Anyone heard of what’s called the doctrine of signatures? This is described as foods that resemble various parts of the body can be used to heal, treat or improve that specific part of the body. Walnuts are considered a doctrine of signature food, as it resembles the brain. However, does this hold true when we dive and dissect the nutritional profile of walnuts? Let’s take a look shall we?


Each walnut kernel consists of two lobes that look similarly to a butterfly. The outside skin of a walnut is covered by a thin, light brown layer. While inside is an off-white collar. Each kernel is then encased by a very hard, round brown shell. There are numerous of varieties of walnuts, however the most popular ones that we consume in our diet include: the English (or Persian) walnut, the black walnut, and the white (or butterfly) walnut. The English walnut, also known as Juglans regis has the thinnest shell that is easily broken with a nutcracker. The black or Juglans nigra has thicker shells and offers a more pungent and distinct flavour. While the white or Juglans cinerea offers a sweeter and oilier taste. Regardless of the variety, walnuts offer not only a crunch but also flavour to any meal.

When purchasing shelled walnuts, avoid ones that look rubbery or shrivelled. If you are able to smell them, make sure they are not rancid. Shelled walnuts are extremely perishable and so they should be kept in an airtight container and placed in the refrigerator or a cool and dark place at best.


The popular English walnut originated in India. The walnut tree offers not only food for our consumption but are used for medicine, shelter, dye and lamp oil as well. Black and white walnuts are native to North America, playing a large role in the diets and lifestyle of Native Americans within the Central Mississippi Valley and Appalachian area.

Today, China is the largest commercial producer, followed by United States and Iran.


1/4 cup walnuts, halves:

163.5 kcal
3.4 g Carbs
1.7 g Fiber
16.3 g Fat
3.8 g Protein
2.3 g Omega-3
9.5 g Omega-6
0.4 mg Copper
0.9 mg Manganese

Walnuts are high in both omega-3 and omega-6 fatty acids. Low intake of omega-3 fatty acids have been found to be linked to depression and cognitive degeneration. Both of these fatty acids have also been shown to boost brain health and function. These essential fatty acids also have a special relationship to inflammation, necessary for the natural healing process within our bodies.

Omega-3 fatty acids, also known as Alpha Linolenic Acid (ALA) are anti-inflammatory, following the PG-3 (Prostaglandin-3 series) metabolism pathway. Yes it may sound slightly complicated, however the key take away is that sources such as walnuts are high in ALA which the body will convert through a series of steps leading to the benefit of anti-inflammatory properties. This means they are immune building and block the release of inflammatory products such as from mast cells & basophils.

The increased omega-3 fatty acids also increases the amount of red blood cells, which can help improve blood quality, decreasing LDL cholesterol and total cholesterol. Walnuts have also been found to impact the vascular reactivity in our bodies, meaning improving the ability of our blood vessels to respond in various situations and stimuli.

As always, being high in antioxidants and anti-inflammatory properties will help reduce free radicals in the body and thus reducing the risk of cancer. Other health benefits include: support of bone health, support of weight loss and prevention of obesity, benefits in treatment of type 2 diabetes, and help reduce problems in metabolic syndrome.


There really are endless amounts of ways you can incorporate walnuts into your diet. Anything from, sweet baked goods to savoury sides and mains, or chopped and crushed and sprinkled on top of any of your dishes as well. I have created a list of various recipes to try and gain inspiration from:


  • Walnuts are the only nut that has omega-3 fatty acids!
  • Around 30 different walnut varieties are consumed in the human diet.
  • Lifespan of walnut tree depends on the species. Walnut tree can survive from 50 to 250 years
  • Speaking of walnut trees, it is one of the oldest tree food known to man, dating back to 7000 B.C.
  • Walnuts are actually the seed of a drupe or drupaceous nut, and it is technically not a true botanical nut.


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