenic acid (ALA), which may prevent the formation of pathological blood clots.
Research shows that people who eat a diet high in ALA are less likely to have a fatal heart attack and have a nearly 50% lower risk of sudden cardiac death.
5. Improve male fertility
Walnuts are a natural source of omega-3 fatty acids that, along with other polyunsaturated fatty acids, have been linked to better sperm quality.
Research from the University of California, Los Angeles (UCLA) has showed that eating 75 grams of walnuts a day for three months increases men’s sperm count and fertility.
6. Relieve stress
One of the significant advantages of eating walnuts every day is that it helps to keep the stress away. The nut is a rich source of fiber, antioxidants, and omega-3 fatty acids, which have been found to reduce stress levels.
7. Helps in losing weight
Nutritionists suggest eating walnuts every day to accelerate the process of healthy weight loss. Walnut is packed with fiber, protein and omega-3 fatty acids, thus satiates our hunger and keeps our stomach full for a longer period. Despite being considered a heavy calorie, walnuts help in healthy weight loss.
8. Improve sleep
Walnuts are a good source of tryptophan, a sleep-enhancing amino acid that is needed to make serotonin and melatonin, both of which are thought to induce sleep. Omega-3 fatty acids are another element of walnut which have a role to maintain a relaxed mind as well as good sleep patterns.
9. Beneficial for pregnant women
Eating walnut daily can greatly benefit those who are expecting. Walnuts contain healthy vitamin B-Complex groups like folate, riboflavin, thiamin, etc, all of which are necessary for a pregnant woman and the fetus.
10. Promote healthy hair
Walnut is a great food for hair too. This is because walnut contain biotin (vitamin B7) that can help reduce hair loss and improve hair growth to particular extent. Other than that, the presence of a number of nutrients like vitamin E, potassium, omega-3, omega-6, omega-9 fatty acids on walnut, can help strengthen the hair follicles.
When choosing walnuts, select those without cracks or holes. Shelled walnuts should be plump and crisp. To avoid rancidity, refrigerate or freeze shelled walnuts in an airtight container. For long-term storage, it is best to buy unshelled nuts and store them in the refrigerator.