Why We Eat (Too Much) Page 16
Hybridization and Genetic Engineering
A critical factor in industrialization was the availability and the cost of staple foods. For example, wheat had come a long way since the advent of agriculture in Egypt. The natural wheat of those times had slowly been changed, first by hybridization techniques (where the two different strains of wheat could be combined to grow a stronger or taller crop), then more recently by genetic engineering. If you are now forty years old or more, and you remember visiting the countryside when you were young, you probably noticed when walking through a fully grown wheat field that the crop was very high, usually 4 feet tall. In fact, if you walked through these fields when you were a child, you probably wouldn’t have been able to see over the top of them. But things have changed quite dramatically over the last thirty years. Now the wheat in most of the fields in the world is a strain that has been genetically engineered to be strong and not too tall, and to produce large buds of wheat germ. This strain is called ‘dwarf wheat’. If you walk through a full-grown wheat field today – in England, America, Asia and most places – you will notice that the wheat is now only 2 feet high. The tall swaying wheat fields of relatively recent times have disappeared, probably never to return – and certainly never to be seen by the younger generations. Why does this matter?
First, because dwarf wheat is much more profitable for farmers: it guarantees a larger volume of wheat per acre of land at the expense of the quality of the grain, and therefore our nutrition. The story of how wheat has changed does not stop at the hybridization techniques to produce a single strong worldwide strain. The processing of wheat has dramatically changed from the days of wheat mills that were situated picturesquely along sparkling rivers. Those mills used the power of water to split and grind down the wheat. This made it easier to store, transport and cook. Now the old flour mills have been replaced with high-tech processing plants where the goodness of the wheat, the outer covering, is removed, leaving the sweet inner wheat germ. The dwarf wheat that makes up the flour present in many of our foods today, from bread (white or brown – there is not much difference) to crackers and pasta, is so highly processed that within thirty minutes of us eating it, it has turned into pure sugar in our bloodstreams (we will see the metabolic effect this has on our bodies in chapter 11). This goes part of the way to explaining why many of the patients I see, who have struggled with their weight throughout their lives, will label themselves ‘breadies’. They are addicted to the reaction their body gives them to this highly processed food, just as some people are hooked on the buzz they get from sugar, and still others hooked on opiate drugs – the brain-signalling pathways are just the same.
Summary
We learned in this chapter that the way our cells process energy, and how we are reliant on those ATP micro-batteries, follows the ancient biological rules set down 4 billion years ago when cellular life first began. It wasn’t until over 3.5 billion years later that evolution accelerated, when our one-celled ancestors took in and nurtured those powerful bacterial tenants (the mitochondria) using oxygen to super-charge our micro-ATP batteries. This type of energy is used by all animals, including us. These ancient energy rules are embedded deep within the layers of our evolutionary history. They ensure that energy use is budgeted for, depending on the size of the animal.
So, humans could not develop their large, energy-sapping brains without sacrificing another organ’s use of their limited energy budget. We learned that prior to Homo sapiens developing, Homo erectus, our nearest relative, had tamed fire. More importantly they had started to use fire to break down the energy in food, to make it easier to digest – or, as we now call this, cooking. The energy saved by starting the digestion process of foods before they were eaten rendered our long digestive system redundant. As time passed, we evolved shorter guts and the energy saved meant that finally we could afford to develop a larger brain.
It also explains why we, as humans, are so inquisitive about food, why we love to prepare and cook and experiment with it, why it fascinates us so much. Cooking defines us.
As the millennia passed, our evolutionary instinct to control food led us to develop agriculture, and then to trade food in markets. More recently we discovered how to process food so that it could be preserved for overseas trade, becoming a business commodity. Sugar and wheat became staples in our diet.
But then, a final chapter emerged in our relationship with food. Our natural fascination with it meant that controlling its production was not enough. We wanted to understand it. In chapter 8 we learn the unfortunate consequences of this.
As we wearily pour our bowl of Frosties (almost 50 per cent sugar) in the morning, we humans know our food nirvana has arrived. Finally, we have constructed a world where our beloved sugar has found its way well and truly into our very own food chain. The feeling of calm ecstasy as our cereal goes down is our developmental pinnacle. The energy saved from preparing and cooking foods has helped us to evolve to be human. Now we have taken the next inevitable step and processed and manipulated food to make ourselves feel great. We are the Master Chef. The Master Chef has won.
But as we open our morning newspaper and sip our tea, a report catches our eye. Next to the advert for Disneyland is the headline ‘SCIENTISTS DISCOVER A NEW SUPERFOOD’. Intrigued, we read on.
EIGHT
The Heart of the Matter
How Poor Nutritional Science Led to Bad Eating Habits
‘If we knew what it was we were doing, it would not be called research, would it?’
Albert Einstein
The heat was unbearable, the crowds were massive. We lurched up the picturesque street to our next destination. Families with very loud, small children surrounded and jostled us. The occasional battering ram of a pushchair made us scurry sideways. I had tried and failed to fix our transport problem by going to the electric buggy store, but was told I did not qualify for one: I was not ‘big’ enough. I watched enviously as others rode them around. We struggled on.
This was a closed community where everything was controlled by the company. The security detail herded us safely over roads, the cleaners kept the streets immaculate despite the untidy throng, and the storekeepers wore smiles of joy. People came from far and wide to be immersed in this utopia. There was no crime, no advertising, no politics. It was a dream world in which to bring your children for a few days.
The entertainment was focused on causing you to feel terrified. This may sound like a strange way to enjoy yourself, but the adrenaline and endorphin (like morphine) surge to the brain afterwards was what drew us all in. It was a safe kind of danger. When the post-terror rush wore off there was another way to get high. This was why the children flocked here. The only foods available were burgers, fries and sweet sodas. Every other store on the street was a sweetshop – laden with that wonderful food drug: sugar.
We found a bench to rest on. I needed to relax as I was scared of the terror to come; embarrassed because my eldest daughter was not afraid. I opened the large bag of pick ’n’ mix sweets and felt the calmness fill me as the sugar hit my brain. My children wanted to move and live here for ever.
I looked at the families walking past us. I noticed that in this place most people were large. Only occasionally did we see a family that looked fit and healthy. A mother was laden down by both her bags and her belly fat; the father, bear-like, stabilized himself by pushing a pram. Two big live-wire kids jumped and fought; and in tow the grandma, regally corpulent in her prized electric buggy. Most of the families had sorted out their food for the day by signing up to an all-you-can-eat all-day meal deal. They clutched gigantic cups containing Coca-Cola and other ‘soft’ drinks. Refill stations were readily available, so their sugar rush could be continually topped up through the day by sipping through a straw.
Maybe this was the kind of world that humanity was moving towards? My reverie was interrupted by a tall and disturbing figure walking menacingly towards us. As he neared us, I recognized his familiar features �
� Goofy had arrived. It was time to get up and walk towards the Fairy Castle. The ‘Runaway Train’ could wait for now.
*
Are we slowly constructing a world like a theme park around ourselves? A world where it is difficult to access natural, fresh food? A world built on the hedonic enjoyment of sugar and fast food, but one where anxiety and stress stalk its inhabitants and that ultimately leads to a population suffering with obesity?
We know from our history lesson in the previous chapter that, as humans, we could not have evolved into the intelligent beings we are today without the help of our relationship with food and cooking. Cooking and preparing food gave us the metabolic room to shrink the size of our guts and expand the capacity of our brains. It is perhaps only natural that we would continue developing our relationship with food by discovering more and more ways of making food enjoyable. Once we opened the Pandora’s box of sugar and discovered the pleasure it could give, was it not just a matter of time before we mass produced it for the whole population?
Let’s take a look at the figures. If we measure sugar consumption per person since the 1820s (the golden age of healthy eating), there was a slow and inexorable rise over the next 100 years. In 1820, consumption was just 5lb per person per year; by 1920 this had increased to 80lb per year.1
Figure 8.1 USDA graph showing the increase in sugar consumption from 1822 to 2000. Sugar consumption then stabilized until the 1980s Source: US Department of Commerce and Labor, USDA Economic Research Service.
This coincided with the more widespread availability of sugar once the beet variety was available as well as sugar cane. Sugar became cheaper during this period, which encouraged food manufacturers to include it in a wide range of products. However, from 1920 sugar consumption stabilized. The Great Depression and the Second World War would have had a significant effect on sugar availability and affordability until the 1950s, but after this time and for a further thirty years, sugar consumption remained stable. It was as if we had reached a natural saturation point, or peak of consumption.
What happened next could not have been predicted. In the 1980s, after thirty years of consuming roughly the same amount of sugar each year, suddenly we started to consume more and more of it again. The price of sugar rose, doubling on average over this period, but this did not stop an inexorable rise in our sugar consumption: from 80lb per person each year in 1980 to 100lb in 2005. Why did we suddenly change our eating habits again?
The Fat Scientists
The audience of eminent doctors and scientists rose as one to applaud the famous keynote speaker. He had delivered a master class on his research. He had won the argument over his biggest rival, trouncing him with indisputable facts, exposing his flawed logic. The crowd’s adulation filled him with joy and ecstasy. His life’s work had reached fruition. The funding for his research would come rolling in, his reputation as the leading scientist in his field would be secure for years. Fame was good, but now he had secured the top two real prizes – power and influence.
The pressure to win the argument had been intense. He had to be congratulated on how he had done it. He had not been dishonest about his research – that would have been unethical and discredited him. Technically what he had presented was the truth. But he knew very well that it was not the whole truth. The facts that did not fit in with his theory had been conveniently left out.
What he did not expect was for his research to harm people. Unfortunately, in this case it did. Sometimes there are unpredictable outcomes to seemingly well-intentioned research ideas being ‘proven’, particularly if those ideas turn out to be false. In the case of Dr Ancel Keys those outcomes amounted to ill health, misery and early deaths for millions of people.
In the 1950s there was a sharp rise in the incidence of heart disease in the USA. More and more people, particularly men, were succumbing to heart attacks or becoming disabled with angina. The emerging public health problem was brought starkly to the top table of government with the sudden heart attack of President Eisenhower in 1955. Scientists began to think that there might be a link between the rise in heart disease and diet. And the two main suspects in the diet were fat and sugar.
Dr John Yudkin was a British nutritional scientist who was convinced that sugar was the culprit. Since 1957 his articles and research have cited sugar as the primary cause of not just cardiovascular disease but also tooth decay, obesity and diabetes. He published a damning book on sugar entitled Pure, White and Deadly. In it he wrote: ‘If only a small fraction of what is already known about the effects of sugar were to be revealed in relation to any other material used as a food additive, that material would promptly be banned.’2
His research received a large amount of interest and it looked as if his arguments were compelling enough to change the public perception of sugar. However, the sugar industry had taken note of the shifting negative publicity and decided to act first. In 1967 they donated large sums of money to three prominent Harvard scientists who conducted research that exonerated sugar and shifted the blame for heart disease firmly onto fat. The scientists were very well respected and their joint paper was published in The New England Journal of Medicine, the most respected US medical journal of the time.3 The sugar money was well spent: publication of such a review in a highly respected journal could not be ignored by the medical community, and the scientists’ views and opinions diffused into mainstream thinking about the dangers of fat, particularly cholesterol, to the heart.
The sugar donations were kept secret until 2017 as scientists at the time did not have to reveal who was paying them and conflicts of interest were commonplace.4 Most of the scientists are no longer with us, but the legacy of their work was the first part of the jigsaw of evidence in what was to become known as the ‘diet–heart hypothesis’. The theory was that saturated fat caused heart disease. Several more pieces of the poorly fitting jigsaw were needed before the argument was won and our nutrition was changed for generations.
Ancel Keys was an American epidemiologist with a background in high-quality nutritional research (including the Minnesota Starvation Experiment discussed in chapter 1) and had convinced himself during a sabbatical period living in England that the high-fat diet of fish and chips or Sunday roasts was the cause of high levels of heart disease in the British. He proposed that the cholesterol found in saturated or animal fats caused atherosclerosis (furring and narrowing of the blood vessels of the heart), which led to heart disease. He was another respected scientist the sugar industry was looking to for support. He did not disappoint his backers. His first attack on John Yudkin’s theory was to highlight research that linked sugar intake to smoking. The research suggested that the more you smoked, the more sugary hot drinks you were likely to consume. How could Yudkin’s theory hold up in view of this correlation between smoking and sugar? Ancel Keys did not hold back with his criticism of his nemesis and whenever possible tried to humiliate him and belittle his research in the scientific press or at conferences.
As part of his research, Keys published the Seven Countries study.5 This research study looked at the relationship between heart disease and the amount of fat in the diet in seven different countries. When the relationship was plotted on a graph, it showed a significant correlation between the two factors. This research seemed to prove beyond dispute that a high-fat diet caused heart disease. The two countries with the lowest fat intake were Italy and Japan and these countries also had the lowest levels of heart disease. The UK (England and Wales) and USA had the highest fat intake and also the highest rates of heart disease. The results when plotted on a chart were compelling; such a high degree of correlation between the amount of fat that a population ate and its level of heart disease meant there had to be a direct link.
However, what was not clear from the research paper was that Keys had originally looked at the eating habits and rates of heart disease in a total of twenty-two countries, not just seven. Ancel Keys’ study had only examined countries that he thought would prove th
e theory; for instance, he did not study two European countries whose populations ate a lot of saturated fats but did not seem to suffer high rates of heart disease – France and Germany. These countries were not selected for research despite being two of the largest countries in Europe. The Dutch ate the same amount of fat as the Italians, but had double the rate of heart disease. The Swedes ate much more fat than the Australians, but the Australians had double their rate of heart disease. All the countries which did not fit into Keys’ thesis that dietary fat causes heart disease were excluded.
If the paper had been ‘The Twenty-Two Countries Study’, it would have concluded that there was in fact no significant correlation between heart disease and saturated fats.
Shaky Foundations
Research bias by omission has been endemic in the scientific community for many years. Although, finally, this has started to be addressed, unfortunately it has left a legacy that much of our medical science is based on shaky and biased evidence. When you combine this with the influence the pharmaceutical and food industries have had over scientists, not only do you have poor research but also research that has been financed by big business and that does not always benefit those it should benefit.