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Mediterranean Diet Pyramid Says Eat Nuts Daily
Nuts are back! So say the world's leading researchers, food experts, nutritionists and food communicators who propose that tree nuts should be a regular part of a healthy diet.
In the newly-released Traditional Healthy Mediterranean Diet Pyramid developed by the World Health Organization's European office, along with the WHO/FAO Collaborating Center on Nutrition at the Harvard School of Public Health, and Oldways Preservation and Exchange Trust, tree nuts are placed in the same category as fruits, vegetables and legumes.
Putting tree nuts with fruits and vegetables is a significant change from the current USDA pyramid where nuts are in the same category as meat and dairy products. The rationale is an old one, dating back to World War II when rationing caused the U.S. government to suggest that Americans look to high-protein substitutes like nuts for meat.
But the likeness to meat stops at protein according to Dr. Gary Fraser, professor of epidemiology and medicine and the director of health research at Loma Linda University. His research concludes that eating tree nuts regularly could help lower the risk of heart disease and possibly reduce the risk of cancer.
Nuts are a plant food and are nutritionally very different from foods derived from animals. The compelling reason for putting nuts in with fruits and vegetables is that the fat in nuts is low in saturated fat versus meats -- a whopping 28 to 64 percent saturated fat in common fatty animal products versus 9 percent in almonds!
Nuts are also packed with micro-nutrients and other substances known to help lower cholesterol and prolong life. For these reasons, nuts are recommended for daily consumption in the Mediterranean Diet instead of a few times a month in the USDA Diet.
In an unprecedented joint effort originally endorsed by Blue Diamond® President Walt Payne at an International Nut Council (INC) meeting, seven tree nut groups - including the Almond Board of California -- are uniting to promote tree nuts as an integral part of a healthy diet. The U.S. boards and commissions representing almonds, cashews, hazelnuts, pecans, pistachios, walnuts and macadamias funded a recent INC tree nut symposium in San Francisco, where renowned chefs prepared menus using tree nuts in traditional Mediterranean recipes, while scientist and nutritionist from around the world presented their latest research regarding fat, fiber and antioxidants in nuts. Over one-third of nearly 500 scientists, chefs, policy makers and opinion leaders were also food and health journalists.
The INC is now organizing to continue its effort to fund educational and research programs for tree nuts. A similar program is also being formulated by INC members representing the European Union. Blue Diamond® endorses any effort which encourages the tree nut industry to work together to increase consumption globally.
Research and nutrition reports will be used with major food manufacturers, food service operators and opinion leaders to increase consumption. Beginning with Almond Facts Magazine, Blue Diamond® will continue to bring the latest news about this new opportunity to put tree nuts in the everyday diet to our growers, employees and friends. Following is an excerpt from the June 1994, Harvard Medical School Harvard Heart Letter.
Nuts
Until recently, the conventional wisdom among health-conscious Americans was to avoid nuts because of their extremely high fat content. But within the past several years, nutritionists and health researchers have taken another look at nuts. Have they been "rehabilitated?" What is the story behind the shifting reputation of the nut?
Much of the momentum for giving nuts a second chance comes from a long term study of diet and heart disease in more than 26,000 Seventh Day Adventists in California that began in the mid-1970s. This group, which tends to be intensely interested in diet and health, was a relatively homogeneous -- if unusual -- population. Virtually none of them smoked, very few drank alcohol, many adhered to a vegetarian diet, nearly half consumed meat products less than once a week, and they had about half the heart disease rate of the rest of the U.S. population. Nearly two decades after the study's start, one of the results, reported in 1992, aroused the curiosity of health researchers -- a strong association between higher nut consumption and lower risk of heart disease.
The Frequency Factor
The research team that conducted the Adventist Health Study did not intend to examine the effects of nuts on health, and they did not provide nuts for the participants to eat. Rather, they asked the study subjects to complete a questionnaire to indicate the frequency with which they ate 65 food items by ranking them on a scale of 1 to 8, ranging from "never consume" to "eat more than once per day." The data showed a startlingly high level of nut consumption among the Adventists. Twenty-four percent consumed nuts at least five times a week, while 34 percent ate them less than once a week. By comparison, a large study of U.S. women found that 5 percent ate nuts five or more times a week, while 70 percent ate them less than once a week.
The amount of nuts the Adventists ate in any one serving is not known because the researchers did not solicit this information. However, they surveyed a small sub-group of the study population and discovered the type of nuts consumed: about 32 percent of the nuts were peanuts, 29 percent almonds, 16 percent walnuts, and 23 percent other types. The researchers did not ascertain whether the nuts were fresh, oil-roasted, or dry-roasted .
During the six years following the diet survey, the people who consumed nuts frequently (at least five times a week) had roughly half the risk of a heart attack or a coronary death as those who rarely ate them. People who ate a portion of nuts even once a week had about 25 percent lower risk of heart disease than those who avoided nuts.
While findings of the Adventist study are intriguing, many questions remain. Are nuts themselves protective, or do people who eat them have some other reason for a lower risk? Did the reduced risk of heart disease in the nut eaters result from the combined effect of nuts and other foods in their diet? Is the type of fat in nuts the important ingredient, or is it some other component in this food? Are the results of this study relevant to people who eat a more typical American diet?
Nuts and Blood Fat
Some of these questions have been addressed in more recent studies. While the Adventist study examined food-frequency data, two investigators have focused directly on the impact of nut consumption. In these clinical trials, investigators provided participants with precise amounts, and types of nuts, and then measured changes in blood fat levels and blood pressure.
In the first study, researchers enrolled 13 women and 13 men from a YMCA cardiac rehabilitation program and placed them on a special nine week diet that substituted almonds for some of their usual calories. These volunteers had fairly high cholesterol levels that averaged 235 mg/dl, and many had already modified fat intake to lower them. Each of the participants ate 3.5 ounces a day of almonds. Half the almonds were provided as whole, unbleached raw nuts, and the other half as ground nuts.
The participants were also given a supply of almond oil to prepare food and to replace other fats they would normally use, such as salad dressings, butter, and margarine. Grains, beans, vegetables, fruit, and low-fat dairy products were the foundation of the diet, and participants ate only limited amounts of meat, fatty fish, high-fat dairy products, eggs, and saturated fat. The volunteers were instructed to avoid nuts, except the almonds provided by the study.
The usual diet of the participants contained approximately 30 percent of total calories from fat (as recommended by the National Cholesterol Education Program). The almond regimen increased dietary fat to 37 percent of total calories. After three weeks on the experimental diet, the average cholesterol level of the volunteers dropped by about 20 mg/dl, a reduction that remained stable during the full nine weeks of the almond diet. The participants also experienced a sustained reduction of the "bad" low-density-lipoprotein (LDL) cholesterol, but the "good" high-density-lipoprotein (HDL) cholesterol did not fall, so the LDL-to-HDL ratio became more favorable.
SELECTED NUTRIENT COMPOSITION OF ALMONDS VERSUS ANIMAL PRODUCTS
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Arginine (g)
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Magnesium (mg)
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Cholesterol (mg)
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Almonds
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2.5
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296
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0
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Beef
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1.8
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27
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81
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Pork
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1.7
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17
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89
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Chicken
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1.3
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20
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74
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Whole Milk
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0.
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13
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14
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Eggs
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0.8
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12
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548
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Cheddar Cheese
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0.9
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28
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105
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Per 100 grams of edible food
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What's In A Nut?
Nuts have a unique nutrient composition, and it is plausible that they could favorably affect heart disease risk factors and interfere with the development of plaque in the arteries. The fat in nuts is predominantly mono-unsaturated -- the type also found in olive oil, an important part of the traditional Mediterranean diet. Historically, the people of the Mediterranean region have had a lower rate of heart disease than Americans. A number of research investigations have shown that mono-unsaturated fats lower over-all cholesterol and improve the ratio between LDL and HDL cholesterol, and thereby lower the risk of heart disease.
Recently, nutritionists have become very interested in another fat -- Omega-3 fatty acids, which are believed to help protect blood vessel walls from the harmful effects of LDL cholesterol. These fats are found predominantly in fish but also in some nuts, whole grains, beans, seaweed, and soybean products. The highest concentrations among plant sources are in walnuts and rapeseed (the source of canola oil). Some studies have demonstrated that Omega-3 fatty acids from fish are protective against heart disease.
In addition to their favorable fatty acid content, nuts are a good source of Vitamin E, an antioxidant that may guard arterial walls and lipoproteins from damage and thereby protect against the development of atherosclerosis and heart disease.
Nuts also contain protein. Like legumes, they offer about twice as much protein as the common cereal grains. In fact, botanically, peanuts belong to the legume family but are usually classified as nuts because of the striking similarity in fat and protein composition.
The content list of nuts reads very much like that of a multiple-vitamin capsule. Nuts are rich in magnesium, zinc, selenium, and copper, and most nuts are good sources of phosphorous, biotin, riboflavin, niacin, and iron. In addition, moderate amounts of calcium are found in almonds, Brazil nuts, and Filberts. A high fiber content is another nutritional advantage of nuts, since fiber has been shown to lower cholesterol levels.
Many Merits
Before people start munching nuts with abandon, they must be aware of the food's caloric density - about 170 calories per ounce. For example, a 4-ounce serving of almonds (about 96 nuts) contains close to 700 calories. The nutritional benefits and potential risk-reducing properties of nuts would be lost if people were to become overweight. Surprisingly, nut eating was not associated with weight gain in the Adventists.
What seems likely is that there is no one factor in nuts that protects against heart disease. Rather, nuts have several nutritional merits, including monounsaturated fat and omega-3 fatty acids, fiber, vitamins, and minerals. People eat food, not isolated nutrients. Because nuts are tasty and available, they can be incorporated into any diet.
Nuts alone are not a "magic bullet" against coronary heart disease. No amount of nuts can offset a poor diet that is high in saturated fat, but they can be a substitute for saturated fat, snacks, and desserts. Furthermore, nuts can be used creatively in place of meat, mixed with pasta, sprinkled on a salad, stir-fried with vegetables, or stuffed into mushrooms. A healthy lifestyle that protects against heart disease should include regular exercise and a diet that contains plenty of fruits, vegetables, grains and legumes - and some nuts.
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