Elson M. Haas M.D.
Excerpted from Staying Healthy with Nutrition:
The Complete Guide to Diet and Nutritional Medicine
Nuts are one of nature’s richest foods. They have good-quality protein and are even higher in fats (as oils) than the seeds. Because of that, they are more caloric than other vegetable foods (remember, each gram of fat has nine calories, over twice that of protein or carbohydrate), so they are not a food that should be eaten in abundance unless we are trying to gain weight. For vegetarians, nuts may be the most concentrated foods they eat, and their main source of oil.
Like the seeds, nuts are bundles of potential, the part of the plant that feeds the future generations. The calories, proteins, fatty acids, and many vitamins and minerals are what provide the energy for the early growth of the next nut tree. There are more than 300 types of nuts. Besides those discussed below, hickory nuts, macadamias, and pinenuts are also common. Most nuts are the fruit or seed that follows the blossoming of the tree. They are usually contained in a hard shell to protect them from birds, insects, and germs and also to keep them fresh, since the concentrated oils contained in nuts can easily rancidify and spoil in the air.
Because of the spoilage problem of these oil-rich nuts, picking or buying the fresh, raw, unshelled (with shells) nuts are the best. They will store longer than any other. Once the shells are removed, nuts should be kept in closed containers or plastic bags in the refrigerator or even the freezer. If left out in containers or bags, they should be eaten within a month. Nuts will store longer in a cool, dry place in closed containers than left in the air or in damp areas. Roasted, salted nuts are best avoided. The salt is not needed, and roasting affects the oils and decreases the B vitamin and mineral content. Be aware of places that feed you free salted nuts, such as bars or airplanes, to increase your thirst, and your drink tab!
Sadly, most nuts in American society are eaten after they are roasted in even more oil and salted, and often with other additives or sugars. Raw nuts, especially almonds, walnuts, and hazelnuts, are probably the best. Peanuts, especially in peanut butter, are not easy to digest, and there is concern about potentially toxic molds containing aflatoxin, a potential carcinogen that grows on this leguminous nut/bean. Many people have some trouble digesting nuts because of the high fat content, which is even worse after roasting. The nut foods are not the easiest to digest; this is true especially in people with low stomach acid or gallbladder problems. Overweight individuals with gallstone or gallbladder disease often have difficulty digesting fatty foods in general. To process the nuts in our body, we usually need a good level of hydrochloric acid, fat-digesting enzymes ( lipases ), and bile secreted by our gallbladder and liver.
Besides raw, fresh nuts and the roasted varieties, nuts can be cooked into foods such as grains and vegetable dishes. This will often add the other needed essential amino acids to make more complete proteins. A nut-seed blended mix such as almonds-sunflower-sesame with a little added sea salt can be kept in a jar in the refrigerator and used as a protein seasoning. Nuts can be blended into flours as well as used in baking with other flours. These also need refrigeration to keep the other, lighter flours from rancidifying. The use of nut butters as snack foods is growing. Peanut butter is, of course, the most common, but now many other butters are commercially available, such as almond, cashew, and even pistachio and macadamia nut butters, as many people move away from peanut butter. Nut milks are also becoming popular as nourishing milk substitutes and as wholesome drinks, especially for children. If we do not already have a high-fat diet, nuts and even a little bit of the nut butters are a much better snack than sugary foods, particularly in regard to nutrition and the sustained level of energy that comes from their metabolism.
In terms of nutrient content, nuts are among the best of the vegetable foods. Their fat content is, of course, fairly high, but it is mostly unsaturated fats, which are better for us than the saturated. The inner white meat of the dried coconut, however, is rich in saturated fats and thus more of a concern in regards to cardiovascular problems. The essential fatty acids and vitamin E are also part of the nut oils. Almonds, Brazil nuts, hazelnuts, and peanuts are the best in vitamin E content. Total fat content varies, from peanuts at 50 percent to pecans (and macadamias), the richest, at 70 percent fat.
The protein content of nuts is very good, with a fairly balanced amino acid distribution, which may be why the edible part of the nuts are termed “meats.” They are the meat of the plant world. The nuts are somewhat lower in tryptophan and methionine, so the amino acid balance becomes more balanced when nuts are combined with a grain food at meals.
Most nuts have a general cross section of the B vitamins but are not real high in any, though peanuts are pretty rich in niacin. They are, however, very well endowed with the minerals, particularly potassium, magnesium, calcium, iron, zinc, and other trace minerals. Nuts are very low in sodium when unsalted, and some nuts, such as almonds, Brazil nuts, and pecans, even have some selenium.
In general, nuts can be used as a protein- and energy-rich snack food as a midmorning or midafternoon treat. Eaten alone in their raw state, and not much more than a handful, they should be fairly easily digested and assimilated by our bodies.
Brazil nuts Peanuts
Almonds. Almonds are probably the best all-around nut. Their fat content is less than most, about 60 percent, and the protein concentration is nearly 20 percent. The almond nuts are the fruits of a small tree that grows nearly thirty feet tall and is abundant in many areas of the world, including Asia, the Mediterranean, and North America. Almonds which are of the soft-shell variety possess a sweeter nut than those in hard shells, which may be slightly bitter. The presence of 2–4 percent amygdalin, commonly known as laetrile, has caused almonds to be considered as a cancer-preventing nut.
Most of the fats of the almond are polyunsaturated and are high in linoleic acid, our main essential oil. Almond oil is a very stable oil used in pharmaceutical preparations, to hold scents in fragrant oils, or for massage therapy. Almonds are very high in vitamin E, and contain some B vitamins. Calcium is also found in high amounts, and almonds or homemade almond milk (see recipes in Chapter 14) can be used as a tasty calcium source. Copper, iron, zinc, potassium, and phosphorus are also present in good amounts, as are magnesium and manganese. Sodium is very low. Some selenium is present.
Brazil Nuts. These are the very meaty and high-fat hard-shelled “seeds” of which about 10–20 are found in each big fruit of the very large (nearly 100 feet high) Brazil nut trees. Brazil nuts are a good-quality protein, yet are also about two-thirds fat, of which over 20 percent is saturated. The oil from this nut turns rancid easily and is not used commercially.
Brazil nuts are known to be rich in calcium, as well as magnesium, manganese, copper, phosphorus, potassium, and selenium. Zinc and iron are also found in good proportions in this high-mineral nut.
Cashews. Cashews are thought by some to be a toxic nut, probably because of the caustic oils found in the hard shell. Lightly roasting cashews may help to clear these oils. These sweet nuts are the real fruit of their 25- or 30-foot trees that grow best in tropical climates. These trees also provide another “fruit,” the edible “cashew apple” that grows prior to the nut. Cashews are fairly rich in magnesium, potassium, iron, and zinc. Calcium is lower in cashews than in other nuts, as is manganese; cashews also have a lower fat and higher carbohydrate level than most other nuts. Some B vitamins are present, as is vitamin A, though very little vitamin E is found in cashews.
Chestnuts. These are the classic nut of the winter holiDay s throughout the world. Hot, roasted chestnuts can be a warming and nourishing snack for our innards. Chestnuts are very high in starch (carbohydrate) and low in protein and fats and therefore lower in calories (less than half) than other nuts. Chestnuts have lower levels of most minerals than other nuts, but they are still very good in manganese, potassium, magnesium, and iron.
Coconuts. The big nuts (fruits) of the common tropical palm tree, this large fruit has a thick husk covering, a very hard shell that surrounds the rich coconut meat. A nourishing liquid, called the coconut “milk” comes from the soft meat of the fresh green coconut. When the coconut dries or ripens, this “meat” becomes hard and much of the oils become saturated. The dried coconut meat contains about 65 percent oil, mainly as saturated fat which is solid or semisolid at room temperature. This oil, though, also has some nourishment and essential fatty acids and has been used in cooking and baking as well as in soaps, shampoos, and cosmetics. Coconut is used in cooking much more in the South Pacific and East Indian cultures than in ours, probably because they have fewer foods with good fat content. The fresh milk can be used as a marinade for fish, as salad dressing, or made into a yogurt-like dish. Coconut has a little protein, about 10 percent; some carbohydrate and fiber; and traces of the B vitamins, vitamin C, and vitamin E. It has some amounts of many minerals, with potassium, magnesium, manganese, copper, and iron being the best.
Hazelnuts. These are the fruits or seeds of a small shrub or tree that usually grows between six and twelve feet tall. They are also called filberts because they ripen about the time of St. Philibert’s Day , August 20. The numerous varieties produce either round or elongated nuts. They are usually eaten raw or fried and are often used in confection making or as flavorings in sweet sauces.
Hazelnuts have one of the higher vitamin E levels of the nuts. Their protein content is about 15 percent, and they are nearly 65 percent fat, mostly unsaturated, being high in essential linoleic acid. Hazelnuts have a fairly good level of the B vitamins and are rich in most minerals such as calcium, magnesium, manganese, iron, copper, and potassium, as well as some trace minerals, including zinc and selenium.
Peanuts. The most peculiar of the nuts, and the most common in our culture, peanuts are not in fact a true nut but a legume or pea (thus “peanuts”), which grows on a small bush that yields small, soft, fibrous shells each containing usually two or three “nuts.” Peanuts, or “goobers,” grow commonly in the southern United States but are now grown largely in China and India, where their oil is used widely in cooking. Peanuts are also called “monkey nuts” because monkeys love them, as do little human monkeys, especially as peanut butter here in the United States. In poorer, more populated countries, such as China, India, and Africa, peanuts are used in the daily diet in many vegetarian dishes, to which they add more complete proteins.
Peanuts probably have as good an amino acid balance as any vegetable food. They are about 25 percent protein and very rich in nutrients. Their fat content is about 50 percent of the nut, and three-fourths of it is unsaturated. The B vitamin content of peanuts is better than that of most nuts, probably because they are a bean. Niacin and biotin are best, but all B vitamins are represented except B12. Potassium, magnesium, and phosphorus are highest of the minerals, while calcium, iron, zinc, copper, and manganese are also found in substantial amounts.
Stored peanuts may easily become moldy, a concern especially for those sensitive to molds. Peanuts have been known to become contaminated with molds containing aflatoxin, a substance that is thought to be carcinogenic. Also of concern is that much of the peanut butter consumed in this country is the processed variety, with not only the high fat and oil content of peanuts but additional hydrogenated fats, which are more toxic in the body. (See discussion of hydrogenated oils in Chapter 4, Lipids , and in the next section, Oils .) More additives—salt, sugar, dextrose, and others—make this manufactured peanut butter a poor quality food. Many companies now use ground peanuts only to make their butters; better yet, some stores have nut grinders where we can make our peanut butter right on the spot. It is best to refrigerate shelled peanuts and peanut butter to avoid rancidity.
Many people eat roasted and salted peanuts more than the fresh variety. Though a mild roasting of the peanut may make it a little easier to digest and not lower the nutrient value too much, the extra salt is not really needed. Some people do not do well on peanuts at all. Digestive problems, gallbladder irritation, or just plain allergy to these nuts are possible. Overall, they are still the most popular American nut and a good-quality food.
Pecans. Pecans are nuts for a special treat, such as for holiDay s or in the traditional pecan pie, usually sweetened with maple syrup. Pecans (and macadamias), however, contain the lowest protein (about 10 percent) and highest fat (over 70 percent) of all the nuts. They grow on large trees often taller than 100 feet; the nuts are about four to a pecan fruit, each nut protected by a hard, woodlike shell. In fact, pecan shells can be ground and used as wood sculpture material (I have a pecan shell lion in my collection).
Pecans contain some vitamins A, E, and C, niacin, and other B vitamins. They are low in sodium and high in most other minerals, including zinc, iron, potassium, selenium, and magnesium. Copper, calcium, and manganese are present in fairly good amounts as well.
Pistachios. Pistachios are those sweet and flavorful nuts of which it is “hard to eat just one.” The pistachio nut or fruit grows on a small tree usually about 10–15 feet high and is very popular in the Mediterranean and middle Eastern countries. It is most commonly eaten in the shell but is also used in cooking, in making sauces, as flavoring in baking cakes, and in ice creams. It is best to avoid the less healthy salted and red-dyed pistachio nut and go with the natural variety.
Pistachios are about 20 percent protein and 50–55 percent fat and have good levels of thiamine, niacin, folic acid, and a little vitamin A. The potassium and iron levels are both very high; sodium is very low; phosphorus, magnesium, and calcium are all present in pretty fair amounts; while zinc, copper, and manganese are at modest levels.
Walnuts . Another of the great nuts, walnuts are a real brain food (they even look like little brains). The fatty acids and the 15–20 percent protein level nourish the nervous system, and the walnut when shelled looks remarkedly like the human cerebral cortex. The walnut is about 65 percent fat. It can be eaten raw or used in baking, and the pressed walnut oil can be used in cooking or even for oiling wood. It should be used fresh, though, as it is not very resistant to spoilage.
Walnuts have a modest mix of vitamin A, the Bs (including biotin), C, and E. Their mix of minerals is similar to that of most of the other nuts, with many at good levels. Probably iron and potassium are the best in this very balanced nut, which grows on large trees as high as 40–50 feet in many parts of the world, including the United States.