Editor's note: Gary Taubes, the famous writer of Good Calories, Bad Calories: Challenging the Conventional Wisdom on Diet, Weight Control and Disease, answers the third and final round of your questions here. Check out the original posts here, Gary's first set of answers, and his second set o...
-
speculation re: atherosclerosis in herbivores
Karen LaVine
Thursday, February 07, 2008 at 02:38 AM
Your comment "grassland elephants had extensive atherosclerosis but woodland elephants -- living on leaves more so than grasses -- did not" reminded me of a study contrasting diet and behavior of howler monkeys to spider monkeys.
"the colons of howlers were considerably wider and longer than those of spider monkeys. Food had to travel much farther and remained much longer in howler guts, and the monkeys had room for much more bulk. As a result, bacteria had a chance to ferment masses of fibrous leaves in the monkeys’ colons, producing energy-rich fatty acids. Milton eventually found that howlers receive more than 30 percent of their daily energy from such fatty acids."
http://discovermagazine.com/1995/may/gutthinking503/?searchterm=howler%20monkey
Therefore, thanks to their gut bacteria, howler monkeys were actually surviving on a much higher fat (and subsequently lower carbohydrate) diet than the spider monkeys. Would the howlers also have lower insulin levels and significantly less atherosclerosis than their fruit eating cousins? And is it absorption of fatty acids via bacterial conversion of fiber in their guts that also helps give the leaf eating elephants their cardiovascular advantage? i'm sure some biologists somewhere are trying to answer these questions. Thank you Gary, for provoking more thoughts.
Your comment "grassland elephants had extensive atherosclerosis but woodland elephants -- living on leaves more so than grasses -- did not" reminded me of a study contrasting diet and behavior of howler monkeys to spider monkeys.
"the colons of howlers were considerably wider and longer than those of spider monkeys. Food had to travel much farther and remained much longer in howler guts, and the monkeys had room for much more bulk. As a result, bacteria had a chance to ferment masses of fibrous leaves in the monkeys’ colons, producing energy-rich fatty acids. Milton eventually found that howlers receive more than 30 percent of their daily energy from such fatty acids."
http://discovermagazine.com/1995/may/gutthinking503/?searchterm=howler%20monkeyTherefore, thanks to their gut bacteria, howler monkeys were actually surviving on a much higher fat (and subsequently lower carbohydrate) diet than the spider monkeys. Would the howlers also have lower insulin levels and significantly less atherosclerosis than their fruit eating cousins? And is it absorption of fatty acids via bacterial conversion of fiber in their guts that also helps give the leaf eating elephants their cardiovascular advantage? i'm sure some biologists somewhere are trying to answer these questions. Thank you Gary, for provoking more thoughts.