Last month I wrote about the tsunami of diabetes threatening to engulf India. Recent data shows that 20 per cent of people aged 40 and 40 per cent aged 60 in Delhi and Chennai suffer from diabetes. This number is increasing rapidly. Undoubtedly, lifestyle changes have a major role to play. The two pillars of a healthy lifestyle are diet and physical activity, both of which have drastically changed in the last few decades.
What are the dietary changes that have contributed to the increase? Changes in carbohydrate intake are commonly blamed. Carbohydrates, or carbs, are an important source of energy. Carbs are converted to glucose by our body. There are three main types of carbs—starch, sugar and fibre. Starch includes potatoes, peas, corn, beans, lentils, and grains. A grain contains three parts—the hard outer shell called bran, which is rich in vitamin, mineral and fibre; the next layer, germ, is replete with essential fatty acids and Vitamin E; and the soft starchy centre called the endosperm. Whole grains contain all three layers; refined grains contain only the inner starchy part and are devoid of nutritious minerals and vitamins.
In the pre-agricultural period, humans, as hunter gatherers, were dependent on wild animals for their survival. Their diet was predominantly composed of animal meat and wild vegetation. Only the fittest survived.
About 10,000 years ago, humans discovered agriculture— they began to cultivate grains. Wild growing grains were difficult to consume and digest. Grains were thus consumed after stone-grinding and without sieving, so that they contained all three layers (whole grain) with fibre, minerals and vitamins intact. Over thousands of years, grains (cereals) became the mainstay of our diet. With the advent of processing by roller mills—in the latter part of the 19th century in the West, and more recently in India—the outer two layers were removed, leaving the small sized starchy core, devoid of fibre and nutrients. These highly refined grains are more easily digestible and seem to suit human taste buds. Indians get most of their calories from grains, commonly rice and wheat. Increasingly, most grains used in India are processed—shiny white rice is a delicacy, refined white flour or maida is used to make bread, chapattis and confectionery, while the bran-rich unprocessed flour is considered inferior. Refined grains suit our cooking, our taste and our stomach, but not our health. I tend to agree with experts like Dr Cordain of the University of Colorado that cereals are a ‘double-edged sword’. Whole grain cereals—when included in moderate amounts in our diet—provide a cheap and rich source of calories. However, when refined, and consumed in excess, they can have significant deleterious consequences on human health; in particular, they can increase diabetes and obesity.
What about the second group of carbs—sugar itself? In every culture, the use of the word ‘sweet’ (or its equivalent) conjures up pleasant sensations. Terms of endearment like ‘sweetheart’ or ‘honey’ are often sugar centric. The human palate seems to have a particular affinity for sweet taste. In India, sweets form an integral part of all festivals. India is the largest sugar consumer and the second largest sugar producer in the world. Over the last two decades or so, increase in sugar consumption in India has been linked to the marked increase in the consumption of sweetened beverages.
When did sweets become an integral part of our diet? In ancient times, honey was probably the source of all sweetness. The first evidence of crystalline sugar in human history comes from the 5th century from India (source: The Cambridge World History of Food). The etymology of sugar can be traced to the Sanskrit sarkara (gravel). It is thought that Alexander’s army was amazed to find this ‘non-honey’ source of sweetness and introduced it to the world.
Why should we be worried about increasing refined grains and sugar intake? They are rapidly absorbed, leading to high blood glucose levels, provoking insulin secretion. They are rapidly ‘metabolised’, provide poor satiety, lead to progressively greater calorie intake, and ultimately promote diabetes and obesity. Try eating a white bread jam sandwich for breakfast and you are likely to feel hungry by noon. Replace it with an equal calorie oatmeal bread slice with boiled egg, and you will last much longer.
What dietary changes will help us reduce our risk of becoming obese and/or diabetic? The principles include reducing free or added sugars—as found in sweet beverages, confectionery and desserts. It also means avoiding or reducing refined cereals—white bread, refined white flour, polished white rice, and replacing them with grains such as whole wheat, oats, millets, buckwheat, bulgur and brown rice.