Principles of Healthy Eating: Nuts and Seeds

Principles of Healthy Eating: Nuts and Seeds

Consuming a variety of nuts and seeds daily constitutes another principle of healthy eating. Nuts played a significant role in human nutrition from prehistoric time. One of the oldest texts that mentioned nuts is found in the Book of Genesis. “Take some of the best fruits of the land in your vessels and carry down a present for the man – a little balm and a little honey, spices and myrrh, pistachio nuts and almonds.” (Genesis 43, 11) These are words of the Patriarch Jacob to his sons, before traveling to Egypt. In another book of the Scriptures, Song of Solomon from about 3000 years ago, we find a mentioning about nut garden: “I went down to the garden of nuts.” (Song of Solomon 6, 11) According to a legend, the Queen of the ancient Kingdom of Sheba, established a decree which designated pistachios as a royal food. According to the same legend, this decree forbade ordinary people to even cultivate these nuts to use them for their own needs. King Nebuchadnezzar, who was the builder of ancient Babylon, had pistachio trees planted in his famous hanging gardens.

In ancient China it was believed that hazelnuts were the food of gods. Ancient Greeks and Romans believed that walnuts were the food of gods. The Greeks called walnuts “kara” (head), because their appearance resembles the shape and appearance of the human brain. The appearance of nuts was also a source of popular beliefs in medieval times, when it was thought that walnuts could cure a headache. Nuts played an important role as a trading commodity in Asia and the Middle East.

At the end of the 18th century Reverend David Zeisberger recorded that Indians gathered hickory nuts also known as the American white walnut “in great quantities.” He also described the procedure the Indians followed to make peanut extract that they used to make a milk-like beverage as well as in other “various provisions.” Nuts also played a significant role during the colonization of America keeping both the Indians and the settlers from starvation.

The importance of nuts consumption in modern times was already stressed by Ellen G. White, one of the most influential health reformers of the 19th century, who wrote: “Nuts and nut foods are coming largely into use to take the place of flesh meats. With nuts may be combined grains, fruits, and some roots, to make foods that are healthful and nourishing.”

Studies conducted in the past 20 years have shown that the regular intake of nuts, including peanuts, lowers the risk of developing and dying of heart disease, other cardiovascular diseases and diabetes. For example, a study that included 21,454 male health care professionals, showed that people who ate nuts two or more times a week had a nearly 50 percent reduced risk of sudden death due to heart attack compared with those who never or almost never ate nuts. According to another study conducted at the Loma Linda University in California with 31,208 members of the Seventh-day Adventist Church, people who ate nuts four times a week or more often had almost 50 percent lower risk of death from coronary artery disease compared with people who ate nuts only once a week. Results of another study, which included nurses showed that consumption of one ounce (about 30 grams) of walnuts in place of products that are high in carbohydrate lower the risk of developing coronary disease by about 30 percent. A replacement of the same amount of saturated fat with nuts could reduce the risk of coronary heart disease by about 45 percent.

Epidemiological studies have confirmed the beneficial impact of consuming nuts on heart disease and the circulatory system. Also, several studies designed to determine the impact of nut intake on serum cholesterol showed that nuts improve blood cholesterol and triglyceride levels. In one study, a group of 27 individuals with elevated cholesterol level were asked to add about 73 grams (2.5 oz.) of almonds every day for a month. After this period, the so-called bad cholesterol (LDL) was reduced by 9 percent. This decrease in LDL cholesterol translated to the reduction in a risk of developing coronary disease by 18 percent. The same effect on cholesterol (reduction of about 9 percent) has been shown in people who ate an average of 68 grams of walnuts every day for three weeks. Other types of nuts have a similar impact.

In another study, researchers compared the impact of consuming macadamia nut, using two diets. In one of the diets 40 percent of calories were derived from fat, 20 percent of which came from the macadamia nuts. The second diet consisted of high carbohydrate content and was low in fat. The experiment was completed by 14 people, 7 women and 7 men between 25 and 59 years old, who followed these two respective diets for four weeks. The results showed that both diets reduced total cholesterol by almost 8 percent and bad cholesterol by almost 11 percent. In addition, the diet with macadamia nuts lowered triglycerides by about 21 percent, and the diet rich in carbohydrates had no effect on triglycerides. This study revealed not only that nuts lower cholesterol and triglycerides but that a diet containing nuts is more effective than a high-carbohydrate, low-fat diet in reducing heart disease risk factors, because in addition to lowering cholesterol the nut-containing diet also lowered triglyceride levels.

Studies have shown that nuts lower oxidative stress (oxidative stress is the basis of many diseases, such as atherosclerosis, Parkinson’s disease, Alzheimer’s disease, and it also plays a role in the aging process), reduce inflammation and improve the function of blood vessels. There are several reasons that explain the health benefits of nuts. Despite the fact that nuts contain a relatively large amount of fat, most of them are rich in this specific type of fat called monounsaturated fat. Walnuts are the exception and they mainly contain another type of fat known as polyunsaturated fat. In addition, walnuts and peanuts also contain alpha-linolenic fat (this type of fat belongs to the omega-3 family of fats). All the above-mentioned types of fat are actually beneficial to human health.

Nuts are also rich in protein, fiber and some micronutrients (vitamins and minerals), such as, folic acid, magnesium, potassium, and copper. They are also one of the richest sources of vitamin E, which is an antioxidant vitamin. Nuts contain a large amount of phytosterols such as stigmasterol, campesterol, and sitosterol. In addition, peanuts are rich in polyphenols such as catechins, procyanides and, above all, resveratrol. Scientists have shown that walnuts had the second highest antioxidant activity from a list of 1113 different products. Studies have provided evidence that antioxidants not only protect against heart disease and the cardiovascular system, but are also effective against the aging process, neurological diseases, and protect against cancer.

Studies have also shown that frequent nut consumption lowers the risk of other chronic diseases, such as diabetes, metabolic syndrome, hypertension and even osteoporosis. For example, one such study showed that women who ate nuts at least five times a week had a 30 percent lower risk of developing type 2 diabetes compared with those who never or almost never ate nuts.

Until recently, many nutritionists believed that nut consumption may contribute to weight gain. However, studies conducted in the last two decades showed that the opposite is true. Most studies showed that people who consume more nuts (both larger quantity and more frequently), have lower body weight than people who eat nuts occasionally. In a review of epidemiological studies completed in 2006 by the Food and Nutrition Australia, authors stated that the epidemiological evidence suggests that people who eat nuts at least five times a week does not weigh more than those who eat nuts less than once a week or do not eat nuts in general. This organization further stated that the evidence also indicates that people who frequently eat nuts, have a lower body mass index (a proxy for weight status) compared with those who do not eat nuts. Based on the available research, the Food and Drug Administration in 2003 allowed food manufacturers, which sell nuts and products that contain nuts, to include a note on the label that says that research suggest that consumption of 1.5 ounces (about 45 grams) of nuts a day can lower the risk of heart disease.

Heart and other cardiovascular diseases are the leading cause of mortality in the world. Diabetes is one of the fastest causes of disabilities and death in the world. Thus, nut intake may have an important role in the prevention of these health conditions and in the prevention of their complications. Therefore, nuts should be recommended by doctors, nutritionists and other health professionals. The recommended intake of nuts equals about a handful or 1.5 oz. per day. It is important to consume a variety of nuts including walnuts, almonds, peanuts, Brazil nuts, hazelnuts, pecans, cashews, pistachios and pine nuts to achieve the best results. Nuts can be eaten raw, as nut butter (in addition to peanut butter, almond butter is available in many grocery stores and health food stores carry butter made of cashews and other nuts) and nut milk such as almond milk. Nuts can be spread on bread, chopped and added to salads. They can be used to make home-made dressing and burgers and can be incorporated in many other recipes.

As in the case of nuts, consuming seeds, including sunflower seeds, flax seeds, sesame seeds, chia seeds or pumpkin seeds is associated with the prevention of chronic diseases. Historically, seed intake played an important role in human health, not only as food but also for example as a source of raw material in the manufacturing of materials/clothes and oil used as a source of light and heat. In the Scriptures, for example, the Book of Proverbs mentions flax seeds in describing the virtuous woman: “she seeks wool and flax.” (Proverbs, 31, 13) Archaeological discoveries have shown that sesame seeds were used in various ancient cultures including the Assyrians, Babylonians, Egyptians and Chinese cultures. Sunflower seeds and pumpkin were grown by the Incas in South America and from there have been adapted to Europe by the Spaniards.

Flax seeds are the richest known sources of alpha-linolenic acid, a type of fat from the omega-3 family of fats. Alpha-linolenic type of fat belongs to polyunsaturated fats. It is liquid at room temperature. It is associated with prevention of cardiovascular diseases and other chronic diseases. In addition, the consumption of these fatty acids is linked with better development of the brain in newborns.

Seeds can help reduce blood cholesterol. In one study, adding of 38 grams per day of sunflower seeds (about 2.5 tablespoons) to a usual diet for 6 weeks resulted in a 5.4 percent reduction of total cholesterol. The results of the same study showed that adding the same amount of flax seeds lowered LDL-cholesterol by as much as 16 percent. Both flax seeds and sesame seeds are rich in lignans, which have antitumor activity. Seeds are also rich in vitamin E, magnesium and, in the case of sesame seeds, calcium. For example, just one tablespoon of butter made of sesame seeds contains about 150 mg of calcium, or about 20 percent of the recommended by the European Union daily amount of calcium. Similarly, only one tablespoon of sunflower seeds contains approximately 3 mg of vitamin E, or about 20 percent of the daily recommended amount for an adult. Consuming the recommended amount of magnesium is associated with a lower risk of hypertension and stroke. It also plays an important role in the prevention of asthma attacks (prevents from the narrowing of the airway).

Pumpkin seeds are a very good source of iron. Just one tablespoon of these seeds provides about 2 mg of iron, or about 25 percent of the recommended intake of iron for men and postmenopausal women. Therefore, regular intake of pumpkin seeds can play a significant role in the prevention of anemia especially among vegetarians. According to a study from Sweden, pumpkin seeds can reduce the risk of having an enlarged prostate. Other studies have shown that pumpkin seeds can reduce the risk of urinary bladder stone formation.

Seeds are a good source of phytochemicals including phytosterols. Although it is commonly believed that soy and flax seeds are the best sources of phytosterols, studies have shown that sesame seeds contain larger amounts. These phytochemicals are associated with a lower risk of cardiovascular disease, some cancers, osteoporosis, and may even alleviate the symptoms of menopause.

As it was the case with whole grains, fruits and vegetables, nuts and seeds are rich in micronutrients, phytochemicals, fiber, and other beneficial compounds. Their consumption is associated with a reduced risk of many diet-related health conditions including cardiovascular diseases, cancer, diabetes, obesity, arthritis, osteoporosis and Alzheimer’s disease. Therefore, a healthy diet should include a variety of these products.

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Roman Pawlak, Ph.D, RD

Ph.D, RD is an Associate Professor of Nutrition at East Carolina University in North Carolina. He is the author several books including “Forever young. Secrets of delaying aging and living disease free,” “Healthy diet without secrets,” “In defense of vegetarianism” and “I am the Lord who heals you,” and a co-author of “Vegetarian mother and her baby.”

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