Book review of Gary Paul Nabham's Why Some Like It Hot: Food, Genes, and Cultural Diversity,
for the Nutritional Therapist Winter 2010
As a newly hatched Nutritional Therapist, making my way through the sea of conflicting opinions in this fascinating world of nutrition, I find both spiritual comfort and logical grounding in the study of ancient cultures. In our modern world, where science is revered as a kind of religion, where there is a love of precision and a bias in the funding of research towards understanding things on a molecular level, we can sometimes forget to honor the extraordinary wisdom and complexity of our own bodies, and the wisdom of the cultural traditions that evolved in an interactive dance with these bodies in which we dwell. The study of long standing cultural traditions and of ancient human populations can be an extraordinary tool, and can indeed provide the longest and broadest of epidemiological studies.
Among those trying to find dietary guidance by looking at our ancient roots, there can be considerable controversy.Proponents of the vegetarian diet and proponents of a meat-heavy Paleolithic diet both draw validation from their interpretation of ancient diets. The followers of the Paleolithic diet claim that a predominantly animal product diet is the best for all people and that our genes, formed hundreds of millions of years ago have changed little since then. Dr Boyd Eaton, medical anthropologist and leader in the Paleolithic diet movement, says: “99.9% of our genes were formed before the age of agriculture”. Loren Cordain, another significant figure in the field, describes the Paleo Diet as “the only diet that ideally fits our genetic make-up.” How can this claim of universality of nutritional requirements be reconciled with the work of Weston A. Price, the nutritional pioneer of the turn of the century who made in depth studies of surviving traditional cultures the world around, and found significant differences between the groups that he studied? I am always on the look out for sources who have studied ancient and traditional cultures who will contribute tools with which to weigh these different perspectives
Who should I find this winter, but Gary Paul Nabham, an ethno botanist and ecologist, (who, I just learned, with great excitement, will be a speaker at our spring Nutritional therapy Association symposium). Starting in the American southwest, he has studied the dietary and cultural relationship of societies around the world to the foods that were local and available to them. Rather than searching for the ancestral diet, Nabham suggests that there are many different diets that evolved in different areas in an adaption to the local circumstances. He make a compelling case that genes can change over a much shorter time span than previously recognized and gives several examples of microevolution where genetic change has taken place over the course of a relatively few generations. He shows where more rapid genetic change is most likely to happen where there is a dietary or environmental factor which provides a pronounced advantage or disadvantage for survival.
Tales about his personal experiences and deep connections with people lend a delightful aspect to this book. One such story, from his early adventures in Arizona gives an example of microevolution. A friend brings him out to a remote town where he learns of the Pima Indians using government-issue powered milk to whitewash the lines on their ball fields. That was the day that he learned that the Arizona Indians, a cultural group with no long history of herding in their ancestral past, are lactose intolerant. According to Nabham, Lactose tolerance strongly correlates to the distribution of ancient herding cultures in Europe, Asia Minor and North Africa. In these groups, it appears the advantage of being able to consume the rich protein and fats found in milk was so great that those who were lactose tolerant were rapidly favored, so much so, that with in a mere 15 generations of eating cheese and yogurt, lactose tolerance increased.
Nabham became close friends with many Native Americans, and seeking to understand the particular dietary and health challenges that they faced was a major catalyst for him to embark on his studies of ethno botany. Two other interesting discussions of microevolution also involve challenges particularly significant for Arizonan natives: alcoholism and diabetes.
The relationship between cultural history, genetic makeup and alcoholism can also be looked at through the lens of microevolution. Curiously, says Nabham, cultures that produce enough alcohol dehydrogenase (an enzyme in the liver which allows a greater tolerance to alcohol) have, in their history, traditions of herding and agriculture. In these peoples, pollution of the water supply by the livestock contributed to the problem of dysentery: a significant health problem. Nabham cites Matt Rikley, author of a book called Genome, who theorized that drinking beverage made from fermented fruits, potatoes, grains, gave a survival advantage by reducing exposure to untreated water. Having a greater tolerance to alcohol provided a health advantage for those cultures with herding and agriculture in their past. Conversely, alcoholism is more pronounced in cultures which do not have a history of agriculture and supporting livestock. The natives of the American Southwest, one such culture, are highly susceptible to alcohol poisoning.
Diabetes is another disease that strikes natives of Arizona disproportionally. The Pima Indians have the highest incidence of diabetes in the US. In hoping to find a genetic clue for the cause of diabetes, NIH has invested thirty years and millions of dollars into research on the Pima Indians. This interest was guided in part by the “Thrifty gene theory”, which, still espoused by many today, was originally hypothesized by James Neel in 1962.
Neel theorized that, as hunter-gatherer cultures were subject to alternating times of feast or famine, they were likely to have what he termed a “thrifty gene”. The understanding being that repeated cycles of feast or famine over the course of evolution among certain peoples had “selected for a genotype that promoted excessive weight gain during times of food abundance and gradual loss of those “reserves” during times of famine”. Neel theorized that when people with former hunter gatherer ancestors were living in times of abundance with consistent food, what had been an adaptive genetic predisposition to gain weight during times of abundance, became maladaptive. This “Thrifty Gene” concept has contributed to a focus on genetics and food quantity rather than food quality in the search for answers for diabetes.
Nabham colleague and questions this orientation and propose looking in a different direction. One colleague, Jennie Brand-Miller, while looking for examples of hunter gatherer societies experiencing periods of feast and famine, found scant evidence of such famine. What she found instead, was repeated examples of famine during the post agricultural period, particularly among European Caucasians. If Neel’s hypothesis had been correct, this group would have been more likely to be predisposed to insulin resistance and diabetes. In fact, Caucasians are one of the groups least likely to experience diabetes and insulin resistance.
Could this lack of an ancestral history of agricultural practices be a factor in the extraordinary challenges that the Pima Indians face with diabetes? Nabham’s presention at an international conference indicated that people of European decent were less likely to exhibit symptoms of Syndrome X or diabetes than people from cultures where agricultural practices had been introduced more recently. At this conference Nabham and colleagues enumerated dietary changes which might have brought about the increase in diabetes: abandoning the protective qualities of a diverse group of wild foods; the introduction of foods which release sugars into the blood more rapidly and reduced nutritional value caused by breeding, changed agricultural practices and processing of food.
Nabham describes the successes of his own work and that of a locally run Hawaiian clinic (the Polynesians are another ethnic group with extraordinarily high levels of diabetes) where culturally traditional, slow release foods were eaten in the context of activities reviving cultural heritage. This holistic approach of looking at the protective qualities of both foods and customs yielded heartening results in both settings.
Further tales of traveling in the Mediterranean add depth to his (and our own) understanding of the protective nature of traditional foods as well as deepening our understanding of the role of microevolution in creating individuals who are biochemically unique. This orientation challenges both the exclusive claims made by the proponents of the Paleolithic diet and the narrow genetic focus of contemporary research. Although genes are appealing in their extraordinary power, it appears that the complexity of relationship between humans and their environment as it evolved over the eons is best understood while looking with a more holistic lense.
Be ware: a dangerous discovery for those with a proclivity for books about food and culture. Gary has written quite a few books in what the LA times describes as “a perspective ecological, humanistic and spiritual”. A couple of compelling titles are: Coming Home to Eat, the Pleasures and Politics of Local Foods, and Salmon Nation, a look at both indigenous and ethnic immigrant food traditions in the Pacific Northwest. I look forward to his presentation this spring.
As a newly hatched Nutritional Therapist, making my way through the sea of conflicting opinions in this fascinating world of nutrition, I find both spiritual comfort and logical grounding in the study of ancient cultures. In our modern world, where science is revered as a kind of religion, where there is a love of precision and a bias in the funding of research towards understanding things on a molecular level, we can sometimes forget to honor the extraordinary wisdom and complexity of our own bodies, and the wisdom of the cultural traditions that evolved in an interactive dance with these bodies in which we dwell. The study of long standing cultural traditions and of ancient human populations can be an extraordinary tool, and can indeed provide the longest and broadest of epidemiological studies.
Among those trying to find dietary guidance by looking at our ancient roots, there can be considerable controversy.Proponents of the vegetarian diet and proponents of a meat-heavy Paleolithic diet both draw validation from their interpretation of ancient diets. The followers of the Paleolithic diet claim that a predominantly animal product diet is the best for all people and that our genes, formed hundreds of millions of years ago have changed little since then. Dr Boyd Eaton, medical anthropologist and leader in the Paleolithic diet movement, says: “99.9% of our genes were formed before the age of agriculture”. Loren Cordain, another significant figure in the field, describes the Paleo Diet as “the only diet that ideally fits our genetic make-up.” How can this claim of universality of nutritional requirements be reconciled with the work of Weston A. Price, the nutritional pioneer of the turn of the century who made in depth studies of surviving traditional cultures the world around, and found significant differences between the groups that he studied? I am always on the look out for sources who have studied ancient and traditional cultures who will contribute tools with which to weigh these different perspectives
Who should I find this winter, but Gary Paul Nabham, an ethno botanist and ecologist, (who, I just learned, with great excitement, will be a speaker at our spring Nutritional therapy Association symposium). Starting in the American southwest, he has studied the dietary and cultural relationship of societies around the world to the foods that were local and available to them. Rather than searching for the ancestral diet, Nabham suggests that there are many different diets that evolved in different areas in an adaption to the local circumstances. He make a compelling case that genes can change over a much shorter time span than previously recognized and gives several examples of microevolution where genetic change has taken place over the course of a relatively few generations. He shows where more rapid genetic change is most likely to happen where there is a dietary or environmental factor which provides a pronounced advantage or disadvantage for survival.
Tales about his personal experiences and deep connections with people lend a delightful aspect to this book. One such story, from his early adventures in Arizona gives an example of microevolution. A friend brings him out to a remote town where he learns of the Pima Indians using government-issue powered milk to whitewash the lines on their ball fields. That was the day that he learned that the Arizona Indians, a cultural group with no long history of herding in their ancestral past, are lactose intolerant. According to Nabham, Lactose tolerance strongly correlates to the distribution of ancient herding cultures in Europe, Asia Minor and North Africa. In these groups, it appears the advantage of being able to consume the rich protein and fats found in milk was so great that those who were lactose tolerant were rapidly favored, so much so, that with in a mere 15 generations of eating cheese and yogurt, lactose tolerance increased.
Nabham became close friends with many Native Americans, and seeking to understand the particular dietary and health challenges that they faced was a major catalyst for him to embark on his studies of ethno botany. Two other interesting discussions of microevolution also involve challenges particularly significant for Arizonan natives: alcoholism and diabetes.
The relationship between cultural history, genetic makeup and alcoholism can also be looked at through the lens of microevolution. Curiously, says Nabham, cultures that produce enough alcohol dehydrogenase (an enzyme in the liver which allows a greater tolerance to alcohol) have, in their history, traditions of herding and agriculture. In these peoples, pollution of the water supply by the livestock contributed to the problem of dysentery: a significant health problem. Nabham cites Matt Rikley, author of a book called Genome, who theorized that drinking beverage made from fermented fruits, potatoes, grains, gave a survival advantage by reducing exposure to untreated water. Having a greater tolerance to alcohol provided a health advantage for those cultures with herding and agriculture in their past. Conversely, alcoholism is more pronounced in cultures which do not have a history of agriculture and supporting livestock. The natives of the American Southwest, one such culture, are highly susceptible to alcohol poisoning.
Diabetes is another disease that strikes natives of Arizona disproportionally. The Pima Indians have the highest incidence of diabetes in the US. In hoping to find a genetic clue for the cause of diabetes, NIH has invested thirty years and millions of dollars into research on the Pima Indians. This interest was guided in part by the “Thrifty gene theory”, which, still espoused by many today, was originally hypothesized by James Neel in 1962.
Neel theorized that, as hunter-gatherer cultures were subject to alternating times of feast or famine, they were likely to have what he termed a “thrifty gene”. The understanding being that repeated cycles of feast or famine over the course of evolution among certain peoples had “selected for a genotype that promoted excessive weight gain during times of food abundance and gradual loss of those “reserves” during times of famine”. Neel theorized that when people with former hunter gatherer ancestors were living in times of abundance with consistent food, what had been an adaptive genetic predisposition to gain weight during times of abundance, became maladaptive. This “Thrifty Gene” concept has contributed to a focus on genetics and food quantity rather than food quality in the search for answers for diabetes.
Nabham colleague and questions this orientation and propose looking in a different direction. One colleague, Jennie Brand-Miller, while looking for examples of hunter gatherer societies experiencing periods of feast and famine, found scant evidence of such famine. What she found instead, was repeated examples of famine during the post agricultural period, particularly among European Caucasians. If Neel’s hypothesis had been correct, this group would have been more likely to be predisposed to insulin resistance and diabetes. In fact, Caucasians are one of the groups least likely to experience diabetes and insulin resistance.
Could this lack of an ancestral history of agricultural practices be a factor in the extraordinary challenges that the Pima Indians face with diabetes? Nabham’s presention at an international conference indicated that people of European decent were less likely to exhibit symptoms of Syndrome X or diabetes than people from cultures where agricultural practices had been introduced more recently. At this conference Nabham and colleagues enumerated dietary changes which might have brought about the increase in diabetes: abandoning the protective qualities of a diverse group of wild foods; the introduction of foods which release sugars into the blood more rapidly and reduced nutritional value caused by breeding, changed agricultural practices and processing of food.
Nabham describes the successes of his own work and that of a locally run Hawaiian clinic (the Polynesians are another ethnic group with extraordinarily high levels of diabetes) where culturally traditional, slow release foods were eaten in the context of activities reviving cultural heritage. This holistic approach of looking at the protective qualities of both foods and customs yielded heartening results in both settings.
Further tales of traveling in the Mediterranean add depth to his (and our own) understanding of the protective nature of traditional foods as well as deepening our understanding of the role of microevolution in creating individuals who are biochemically unique. This orientation challenges both the exclusive claims made by the proponents of the Paleolithic diet and the narrow genetic focus of contemporary research. Although genes are appealing in their extraordinary power, it appears that the complexity of relationship between humans and their environment as it evolved over the eons is best understood while looking with a more holistic lense.
Be ware: a dangerous discovery for those with a proclivity for books about food and culture. Gary has written quite a few books in what the LA times describes as “a perspective ecological, humanistic and spiritual”. A couple of compelling titles are: Coming Home to Eat, the Pleasures and Politics of Local Foods, and Salmon Nation, a look at both indigenous and ethnic immigrant food traditions in the Pacific Northwest. I look forward to his presentation this spring.