The effect of Indian or angle dietary preference on the incidence of diabetes in Pima Indians

OBJECTIVE - In short-term studies, adoption of a traditional diet is associ ated with reduction in metabolic abnormalities often found in populations e xperiencing rapid lifestyle changes. We examined rile long-term effects of a self-assessed traditional or nontraditional dietary pattern on the develo pment of type 2 diabetes in 165 nondiabetic Pima Indians. RESEARCH DESIGN AND METHODS - Dietary intake was assessed in 1988 by a quan titative food frequency method. and subjects were asked to classify their d iet as "Indian.'' "Anglo," or "mixed." The Indian diet reflects a preferenc e for Sonoran-style and traditional desert foods. The Anglo diet reflects a preference for non-Sonoran-style foods typical of the remaining regions of the U.S. RESULTS - in women, the intake of complex carbohydrates, dietary fiber, ins oluble fiber, vegetable proteins, and the proportion of total calories From complex carbohydrate and vegetable proteins were significantly higher (P < 0.05) in the Indian than in the Anglo diet. The mixed diet was intermediat e in of ail these constituents. in men, the intake For these nutrients was also higher in the Indian than in the Angle group, but not significantly. D iabetes developed in 36 subjects (8 men and 28 women) during 6.2 years of f ollow-up (range 0.9-10.9). The crude incidence rates of diabetes were 23, 3 5, and 63 cases per 1,000 person-years in the Indian, mixed, and Anglo grou ps, respectively. After adjustment for age, sex, BMI, and total energy inta ke in a proportional hazards model, the risk of developing diabetes in the Angle-diet group was 2.5 times as high (95% CI 0.9-7.2) and the rate in the mixed-diet group was 1.3 times as high (0.6-3.3) as in the Indian-diet gro up. CONCLUSIONS - This study suggests that the adoption of an Anglo diet may in crease the risk of developing diabetes in Pima Indians, but it does not pro vide unequivocal evidence For or against this hypothesis.