Grains have been in the press of late, and there is an emerging movement of anti-grain advocates. They tell us grains are toxic, making us fat and causing many of the chronic diseases that afflict the developed world. (Yet if you live in the developing world you don’t have the luxury of this debate – eat the foods that are available or you starve). On the other hand there are numerous studies showing that consumption of whole-grains are beneficial for weight control and reducing risk of chronic disease, particular gut diseases such as colon cancer. Adding to this the data from studies looking at vegetarian diets shows that they are less likely to be obese and have lower levels of chronic disease including heart disease. So should we or should we not be eating grains?
The argument against eating grains is primarily one of evolution. Genetically we have changed little since the days of our hunter-gatherer ancestors. At this time the best evidence shows that animal-foods (including fish and seafood) dominated the human diet, alongside an abundance of plant foods. Grains are not easily harvested and can almost never be eaten direct from the plant – they require some level of processing and/or cooking to make them edible. They did not therefore become major dietary players until the dawn of agriculture when man learned how to farm the land, grow and harvest crops to support the community. This process started some 10 000 years ago and from this time grains became an increasingly important part of human diets around the world. So much so that today grains provide the staple food for many communities all around the world. Indeed from a purely environmental point of view we could no longer feed the world’s population on an animal-based diet – we need grains and other plant foods to sustain us. However, in evolutionary terms this is a very short period of time. There is therefore a valid argument that genetically we have not (yet) evolved to cope with the change from a predominantly animal-based to a grain-based diet.
Yet there is a major flaw in this argument – while we have eaten grains for thousands of years, overweight and obesity have only really become a major problem in the last 50 years. In fact the exponential rise in obesity is only in the last 20 years. Furthermore traditional diets all around the world consume grains and yet are considered healthy – just think of the amount of rice consumed throughout Japan and the rest of Asia. Yet they have lower rates of obesity and chronic disease. Perhaps the answer lies not in grains themselves but in what we do to the grain.
When man started to eat grain foods he harvested the grain and would have roughly ground the grain between stones to crack the hard outer shell, added water to the resultant mix and then cooked it in some way. Over time we learned how to use grain to make bread, cook up porridge or add it to thicken stews. We learned that grains could plump out a meal making the meat in the meal go a lot further while filling everyone up relatively cheaply. It’s the same story today – animal foods tend to be much more expensive while grain foods are cheaper and readily available. But we have now learned how to grind the grain, remove the tough outer husk and polish the grain down to just the starch-rich centre. We can then cook the polished grain to give a fluffy white rice for example, or can grind this starch centre to a fine flour to produce fluffy white breads. Or we take the fine flour and mix it with fat and/or sugar and make biscuits, cakes, crackers, breakfast cereals and so on. You can see that over time with sophisticated food manufacturing techniques we have moved further and further away from the grain in its’ natural state. In fact all we do is strip the grain of almost all its fibre and micronutrient content, and use only the energy-containing part of the grain – the starchy centre.
We can measure the effect of this processing on our body. When carbohydrate-containing foods such as grains are eaten, the food is digested and broken down in the intestines to release the individual sugars, principally glucose. These are then absorbed up into the blood stream where the glucose is transported to cells all around the body to be used as fuel or stored for later use. How quickly this happens varies depending on the food. This is the basis for the Glycaemic Index or GI. The GI compares foods, gram for gram of carbohydrate, by directly measuring the rise in blood glucose after eating the food. If we compare directly the GI of grains under increasing levels of processing i.e. whole-grains, cracked grains, wholemeal flour and so on to fine flour, we see a step wise increase in the glycaemic response. While we have eaten grains for thousands of years, the change in the last 20-50 years has been the dramatic increase in the consumption of processed grains with a high GI. As a result, the rises and falls in our blood glucose levels today are far larger than in the past and our bodies are just not designed to cope with this.
In the argument as to whether or not grains are good for us, the answer is clearly dependent on what form the grains are in. The positive research supporting the role of grains in the diet is almost always for whole-grains or minimally processed grain products. Similarly the evidence for consuming low GI foods grows and this supports the same conclusion. In practice this means fewer foods made from white flour including bread, biscuits, cakes and other baked goods, and less polished white rice (at the very least choose a lower GI variety).
Instead we can increase our range of grains focusing on those we can consume with minimal processing and/or that have a low GI. Venture into the health food aisle of your local supermarket and you will find many grains that fit the bill. While some of these may be new to you, interestingly they are almost always part of traditional diets from other parts of the world. Barley, thought to be one of the first grains to be cultivated by man, makes a fabulous nutty base for a risotto style dish; bulgur, popular in Middle-Eastern cuisine in dishes such as tabouli; Freekeh™, an ancient Eastern Mediterranean grain with more fibre, protein and micronutrients than many other grains; rolled oats (even Scotland has its healthy food!) which makes a nutritious breakfast as porridge or muesli; and quinoa (pronounced keen-wa), a tiny South American grain that was once the food of the ancient Incas, that has a high protein content as well as being nutrient-rich and can be used in a similar way to couscous.
In the bread aisle look beyond your basic sliced white bread and be adventurous in trying a selection of wholegrain options – European-style grainy breads; flat bread based on barley, rye or corn; rye sourdough breads; spelt flour breads are all far more nutritious choices. Expand your culinary diversity beyond processed wheat and rice and the bottom line is that grains can indeed be a nutritious and delicious part of our diet. We needn’t look so far back in time as hunter-gatherer man for lessons from the past – we can learn much from the traditional diets of our relatives all around the world.