Walnuts deserve their superfood reputation. They are full of healthy fats, fiber, minerals and vitamins, but there are so many more ways in which they support health.
For the past 50 years, scientists and industry experts have gathered every year for a walnut conference at the University of California, where they talk about the newest health research into walnuts.
The English walnut is the most common type, and is also the most studied variety. What’s so great about them? Read on to find out.
1. Antioxidant Rich
Walnuts contain more antioxidants than any other commonly-eaten nut. These antioxidants are vitamin E, melatonin and compounds called polyphenols, and they are concentrated particularly high in the brown, papery skin on shelled walnuts.
A small, preliminary study of healthy adults showed that eating a diet rich in walnuts prevented oxidative damage from bad LDL cholesterol after eating, while a refined fat meal didn’t. LDL can build up in your arteries and cause atherosclerosis.
2. Good Plant Source of Omega-3s
Walnuts are higher in omega-3 fat than any other nut. Plant-based omega-3 is called alpha-linolenic acid (ALA), and it is an essential fat that has to be absorbed from your diet.
There have been observational studies that show that for each gram of ALA you eat every day, your risk of dying from heart disease drops by 10%.
3. May be Anti-Inflammatory
Inflammation plays a role in many diseases, including heart disease, Alzheimer’s, type 2 diabetes and cancer, and inflammation can be caused by oxidative stress.
Polyphenols in walnuts can help combat this inflammation and oxidative stress, especially a subgroup of walnut polyphenols called ellagitannins. Good bacteria in your gut convert ellagitannins to compounds called urolithins, which can protect against inflammation.
4. Gut Health
There are studies that suggest if your gut contains health-promoting bacteria and other microbes, then you are more likely to have good gut health and be healthier overall.
If your gut bacteria are unhealthy, it can contribute to disease and inflammation in your gut and in other places in your body. This can increase the risk of obesity, cancer and heart disease.
The things you eat can have a significant effect on your gut bacteria, and walnuts may help to keep your gut healthy. A study showed that when healthy adults ate walnuts every day for eight weeks, they increased the amount of beneficial, probiotic bacteria, compared to a period of not eating any walnuts.
5. Could Reduce Some Cancer Risks
Walnuts may reduce your risk of getting certain cancers. Test-tube, animal and human observational studies have suggested eating walnuts could help prevent some cancers, such as breast, prostate and colorectal cancers.
Walnuts provide our gut microbes with polyphenol ellagitannins, which they then convert to compounds called urolithins. These urolithins can have anti-inflammatory effects in your gut, which could be one way walnuts may protect against colorectal cancer, and they may also protect against other types of cancer.
6. Could Help Control Weight
Walnuts do contain a lot of calories, but some studies suggest that the energy absorbed from them is 21% lower than would be expected. Walnuts may even help control the appetite, as a study of 10 obese people showed. Some drank a smoothie made with walnuts once a day for five days, and they reported decreased hunger and appetite, while those who took a placebo drink equal in calories and nutrients did not report the same observations.
7. May Help Control Type 2 Diabetes, and Lower Your Risk
There have been observational studies done that suggest one reason that walnuts are linked to a lower risk of type 2 diabetes is that they help to control weight – extra weight increases your risk of high blood sugar and diabetes.
Walnuts may also help control blood sugar in other ways, too.
A study of 100 people with type 2 diabetes who took walnut oil every day showed an 8% decrease in fasting blood sugar.
8. Could Help Lower Blood Pressure
Having high blood pressure increases the risk of heart disease and stroke, and there are some studies that suggest walnuts could help lower blood pressure in both people with high blood pressure and healthy people under stress.
Eating 1 ounce (28 grams) of nuts (including walnuts) a day as part of a healthy diet could improve blood pressure.
9. Helps Preserve Age-Related Physical Function
As you get older, it becomes even more important to maintain good physical function to aid your mobility and independence, and one thing that could be important is keeping to healthy eating habits.
Although walnuts are calorie dense, they area also full of vitamins, minerals, fiber, fats and plant compounds that could help support physical function into old age.
10. Could Support Brain Function
Animal and test tube studies have found that walnut nutrients including polyunsaturated fat, polyphenols and vitamin E, could reduce inflammation and oxidative damage in your brain.
Observational studies in older people have linked walnuts with better brain function, including more mental agility and improved memory.
More testing in these areas is needed to show a firm link.
11. Good for Male Reproductive Health
The average Western diet, which is high in sugar, salt, processed foods and refined grains, has been linked to reduced sperm function.
Walnuts may be the answer, as they could support sperm health and male fertility. A study of 117 healthy men who had 75 grams of walnuts daily with their Western diets for three months showed that they had improved sperm shape and mobility compared to the men who didn’t eat nuts.
12. Improves Blood Fats
Triglycerides and LDL cholesterol are linked to an increased risk of heart disease, but eating walnuts regularly has been shown to reduce cholesterol levels.
One study showed that those who ate 43 grams of walnuts daily for eight weeks had a 5% decrease in total cholesterol, a 5% decrease in LDL cholesterol and another 5% decrease in triglycerides, compared to the control group.
13. Easy to Find, and Simple to Add to Your Diet
Walnuts are found in nearly any grocery store, and you can find raw walnuts in the baking aisle, roasted walnuts with the other nuts, and cold-pressed walnut oil in with the other specialty oils.
Walnuts make a great snack, but you could also use them in your favorite recipes too. Make sure that no-one is allergic to walnuts before adding them to your dishes.