Thursday, August 14, 2008

Cardiovascular Risk Factors on Kitava, Part I: Weight and Blood Pressure

The Kitavans are an isolated population free of cardiovascular disease and stroke, despite the fact that more than three quarters of them smoke cigarettes (although not very frequently). They eat a carbohydrate-heavy, whole-foods diet that is uninfluenced by modern food habits and consists mostly of starchy root crops, fruit, vegetables, coconut and fish. Their intake of grains and processed foods is negligible.

Naturally, when Dr. Lindeberg's group discovered that Kitavans don't suffer from heart disease or stroke, they investigated further. In the second paper of the series, they analyzed the Kitavans' "cardiovascular risk factors" that sometimes associate with heart disease in Western populations, such as overweight, hypertension, elevated total cholesterol and other blood lipid markers.

Kitavans are lean. Adult male body mass index (BMI) starts out at 22, and diminishes with age. For comparison, Swedes begin at a BMI of 25 and stay that way. Both populations lose muscle mass with age, so Kitavans are staying lean while Swedes are gaining fat. The average American has a BMI of about 28, which is considered overweight and 2 points away from being obese.

Kitavans also have a low blood pressure that rises modestly with age. This is actually a bit surprising to me, since other non-industrial groups like the Kuna do not experience a rise in blood pressure with age. Compared with Swedes, Kitavans' blood pressure is considerably lower at all ages.

In the next post, I'll discuss the Kitavans' blood lipid numbers ("cholesterol"), which challenge current thinking about heart disease risk factors.


WoLong said...

I suppose that a lack of stress must be an important factor in Kitavans' healthier outcome.

Stephan Guyenet said...

Hi WoLong,

Perhaps, although Lindeberg notes that Kitavans are extremely superstitious and are gripped by an intense fear of the supernatural.

Fiona said...

great article by Dr. Rosedale..