Macadâmia: deliciosa e mantem o coração saudável!
Macadamia Nuts Taste Great And Keep You Heart Healthy
Saturday, October 18, 2008 by: Barbara L. Minton (see all articles by this author)
In a study from the April, 2008 Journal of Nutrition, researchers note that epidemiologic studies and clinical trials have demonstrated that the unique fatty acid profile of nuts beneficially affects serum lipids and lipoproteins, reducing cardiovascular disease risk. Nuts are low in saturated fatty acids and high in polyunsaturated fatty acids and monounsaturated fatty acids.
In a randomized controlled feeding study over five week periods, researchers compared the results on the lipid/lipoprotein profile of a macadamia nut-rich diet vs. an average American diet on male and female subjects with mildly elevated cholesterol levels. They found that serum concentrations of total cholesterol and LDL cholesterol in the macadamia group were significantly lower than the levels of the American diet group. The serum non-HDL cholesterol concentration and the ratios of total cholesterol to HDL and LDL were reduced in those on the macadamia diet compared with the American diet. There was no change in serum triglyceride concentration. These results indicate a lowering of overall cardiovascular disease risk.
In a study reported in the June, 2007 journal Lipids researchers note that in addition to being rich sources of oleic and palmitoleic acids, macadamia nuts contain polyphenol compounds that lead them to conclude that consumption of macadamias can be expected to confer health benefits. Their study was conducted to examine the effects of macadamia consumption on biomarkers of oxidative stress, coagulation and inflammation in males with high cholesterol levels. Seventeen such males were given macadamia nuts equivalent to 15% of energy intake for a period of 4 weeks.
As expected by the researchers, monounsaturated fatty acids were elevated in the plasma lipids of all study participants following the period of consumption of macadamias. Plasma markers of inflammation and oxidative stress were significantly lower. This study demonstrated for the first time that short-term macadamia nut consumption favorably modifies the biomarkers of oxidative stress, thrombosis and inflammation, the risk factors for coronary artery disease, despite an increase in dietary fat intake.
Another dietary trial in Hawaii also demonstrated that macadamia nut consumption lowered risk indicators for heart disease. And a study in at the University of Newcastle, involving subjects with elevated cholesterol levels, found that participants who ate macadamia nuts showed significant reduction in blood serum cholesterol, total blood triglycerides, LDL cholesterol, and blood clots.
A study in Japan involving young women as subjects found that after only three weeks on a diet high in macadamia nuts, the subjects revealed a significant reduction in both serum and LDL cholesterol levels. These benefits were produced with as little as a 20 gram consumption of macadamia nuts per day.
Macadamia nuts also contain a significant level of protein, comprising essential and non-essential amino acids. They are a good source of minerals so essential to a healthy diet, and so needed to maintain ideal weight. These include per 100 grams: 410 mg potassium, 200 mg phosphorus, 120 mg magnesium, and 64 mg calcium. Selenium, iron, manganese, copper and zinc are present in small amounts. Macadamias contain significant amounts of a broad range of vitamins including Vitamin E as tocopherols and tocotrienols, B1 (thiamine), B5 (pantothenic acid), B6, B2 (riboflavin), niacin and folate. They also contain phytosterols.
Macadamias improve the balance between omega-6 and omega-3 fatty acids. They also have a high dietary fiber content of approximately 7%. Dietary fiber is the term for carbohydrates that are resistant to enzyme digestion in the stomach. These consist of complex soluble carbohydrates and soluble fiber such as, hemicellulose, amylopectins, mucilage, gums and insoluble cellulose. Dietary fiber promotes the feeling of dietary satisfaction, slows digestion, promotes desirable intestinal bacteria, and keeps bowels healthy. It plays a role in reduction of cancer and diabetes risk.
Macadamias also contain the phytonutrient classes of phenolic compounds: flavonoids, phytoestrogens, phytic acid, tannins which convert to ellagic acid in the body, saponins, and lignans.
And we saved the best news for last. Studies of tree nut eaters, a category that includes macadamias, usually weigh less than control subjects when studied.