After a busy spate, I'm catching up. Perhaps you saw articles published last week (for example, in the Boca Raton News , June 15) discussing a recent study by the National Academy of Sciences on teh question of whether teh flavanol in cocoa reduces the incidence of cardiovascular events.
Boca Raton News writer Nicol Jenkins, interviewed eminent Harvard researcher Norm Hollenberg who had published earlier work in this area in 2003 and 2004 , describing the study results:
Researchers provided participants with a cocoa drink that was either high or low in certain cocoa flavanols. Only the group consuming the flavanol-rich cocoa experienced increased blood vessel relaxation.
"Pinpointing specific nutrients responsible for the observed cardiovascular effects, as we are seeing here with (-) epicatechin, opens up new possibilities for the development of dietary or therapeutic interventions for cardiovascular disease," said co-author Norman Hollenberg, MD, PhD, professor of medicine at Harvard Medical School.
To assess the long-term benefits of a flavanol-rich diet, the researchers further studied two populations of Kuna Indians of Panama. A previous study has shown that hypertension is rare among the indigenous Kuna Indians living on the islands compared to those living on the mainland. The island-dwelling Kuna Indians traditionally consume large quantities of flavanol-rich cocoa (an average of 3-4 cups daily), while those who live in the suburbs of Panama City consume very little cocoa. This supported the idea that cocoa flavanols may be responsible for lower blood pressure in the island dwellers.
Every time I read about Hollenberg's research on the Panamanian Kuna Indians, my mind recalls his findings that so clearly resolved a long-standing contention of the anti-salt crowd that when primitive peoples migrate from their customary isolated, rural homelands to settle in urban centers their blood pressure increases. Of course, they conclude, this is because their primitive diet was low in sodium and their city-dwelling diet is substantially higher. And usually that is the salt consumption pattern of migrants. But, of course, one could argue that many things change in the migration. Instead of avoiding snakes, they have to dodge taxis and buses; instead of a relatively simple and slower-paced lifestyle, they have to function in high-energy and fast-paced urban settings. Even in the diet, a lot changes, not just salt.
So what did Hollenberg do regarding these Kuna Indians? He studied two groups, one that stayed at home on their remote, isolated islands and another group that migrated to Panama City and published his findings in a 1997 article in the American Heart Association's Hypertension magazine . What did he find? Migrants had a significant increase in hypertension when they moved from their home islands to Panama City -- so what? That's what other migrant studies have found. What is different about the Kuna is that, at home on their isolated island homes, they consume salt in about the same amounts as Americans do. Thus, it is some other aspect of their personal urbanization that contributes to their increased blood pressure -- not salt! Perhaps rush hour traffic? Job stresses? Simple adjustment to a lot of new things? No one knows, but we know it wasn't higher salt intake levels. For the record, Hollenberg doesn't buy the "stress " theory either.
Thanks for making that clear, Dr. Hollenberg.
