Walnuts are edible seeds that come from the trees of the Juglans genus. The walnut fruit, known as a drupe, develops within a thick, hard shell or husk. The husk is green and fleshy when young, gradually turning brown and becoming hard as the fruit matures. Inside the shell is the edible walnut kernel, which is rounded and characterized by its deeply furrowed surface.
Walnuts are distinctive due to their rich, earthy flavor and unique, convoluted shape. The kernel consists of two lobes separated by a central partition, resembling the appearance of a brain. The outer shell is extremely hard and requires cracking to access the nutritious kernel within.
Nutrient Content in Walnut:
|Nutrient||Amount per 1 ounce (28 grams)|
|Total Fat||18.5 grams|
|– Saturated Fat||1.7 grams|
|– Monounsaturated Fat||2.5 grams|
|– Polyunsaturated Fat||13.4 grams|
|– Dietary Fiber||1.9 grams|
|– Sugars||0.7 grams|
|Vitamin E||1.9 milligrams (9% DV)|
|Folate||28 micrograms (7% DV)|
|Magnesium||45 milligrams (11% DV)|
|Phosphorus||98 milligrams (10% DV)|
|Copper||0.4 milligrams (18% DV)|
Walnuts offer a range of health benefits due to their unique nutritional composition. Here are some of the notable health benefits associated with consuming walnuts:
1. Reduce the risk of cardiovascular disease:
Alpha-linolenic acid (ALA), a plant-derived omega-3 fatty acid present in walnuts, exhibits potential cardiometabolic benefits. Observational studies indicate that higher ALA intake is associated with a reduced risk of cardiovascular disease, particularly fatal coronary heart disease. Randomized controlled trials (RCTs) demonstrate that diets high in ALA can lower total cholesterol, LDL cholesterol, triglycerides, and blood pressure. ALA may also exert anti-inflammatory effects, contributing to its cardiovascular benefits.
Walnuts have shown promising anti-cancer effects through multiple mechanisms, including reducing carcinogens, regulating cell signaling and apoptosis, and inhibiting tumor growth. Walnut extracts and compounds have been found to inhibit the proliferation of various cancer cells, including prostate, breast, and endometrial cancer. They exhibit antitumor and antioxidant properties with minimal toxicity. Studies highlight the potential of walnuts as a natural anticancer agent and their ability to inhibit tumorigenesis and slow tumor growth.
3. Digestive Benefits:
Walnut kernels contain various health-promoting components, including polyunsaturated fatty acids, phenolics, phytosterols, and endogenous proteases. The identified proteases, such as endopeptidases, aminopeptidases, and carboxypeptidases, assist in the digestion of walnut proteins. These proteases exhibit activity in a broad pH range and contribute to the optimal digestion of proteins. Additionally, soaking and peeling walnuts enhance their in vitro digestibility. Improved protein digestion can potentially enhance nutrient absorption and utilization, providing health benefits to individuals consuming walnuts.
4. Weight Management:
Despite being calorie-dense, walnuts can still be beneficial for weight management. The high fiber and protein content of walnuts contribute to increased satiety and reduced calorie intake from other foods. Additionally, the healthy fats in walnuts promote a feeling of fullness and may help control cravings.
5. Anti-Inflammatory Effects:
Walnuts are a source of various bioactive compounds with anti-inflammatory properties, including polyphenols and omega-3 fatty acids. These compounds help reduce inflammation in the body, which is associated with chronic diseases such as heart disease, cancer, and diabetes.
6. Brain Functioning:
Walnuts contain polyphenols, antioxidants, and omega-3 fatty acids, which have been associated with improved cognitive function and neuroprotective effects. Regular consumption of walnuts may contribute to enhanced memory, learning abilities, and overall brain health.
7. Supportive during pregnancy:
Walnuts are a good source of essential nutrients for pregnant women, including folate, omega-3 fatty acids, and protein. These nutrients play a vital role in fetal development, brain health, and reducing the risk of birth defects.
8. Enhanced Male Reproductive Health:
Walnuts have been found to be beneficial for male reproductive health. They are a rich source of nutrients like antioxidants, omega-3 fatty acids, and arginine, which can improve sperm quality, motility, and morphology. Incorporating walnuts into a balanced diet may support male fertility.
Walnuts are not technically nuts! They are seeds of a drupe fruit. A drupe is a type of fruit that has an outer fleshy part (the husk) surrounding a hard shell with a seed inside. In the case of walnuts, the shell is the hard outer layer, and the seed inside is what we commonly refer to as the walnut. This makes walnuts a unique example of a seed commonly referred to as a nut. So, the next time you enjoy a walnut, remember that you’re actually eating a seed from a drupe fruit rather than a true nut!