Investigations in numerous populations around the world have supported the hypothesis that >>Westernization<< is associated with elevated levels of blood pressure and consequently with increased incidence of hypertension and associated cardiovascular diseases. In this article, blood pressure readings from adult Karaja Indians (N=63) and from admixed inhabitants of three different localities on Marajo Island (Para, Brazil) are reported. The three Marajo Island populations are trihybrid combining Amerindian, European, and African ancestries. Although they all live in the same geographic area, each group is characterized by substantially different patterns of subsistence. The Paricatuba group (N=26) fish and collect palm fruits for their own consumption as well as for trade. The Praia Grande group (N=30) is composed of agriculturalists who work cooperatively on their farms and sell their products in nearby cities. The third group is a subsample from the city of Ponta Pedras (N=37) composed predominantly of urban office workers. Covariance statistics were used to control for age, sex and locale of origin. Among men higher average systolic blood pressure was found in the Paricatuba subsample (120 mmHg), but higher average diastolic blood pressure was observed in Ponta de Pedras (79 mmHg). The lowest systolic and diastolic blood pressures were found in Karaja Indians (106/68 mmHg). Among women, the highest average systolic blood pressure was found in Praia Grande (120 mmHg), but the highest average diastolic blood pressure was observed in Ponta de Pedras (72 mmHg). The lowest average blood pressures were found in Karaja Indians (103/64 mmHg). Such results support a hypothesis that altered life styles, including, changed diet, subsistence activities, and increased social stratification that occur with Westernization may be associated with increased blood pressures.
