OBJECTIVE—Type 2 diabetes and obesity have genetic and environmental determinants. We studied the effects of different environments on these diseases in Pima Indians in Mexico and the U.S. RESEARCH DESIGN AND METHODS—Adult Pima-Indian and non-Pima populations in the Sierra Madre mountains of Mexico were examined using oral glucose tolerance tests and assessments for obesity, physical activity, and other risk factors. Results were compared with those from Pima Indians in Arizona. Both Pima populations were typed for DNA polymorphisms to establish their genetic similarity. RESULTS—The age- and sex-adjusted prevalence of type 2 diabetes in the Mexican Pima Indians (6.9%) was less than one-fifth that in the U.S. Pima Indians (38%) and similar to that of non-Pima Mexicans (2.6%). The prevalence of obesity was similar in the Mexican Pima Indians (7% in men and 20% in women) and non-Pima Mexicans (9% in men and 27% in women) but was much lower than in the U.S. Pima Indians. Levels of physical activity were much higher in both Mexican groups than in the U.S. Pima Indians. The two Pima groups share considerable genetic similarity relative to other Native Americans. CONCLUSIONS—The much lower prevalence of type 2 diabetes and obesity in the Pima Indians in Mexico than in the U.S. indicates that even in populations genetically prone to these conditions, their development is determined mostly by environmental circumstances, thereby suggesting that type 2 diabetes is largely preventable. This study provides compelling evidence that changes in lifestyle associated with Westernization play a major role in the global epidemic of type 2 diabetes.

OBJECTIVE: The Pima Indians of Arizona have the highest reported prevalences of obesity and non-insulin-dependent diabetes mellitus (NIDDM). In parallel with abrupt changes in lifestyle, these prevalences in Arizona Pimas have increased to epidemic proportions during the past decades. To assess the possible impact of the environment on the prevalences of obesity and NIDDM, data were collected on members of a population of Pima ancestry (separation 700–1,000 years ago) living in a remote mountainous location in northwestern Mexico, with a lifestyle contrasting markedly with that in Arizona. RESEARCH DESIGN AND METHODS: Pima heritage was established by history and by use of Pima language. Measurements of weight, height, body fat (bio-impedance), blood pressure, plasma levels of glucose, cholesterol, and HbA1c were obtained in 19 women (36 ±13 years of age) and 16 men (48 ±14 years of age) and compared with sex-, age- and diabetes status-matched Pimas living in Arizona (10 Arizona Pimas for each Mexican Pima). RESULTS: Mexican Pimas were lighter (64.2 ± 13.9 vs. 90.2 ± 21.1 kg, P < 0.0001; means ± SD) and shorter (160 ± 8 vs. 164 ± 8 cm, P < 0.01) with lower body mass indexes (24.9 ± 4.0 vs. 33.4 ± 7.5 kg/m2, P < 0.0001) and lower plasma total cholesterol levels (146 ± 30 vs. 174 ± 31 mg/dl, P < 0.0001) than Arizona Pimas. Only two women (11%) and one man (6%) had NIDDM, contrasting with the expected prevalences of 37 and 54% in female and male Arizona Pimas, respectively. CONCLUSIONS: This preliminary investigation shows that obesity, and perhaps NIDDM, is less prevalent among people of Pima heritage living a “traditional” lifestyle than among Pimas living in an “affluent” environment. These findings suggest that, despite a similar potential genetic predisposition to these conditions, a traditional lifestyle, characterized by a diet including less animal fat and more complex carbohydrates and by greater energy expenditure in physical labor, may protect against the development of cardiovascular disease risk factors, obesity, and NIDDM.

Peer reviewed article authored by (Alemán-Mateo H, Macías L, Esparza-Romero J, Astiazaran-García H, Blancas AL). Read article or submit your manuscript for publishing.

Several studies suggest that the holiday season, starting from the last week of November to the first or second week of January, could be critical to gaining weight. This study aims to review the literature to determine the effects of the holidays on body weight. In studies of adults, a significant weight gain was consistently observed during this period (0.4 to 0.9 kg,p<0.05). The only study in college students found an effect on body fat but not on weight (0.1 kg,p=0.71). The only study found in children did not show an effect on BMI percentile (−0.4%,p>0.05) during this period. Among individuals with obesity who attempt to lose weight, an increase in weight was observed (0.3 to 0.9 kg, significant in some but not in all studies), as well as increase in weight in motivated self-monitoring people (0.4 to 0.6%,p<0.001). Programs focused on self-monitoring during the holidays (phone calls and daily mailing) appeared to prevent weight gain, but information is limited. The holiday season seems to increase body weight in adults, even in participants seeking to lose weight and in motivated self-monitoring people, whereas in children, adolescents, and college students, very few studies were found to make accurate conclusions.

The blood pressure-lowering effect of fermented milk with Lactococcus lactis NRRL B-50571 was evaluated in a double-blind randomized controlled clinical trial with prehypertensive subjects. Participants were randomized into 2 groups (n = 18 each group): one group treated with fermented milk with Lactococcus lactis NRRL B-50571 and a control group treated with artificially acidified milk. Results revealed that during daily consumption of fermented milk for 5 wk, systolic [(116.55 ± 12.26 mmHg vs. 124.77 ± 11.04 mmHg) and diastolic blood pressure (80.7 ± 9 vs. 84.5 ± 8.5 mmHg)] from the fermented milk group was lower than the control group. Additionally, triglyceride, total cholesterol, and low-density lipoprotein in blood serum were lower in the fermented milk group than in the control group. Results demonstrated that daily consumption of fermented milk with Lactococcus lactis (NRRL B-50571) had a blood pressure-lowering effect on prehypertensive subjects. Regular consumption of this product may be used as a potential functional food.