Walnut is an edible seed of the tree Juglans regia. The plant originated in India and the regions surrounding the Caspian Sea, and in the 4th century AD, the ancient Romans introduced the walnut to many European countries. The tree serves a multitude of uses; it can be used as food (edible seed), medicine, furniture and dye. There are many health benefits of walnuts ranging from weight management to prevention and slowing of various cancers.
1. Cancer-Fighting Benefits
Walnuts may help reduce not only the risk of prostate cancer, but breast cancer as well. 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.
Overall the whole walnut diet reduced prostate cancer growth by 30 to 40 percent. According to another study on mice, the human equivalent of just two handfuls of walnuts a day cut breast cancer risk in half, and slowed tumor growth by 50 percent as well.
2. Cardiovascular Benefits
Walnuts contain the amino acid l-arginine, which offers multiple vascular benefits to people with heart disease, or those who have increased risk for heart disease due to multiple cardiac risk factors.
If you struggle with herpes, you may want to avoid or limit walnuts, as high levels of arginine can deplete the amino acid lysine, which can trigger herpes recurrences.
Walnuts also contain the plant-based omega-3 fat alpha-linolenic acid (ALA), which is anti-inflammatory and 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 percent lower risk of sudden cardiac death.
Eating just four walnuts a day has been shown to significantly raise blood levels of heart-healthy ALA, and walnut consumption supports healthful cholesterol levels.
Separate research showed that eating just one ounce of walnuts a day may decrease cardiovascular risk, and among those at high cardiovascular risk, increased frequency of nut consumption significantly lowers the risk of death.
3. Weight Control Benefits
Adding healthful amounts of nuts such as walnuts to your diet can help you to maintain your ideal weight over time. In one review of 31 trials, those whose diets included extra nuts or nuts substituted for other foods lost about 1.4 extra pounds and half an inch from their waists. Eating walnuts is also associated with increased satiety after just three days.
4. Improve Reproductive Health in Men
One of the lesser-known benefits of walnuts is their impact on male fertility. Among men who consume a Western-style diet, adding 75 grams (a bit over one-half cup) of walnuts daily significantly improved sperm quality, including vitality, motility, and morphology.
5. Brain Health
Walnuts contain a number of neuroprotective compounds, including vitamin E, folate, melatonin, omega-3 fats, and antioxidants. Research shows walnut consumption may support brain health, including increasing inferential reasoning in young adults.
One study also found that consuming high-antioxidant foods like walnuts “can decrease the enhanced vulnerability to oxidative stress that occurs in aging,” “increase health span,” and also “enhance cognitive and motor function in aging.”
6. Fight Diabetes
The beneficial dietary fat in walnuts has been shown to improve metabolic parameters in people with type 2 diabetes. Overweight adults with type 2 diabetes who ate one-quarter cup of walnuts daily had significant reductions in fasting insulin levels compared to those who did not, and the benefit was achieved in the first three months.
7. Provide Antioxidant Defense
Walnuts are a great source of anti-inflammatory omega-3 fatty acids, an essential fatty acid that the body can’t manufacture. Its anti-inflammatory, antioxidant defense protects healthy cells from the damaging effects of free radicals.
8. Walnuts in Pregnancy
Although not much research has gone into the safety and benefits of consuming walnut during pregnancy, it is believed that walnut may stave off nausea during pregnancy and boost brain development in the child. However, one study showed that consuming tree nuts (including walnut) during pregnancy could raise the odds of asthma as food allergy in the child by 50 percent. But Harvard School of Public Health nutritionists rather suggest that consumption of peanuts and tree nuts during pregnancy might even decrease the risk of allergic disease development in children.
9. Skin Care Benefits
Walnuts are rich in B-vitamins and antioxidants that prevents your skin from free radical damage and prevents wrinkles and signs of ageing. So if you want glowing skin long into your middle-age, eat walnuts.
10. Walnuts for Bone Health
Alpha-linolenic acid (ALA) is the omega-3 fat found in walnuts, and it has demonstrated a remarkable ability to promote bone health. In a study done by researchers at Penn State University, 23 participants were fed 4 different diets over 6-week periods, one of which was a high-ALA diet. After each segment of the study, the subjects were tested for levels of N-telopeptides, a marker of bone breakdown. Findings showed that in the diet consisting of high levels of ALA, the N-telopeptides count was much lower.
11. Great for Hair
Walnut is a good ‘hair food’ too. This is because walnuts contain biotin (vitamin B7) that helps strengthen hair, reduce hair fall and improve hair growth to certain extent. In addition to walnuts, you can try these foods to prevent hair loss.
12. Help You Deal with Stress
A diet rich in walnuts and walnut oil may help the body deal better with stress. Research published last year in the Journal of the American College of Nutrition found that walnuts and walnut oil lowered both resting blood pressure and blood pressure responses to stress in the laboratory. The researchers said the study shows that a dietary change could help our bodies better respond to stress.
13. Constipation and Digestive System Benefits
Walnuts are rich in fiber and they are a great way to keep your digestive system functioning right. All humans require fiber on a daily basis to keep their bowels functioning correctly. Usually the common sources of protein, such as meat and dairy products lack fiber. Having walnuts daily can help you with the digestive problems and keep your bowels functioning properly.
WARNING: Despite so many health benefits of walnut, it is best to be careful on the amount and frequency of walnut consumption. That is because walnut is high in oxalates and oxalates contribute to kidney stone formation.