Posts tagged: diet
Atossa Araxia Abrahamian on Paleofantasy by Marlene Zuk and the assumptions of the paleo lifestyle set, noting that it has become a popular diet amongst libertarians:
Charges of hypocrisy, however amusing, are facile. Paleo is an improvement on a diet of processed, sugary junk. It’s not the first diet to banish starches, and it certainly won’t be the last. In fact, by any other name, the Paleo diet would be just that — a diet.
But more substantial problems lurk in the reasoning behind Paleo principles. By assuming that all that was once natural is now good, militant Paleo leans on biological determinism to back up its theories. While it may not advocate for a complete reversion to cave-dwelling, it accepts that we evolved in a certain way to do certain things and not others, and that advances in technology, civilization, and culture can do little to change that. This logic, however seductive, is incomplete. You can’t get an ought from a was. […]
Incomplete or flawed interpretations of our biology have long been used to marginalize women, racial groups, even entire civilizations, and nutrition may well become the next variant in this pattern of discrimination. If rice isn’t “natural,” does that make those entire continents with highly developed cultures who eat it “un-natural”? Doesn’t agriculture, however flawed it may be in certain societies, support billions of people? Let’s not forget that for centuries women were considered ineligible to participate in most professions, sports, and diversions on the basis of their supposed female “nature.” Are modern bread-eaters somehow less human than those carrying out “primal” urges by sprinting, lifting, and eating meat?
These troubling questions are probably not the point of an apparently well-meaning lifestyle program. Many adopters of the Paleo diet do so for no reason other than weight loss, or vanity, or ailments caused by certain foods; others are simply curious about how so-called “ancestral” nutrition will affect them, or how certain types of foods affect their bodies. If their giddy testimonials are to be believed, the Paleo diet can cure everything from diabetes to anxiety attacks, which sounds wonderful. Still, the social and political implications of Paleo reasoning ought to be more closely examined, especially as the lifestyle gains adherents.
Full Story: Natural’s Not In It
A high intake of fructose impairs the cognitive abilities of rats by interfering with insulin signaling, but omega-3 fatty acids (n-3) reduces those negative effects effects according to a study from the Department of Integrative Biology and Physiology UCLA published in Journal of Physiology.
Although headlines today, including my own, emphasize the study’s findings regarding the impairing effects of high levels of fructose, the study also highlights the importance of n-3 acids, specifically DHA, to cognitive function. The authors of the study conclude: “In terms of public health, these results support the encouraging possibility that healthy diets can attenuate the action of unhealthy diets such that the right combination of foods is crucial for a healthy brain.”
The study, conducted by Rahul Agrawal1 and Fernando Gomez-Pinilla, consisted of four groups of six rats:
Each group was tested on a Barnes maze, a standard measure of spatial learning and memory in rodents. Prior to beginning their special diets all of the rats had been trained in the maze for a five days were found to be of equal cognitive condition.
The study found that an n-3 deficient diet hampered the rats’ performance on the maze, and that adding high fructose intake to an n-3 deficient diet made things substantially worse. The rats with an n-3 sufficient diet but a high level of fructose did significantly better than those with a n-3 deficient diet and a high level of fructose, but still did worse than those with a deficient n-3 level but no fructose. Here’s an illustration of the latency in completing the maze (lower is better):
The study notes: “Although there was a preference towards fructose drinking in comparison to the food intake, no differences were observed in body weight and total caloric intake, thus suggesting that obesity is not a major contributor to altered memory functions in this model.”
This is a new study and has yet to be replicated, and so far its implications for human diets is unclear. “We’re not talking about naturally occurring fructose in fruits, which also contain important antioxidants,” Gomez-Pinilla said in a pres release. “We’re concerned about high-fructose corn syrup that is added to manufactured food products as a sweetener and preservative.”
Although studies have found positive benefits in taking DHA supplements (see Wikipedia for an overview), previous study by Nutritional Sciences Division at King’s College London on the DHA levels in vegans and vegetarians concluded that although those who don’t eat meat have significantly lower levels of DHA “There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians.” However, there are now a number of algae based vegan DHA supplements.
Researchers in the US have found grains of cooked plant material in the teeth of the remains.
The study is the first to confirm that the Neanderthal diet was not confined to meat and was more sophisticated than previously thought.
The research has been published in the Proceedings of the National Academy of Sciences.
The popular image of Neanderthals as great meat eaters is one that has up until now been backed by some circumstantial evidence. Chemical analysis of their bones suggested they ate little or no vegetables.