Macadamia nuts have the highest fat and lowest protein and carb content of any nut eaten by humans. They also are a big favorite to eat. Raw macadamia nuts contain high amounts of vitamin B1, magnesium, and manganese. Also, since macadamia nuts are gluten free, they are commonly used in the preparation of gluten-free food formulas. They are rich in many important B complex vitamins that are vital for human metabolic functions.

According to the Academy of Nutrition and Dietetics which in the U.S. is the largest organization of food and nutrition professionals, just one serving (28 grams or a small handful) of macadamia nuts can net 58% of what one needs in manganese and 23% of the recommended daily value of thiamin. Moreover, about 60% of the fatty acid in macadamia is the monounsaturated fat oleic acid. This is about the level found in olives, which are well known for their health benefits.

Overall, a number of studies have shown that diets rich in macadamia nuts can lower both total cholesterol and LDL cholesterol in those with high cholesterol. A diet that is rich with macadamia nuts can produce effects similar to a heart healthy diet which is recommended by the American Heart Association. Macadamia nuts can also reduce other risk factors for heart disease, including oxidative stress and inflammation.

Since macadamia nuts are very high in monounsaturated fat, this can best explain their ability to reduce risk factors for heart attacks and other chronic diseases.

More Info: en.wikipedia.org