Estudos provam que o chocolate é bom para a saúde
Chocolate Really Is Good For You: Studies Prove It
Wednesday, November 12, 2008 by: Barbara L. Minton (see all articles by this author)
(NaturalNews) Chocolate lovers, take heart. Reports from recent studies have given you plenty of reasons to keep on eating chocolate without feeling guilty. In fact, the news from several studies released this spring shows that chocolate is quite effective against the number one killer of Americans, heart disease. Another serious threat to our health, environmental pollution, was significantly reduced by eating chocolate. And the news is even better for females.
Studies and results
Epidemiologic investigations have supported the hypothesis that regular consumption of flavonoid-containing foods reduces the risk of cardiovascular diseases. While flavonoids are found in many plants, cocoa is particularly rich in a subclass of flavonoids known as flavanols. Several dietary intervention trials with flavanol containing cocoa products have shown improvements in endothelial and platelet function, as well as blood pressure. These studies have provided direct evidence of the benefits of flavanol containing foods and have helped to substantiate the epidemiological data.
The April, 2008 Journal of Nutrition reports a double-blind controlled study evaluating the efficacy of daily consumption of a cocoa flavanol-containing dark chocolate bar and chocolate bar with added plant sterols on serum lipids, blood pressure, and other circulating cardiovascular health markers in a population with elevated serum cholesterol. Plant sterols are essential components of plant membranes that resemble the chemical structure of animal cholesterol and carry out similar cellular functions in plants. 49 adults participated in the study, eating the American Heart Association style diet for two weeks prior to beginning the study. They were divided into two groups and instructed to consume 2 cocoa flavanol containing dark chocolate bars per day with or without plant sterols. Each bar was nutrient matched and contained approximately 180 mg of cocoa flavanols.
Participants consumed 1 bar 2 times per day for 4 weeks, then switched to the other bar for an additional 4 weeks. Serum lipids and other cardiovascular markers were measured at baseline and after 4 and 8 weeks. Blood pressure was measured every 2 weeks. Regular consumption of the plant sterol containing bar resulted in reduction of 2.0 and 5.3 % in serum total and LDL cholesterol (P<0.05), respectively. Consumption of cocoa flavanols also reduced systolic blood pressure at 8 weeks.
In the International Journal of Immunopathology and Pharmacology, April-June, 2008, researchers note that epidemiological and experimental studies have suggested that diesel exhaust particles which generate free radicals may be involved in the recent increases in the prevalence of lung diseases. Diesel is a distillate of petroleum. The study investigated the effects of dietary supplementation of cocoa proanthocyanidins on mice in which lung injury from diesel exhaust particles was induced. Proanthocyanidins are polyphenols that occur naturally in chocolate and have powerful antioxidative effects. This supplementation of 1.0 percent inhibited the diesel induced lung injury.
Analysis showed that cocoa proanthocyanidins prevented enhanced expression of adhesion molecules caused by the diesel lung injury. Other evidence of lung injury indicative of oxidative stress was also observed in the lungs of diesel treated mice, however these indicators of free radical damage were barely visible in mice pretreated with the cocoa supplementation. In addition, the level of reactive substances indicative of oxidative stress in the lung was decreased by the cocoa supplementation in the presence of the diesel particles.
We have learned that the stress response leads to behavioral and metabolic changes. Exposure to chronic stress can promote the development of physiological and behavioral dysfunction, including alterations in eating behaviors. The aim of a study reported in the April 25 issue of Appetite was to verify whether chronic restraint stress alters the consumption of chocolate chronically offered to the animals. Male rats ate more chocolate than females, and exhibited a higher weight gain, abdominal fat deposition, and higher plasma levels of total cholesterol, LDL-cholesterol and glucose. The stress exposure increased adrenal weight and decreased plasma insulin levels.
The female rats, however, had lower plasma insulin levels and chocolate consumption prevented the increased adrenal gland weight after exposure to chronic stress, suggesting a reduction of stress effects induced by the chocolate consumption. These results imply that at least some of the stress related effects of chocolate consumption are sex-specific. The fact that females often reach for chocolate in times of high stress while males generally do not may be instinctual behavior.
Chocolate has been revered throughout history
Love of chocolate goes back at least as far as the Aztecs. Cocoa beans were so highly valued during the rule of Emperor Montezuma that they were used as currency. Chocolate was believed to boost physical and mental energy, provide memory and wisdom, and act as an aphrodisiac. When explorer Cortez arrived in the central American’s, Montezuma presented him with gold, silver and cocoa, and Cortez brought the recipe for hot cocoa back to Spain. Later, in Sweden, naturalist Linnaeus christened the chocolate plant the Latin equivalent of ‘food of the gods’.
For hundreds of year, healers used chocolate to cure ailments such as tuberculosis, gout, fatigue, diarrhea, weak digestion, hemorrhoids, low virility, and shortness of breath.
More health benefits of chocolate
Chocolate is chock-full of nutrients. It is an excellent source of potassium and magnesium, and calcium. It also contains vitamins A, B1, B2, D, and E.
Chocolate gives us energy. The theobromine in chocolate stimulates the central nervous system and facilitates muscle exertion. The small amount of caffeine it contains increases intellectual activity, watchfulness, and resistance to fatigue. An average size chocolate bar contains about 6 mg. of caffeine, compared to 100-150 mg. in a cup of coffee.
A study conducted in the U.K. found that theobromine may be more effective as a cough medicine than standard drug treatments. The research showed that theobromine acts on the sensory nerve endings of the vagus nerve, which runs through the airways in the lungs to the brain.
The mood boosting effects of chocolate are due to the endorphins it contains. These natural brain chemicals are released when you eat chocolate. Endorphins also help with premenstrual syndrome. Anandamide acts on brain receptors to help promote the mood boost and enhance feelings of well being.
A researcher from the John Hopkins University School of Medicine says that eating a few squares of dark chocolate every day can reduce your risk of dying from a heart attack by as much as 50%. The study found that blood platelets clotted slower in people who ate chocolate.
Another study found that adults with chronic fatigue syndrome who eat 1.5 ounces of 85% dark chocolate were less fatigued.
An Italian study found that eating dark chocolate normalizes the body’s metabolism of blood sugar, reducing the risk of diabetes and hypoglycemia.
In addition to phenols, which promote heart health, chocolate contains catechins which are antioxidants that help protect the body against cardiovascular disease and cancer.
Chocolate is also high in tryptophan, an essential amino acid that increases the production of serotonin, antidepressants and stress relievers. Keeping up your tryptophan level may prevent cravings for starchy and sweet foods, and help you if you are trying to lose weight.
About the author
Barbara is a school psychologist, a published author in the area of personal finance, a breast cancer survivor using "alternative" treatments, a born existentialist, and a student of nature and all things natural.
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