Tuesday, June 1, 2010

'Ancient' super grains

Add nutritional variety to your diet

Grain–based foods make an essential contribution to the diet of Australians. Wheat, oats and rice predominate but interest is increasing in ‘ancient’ grains such as quinoa.

Ancient grains such as quinoa, amaranth and millet are often referred to as ‘super grains’ - a reputation that stems from their excellent nutritional attributes. The heritage of these grains goes far back to biblical times. Not technically true cereal grains, pseudo cereals are broadleaf plants used in much the same way as grains like wheat, barley, rye, oats and rice. Nutritionally superior in some aspects but very similar in others, they offer a wealth of essential vitamins and minerals as well as fibre and phytonutrients.

Quinoa (pronounced keen-wa) is a small disc-shaped grain first cultivated in the Andes of South America. A staple food of the Inca peoples and referred to as the "mother of all grains", quinoa has a slightly higher protein content than other grains, and a more ‘complete’ amino acid profile. Like other grains, quinoa is low in fat and high in fibre and also gluten free for those with coeliac disease. With a light fluffy texture and slightly nutty flavour quinoa can be eaten as an alternative to rice, pasta, barley, cracked wheat and even porridge. You should always soak and rinse quinoa before eating or cooking as the grain has a naturally bitter-tasting outer layer, designed to deter birds from enjoying the crop.

Amaranth is one of North America’s oldest crops and a staple grain of the Aztec people that has been cultivated for over 8,000 years. A tiny, (1-2mm) round ball, amaranth is one of the highest protein grains (14%) and has a slightly peppery taste. The protein found in amaranth is of very high quality - containing the essential amino acid lysine (often lacking in many grains). Amaranth is versatile and can be used for a variety of food uses – as a substitute for rice, popped like pop corn as a snack, or puffed for use in breakfast cereals. Amaranth flour can be used as a gluten free alternative to wheat flour for baking.

Millet is a staple in the diets of some African and Asiatic people but eaten much less commonly in the western world. It features in the traditional cuisine of western India in flat breads, sweet desserts or savoury stews with meat, beans and vegetables. The protein content of millet compares favourably with that of corn and wheat. The tiny grain comes in a variety of colours and has a mild flavour, which is why it is often toasted before cooking. You will find millet in the health foods aisle of the supermarket in some gluten free breakfast cereals and as an alternative to wheat flour for baking.

Buckwheat is most familiar to Australians in the form of Japanese ‘soba’ noodles. The name buckwheat comes from its triangular seeds which can be toasted to bring out their earthy rich nutty flavour, made into honey or even flour – commonly used to make buckwheat pancakes. Buckwheat is more closely related to rhubarb than to wheat, but has similar nutritional properties to other wholegrains in terms of quality protein, fibre and is rich in antioxidants. Buckwheat, like other pseudo cereals, is also gluten free for people with coeliac disease.

Chia (pronounced chee-ah) was first used as food as early as 3500BC by the Mayans, Aztecs and Southwest Native Americans. Chia seeds were eaten as a grain, drunk as a beverage when mixed with water, ground into flour, included in medicines, pressed for oil and used as a base for face and body paints. Chia seeds have a bran, germ and endosperm. What makes them so special is that they are full of fibre, protein and omega 3 fats as well as vitamins, minerals and antioxidants. The protein in chia is of high quality, containing all 8 essential amino acids, which is rare for a plant source of protein. Chia can be sprinkled over salads, cereals and muesli or incorporated into breads, muffins, slices, cookies or porridge. Visit http://www.thechiaco.com.au/ for recipes and ways to incorporate chia into your diet.

If you are keen to add variety to your diet, most pseudo cereals are available from health food stores or the health food aisle of your supermarket. They tend to be more expensive than traditional grains such as wheat, oats and rice which although perhaps less trendy, are just as nutritious but more affordable.

Go Grains Health & Nutrition recommends all Australian adults and teens aim for at least 48g of wholegrains every day. The amount for smaller children is less; however children should increase the amount of wholegrains as they grow. For more information on wholegrains and your health, check out http://www.gograins.com.au.

Wholegrains and fibre

Their role in weight management

The World Health Organisation recognises that healthy weight maintenance is a large challenge, as is overcoming obesity. Despite the public health significance of obesity and the promotion of various weight loss diets, there is no scientifically agreed optimal diet for its prevention and treatment, and opinions differ about the role of nutrients such as dietary fats and carbohydrates in the cause. Research does show, however, that diets including wholegrains and fibre can help to reduce the risk of being overweight.

Wholegrains

'Wholegrain’ foods contain intact and /or milled grains where the grain components - bran (fibre-rich outer layer), endosperm (middle starch and protein layer) and germ (nutrient rich inner core) - are present in the same proportion as in the original grain.

Wholegrains are important sources of carbohydrate, protein, dietary fibre, minerals, vitamins and other bioactive components such as antioxidants. The many benefits of wholegrains are well documented, in particular their association with protection against chronic diseases (heart disease, diabetes and some cancers). They have also been shown to have role in long term weight control.

There is good evidence from scientific studies that a diet high in wholegrains is associated with a lower body mass index (BMI), waist circumference and risk of being overweight.

A study of over 27,000 men showed high wholegrain intake to be inversely associated with long term weight gain. For every 40g of wholegrains eaten daily, weight gain was reduced by an average of 0.49kg.

Another study found a higher intake of wholegrain or high fibre foods to be associated with a 49% lower risk of becoming obese over a 12 year period. Plant based foods and dietary fibre were shown to be protective against excess bodyweight in a large, ethnically diverse research population.

The higher fibre content of diets rich in wholegrains is believed to be one of the means by which they help control body weight. Research shows that increased dietary fibre promotes satiety due to its bulk and low energy density, with hormonal responses leading to reduced hunger and reduced energy intake. The high-fibre content of most wholegrain foods is believed to help in preventing weight gain by increasing appetite control. It does this by delaying carbohydrate absorption, hence promoting the feeling of fullness.

Increasing dietary fibre intake by an additional 14g per day has been shown to result in a 10% decrease in energy intake and a weight loss of over 1.9 kg over 4 months. The effects of dietary fibre were more striking in obese individuals. The authors of this US study concluded that increasing dietary fibre intake from the current average of 15g to 25-30g per day, would be beneficial and may help reduce the prevalence of obesity.

In addition to fibre there are also additional components in wholegrains that contribute to metabolic changes, favouring long term weight management.

The National Health and Medical Research Council recommend a dietary fibre intake of 25-30g per day for adults and 14-18g per day for children above one year of age.

There is currently no official recommendation for wholegrain intake in Australia, but based on the scientific evidence, Go Grains Health & Nutrition recommends 48g of wholegrains a day is an achievable, evidence based target intake.

Wholegrain content of some foods



Sources:

Williams P et al., Cereal grains, legumes, and weight management: a comprehensive review of the scientific evidence. Nutr Rev. 2008 Apr;66(4):171-82.

Koh-Banerjee P et al., Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men. Am J Clin Nutr 2004;80:1237-45.

Liu et al., relation between changes in intakes of dietary fiber and grain products and changes in weight and development of obesity among middle-aged women. Am J Clin Nutr. 2003. 78:920-7.

Slavin J and Green H. Dietary Fibre and Satiety. British Nutrition Foundation Nutrition Bulletin. 2007. 32(suppl 1). 32-42.

Griffiths T. Towards and Australian ‘daily target intake’ for wholegrains. Food Aust 2007. 59(12):600-601.

Harlan J and Garton LE. Whole-grain intake as a marker of healthy body weight and adiposity. Public Health Nutrition: 11(6), 554-563.

NHMRC. Nutrient Reference Values for Australia and New Zealand. Executive Summary. 2006.