Walnuts

Walnuts are part of the tree nut family. This food family includes brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts. It would be difficult to overestimate the potential health benefits associated with this food family.

Walnuts come from an ornamental tree that is highly prized for its beauty. While there are numerous species of walnut trees, three of the main types of walnuts consumed are the English (or Persian) walnut, Juglans regia; the black walnut, Juglans nigra; and the white (or butternut) walnut, Juglans cinerea. The English walnut is the most popular type in the United States and features a thinner shell that is easily broken with a nutcracker. The black walnut has thicker shells that are harder to crack and a much more pungent distinctive flavor. The white walnut features a sweeter and oilier taste than the other two types, although it is not as widely available. Within these basic types of walnuts, there are dozens of different varieties (also called cultivars). It's not uncommon to see research studies that evaluate several dozen different cultivars of English or black walnuts. All types and varieties of walnuts can have unique nutrient composition. 

NUTRITION

Not only do walnuts taste great but they are one of the most antioxidant rich foods, and a great source of heart-healthy monounsaturated fats and precious omega-3 fatty acids in the form of alpha-linolenic acid (ALA). 

Minerals are also provided by walnuts in valuable amounts. In particular copper, iron, manganese, magnesium, zinc, calcium, phosphorous, calcium, chromium, potassium, and selenium. Walnuts are also high in B-complex vitamins, vitamin E, phenolic acids, tannins, and flavonoids. 

HEALTH BENEFITS

No aspect of walnuts has been wider evaluated in science and research than their benefits for the heart and circulatory system. Their anti-inflammatory properties and high levels of omega-3´s have repeatedly shown to improve a wide variety of cardiovascular functions, helping to prevent strokes, coronary artery disease, blood clots and heart attacks.  

When it comes to walnuts having beneficial impact on regulating blood pressure, the research shows mixed results. Researchers have long been aware of the relationship between healthy blood pressure and intake of certain minerals, including potassium, calcium, and magnesium. Even though there are good amounts of these minerals in virtually all varieties of walnuts, some studies have shown statistically significant benefits from walnuts on blood pressure while others have not. This is likely due to a surprising difference in mineral composition among different varieties of walnuts.

Walnuts are also regarded as a great “brain food”and considered particularly beneficial for cognitive health. A limited (but increasing) number of studies have shown potential health benefits for walnuts in the area of memory and general thought processes (often referred to as "cognitive" processes). 

Walnuts are also very important for the neurological and circulatory systems and can help to benefit neuropathy, cerebral palsy, dementia, raynaud’s disease, diabetes and atherosclerosis. 

The anti-inflammatory properties of walnuts are also known to help prevent cancer, particularly colon, prostate, and breast cancers. The antioxidant properties of walnuts help lower risk of chronic oxidative stress, and the anti-inflammatory properties help lower risk of chronic inflammation, and it is precisely these two types of risk, that, when combined, pose the greatest risk for cancer development. Prostate cancer and breast cancer are the best-studied types of cancer with respect to walnut intake, and their risk has been found to be reduced by fairly large amounts of walnut consumption. (Large in this case means approximately 3 ounces per day.) 

Walnuts are also known to help with long term weightloss and prevention of obesity. Not just because they satiate the appetite. Studies show that adding walnuts to the diet can improve metabolism, and can decrease "abdominal adiposity"—the technical term for the depositing of fat around the waist. That finding may be surprising, because often we think of high-fat, high-calorie foods as a factor contributing to weight gain. And yes, overconsumption of high-fat, high-calorie foods is a primary contributing factor to weight gain. However, obesity has also been clearly identified by researchers as involving chronic, unwanted inflammation. Since walnuts are unique in their collection of anti-inflammatory nutrients omega-3 fatty acids; phytonutrients including tannins, phenolic acids, and flavonoids, the benefits can overshadow the high-calorie and high-fat risk posed by walnuts. 

A final fascinating aspect of walnuts and their potential health benefits involves melatonin (MLT). MLT is a widely-active messaging molecule in our nervous system, and very hormone-like in its regulatory properties. MLT is critical in the regulation of sleep, daily (circadian) rhythms, light-dark adjustment, and other processes. It has also been found to be naturally occurring within walnuts. Average melatonin (MLT) content of walnuts is approximately 3.6 nanograms (ng) per gram (g), or 102ng/ounce. Other commonly eaten foods—for example, cherries—have also been found to measurable amounts of MLT. 

Only a few walnuts a day are needed to receive their powerful health benefits. In at least one research study, adults have been able to significantly increase their blood level of omega-3 alpha-linolenic acid (ALA) with as few as 4 walnuts per day.

Walnut oil is a wonderful moisturizer for the skin and is regularly used in skin care products for its healing and protective benefits. Try mashing a few ripe bananas and sprinkling chopped walnuts on top for an energy and brain boosting breakfast. 

HISTORY

While walnut trees have been cultivated for thousands of years, the different types have varying origins. The English walnut originated in India and the regions surrounding the Caspian Sea, hence it is also known as the Persian walnut. In the 4th century AD, the ancient Romans introduced the walnut into many European countries where it has been grown since. Throughout its history, the walnut tree has been highly revered; not only does it have a life span that is several times that of humans, but its uses include food, medicine, shelter, dye and lamp oil. It is thought that the walnuts grown in North America gained the name "English walnuts," since they were introduced into America via English merchant ships.

Black walnuts and white walnuts are native to North America, specifically the Central Mississippi Valley and Appalachian area. They played an important role in the diets and lifestyles of both the Native American Indians and the early colonial settlers.

China is presently the largest commercial producer of walnuts in the world, with about 360,000 metric tons produced per year. The United States is second, with about 294,000 metric tons of production. Within the U.S., about 90% of all walnuts are grown in California, particularly within the San Joaquin and Sacramento Valleys The annual combined walnut output of Iran and Turkey is approximately the same as the United States, and the Ukraine and Romania are next in line in terms of total walnut production.

HOW TO SELECT AND STORE

The higher the fat content in the nut, the more easily it will become rancid. In general, softer nuts tend to have a higher oil content. Due to their high polyunsaturated fat content, walnuts are extremely perishable and care should be taken in their storage. Shelled walnuts should ideally be stored in an airtight container in the refrigerator, where they will keep for six months, or the freezer, where they will last for one year. Unshelled walnuts should preferably be stored in the refrigerator, although as long as you keep them in a cool, dry, dark place they will stay fresh for up to six months.

Smell and taste the walnuts before using. If they are rancid they will have a sharp, chemical like smell. 

TIPS FOR PREPARING AND USING

Walnuts contain enzyme inhibitors which can make them hard to digest. When they are soaked (also called ’activated’ or ’sprouted’) in fresh water for about 8 hours, these anti nutrients are washed away and the nutrients are more bioavailable and easier to metabolize. Soaked walnuts are between 300% and 1200% more nutritious (amazing, huh?) and can be used as they are, or dehydrated and stored. 

ACTIVATED WALNUTS

1 cup walnuts 

2 cups water 

Place the walnuts in a glass bowl, then add the water. Cover the bowl and let it sit in room temperature or refrigerator for approximately 8 hours. If you soak them longer, change water every 8 hours. 

Dispose of the water after soaking, as by now it has absorbed the enzyme inhibitors and is unusable.
Rinse the nuts and store in the refrigerator for use within a day or two. Or, dehydrate at 43°C (110°F) for approximately 24 hours, if you want them dry and crispy. 

Activated and dehydrated nuts/seeds will keep for up to 6 months, stored in a sealed container in a cool and dark place, preferably in the refrigerator. 

ALLERGIC REACTIONS

Although allergic reactions can occur to virtually any food, research studies on food allergy consistently report more problems with some foods than with others. It's important to realize that the frequency of problems varies from country to country and can change significantly along with changes in the food supply or with other manufacturing practices. For example, in several part of the world, including Canada, Japan, and Israel, sesame seed allergy has risen to a level of major concern over the past 10 years.

In the United States, beginning in 2004 with the passage of the Food Allergen Labeling and Consumer Protection Act (FALCPA), food labels have been required to identify the presence of any major food allergens. Since 90% of food allergies in the U.S. have been associated with 8 food types as reported by the U.S. Centers for Disease Control, it is these 8 food types that are considered to be major food allergens in the U.S. and require identification on food labels. The 8 food types classified as major allergens are as follows: (1) wheat, (2) cow's milk, (3) hen's eggs, (4) fish, (5) crustacean shellfish (including shrimp, prawns, lobster and crab); (6) tree nuts (including cashews, almonds, walnuts, pecans, pistachios, Brazil nuts, hazelnuts and chestnuts); (7) peanuts; and (8) soy foods. In the case of walnuts, there is also some evidence showing cross-reactivity with cashews, peanuts, and sesame seeds, such that persons suspecting food allergy to walnuts may also want to determine the dietary safety and appropriateness of these other foods.

Food allergy symptoms may sometimes be immediate and specific and can include skin rash, hives, itching, and eczema; swelling of the lips, tongue, or throat; tingling in the mouth; wheezing or nasal congestion; trouble breathing; and dizziness or lightheadedness. But food allergy symptoms may also be much more general and delayed, and can include fatigue, depression, chronic headache, chronic bowel problems (such as diarrhea or constipation), and insomnia. Because most food allergy symptoms can be caused by a variety of other health problems, it is good practice to seek the help of a healthcare provider when evaluating the role of food allergies in your health.

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