This Week: Walnuts!

Like all nuts, walnuts are packed with vitamins, minerals, antioxidants and phytochemicals beneficial to health. Regularly eating nuts has been shown to contribute to heart health, reduce overall mortality and the risk of developing type 2 diabetes, assist with weight management, reduce the risk of cancer, improve sperm quality, reduce depression and overall promote good health. 
 
What makes walnuts unique?

• Walnuts are one of the few plant sources of omega-3 fats, in the form of alpha-linolenic acid (ALA). Research has shown that ALA can reduce inflammation [7,13] – an important factor in the development of chronic disease.
• They are rich in polyphenols – powerful antioxidants that protect the body’s tissues from damage due to oxidation [9].
• Walnuts contain predominantly polyunsaturated fats.
• Walnuts are a source of polyunsaturated fats and omega 3 ALA’s, and are naturally low in sugar and sodium.
• They are a source of copper, magnesium, manganese, niacin and folate. 

 
Walnuts are one of the most important sources of protective phytochemicals called polyphenols, which makes them one of the most beneficial of the tree nuts to add to your diet. The most notable polyphenol is ellagic acid: its antioxidant and anti-inflammatory properties appear to play an important role in managing the initiation and progression of several diseases, including cancer, type II diabetes and heart disease.

As well as their important phytochemicals, walnuts contain high amounts of polyunsaturated fats that offer potential benefits for both brain health and function. Omega-3 fatty acids play a part by helping reduce oxidative stress in the brain but also by helping to improve brain signalling and neurogenesis, which is how new neurons are formed. Vitamin E, folate and the protective phytochemical, ellagic acid, also contribute to the neuroprotective and memory enhancing properties of walnuts.

The Journal of Nutrition reports that consumption of walnuts may reduce the risk of cardiovascular disease, and that walnut oil provides more favourable benefits to endothelial function, which is the lining of the inside of our blood and lymphatic vessels. A study by the British Journal of Nutrition found that those who consumed nuts more than four times a week reduced their risk of coronary heart disease by as much as 37 per cent.

There has been some evidence to demonstrate that consuming walnuts in the place of other foods does not cause weight gain. This is because, although walnuts are calorie-dense, we aren't able to absorb all of the energy from them, making walnuts a great snack alternative for those looking to manage their weight.
A recent animal study has shown consuming walnuts can enrich the gut microbiota, the community of beneficial microbes which live in our intestines, and in particular increase strains of beneficial probiotic bacteria. This has been repeated in humans with reports of increases in beneficial strains and especially those which produce butyrate, a by-product which supports the health of the gut.

An observational study of more than 50,000 older women over an 18-year period found those with the healthiest diet had a 13% lower risk of physical impairment. One of the foods with the strongest beneficial contribution was walnuts Both animal and human studies suggest that including walnuts daily may improve sperm quality and enhance fertility for men. Further studies are needed to confirm these benefits.
 
Detriments:
The fibre in the nuts may cause gastrointestinal issues if consumed in excess. Though walnuts (and nuts in general) may help treat digestive issues, sometimes, they may aggravate the problem. Hence, please consult your doctor before consuming walnuts if you have any digestive problems. Other common digestive side effects of tree nuts (including walnuts) include constipation, bloating, gas, stomach pain, vomiting, or diarrhea.

Allergies to tree nuts are common. The symptoms include nausea, shortness of breath, difficulty in swallowing, itching of the mouth, throat, or the eyes, headache, and nasal congestion. The most dangerous allergic reaction is anaphylaxis. It impairs breathing and sends the body into a state of shock. You may experience either a primary or a secondary allergy with walnuts. Primary allergies involve the direct intake of walnuts or their products, which can lead to anaphylaxis. Secondary allergies involve pollen, which reacts with walnuts due to cross-reactivity (this is because of the similarities in the nature of proteins in the pollen and walnuts). Here, the symptoms include itching skin irritation, or swelling of the mouth.
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Since nuts, including walnuts, are high in fibre, they may aggravate ulcers in susceptible individuals. However, more research is required to establish this fact. Like all other nuts, walnuts are healthy. A large body of research highlights their anticancer, anti-inflammatory, cardio- and neuroprotective properties. But it is important to take note of the side effects and practice moderation.