Thrifty Gene, Dr. Marcela LeBeau and SNP on ABCA1 gene.
A century of American Indians and Diabetes
When I first read about J.V.Neel’s Thrifty gene theory, I was immediately attracted to its usefulness to explain the epidemic of Type 2 Diabetes among the Indigenous group I was working with .
From his alma mater, University of Michigan:
Jim recognized that the cultural changes accompanying the progression from tribal society to urbanization had created novel environments for selection—and that this contrast might reveal selective pressures, with consequences for human health (Neel 1958b, 1966). Reflecting this view was his “thrifty genotype” hypothesis, suggesting that in modern society susceptibility to diseases such as diabetes might be a deleterious consequence of genotypes that had formerly been advantageous in human ancestral environments (Neel 1962)—arguably one of the most influential hypotheses in genetic epidemiology.
At least in the western world, this probably was the first-time culture and medicine interacted to create new knowledge, such useful knowledge.
Diabetes Mellitus: A "Thrifty" Genotype Rendered Detrimental by "Progress"?
JAMES V. NEEL Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Mich.
I was invited to the Clinic of the Cheyenne River Sioux Tribe of Indians in Eagle Butte to give a presentation on Diabetes and Native Americans, to the Nurses and Doctors working there.
(My visit to Marcela's home in 2012)
I couldn’t help noticing an older lady sitting, erect and elegant in the front row, paying attention to what I was saying.
It was Dr.(h.c) Marcela LeBeau, who had retired many years ago after many years of illustrious service to the Clinic and Hospital of the Lakota Tribe at Eagle Butte. She was their Director of Nursing.
After the presentation, she came over and told me how impressed she was with the Thrifty Gene theory. And each of the other occasions I met her, she would remind me of the Thrifty Gene theory. The last time I saw her was at her home in Eagle Butte reservation . I clearly remember her telling me that she had celebrated her 93rd Birthday climbing the Bear Butte not far from the reservation.
To this day, this theory of Dr J V Neel fascinates me. Of course, I went on to work with many indigenous groups of people including some along the Amazon river.
I couldn’t help think of them when I was trying to understand a paper published from Mexico City.
A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans
Most people who have travelled extensively in Mexico and Guatemala would have noticed that they are a racially mixed race of people. The majority of Mexicans are Mestizos, predominantly of Indian ancestry, about 60%. The Mexicans one encounters in the USA predominantly belong to this class. There is less than ten per cent of the Original Mexican Inhabitants (the Indians) and you can see them, well represented in Yucatan, Oaxaca among other states. About 30 per cent are of European ancestry including Jews and Arabs. There is a small minority of Afro-Mestizos, in Veracruz, Coahuila and Guerrero provinces. The ones in Coahuila are the descendants of American slaves who had escaped into Mexico.
Following Dr. Neel, we can picture that the predominant gene in Mexicans being Indian, the disease patterns also would follow the patterns seen in the Native American Populations. There are Native Indian populations all over the Central and South American geography. I have personally visited Indigenous peoples in Mexico, Guatemala, Panama, Colombia, Ecuador, Peru, Chile, Bolivia, Argentina, Brasil, Venezuela and Guyana.
Single Nucleotide Polymorphism are variants seen in the genes, ATP-binding Cassette transport A1 gene-ABCA1 with a variant R 230c, rs 9282541 is found only in the North American Indian population and also Mestizos from Mexico. Also, as this study would prove that this SNP/Gene is found ONLY in native American population and that it is a unique SNP/Gene for the American continent. Siberians and North Asians do not have this.
This is related to the low levels of HDL-c the so-called Good Cholesterol found in these populations.
It was exciting to read that this SNP may have some evolutionary advantages as postulated by DR J V Neel. The new ways of living opened the path of diseases unknown to them before .
The duty of HDL-c is to carry out the cholesterol as it accumulates, the so-called Efflux. When it is low as in the native/ native descent populations, in times of severe famine (as predicted by Dr J V Neel), it provides ability to accommodate the fluctuations in energy supply. Now in times of plenty and non-nutritious food this genetic advantage has become a liability with Obesity, Type 2 Diabetes and High Triglyceride levels, metabolic dysfunctions unknown to the indigenous peoples before.
I dedicate this note to Marcela LeBeau of Eagle Butte and to the new generation of pioneers, led by my friend, Michele Walking Elk. and to my UmonHon family Vida, Wehnona, Ashleen, MBB and Michele (h.c)
