Why We Eat (Too Much)

by Andrew Jenkinson

  Seeds from vegetable plants are heated to 180°C in a steam bath and compressed to help separate the oil. The oil is then put through another bath, not steam or water this time, but a bath made of the chemical hexane (the solvent glue sniffers are addicted to) and steamed again to help more oil to be extracted. The pulp is then put into centrifuges to spin the oil away from any remaining seed residue and phosphate is added. The crude oil is then separated, but needs further refining because it smells rancid at this stage. To produce a clear odour-free oil, processes known as bleaching and deodorizing are performed on the oil. Bleaching, as the name implies, requires the use of bleaching agents to remove impurities (such as chloroform) from the oil. The deodorizing process uses scorching hot (500°C) steam at high pressure to clean the oil of bad smells.

  The production of our healthy vegetable oils mirrors the production of any type of crude oil. Just as had been achieved with the innovation of sugar production, human ingenuity enabled us to manufacture a new type of food: an apparently pure healthy fat that could be added to foods and used in cooking; a foodstuff that was fit for storage and transport and trade around the world; and a food derived from previously inedible, and sometimes poisonous, plant seeds. We had done it again; ‘progress’ continued.

  Was this really a food – or a man-made chemical that had been adapted for consumption without apparent health consequences? Vegetable oils are suspiciously like the fire-lighting oils that can give you a scare if you put too much on the barbecue. Has evolution taken us so far that our fat consumption can be sorted with substances that can be modified to run a car?

  It’s wishful thinking to believe that these new oils really are healthy options. Yet the consumption of vegetable oils has skyrocketed since the 1970s, helped in every decade by the cholesterol scares (see Figure 8.3). In fact, the popularity of vegetable oil has offset the reduction in animal fat and is responsible for our total fat intake increasing since 2000, the opposite of what the original guidelines advised.

  Figure 8.3 Consumption of added fats and oils increased 63 per cent between 1970 and 2005 Note: In 2000, there was a dramatic increase in the number of firms reporting vegetable oil production to the US Census Bureau.

  Source: USDA, Economic Research Service, Food Availability (per capita) Data System.

  Out of the Frying Pan …

  Vegetable oils are purported to be full of the health-giving omega-3 fatty acid (we will look at the fatty acids in more detail in chapter 9). The problem with omega-3, though, as far as the food industry is concerned, is that it causes food to go off and become rancid (this is actually a sign that it is food and not a manufactured food replacement). This means that vegetable oils have to be treated by a process called hydrogenation to ensure they do not contain too much omega-3, which would shorten its shelf life.

  Hydrogenation turns some of the omega-3 from good guys into very dangerous bad guys called trans-fats. Trans-fats cause heart disease. In fact, they are very potent poisons that once in our bodies will increase those bad-cholesterol particles – the LDL type, small dense molecules that can burrow into your arteries, causing inflammation and atherosclerosis. In addition, trans-fats decrease the amount of the good HDL cholesterol in our blood, exacerbating the risk even more (for further information, consult Appendix 1 on cholesterol).

  We had therefore come full circle in our quest to reduce heart disease risk. By lowering use of animal fats and increasing vegetable oils, we inadvertently increased trans-fats and increased our risk of heart disease. The detrimental effect of this change on heart disease in the population was masked epidemiologically for many years by the decrease in smoking rates and advances in the treatment of blood pressure.

  Trans-fats caused a major public health scare when it was finally revealed how dangerous they are. Governments have now encouraged food manufacturers to decrease or eliminate the amounts found in vegetable oils. However, because of the nature of vegetable oils – the fact that they will turn rancid unless treated by hydrogenation – trans-fats will always be around. Even the process of heating a vegetable oil too high in the frying pan or oven can produce these unwanted toxins. After the McGovern Report, lard and butter, the traditional stable fats (high in saturates) used in baking had been replaced by a solid form of vegetable oil called ‘shortening’. Vegetable oil is liquid at room temperature, and there is only one way to make it solidify: you guessed it, more hydrogenation, meaning more trans-fats in all types of processed foods – cakes, biscuits, crackers, doughnuts, pies and margarine.

  So, how much trans-fat is too much? The new US Food and Drug Administration (FDA) guidelines state that intake should not exceed 1 per cent of total calories (20 calories or 2g/day). This amount can be found in a single serving of cake, biscuits or crackers.

  Hey, This Soap Looks Like Lard!

  One of the most fascinating stories in our roller-coaster ride through the history of food processing is that of Procter and Gamble. William Procter, a British candle-maker, and James Gamble, an Irish soap manufacturer, found themselves related by the sisters they married – and both families settled in Cincinnati. They teamed up in business and bought the patent to a new technique from Europe that processed vegetable oils from a liquid to a solid form. Convinced that this would be a major breakthrough in soap manufacture, they set up a lab and a factory to start production. The lab produced a solid white substance which could have been used for soap but looked remarkably like … lard. By 1910 they had licensed their new product for human consumption. The product was the first and original hydrogenated vegetable oil, named ‘Crisco’. Within a few years, even before the cholesterol scare, it became a regular household food – laden with, you guessed it – trans-fats.

  Mix It All Up

  Most processed food is made up of a combination of sugar and fats, mixed in with a sprinkling of salt. Quite often highly refined flour will also be added. The concoctions are finished with colours, flavourings, emulsifiers and preservatives to imitate the taste of unprocessed foods and to disguise their offensive qualities. Different consistencies of the processed foods, such as soft, chewy or crunchy, add a further level of pleasure when we eat them. Processed foods are designed in labs and tested on volunteers to see which combination hits the ‘sweet spot’. The more pleasurable and addictive the food, the more it will sell. This is basic market economics: you must try and have a better product than your competitor.

  A 2016 survey of the eating habits of over 9,000 US citizens showed that a massive 57 per cent of their daily calorie intake was from highly processed foods, and these foods accounted for 90 per cent of the added sugars in the diet.10 Processed food is big, big business. Nestlé, one of the largest food companies in the world, has an annual turnover of $91 billion.

  Unfortunately, the long-term health consequences of the consumption of addictive high-calorie foods do not need to be considered by the food manufacturers. They provide the product, it is up to the consumers to try and resist eating too much of it. The products sound healthy, but their labelling can be confusing, such as ‘low fat’ (in high-sugar products) or ‘no added sugar’ (in high-fat products). And the nutrition labelling is hidden on the back of the product and is suspiciously difficult to interpret. I find that having a calculator and a maths A-level is helpful, but the labels are still difficult to decipher. So, we have gorgeously tasty foods, with colourful labels saying they are healthy, all at reasonably low prices. And a consumer group of very vulnerable people. Those vulnerable people are you and me, humans, Homo sapiens. The same species which evolved only because it learned to cook food has now manufactured its own types of food – and we love them.

  Adapting to Our New Environment

  We first controlled fire, then learned how to use it to cook. We evolved large brains with the metabolic room cooking gave us. Now we have used our large brains to construct a quite unnatural food environment. Free-market economics have spread our manufactured foods around the world. Our intelligence has also all
owed us to change the world in which we live in favour of one that is supposed to be more comfortable and convenient. This has translated into cities containing millions of people living together as neighbours, but often having no community. People don’t need to move and undertake manual work to survive nowadays. Day- and night-time is blurred by noise and artificial light. Stress levels can be high; sleep can be difficult. There are pollutants that we are not used to all around us. Our Disney utopia may be close, but is it really what we need?

  What has our new environment bestowed upon us? We now have fantastic healthcare systems that have conquered the conditions that killed our hunter-gatherer ancestors, but as our healthcare has improved so we have developed more and more ‘diseases of civilization’. Our healthcare systems are designed to treat these new diseases – that are thought to occur because of the changes in our environment and living conditions. They include heart disease, high blood pressure, Type 2 diabetes, depression and cancer. One overriding condition contributes to all of them – obesity.

  Figure 8.4 Hunter-gatherer food pyramid Source: Adapted from M. Sisson (2012). The Primal Blueprint. London: Ebury Press.

  Let’s compare the food pyramids of these two populations.

  Hunter-gatherers eat mainly meat and a staple carbohydrate. All food is natural and therefore contains an abundance of natural goodness (vitamins, minerals and phytonutrients). The organs of the animals eaten, the offal, is a chief source of natural fats – cholesterol is not avoided.

  The modern food pyramid represents what the governments would like us to eat. Unfortunately, as we have learned, most of our calories come from highly processed foods. Most people are aware of the guidelines but do not really follow them.

  If, as a population, we did stick to the guidelines, let’s look at the food pyramid changes. Animal meat and animal fats (that lovely offal) have been downgraded from the ultimate health- and energy-giving foodstuffs that our nomadic ancestors recognized to what we are now told is a food that can cause obesity and heart disease. Meat (flesh foods) is now near the narrowing summit of the food pyramid – next to what we are also told are dangerous: eggs – and just below condiments. This is quite a relegation from occupying the base of the healthy diet pyramid of the hunter-gatherers. Instead of our staple foods being meat and tubers (sweet potato, cassava, yam, taro, carrot, shallots, ginger etc.), the base of our new twenty-first-century pyramid is occupied by cereal grains. We are told that seeds from grasses are healthier for us and should be our new staple. The fats from meat and dairy products in our new guidelines are replaced with vegetable oils – these come in as part of ‘commercially prepared foods’. Just above this, within the main foods section, is our wonderful sugar.

  Figure 8.5 Modern food pyramid Source: Adapted from USDA, 1992, ‘Food Guide Pyramid’.

  Hunter-gatherer Staple New Staple

  Meat, including fatty offal Grains

  Tubers Vegetable oils/sugar

  Now tell me, honestly, which diet is healthy and which causes obesity, heart disease and a whole host of the diseases of civilization?

  Ouch!

  Sometimes I ask my medical students how they would treat a patient who has pain in his foot because he is standing on a drawing pin? Most of them will list a range of painkillers that could be prescribed, from paracetamol to ibuprofen to codeine. Only very occasionally will a bright student give the correct answer – these are the students who I hope will have a career in public health in the future. The correct treatment is to ask the patient to stop standing on the drawing pin. If the correct advice is given, then no drugs are needed.

  What has happened to our public health in the last fifty years? We have rising rates of cancer and heart disease – our two biggest killers. Both modern medicine and technological advances have had a major impact on our approach to treatment of these conditions. In fact, some would say that we are well on the way to conquering many types of cancer. We can now diagnose them earlier and we have a range of different treatment options, from surgery to targeted radiotherapy, chemotherapy or the newer immunotherapy. Heart disease treatment has advanced too, with stents and cardiac bypass surgery becoming safer. Severe obesity also affects large numbers of people and we have developed bariatric surgery and made it safer in order to reverse this condition. The whole edifice of modern medicine, it seems, is built on the treatment of these diseases of modern civilization.

  But it could be argued that without the changes in our environment we would not have developed these conditions in the first place, and therefore not required these medical advances. Our expensive healthcare systems are fending off the diseases caused by the changes in our lifestyle. As a result, the life expectancy of a working-class man living in Britain in 2017 (seventy-three years) is the same as a working-class man (who had made it past the age of five years) living in the mid-Victorian era.11 Our medical advances have thus been nullified by our new ‘lifestyle diseases’ in terms of life expectancy.

  Vast resources are poured into research and development to beat the new diseases, but are we not overlooking the glaringly obvious treatment? Just like the patient standing on the drawing pin – prevention is better than cure. We have made great progress in curbing smoking and making it more socially unacceptable. This has had a major impact on the rates of heart disease, emphysema and lung cancer. However, other ‘lifestyle diseases’ are beginning to rise again as we are faced with another epidemic – obesity – leading to increasing rates of diabetes, heart disease and cancer. What should we do about this? Continue pouring more money into research and treatment, or do the sensible thing – learn our lesson from history and tackle the cause?

  The New World Epidemic

  Obesity is not a completely new condition, however; it has affected some people for millennia. The first sculptures of humans, dated to 30,000 years BC, depict a voluptuous woman. These clay figurines, named Venus of Willendorf after the area in northern Europe where they were first discovered, are remarkably like each other – they show an obese naked woman with very large breasts and buttocks. Any woman who was lucky enough to become so obese in these times would have been much more fertile than other women. Her buttock fat was a glaring advert for the energy reserves to carry a pregnancy through, even in times of food shortage: the perfect woman for any man looking for a successful mate to bear his children. But invariably he would be unlucky. Obesity was exceedingly rare in nomadic times, its presence probably denoting a rare genetic condition. I would guess that less than 1 per cent of people in this era developed obesity.

  Once farming changed the way humans obtained their food – 20,000 years ago – there would have been a very slow rise in obesity rates, culminating in a rate of 5 per cent of the population in the mid-Victorian era – prior to the common availability of sugar. Then, as industrialization and processing and trading of food progressed, there was a further slow rise in obesity rates over the next hundred years to 15 per cent of the population by 1980.

  In the 1980s there was a sudden sharp rise in the numbers of people developing obesity. The waistlines of Western populations suddenly ballooned and within a single generation obesity had become commonplace in many countries, with a quarter to a third of people affected. WHO figures from 2017 show that worldwide obesity rates tripled during this period.

  The sudden acceleration in obesity rates coincided with the dietary cholesterol experiment – an experiment carried out without adequate proof that it would work, on us, the populations living in the developed (and, now, the developing) world. After the McGovern Report, our food choices which had previously been determined by our culture and family background were hijacked by the scientists. From 1980 onwards, the content of food products changed – they now contained more sugar and vegetable oils and less saturated fat.

  In the fourteenth century the bubonic plague had swept across Europe, killing half of the population; the Spanish flu of 1918–19 caused the death of 50–100 million people worldwide in one year; AIDS ha
s so far taken the lives of 25 million people. Nowadays, there are over 650 million people in the world who suffer with obesity (WHO figures for 2018). In some countries in the Middle East it is more common – if you are a woman – to be obese than not obese. In the future, I suspect, we will be talking in the same way about the obesity epidemic and how, in the early twenty-first century, its side effects – diabetes, heart disease and cancer – caused similar death and suffering to the wealthiest nations.

  Summary

  Let’s recap how we got into this predicament. Why we, as intelligent humans, built this hedonic, dangerously unhealthy world that we now live in. We learned in the previous chapter how our primitive ancestors first began to change their environment and their food by harnessing the energy of fire. This gave them the metabolic room to develop larger brains. Their newly evolved intelligence continued a kinship with food. Farming, trading and processing advanced over generations until finally we saw the rise of processed food produced on an industrial scale in factories and the growth of powerful food companies. But this was not the end; our food was to change some more …

  In this chapter, we learned how, since the 1950s, scientists have disagreed over whether sugar or saturated fat is a cause of heart disease. In the end the financial might of the sugar industry helped it to win this battle. The outcome? Natural saturated fats, particularly cholesterol, were identified as foods that are bad for us. Plenty of research sponsored by the food and pharmaceutical industries (first sugar money, then statin money) has perpetuated the diet–heart hypothesis.