Japanese Americans have been found to have much lower risks for cardiovascular diseases than their white American counterparts. The traditional Japanese diet is rich in fish and soy both of which have been found to decrease risks for cardiovascular diseases (Yamori et al., 2006). With increasing adaptation to the western diet, which includes high meat and less roughage, however, there appears to be an increase in coronary artery disease.
A higher body mass index is also a risk factor for coronary heart disease. In the INTERLIPID study, a collaborative study of Japanese American men and women in Hawaii and their ethnic counterparts in Japan, a higher body mass index was noted in the Japanese American which raises the consideration of a more sedentary lifestyle for those living in the United States (Ueshima et al., 2003). Additionally, natural lifestyle caloric restriction, as opposed to overeating, may have played a role in the subgroup of Japanese American men of the Honolulu Heart Program who were examined for all-cause mortality and caloric restriction. Caloric restriction was associated with reduced risk for all-cause mortality up to the point of 50% of the group mean, after which caloric restriction was associated with a detrimental risk (Wilcox et al, 2004).
CHD incidence and prevalence was compared in the Hispanic and NHW populations of San Luis Valley in rural, southern Colorado (Rewers, Shetterly, Hoag, Baxter, Marshall, & Hamman, 1993). This is a unique sub-group of Hispanics, calling themselves Spanish-Americans, that are descendants of 25,000 Spaniards banished from Spain during the Spanish Inquisition (late 1500s and early 1600s) to look for gold in northern New Mexico and southern Colorado.
The Honolulu Heart Study cohort was found to have a lower risk for strokes than men in Japan. The incidence of strokes also declined during the first two decades since the inception of the studies. This was felt to be possibly related to a decline in blood pressure and smoking. However, there is a higher risk of hemorrhagic stroke among Japanese American men compared to Caucasian men. One theory is that this may be related to the lower fibrinogen levels (Iso et al, 1989). In a more recent study of Asian American ethnic subgroups, Japanese Americans had a high risk of hemorrhagic strokes (Klatsky et al, 2005).