In Beyond the Paleolithic prescription: incorporating diversity and flexibility in the study of human diet evolution (free full text), anthropology researchers Bethany Turner and Amanda Thompson take an interesting and expanded look at what they see as the limitations in much of the current discussions of the so-called paleo diet.
One section I particularly liked was their “Rethinking the human sweet tooth” in the potential nutritional interventions section:
The assumption that humans evolved an affinity for sweet and fatty tastes that is highly adaptive but mismatched to modern contexts might reasonably lead one to conclude that unchecked consumption of sugary and high-fat foods is something of an inevitability. A wider perspective, however, focuses on the mechanisms of an affinity for sweet and fatty tastes rather than ending the explanation with a discordant adaptation. Humans learn to like sugar along with a host of other flavors in utero; moreover, sugars are associated with the secretion of endogenous opiates that confer pleasurable sensations and activate reward pathways in the brain. Similarly, the consumption of fatty foods stimulates the production of endogenous cannabinoids that create comparable reward effects. In modern environments characterized by cheap, readily available sugary and fatty foods and psychosocial stress that is both uniquely human and differentially endured, an unchecked consumption of sugars and high-fat foods could more reasonably reflect socially learned and socially reinforced behaviors than an adaptation gone awry.
Intervention strategies based on this broader perspective would not assume that removal of sugars, other simple carbohydrates, and excessive saturated fats from the diet is necessary because they trigger a mismatch born of adaptation. Instead, interventions could focus on manipulating the intrauterine flavorscape or early-life diets to impart an affinity to a broader range of taste stimuli unrelated to sweet tastes. Plant-based spices and aromatics can play a significant role in forming positive associations with foods based on flavor and olfactory properties. Since these associations are unrelated to fat or caloric content, such spices and aromatics could therefore become useful tools in shaping children’s preferences for plant-rich diets. Importantly, interventions aimed at preventing metabolic diseases could also benefit from focusing as strongly on reducing sources of psychosocial stress as on controlling food intake.
It’s an academic read, but it’s largely a review of existing literature and well worth your time. Some people may think that paleo has jumped the shark, but I think there is a great future in understanding how evolution shapes our interaction with our current environment. I’m happy that researchers like Turner and Thompson are expanding the discussion.