How Our Food has Evolved

The Agricultural Revolution

The first changes began about 10,000 years ago with the Agricultural Revolution, as human societies settled down and started to cultivate grains like wheat, barley and rice, along with fruits like figs and olives. Humans also began to breed livestock like cattle, sheep, goats and pigs, as well as poultry like chickens and ducks. This steady supply of food improved survival. But it resulted in several significant changes to the human diet:

• Cultivated foods replaced wild foods;
• Grains replaced meat and seafood as the main human food. As a result, starch became the main nutrient, replacing protein and fats;
• Food processing began, with foods preserved in salt and dried in the sun;
• Fermented foods, such as yoghurt and cheese from curdling milk and alcoholic beverages from fermenting grains, were introduced to supplement fresh foods.

Not all the changes were detrimental. As we shall see in later chapters, fermented foods have important health benefits.

The Industrial Revolution

The Industrial Revolution began around 1760 and has brought even greater changes to food production and human lifestyles. One major outcome of the Industrial Revolution was the refining of food to improve their shelf life. Another was mass production to make foods cheaper. As a result:

• Refined grains and flour products are stripped of fibre, vitamins, minerals, protein, essential fatty acids and other nutrients. These refined "foods" provide calories but almost zero nutrition apart from carbohydrates. Refined sugar is so pure that it resembles a chemical more than a food.

These refined foods are very quickly digested and their carbohydrates converted into blood glucose. Today, we call them "high glycemic index” foods - because they get quickly digested and absorbed into the bloodstream, causing blood glucose levels to rise suddenly and sharply.

• Mass production made sugar extremely cheap and affordable even by the poor. Previously, it was a luxury food that only the rich could afford to eat in tiny amounts. With mass production, sugar consumption increased from almost zero to over 60kg per person per year in modern societies.
• Salt, too, has refined to become pure sodium chloride, whereas natural sea salt or rock salt contains about 80 different minerals. In this case, salt was refined not to improve its shelf life, but for industrial processes such as paper manufacturing. Yet the same refined salt is used as human "food".

In the past, foods were processed by purely natural means, such as salt curing, pickling, fermentation and sun drying. Some of these processed foods are, in fact, very healthy. With the advent of machines, however, food processing became unnatural, often using extreme high heat and high pressure. Chemicals were also added -as preservatives, artificial flavouring, flavour enhancers, artificial colouring, bleaching agents, emulsifiers (to prevent different components of a liquid food from separating), anti-caking agents (to make salt and powdered foods flow smoothly) and so on.

For the first time, humans began to eat non-foods. Most chemicals are highly toxic. Yet they are approved by government health regulatory authorities because they do not cause any immediate and obvious harm - and because of lobbying pressure from the food industry. The amount of toxic chemicals present in each serving of food may be small and "safe". But the cumulative effect eventually take its toll.

Another impact of industrialisation has been improvements in food storage, packaging and transportation, particularly refrigeration. This has resulted in people eating foods that they did not previously have access to.

One positive outcome is that nutrition has improved. For example, there used to be isolated communities that suffered from cretinism - a disease that causes stunted growth and deformities - due to a lack of iodine in the local diet. With greater access to imported foods, the incidences of such diseases have been greatly reduced.

A possibly negative outcome is that people are now eating foods that are unsuited to their natural environments - people in cold climates eating tropical foods and vice versa. For example, spices promote perspiration and help keep people naturally cool in the tropics. When eaten in cold climates, spices make people feel colder than they should.

People are also now eating foods that are out of season. These are kept "fresh-looking" through the use of chemicals and industrial processes. In reality, they may be several months old and would have lost much of their nutrients.

Finally, industrialisation has led to the advent of many new foods that were previously not possible to make, such as:

• Luncheon meat and sausages made with starch and other fillers instead of just meat;
• Processed cheese, as opposed to natural cheese;
• Ice-cream;
• Breakfast cereals like cornflakes and puffed grains;
• Infant formula to replace human breast milk for babies.

As industrialisation "progressed", we are now in the midst of another, even more disruptive revolution...