A hunter-gatherer diet seems to make sense in the light of evolution, but what evidence do we have that hunter-gatherers truly are healthier? The anthropological record shows quite clearly that human health, longevity, and yes, even height, all dropped off as populations switched to agriculture. The skeletal remains of hunter-gatherers show that they were taller than their agricultural neighbors, had stronger bones, showed no signs of iron-deficiency anemia, had lower incidences of arthritis, and had few, if any, dental cavities.
One of the most compelling studies on this topic, written by Claire Cassidy, PhD, examines two archeological sites in Kentucky, on the bank of the Ohio River, and the remains of two communities – one agricultural and one hunter-gatherer – who lived there. This study is so convincing, first of all, because of the large quantities of data amassed; Cassidy unearthed 296 skeletons from the Hardin Village site (the home of the agriculturalists) and 285 from the Indian Knoll. The hunter-gatherers of Indian Knoll lived at the site approximately 5000 years ago, and they were sedentary hunter-gatherers, that is, they stayed at the site for an extended period of time instead of traveling as most hunter-gatherers do. The agriculturalists of Hardin Village farmed the same area from about 1500 to 1675 AD, but there is no record of any contact with Europeans.
The study presents two societies that lived in the same area, did not travel a great deal, likely were genetically similar, and had the same climate, land, and water. Neither group had contact with Europeans, so there was not disease contamination by that route. The groups are only separated by time, and by their diets. So what did each of the two groups, the agriculturalists at Hardin Village and the hunter-gatherers at Indian Knoll, eat? According to Cassidy:
At Hardin Village, primary dependence was on corn, beans, and squash. Wild plants and animals (especially deer, elk, small mammals, wild turkey, box turtle) provided supplements to a largely agricultural diet. It is probable that deer was not a quantitatively important food source… At Hardin Village, remains of deer were sparse. At Indian Knoll it is clear that very large quantities of river mussels and snails were consumed. Other meat was provided by deer, small mammals, wild turkey, box turtle and fish; dog was sometimes eaten ceremonially. There are several other dietary differences. The Hardin Village diet was high in carbohydrates, while that at Indian Knoll was high in protein. In terms of quality, [some] believe that primitive agriculturalists got plenty of protein from grain diets, most recent [researchers] emphasize that the proportion of essential amino-acids is the significant factor in determining protein-quality of the diet, rather than simply the number of grams of protein eaten. It is much more difficult to achieve a good balance of amino-acids on a corn-beans diet than when protein is derived from meat or eggs. The lack of protein at the Hardin Village signaled by the archaeological data should prepare us for the possibility of finding evidence of protein deficiency in the skeletal material.
Based on the skeletons found at both sites, the inhabitants of Indian Knoll, both male and female, had a longer life expectancy than their agricultural counterparts at Hardin Village. Infant mortality was also higher at Hardin Village. Tooth decay was rampant at Hardin Village and almost nonexistent at Indian Knoll. The adult females of Hardin Village averaged 8.5 cavities per person, while the adult females of Indian Knoll averaged under one. Adult males at Hardin Village averaged almost seven cavities, while the adult males of Indian Knoll averaged .75 cavities per person. That means at least one out of every four adult males, 5000 years ago, in a traditional hunter-gatherer society, lived his entire life, without modern dentistry, toothbrushes, toothpaste, or fluoride, and yet still never got a single cavity.
Iron-deficiency anemia often accompanies low-meat diets, long-term infection, or chronic disease, and is also frequently found in cases of protein-energy malnutrition. In its most severe manifestations, iron-deficiency anemia causes changes in the bone structure. These malformations were present in the Hardin Village skeletons, but not in the Indian Knoll skeletons. Half of these cases of iron-deficiency anemia at Hardin Village were in children. The children in Hardin Village were also stricken with infection at a much higher rate than in Indian Knoll. Again I return to Cassidy.
The health and nutrition situation at Hardin Village may profitably be compared with that in modern peasant villages. In may of these, children are typically fairly healthy until weaned. At this time they are introduced to a soft diet consisting largely of carbohydrates (in much of Africa and Central America, a pap is made of sugar, water, and maize flour: in Jamaica green bananas replace maize). In many cases, within a few weeks or months these children develop diarrhea, lose weight, suffer multiple infections, and may eventually develop the form of protein-energy malnutrition called kwashiorkor. In this disorder caloric intake is usually adequate, but protein and other nutrient intakes are extremely limited; without modern hospital care many victims die. At Hardin Village the highest rate of death occurs between the second and fourth years of life. This is typical for a population experiencing weaning problems. Considering the softness of the adult diet and the high caries rate of both children and adults, it is not unlikely that the children were weaned onto a corn pap of some type. The high prevalence of childhood infection, severity of growth arrest in the first few years of life, and the existence of iron-deficiency anemia all point to a situation at Hardin Village analogous to those in modern peasant villages. In other words the evidence supports a hypothesis that malnutrition began with weaning at Hardin Village, sometimes resulted in kwashiorkor, and continued at low level – just enough to reduce the resistance of the population to infectious disease – throughout the life of the individual.
This is some powerful information to consider when a pediatrician recommends (and most all of them do) that a baby be weaned on to some sort of processed cereal for infants. My child, for one, will not have any cereal grains. After breast milk, I believe the healthiest foods for toddlers are the same as the healthiest foods for adults: good quality animal proteins and fats, along with vegetables and fruits.