THE KITCHEN PHYSICIAN
Nuts Are For The Birds
by Carolyn Swicegood
Do you avoid feeding nuts to your birds because they are nothing more
than fat-laden treats? If so, it is time to rethink this popular myth.
Because of the recent trend toward fat-free diets, nuts have gotten a bad
reputation which is both undeserved and inaccurate. Recently, two major scientific conferences have extolled the virtue of nuts because several large-scale studies found that nuts contribute significantly to human health. In fact, the latest evidence suggests that nuts may play a role in reducing the incidence of coronary heart disease and certain kinds of cancer.
GOOD FATS--BAD FATS
Leading nutritionists have discovered that the type of fats is more
important than the total fats consumed. The main concern about nuts has always
been the fat and cholesterol content, but it is important to distinguish between saturated and unsaturated fats. Saturated fats, found mostly in meat and cheeses, contain cholesterol and choke arteries with plaque. They are considered to be the "bad" fats. Nuts are plant products and are low in saturated fats and contain no cholesterol. Ninety percent of the fats in nuts
are the monounsaturated and polyunsaturated type. These unsaturated fats
are the "good" fats. Eating nuts will raise the percentage of unsaturated
fats and lower the percentage of the "bad" saturated fats in the bloodstream. On average, one ounce of nuts contains 165 to 200 calories and 14 to 21 grams of fat, but ninety-three percent of the fat in walnuts and ninety percent of the fat in almonds is unsaturated.
Harvard's associate professor of medicine, Frank Sacks, advises, "Forget
the total fat. Forget the percentage of calories from fat. Yes, nuts have a
lot of oil but they also happen to have a lot of nutrients essential to a
healthy diet. Frankly, we should be encouraging people to eat more nuts."
Parrots seem to know by instinct what we are only now discovering--that
is, that nuts are one of the most nutritious gifts of nature. Most nuts are
seeds or the dried fruit from trees and natural to the diet of wild parrots.
Nuts are an excellent source of protein, fiber (one ounce of nuts has as much
fiber as two slices of whole wheat bread), vitamin E, magnesium, zinc, selenium, copper, potassium, phosphorus, biotin, riboflavin, niacin, and phytochemicals. Because of their protein content, they are listed as an alternative to meat in the USDA Food Guide Pyramid.
WHY BIRDS NEED FATS
Birds need the three essential unsaturated fatty acids (linolenic,
linoleic, and arachidonic acids) or EFAs, to keep their skin and feathers healthy, among other benefits. Essential fatty acids require Vitamin E for absorption and nuts provide it in the proper balance. Every living cell in a bird's body
needs essential fatty acids for rebuilding and producing new cells. EFAs are used to produce prostaglandins, hormone-like substances that act as chemical
messengers and regulators of various body processes. The two basic categories of EFAs are Omega-3 and Omega-6 which contain linoleic and linolenic acids. These are found primarily in raw nuts, seeds and legumes.
In addition to providing energy, fats act as carriers for the
fat-soluble vitamins A, D, E, and K, all important to the health of parrots. Fats aid in the absorption of vitamin D which helps to make calcium available to
body tissues. Fats also are important for the conversion of carotene to vitamin A, a most important vitamin for the health of parrots.
Fats are especially important to parrots housed outside in the cooler northern climates because a layer of fat insulates the body from environmental temperature changes and preserves body heat. Nutrient-dense nuts are the healthiest form of fats to offer birds for the purpose of creating and maintaining body heat in cold weather.
Because of the sedentary lifestyle of captive birds, nuts cannot be offered in unlimited quantities, but it would be a mistake to deprive parrots entirely of this natural food source because of outdated attitudes toward all fats. It is far better to provide our birds a means of exercise in order to work off calories than to avoid feeding foods that contain good fats--remember that all fats are not created equal! Birds were designed to consume high-calorie foods such as nuts and to burn the calories through physical activity, such as flying. In captivity, moderate caloric intake and moderate exercise are far better than low calorie diets and little or no exercise. The lack of exercise is likely to be the cause of many of the physical and psychological problems of captive birds. If given an energy-producing diet, as well as the opportunity to exercise, former "perch potatoes" will become more active, improving their quality of life and perhaps their longevity as well.
VET RECOMMENDS DAILY NUTS
Dr. Joel Murphy, DVM, founded the Florida Exotic Bird Research Center to research exotic bird medicine, nutrition and reproduction. Here is a quote from his book How to Care for Your Pet Bird. "Fats are the most concentrated sources of dietary energy. Fats provide 2.25 times the amount of energy per weight than carbohydrates or protein. Birds crave high fat food. In the wild, parrots are flying and searching for food, shelter and safety. This requires calories Foods that parrots seek out in the wild tend to be high fat foods. Palm nuts and nuts in general are favorites of wild parrots... Nuts are generally high in protein, fats, and trace minerals. In addition, nuts provide entertainment value to parrots. We strongly recommend feeding nuts to parrots on a daily basis. In the wild, the main food for many parrots is tropical palm nuts."
"These foods are very high in fats and in protein. Analyses of wild macaw diets suggest that their diet may be 28% fat. Pet birds are much more sedentary than their wild counterparts. Like retired athletes, some pet birds have a desire for more calories than their bodies need. This is very common in Amazon parrots. High fat diets, if fed to excess, can result in obesity--something that rarely happens to wild parrots."
Rose-breasted Cockatoos, Sulphur-crested Cockatoos, Amazon parrots and Budgerigars, are particularly prone to obesity and may develop secondary lipomas, fatty liver degeneration and heart disease if they are overfed. When feeding nuts to any parrot species, moderation is important. For obesity-prone parrots, a better use of nuts would be to grind them in a nut mill or food processor and use the nutmeal sparingly to give flavor to other nutritious, low-calorie foods. Parrots have a natural taste for nuts and will try almost any new food that tastes like nuts. Almond meal and almond butter are good choices for flavoring foods to tempt finicky parrots. Even birds prone to obesity could be given one almond (about ten calories) in the shell as a food toy that will not add significantly to their caloric intake. If used sparingly in this manner, no parrot species needs to be deprived entirely of the enjoyment and the health benefits of nuts. I personally know of a small flock of Scarlet Macaws that get a half dozen nuts every day during the breeding season. They are active, healthy, and in fine feather.
AN OUNCE OF NUTS IN PERSPECTIVE
Although an ounce of nuts contains 165-200 calories, that amount of nuts is much more than most parrots would consume if given the opportunity. According to the Mayo Clinic, one ounce would equal about 22 almonds. According to Dr. Pat Kendall, Food Science and Human Nutrition Specialist of Colorado State University Cooperative Extension in a December, 1997 article, "...an ounce of nuts is only a couple of tablespoons, not even a small handful. About eight Brazil nuts, 12 macadamia nuts, 20 mixed nuts or 25 roasted almonds, all shelled, equal an ounce". If a parrot ate one tenth of an ounce, it would amount to only about a half teaspoonful or 20 calories at the most.
AVICULTURAL BREEDING AND RESEARCH CENTER
Dr. Susan Clubb, principal author of PSITTACINE AVICULTURE mentioned the feeding of various nuts when writing about the hundreds of pairs of Macaws and other parrots maintained at the research and conservation facility in Loxahatchee, Florida. Dr. Clubb wrote, "PALM NUTS from the queen palm are fed, when available, to Hyacinth Macaws and occasionally Palm Cockatoos. These fruits are similar in appearance, structure, taste and composition to the fruit of the Acrocromia sp. upon which the Hyacinth Macaws feed in the wild...COCONUTS are supplied during the breeding season to stimulate breeding by mimicking the wild palm nut diet...Thick-billed parrots of Mexico and Southwestern U.S. feed almost exclusively on PINE SEEDS (often called pine nuts)...Palm Cockatoos and Macaws also relish pine seeds. HAZELNUTS and BRAZIL NUTS are offered to selected species for variety. Hyacinth and Buffons Macaws and Palm Cockatoos receive these nuts as a supplement to their diet."
HYACINTH MACAWS AND PALM NUTS
According to Karl Fr. Hohenstein of Germany in issue 12/87 of Gefiederte Welt, "Anyone, who has had to accustom Hyacinth Macaws just once to new foods, will know how nerve-wracking it is to wean them off palm nut kernels onto the parrot food available here. In Brazil or Paraguay, where the macaws known to me have come from in recent years, they are fed exclusively on the kernels of the Acrocomia totai palm nut."
Unfortunately, the palm trees from which the Hyacinth Macaws gather palm nuts in the wild do not grow in the United States and it is difficult to import these foods. In the wild, a number of birds make palm tree foods a staple of their diet and various nuts can be substituted in captivity.
Until specific research is done on the role of nuts in the avian diet, we can only speculate about the extent to which studies of the human diet can be applied to the avian diet. Research has shown that nuts added to the human diet do not lead to weight gain but, in fact, by contributing to a feeling of satiety, or fullness after eating, can contribute to weight maintenance or even weight loss. Nuts have been shown to decrease cholesterol levels. Many reputable studies have shown that nuts improve cardiovascular health in humans. These include a Harvard study of 86,000 women and another study of over 25,000 Seventh Day Adventists. The recent series of nutrition studies done by California's Loma Linda University revealed that eating two ounces of nuts five times a week can reduce the risk of having a fatal heart attack by one half. Previously regarded as only a high-fat indulgence, nuts are now being rediscovered as a nutritious part of a healthful diet.
The best time to buy nuts is when they are freshly harvested during the Fall months. For best quality, select clean, unshelled nuts free from splits, cracks
and holes. Nuts in the shell should be heavy for their size, indicating a fresh, meaty kernel. Nutmeats that rattle around in their shell are usually stale. Crisp, plump and meaty nutmeats indicate high quality. Shriveled nutmeats indicate poor quality. Nuts that are not tightly sealed could be contaminated with deadly mycotoxin, including aflatoxin. Prevention is infinitely better than the cure in this case and nuts should always be examined carefully before they are offered to birds.
SAFE STORAGE OF NUTS
The importance of proper storage of nuts cannot be overemphasized because an extremely potent carcinogen, "aflatoxin", one of the mycotoxins, is found on improperly stored nuts, corn and grains. According to the authors of AVIAN MEDICINE: PRINCIPLES AND APPLICATION, "Fatty degeneration and the feeding of feeds contaminated with mycotoxins causing aflatoxin hepatosis are likely to be involved in the high incidence of liver disease in birds. Peanuts and Brazil nuts are notorious sources of aflatoxins..."
Humidity is the biggest problem for those of us who stock up on whole nuts in the fall or when they go on sale after the holidays. The best way to store nuts is to leave them in their shells. The shells protect them from light, heat, moisture and exposure to air, all of which cause rancidity in shelled products. Unshelled nuts have a much longer shelf life than do shelled nuts, and will keep for several weeks at room temperature. For longer storage, nuts in the shell should be kept cool and dry to prevent flavor changes due to rancidity of the fat. Keep them below 70 degrees Fahrenheit in airtight, sealed plastic bags or in tightly closed containers. They will remain fresh for about six months in the refrigerator. The lower the storage temperature, the longer the shelf life of nuts will be. Nuts can be frozen if sealed in moisture-proof containers and they can be kept for a year or more.
Here are a few facts about our favorite nuts. Technically speaking, nuts are seeds, tree seeds to be exact, so it is not surprising that they are so rich in nutrients. Only seeds and eggs are capable of producing an entire new living plant or animal, and a tree seed (nut) can grow one of our largest and most versatile plant forms.
ALMONDS--The almond tree, Prunus amygdalus, is also known as Prunus dulcis. Almonds are the oldest and most widely grown of all of the world's nut crops. The dry, leathery almond fruit surrounds the almond kernel which is harvested when the fruit dries and splits open. Of the two major types of almonds grown, the sweet almond, P. amygdalus dulcis, is cultivated for its edible nut. The bitter almond, P. amygdalus amara, is inedible and difficult to find where edible nuts are sold. Mildly flavored with a sweet aftertaste, almonds are the favorite nut of many parrots and are a significant source of calcium. Almonds are a good "food toy" because parrots enjoy chipping away at the shell to reach the tasty treasure inside. Studying the effects of a diet rich in fats derived predominantly from almonds, scientists found that blood cholesterol dropped by around 11%, and the dangerous LDL cholesterol dropped 17%. Almonds have good amounts of protein, calcium, magnesium, and niacin. Almonds contain 165 calories and 6 grams of protein per ounce.
BRAZIL NUTS--The Brazil nut tree (Bertholettia excelsa) is a magnificent jungle tree of the steamy Amazon Rain Forest. The extremely hard-shelled seeds are dark brown and wedge shaped. The kernel is white, oily, and rich tasting. Brazil nuts are extremely rich in the antioxidant, selenium. Many parrot owners do not feed their birds Brazil nuts because of the danger of mycotoxins such as aflatoxin. One knowledgeable birdkeeper recommends checking for possible fungal contamination by placing the Brazil nuts in water. If tiny air bubbles are seen rising from the shells, the shells are not airtight and contamination is possible. If no bubbles are seen, it is assumed that the shells are intact and that the nuts are safe. Only the largest Macaws can crack the rock-hard shell of Brazil nuts, but cracking them before feeding them to birds in order to check for obvious contamination is a good precaution anyway. Brazil nuts are a good source of calcium, an excellent source of magnesium, and a particularly good source of selenium. Brazil nuts contain 184 calories and four grams of protein per ounce.
CASHEWS--The cashew belongs to the Anacardiaceae or cashew family. The cashew tree, Anacardium occidentale, is a fast growing, spreading, tropical tree, reaching around 30 feet at maturity that starts bearing only four years from planting. The tree is from the same plant family as the mango, pistachio, poison ivy, poison oak, and poison sumac. The raw cashew nut is enclosed in a tough, leathery shell that contains caustic, toxic substances similar to the active ingredients of poison ivy. Cashew processing separates the edible nut from the toxins. Salted nuts are not suitable for parrot food but many health food stores sell unsalted cashew pieces which parrots enjoy. There is a folk remedy for toothache that calls for the painful tooth and gum area to be packed in cashew nutbutter. It is claimed that this will stop the pain in as little as five minutes. Cashews have about 45 grams of fat per 100 gram serving. They are an excellent energy food. They are very high in magnesium, having only slightly less than almonds. Cashews contain 165 calories and 4 grams of protein per ounce.
CHESTNUTS--American chestnut trees (Castanea dentata) once covered 200 million acres in the U.S. but a fungal disease from Asia killed 3.5 billion of the trees between 1904 and 1940, so most of the chestnuts sold in the U.S. are imported from Europe. Chestnuts have the lowest fat content of all major nuts (only 4-6%). Parrots enjoy them raw and I feed them plentifully in the fall when they become available. I simply cut them in halves to be sure that they are not moldy inside, and serve. If you want to cook them, use a sharp knife to make a half-inch slash on the flat side of the chestnut and roast in a 400°F oven for about ten minutes and cool before offering to birds. To microwave chestnuts, make a small slash in each nut, arrange in a single layer in a shallow dish, and microwave up to a half pound for six minutes on high, or a pound for eight minutes. If you fail to make a cut in the chestnuts, they will explode in a microwave oven. They spoil quickly after harvest, so they should be refrigerated and used quickly. Chestnuts contain a record low 70 calories per ounce. They contain one gram of protein per ounce.
HAZELNUTS--Also known as filberts, hazelnuts are mild and sweet tasting and are rich in protein, complex carbohydrates, dietary fiber, calcium and vitamin E. They are low in sodium and sugar and like most other tree nuts, contain no cholesterol. The larger parrots can crack the shells to eat the tasty ovoid nut inside, but shelled hazelnuts can be purchased during the Thanksgiving and Christmas season. They can be frozen for later use. Over 80% of the total fat in hazelnuts is monounsaturated. Hazelnuts contain 179 calories and four grams of protein per ounce.
HICKORY NUTS--The most edible hickory nut is the "shagbark hickory", but there are other varieties that grow in the woodlands of North America. The hickory nut has an extremely hard shell that most parrots cannot crack so they rarely are fed to birds. They are small and have a rich flavor due to their high fat content. They usually are sold unshelled and contain good amounts of calcium, magnesium, potassium, and phosphorus. Hickory nuts contain 187 calories and 3 grams of protein per ounce.
MACADAMIA NUTS--The macadamia tree grows in Australia, Hawaii, Costa Rica, Florida, Indonesia and Southern California. The nuts have an extremely hard shell which requires a hammer, a vise, or one of the special nut cracking machines to get to the buttery tasting round nut. Most U.S. residents think of it as a Hawaiian nut and it is grown extensively there. My Eclectus parrot pets play with unshelled macadamia nuts like marbles, so when friends or family members visit Hawaii, I always request a fresh supply. The fresh unprocessed nuts are delicious, but very difficult to open! A hammer or vise will crack them and it is best to wrap the nuts in a towel. Macadamia nuts contain 199 calories and two grams of protein per ounce.
PEANUTS--This hard, nut-like seed is a member of the legume family, as are soybeans, peas, beans, and licorice. Many years ago, they were accurately called "ground peas". Peanuts have been a part of the parrot diet for many years. Some parrot owners choose not to feed them to their birds because of the possibility of aflatoxin contamination. Aflatoxin is the most potent, naturally occurring carcinogen known to man and is a by-product of mold growth in peanuts and tree nuts. It has been linked to a wide variety of health problems in humans and other animals. Peanuts also are a common food allergen of parrots. Food choices of birds that are allergic to peanuts must be restricted due to the extensive use of peanuts in pelleted diets, Nutriberries, and other foods. Peanuts contain 167 calories and seven grams of protein per ounce.
PECANS--The nut-bearing pecan tree, Carya illinoinensis, of the walnut family, is classified botanically as a hickory tree and can grow 70-90 feet tall. Pecans have hard, thin, brown shells and a rich, sweet flavor relished by parrots. They should always be refrigerated or frozen if kept for longer than a couple weeks due to the risk of the high oil content becoming rancid. Pecans are low in sodium, high in protein and unsaturated fats, have no cholesterol, and are a good source of calcium, iron, phosphorus, potassium, and magnesium. Researchers have found pecans to be a good source of oleic acid, a fatty acid found in abundance in olive oil and other monounsaturated fats. Although 90 percent of the calories in pecans comes from fats, almost all of the fat is unsaturated. Pecans contain 200 calories and three grams of protein per ounce.
PINE NUTS--Not actually a nut, but a seed from the cones of pine trees, birds
love pine nuts! It is the major portion of the diet of Thick Billed Parrot. There are two main types of pine nuts in the U.S. that are harvested--hard shells and soft shells. These are not the same as the Italian pignolia from the stone pine from Europe or the Chinese pine nut from Asia. Medium and large parrots enjoy unshelled pine nuts, but great care must be taken to offer only those that have been stored properly. There are several known cases of illness occurring after parrots consumed improperly stored unshelled pine nuts. Each batch should be checked by cracking several of the nuts and checking for freshness. I avoid the problem by feeding only shelled pine nuts. They are expensive, but since I feed them sparingly, a little goes a long way. Costco, a buying club similar to Sam's, sells shelled Chinese pine nuts for less than ten dollars for thirty-two ounces. They are an excellent weaning food for baby parrots because they are soft and easy for the babies to eat. Pine nuts contain 146 calories and six grams of protein.
PISTACHIOS--Pistachios are grown in California, Italy, Turkey and Iran and they have a hard shell that encloses a pale green nut. Pistachios grow on trees in clusters similar to grapes. When conditions are favorable, the pistachio shell splits open along its sutures prior to harvesting. Pistachios are available year-round shelled and unshelled. When buying unshelled pistachios the shells should be partially open; closed shells are an indication that the nutmeat is immature. Pistachio nuts have a delicate, subtle flavor that parrots enjoy almost as much as they enjoy picking the nutmeat out of the shell, making it a healthy form of entertainment. However, it is difficult to find unsalted pistachios outside health food stores, and if one cannot find natural, unsalted pistachios, it would be better not to feed this nut to parrots. Pistachios contain 170 calories and six grams of protein per ounce.
SOY "NUTS"--Not really nuts but a delicious nutty-tasting food, dry roasted, unsalted soy nuts are high in protein and fiber and very low in fat. Soy contains most of the amino acids in protein, as well as isoflavones, saponins, and phytosterols. It is low in fat and it is cholesterol-free. The isoflavones in soy, primarily genistein and daidzein, have been well researched by scientists for their antioxidant properties. Phytosterols and other components of soy have been reported to lower cholesterol levels, making it a valuable food for parrots that have high blood levels of cholesterol. One half cup of soy nuts contains 61 calories, three grams of total fat, five grams of protein, one gram of fiber, and zero cholesterol. Soy nuts are available at most health food stores and online at the following web address, which also has a recipe for making your own "soy nuts" from soy beans. http://www.soybeanstore.com/soybeans.htm
WALNUTS--The two most popular varieties of walnut are the English and the Black walnut. English walnuts are more widely available and can be purchased year-round. The easily extracted kernel is about 15% protein, 65% fats, and 16% carbohydrate. The kernel has about 100mg of calcium per 100mg kernel. They also are a reasonable source of B1, and thiamin. Walnuts are a good source of calcium--100mg per 100grams--important to the health of parrots who readily eat this nut. Black walnuts are rarely fed to parrots due to the difficulty of cracking the hard shells. English walnuts contain 180 calories per ounce and black walnuts contain 170 calories per ounce.
Copyright© 1998 by Carolyn Swicegood. All Rights Reserved.