Macadamias the indulgent snack that is good for you
We all love that soft crunch and buttery flavour of macadamias, but did you know that macadamias also provide a range of health benefits? When a healthy handful of macadamias (30g) is consumed each day as part of a healthy diet, research tells us you lower your risk of heart disease, type 2 diabetes, oxidative stress and can assist in weight management and
A balanced diet containing macadamias promotes good health, longevity and a reduction in degenerative diseases.
Macadamias are a naturally grown nut product. They are not genetically modified and only contain natural plant genes. Macadamias contain no cholesterol and do not contain any trans-fatty acids A high proportion of the available fat content is good monounsaturated fats, which are also found in olive oil, avocados and almonds. This ‘good oil’ does not deteriorate as fast when exposed to heat, like lower heat threshold oils such as olive oil.
The image of macadamia and other tree nuts is changing as research, dietary trials and population studies demonstrate their importance as part of a healthy diet. There is very strong evidence that they have a positive effect on many aspects of our health and they are full of important nutrients including monounsaturated fats, proteins, dietary fibre, minerals, vitamins, and phytochemicals.
A dietary trial at Harvard University compared a low fat, low calorie diet with a low calorie diet containing ample fat from nuts and olive oil. Over 12 months both groups lost an average of 4.5kg, but those participants who undertook the diet containing nuts proved more successful in keeping weight off after a further 6 months, and all participants in both groups showed no change in blood pressure.
The summary concluded that healthy fats can be part of a weight loss program as long as total calories are controlled. When adding fat calories to a reducing diet it is essential to choose foods such as nuts that are rich in monounsaturated fats, vitamins, minerals, dietary fibre and phytochemicals as well as flavour.
A series of dietary research trials on tree nuts throughout the world has demonstrated a risk reduction link with heart disease, inhibiting certain cancers and have been shown to lower blood pressure in hypertensive people.
The University of Newcastle completed a dietary study project on the health benefits of macadamias. It demonstrated a significant improvement in markers for oxidative stress, clotting tendency and inflammation.
Persons with elevated cholesterol levels showed an improvement in cholesterol and blood fats. These people also had a slight weight reduction despite an increase in the total amount of fats consumed during the study.
Separate dietary trials in Australia and Hawaii with macadamias have also demonstrated a significant reduction in total blood serum cholesterol, a reduction in total blood triglycerides. This means a reduction of the undesirable low density cholesterol (LDL), with little or no effect on the desirable high density cholesterol (HDL)].
Macadamias and nutrition
Protein – Macadamias contain significant levels of protein which are an essential component of our diet and in our bodies form muscle and connective tissues, hair and nails, are part of our blood and act positively on many aspects of our health when consumed moderately. The protein in macadamias comprises of essential and non essential amino acids. Macadamias contain all the essential amino acids, with most present at optimum levels.
Dietary Fibre – Macadamia contains approximately 7% dietary fibre. A handful of macadamias contains about the same amount of fibre as a slice of wholegrain bread? A high fibre diet is necessary for maintaining healthy bowel function.
Dietary fibre provides roughage, slows digestion and reduces hunger, and is a complex carbohydrate resistant to acid and enzymatic attack in the stomach and first intestine. Thus they pass through into the digestive tract where they may assist in reducing constipation and diabetes symptoms, reduce hemorrhoids, bowel cancers and irritable bowel syndrome.
A handful of macadamias contains around 30% of your daily requirements of thiamin – also known as B1. B1 is vital for turning food into energy.
Macadamias are rich in manganese – a mineral that is essential in bone formation and the breakdown of carbohydrate, cholesterol and amino acids. A handful of macadamias provides nearly 25% of RDI for manganese.
Vitamins and minerals
Macadamias contain small but significant amounts of a range of vitamins.
Typical levels are:
- Vitamin E: 1.5mg per 100g
- Vitamin B1 [thiamin]: 0.7mg per 100g
- Vitamin B5 [pantothenic acid]: 1mg per 100g
- Vitamin B6: 0.4mg per 100g
- Vitamin B2 [riboflavin]: 0.1mg per 100g
- Niacin: 2mg per 100g
- Folate [folic acid]: 10 mcg [microgram] per 100g
Vitamin E content varies largely due to the freshness of the kernel and is present as derivatives of Vitamin E. It acts as an important antioxidant, protects cell walls and red blood cells.
Vitamin B1 is a co-enzyme important in releasing energy from carbohydrates.
Vitamin B5 promotes a healthy nervous system and releases energy.
Vitamin B6 is involved with protein metabolism and is more important in pregnancy, the elderly and with heavy drinkers.
Vitamin B2 is important in growth of new tissues, healthy skin and eyes.
Niacin converts food into energy and promotes healthy skin.
Folate assists in forming red blood cells and in utilization of protein. It is regarded as essential in pregnancy in minimizing birth defects.
Phytochemicals are an important group of natural chemicals of plant origin that are becoming increasingly important in our health. They are trace constituents that are not nutrients as such but play an important role in maintaining health. Their chemistry is complex and interrelated. There are many thousands of phytochemicals which is a new form of science where our knowledge will rapidly increase. They can be compared with the discovery of vitamins nearly 100 years ago.
Research is currently being undertaken to identify and better understand their role in macadamias and a number of different types have been found. A wide range has been found in other tree nuts and it is reasonable to expect that at least some of these will be present in macadamias.
Phytochemicals exhibit physiological effects and may modify risk factors with a number of diseases.
The main class of phyto chemicals present in macadamias is antioxidants. Antioxidants are scavengers of free radicals and play a significant role in protecting living systems from oxidation and damage. They may minimize degenerative diseases such as cancer, cardiovascular disease and others. Macadamias contain a range of antioxidants including Vitamin E as tocopherols and tocotrienol, epicatechin [which is the principle antioxidant in tea], the amino acids methionine and cysteine and selenium. Macadamias also contain antioxidants in the form of Omega 3 that are noted to be beneficial to health. Other antioxidants have been detected in lesser amounts.
Macadamias also contain phytosterols [plant sterols] which are believed to lower total serum cholesterol and the undesirable low density cholesterol. Macadamias contain a range of sterols constituents of which sitosterol is the most significant.
To see our nutrition table, click this link
Where can I get more information?
There is loads of information available on the health benefits of eating macadamias. Try these sites to find out more.
Nuts for Life (www.nutsforlife.com.au) – this website is dedicated to information about the health benefits of all tree nuts. They only cite credible sources.
Australian Macadamia Society (www.australian-macadamias.org/consumer/en/health/nutrients) – the AMS has loads of information on the health benefits of eating macadamias. There is information on the benefits of macadamias on heart health, brain function and even how to include macadamias in a kids diet!
Nutrition Australia (http://www.nutritionaustralia.org/national/frequently-asked-questions/general-nutrition/nuts-and-health) – Nutrition Australia is a non-government, non-profit, community based-organisation with offices throughout Australia. Nutrition Australia is an independent, member organisation that aims to promote the health and wellbeing of all Australians.