Amylase and Decolonization of Diets
Essential Question: Why are people of certain ethnicities at greater risk for nutritional diseases such as obesity?
Standards:
PS1B: Chemical Reactions
PS3D: Energy in Chemical Processes & Everyday Life
LS4B: Natural Selection
LS4C: Adaptation
Photo: Tono Balaguer
As the obesity epidemic continues to escalate in the United States, not all races and ethnicities are affected equally. People of African, Latinx, and Native ancestry are considerably more likely to suffer from obesity than those of European and Asian descent. There are many causal explanations for this including wealth disparities, food deserts, chronic stress, and unequal access to health care. While all of these issues are worth discussing in a science classroom, the colonization of the American diet can offer relevant biological explanations. A case study of amylase can be used to teach topics including biomolecules, chemical catalysis, DNA, and evolution. The amylase gene produces an enzyme in saliva that converts starch into glucose. All people produce the amylase enzyme but individuals whose ancestors ate high-starch diets are likely to have many copies of the gene, leading to higher concentrations of amylase and more efficient breakdown of starch. While historically this made individuals suited to their particular diet, as Western colonization erased indigenous food traditions and replaced them with high-starch European diets, this has contributed to the disproportionate obesity rates in people whose ancestors did not eat much starch (eg. African, Latin American, Alaskan Inuit, Native Hawaiian). A French study has shown that in European countries where a high-starch diet prevails, those with the lowest numbers of amylase genes are ten times more likely to be clinically obese at that each additional amylase gene can reduce this chance by 20 percent.
Engage students in this topic by testing how much amylase they produce (ask them to chew a cracker and observe whether it gets sweeter) or having them share foods traditional in their cultures (note: it may take some research to learn about pre-colonial diets). As students learn that colonization of the modern diet is a form discrimination, they may brainstorm ways to combat the problem.
