New Under the Sun:
Volume 6, Issue 6
The Staff of Life?
Probably everyone reading this essay is familiar with the phrase "The Staff of Life" and has never really given it much thought. But if bread is, indeed, the staff of life, how did humans survive before the grains were domesticated and we learned how to bake? In the long history of human existence, agriculture is a relatively recent invention. In fact, it never may have been invented if environmental changes had not forced it upon certain groups.
Until around 10,000 years ago, the world was in the grip of an Ice Age. The sea levels were about 300 feet lower than today because so much water was locked into massive ice sheets which covered a large portion of the northern hemisphere. Since there are more archaeological and skeletal materials for the Eurasian-circum-Mediterranean region, this discussion will focus on that area. However, environmental changes occurred worldwide and agriculture developed independently in many different regions of the world between 5,000 and 10,000 years ago.
Prior to 10,000 years ago, the portion of Europe not covered by ice sheets was a relatively treeless, tundra-grassland environment populated by herds of extremely large animals including the mammoth, reindeer, and giant elk and cattle. Big-game hunting was the rule, although other foods were also gathered. The average male height was 5'10" with females averaging 5'6", about what it is today in the 21st century in the United States and northwest Europe.
The eastern Mediterranean region of southwest Asia was covered by grassland interspersed with forests of nut trees such as oak and pistachio. Along the rivers was dense vegetation. Based on archaeological material found in the region, the people made heavy use of nuts, the plants along the river's edge, and the gazelle herds which migrated through the grasslands on their yearly cycle.
When the ice sheets began to melt and retreat, the climate became warmer and the vegetation changed. The tundra grasslands retreated northward in Europe and were replaced by dense forests. The giant herd animals could not adapt well to the changing environment and most became extinct. Only the reindeer survives in far northern Europe. Big game hunting was no longer the way to make a living, but there was plenty of other types of foods available: smaller game, nuts, berries, fish, shellfish, eggs, etc. The people of Europe continued to be well-fed and healthy. The same would not be true for those living in southwest Asia.
The change in climate in southwest Asia caused the nut trees to retreat to higher ground and for the forests to thin out. The people needed to stay near the rivers and other water sources in the lowlands, but doing so caused them to lose the major staple of their diet: nuts. They were forced to turn to collecting the seed heads of the grasses. This had been done to a limited extent for a long time, but as a great deal of labor was involved for relatively little return (the seed heads were too easily knocked to the ground as the individual moved through the fields), grass seeds had never been an important part of the diet. But that was to change.
Domestication of Grains and Animals
Limited options forced a dietary change that was to have a major, far-reaching impact on the future of the world's populations. The gradual domestication of plants (seed grasses) and animals (sheep, goats, pigs, cows, etc.) led to permanent settlements. Very quickly, wild resources were wiped out in the vicinity of the villages so that villagers were even more reliant on their crops and herd animals. When times were good, there was plenty to eat and population boomed. But when droughts occurred, the villagers were trapped with little to eat. Unlike their ancestors, they could not move to a new place and start over. But droughts were only one of many problems for the villagers.
Permanent settlements made it easier for women to be pregnant. They did not need to worry about traveling long distances on a daily or weekly basis. When there is plenty to eat, it is easier to maintain a pregnancy. Older individuals who could not help with the crops or the herds were available to take care of small children. The result was that the time period between births dropped from about four to five years to about two years. This allowed the population to rapidly double.
A rapidly-increasing population required even more investment in grains since they could be easily stored for future need, unlike other foodstuffs. The variety of foods available to eat became narrower as the population grew. Unlike the populations living in Europe at this time whose very diverse diets contained a wide variety of nutrients, the villagers relied for the majority of their nourishment on grains in the form of breads, porridges, and beer, among other grain-based food items. You may be wondering, "But what about the herd animals?" Animals actually provided only a limited portion of an individual's daily nutrients. Milk, and later cheese, were available, but since the major herd animals in southwest Asia were sheep and goats, the quantities were limited. Also, animals were wealth, so killing an animal was destroying your wealth. Meat formed a very limited part of the diet. While whole grains do provide nutrients, a heavily grain-based diet is inadequate to maintain good health.
The skeleton is affected by chronic disease and malnutrition which means that scientists who analyze skeletal remains have enough information to determine the general health status of that individual. When they analyze the skeletons of these early villagers they find that the villagers were in very poor health. One sign of poor health in a population is the number of infant and child skeletons relative to adult skeletons. At least 50% of all infants and children died by age five in village populations. There was a peak in death rates around age two. Remember, the period between births was cut to two years among villagers. When a new baby was born, the toddler was weaned to cereal gruel. This provided the toddler with only limited nutrition, making her more susceptible to disease and death. Adults also showed signs of poor nutrition.
Among the foragers of Europe, the average male height was 5'10". Prior to the development of agriculture, this had also been the case in southwest Asia. After villagers became totally reliant on agriculture and, in particular, on grains, height plummeted to an average of 5'2" for males. The skeletons show other signs on the skull and long bones of malnutrition, which, as with children, made them susceptible to death from disease.
Diseases, particularly contagious ones, were not much of a problem for foraging populations. Since they did not live in permanent villages and since their population was kept low, waste products did not build up. This was not true of villages where ever-growing waste piles created inviting habitats for rodents and other vermin, the source of many diseases. In addition, the villagers lived close to their herds; in some cases, separated by only a wall. Many of our contagious diseases came from our close contact with infected animals and include measles, smallpox, and influenza.
If we compare the diets and health of foragers to villagers, we will find that the foragers had a very diverse diet which included many types of fruits, nuts, berries, and other vegetation along with many sources of protein including game, fish, shellfish, birds, and eggs. Grains played little or no role in their diet unlike that of the villagers for whom grains were the major portion of their diet. Foragers were tall and healthy while villagers were short and sickly.
From this analysis we can conclude that bread is the staff of life only when there is little else to eat. If you want to remain healthy, your diet must be quite diverse and include a good variety of proteins. Grains do not need to be included at all. This may be difficult to accept since grains (wheat, oats, barley, rye, corn/maize, rice, and millet) form the dietary basis for most populations. But if we take a historical perspective, it is clear that grains play this dominant role not because they are particularly healthy for us but because they are relatively cheap, and are easy to grow and store in large quantities. Huge populations can be fed with little effort or cost. Of course, the populations will probably not be particularly healthy, but high birth rates compensate for high death rates.
Domestication led to:
Dairy products also play no role in the diets of foragers. Foragers breast feed their children for four to five years after which no milk or milk products are eaten. Individuals in most human populations, particularly those with no history of dairying, cannot process the milk sugar lactose after weaning from the breast. An enzyme, lactase, is needed to break down the lactose, but production of this enzyme virtually ceases by age five in most human populations. Without the enzyme, eating or drinking milk products causes great gastric distress and, in extreme cases, can result in death. Even among those populations using dairy products, in only a very few of these populations can the majority of individuals drink fresh milk. In most populations they must first process the milk into cheese and yogurt before it can be eaten without causing gastric distress.
Dairy products are advertised as the best source of dietary calcium, and that may well be true. But foragers do not consume dairy products and yet analysis of their skeletons shows that they were strong, sturdy, tall, and without chronic disease, except for arthritis caused by overusing certain joints. Vegetation, particularly dark green, is a good source of calcium. But, and this needs to be emphasized, the amount of calcium eaten is less important than the blood levels of vitamin D because vitamin D is needed to properly use the calcium.
Vegetarian diets are being pushed as the most healthy and environmentally conscious diets for humans. While such diets might be environmentally conscious, humans are not adapted for a vegan diet. We are not herbivores or plant eaters. We also are not carnivores or meat eaters. Humans are omnivores which means we can eat pretty much anything that is edible and that we require a balance between vegetable and animal foods in order to be optimally healthy.
The body is composed of a huge variety of proteins. Proteins are constructed from twenty different amino acids, nine of which we must obtain from our diet. The most efficient way to get the needed amino acids is to eat animal protein: fish, shellfish, fowl, red meat, etc. Amino acids can be obtained from non-animal sources, but it is much more difficult to get them that way because foods must be eaten in certain combinations such as beans with corn tortillas or peas with rice. If the diet does not provide the necessary amino acids, the body itself will be used, beginning with the muscle tissue. Vegetarians are often thin in part because of their low-fat diet, but also because they have a thinner muscle mass.
We also know that we need animal protein in our diets because of our large brains. There is a trade-off in organ size between the brain and the gut. Animals who eat only a vegetarian diet (herbivores) have a relatively large gut and a relatively small brain-to-body ratio. The large gut is needed because vegetation (particularly leafy vegetation) requires much more processing to obtain the needed nutrients than does animal protein. So long as an animal's diet requires extensive processing, the resources do not exist to provide for brain growth because that requires a nutrient-dense diet. Fruits and nuts are nutrient-dense vegetable products, and monkey species eating primarily fruits and nuts have a much larger brain/body ratio than do monkey species eating primarily leaves. Chimpanzees (an ape species) have a diet that is about 80% - 90% (depending on season) fruits and nuts, but they also eat 10 - 20% animal protein in the form of eggs, monkeys, and bush pigs, among other animal sources. This diet results in an even better brain/body ratio than that of fruit-and-nut-eating monkeys.
Early in human evolution, our brain/body ratio wasn't much better than a chimpanzee's so we can assume that the human diet was pretty similar to that of the chimpanzee. However, by 1.5 million years ago, human brain size was at least double that of chimpanzees and there is strong archaeological evidence that humans were hunting sizeable game by this time. Over the course of the next million plus years, human brain size gradually grew until it reached the modern size by around 300,000 years ago. Ancient human remains are frequently found near streams, ponds, lakes, and along the coastal shoreline. This, along with the finds of harpoons and large shell piles (middens), indicates that fish and shellfish also played an important role in the diet. In fact, fish and shellfish may have had a bigger role to play in brain expansion than did large game hunting. The omega-3 fatty acids in fish and shellfish appear to play important roles in brain function.
The diet which best will maintain human health is the one to which humans have adapted over the course of the past 1.5 million years and which was eaten by all foraging populations prior to the development of agriculture. The evolved diet is about 70% - 80% fruits, nuts, and vegetation and 20 - 30% animal products such as eggs, fowl, fish, shellfish, and lean red meat. Grains and dairy products were not eaten and, therefore, are unnecessary as long as the other foods are eaten in appropriate quantities. The major catch with this diet is that it can be more expensive than the grain-based diet typical of agricultural societies. However, with modern world-wide market distribution, it is now possible for those with adequate income to have the healthy diet of our forager ancestors on a year-round basis.
Agriculture developed as a last-ditch effort to survive in an environment that could no longer provide a diverse diet to settled populations with accelerated population growth. Many benefits can be traced to the settled lifestyle and population growth that resulted from domestication and agriculture. But the negative consequences of agriculture are also with us.
Agriculture laid the foundation for overpopulation, the spread of disease, and the burden of massive poverty. Disease and poor overall health are so much a part of our lives that in some respects they are considered normal. However, the modern diet with its heavy reliance on grains and dairy products, a direct result of agriculture, is actually abnormal, inadequate, and inappropriate for maintaining optimal health. Replacing this diet with the one for which humans evolved will increase the chances that each of us will live a long, healthy life. Let's get real. Bread isn't the staff of life and every body doesn't need milk.
Next month: Premier Nutrition
© 2001-2009 Kathleen E. Fuller, PhD. All rights reserved.