COMIDAS Comparing Original Mexican Diets and Standard US Diets
Condition: Healthy
Study type: Interventional

Summary: 
      The foods eaten daily are considered the "dietary pattern" of a culture or country. The
      dietary pattern of Mexico is different from that of the United States. To look at the effects
      of these patterns, participants in this study eat a Mexican menu for three and a half weeks
      and an American menu for the same length of time. At the beginning and end of each menu
      period participants provide blood and urine samples which we analyze to compare the effects
      of each diet. More info at www.ProyectoCOMIDAS.info
    

Detailed description: 
      Chronic disease risk, including breast cancer risk, is not uniform across race and ethnic
      groups in the United States. This variation in disease risk may be due to environmental
      exposures (including diet), genetic susceptibility, disparities in access to health
      screening, diagnosis and medical care, or combination of these factors. Here we have shown
      that Hispanic women in the U.S. are more likely to be overweight or obese compared to
      non-Hispanic whites. Some of the excess obesity risk is likely due to the lack of
      neighborhood availability and affordability of fruit, vegetables, lean protein and whole
      grains. Whether an inexpensive and widely available highly processed/refined, nutrient poor
      diet superimposed on a genetic background favoring adipose deposition (i.e., the "thrifty
      genotype") is metabolically detrimental has not been investigated. Research to test the
      metabolic response to Indigenous and Western diets in Hispanic women may provide important
      information about the etiology of obesity and obesity-related diseases in Hispanic women,
      including risk of breast cancer. Since reducing disparities in obesity-related diseases,
      including breast cancer, is an important public health goal, identifying potential programs
      for prevention should receive high priority.

      Mexicans are the largest immigrant group in the United States with an estimated 10 million
      Mexican-American women currently in the U.S. As they acculturate to this country, Mexican
      immigrants change their dietary habits from traditional (indigenous) foods with plentiful
      fruit, vegetables and complex carbohydrates rich in fiber and other compounds to a
      Western-style diet high in fat and refined carbohydrate, but low in plant foods. Particularly
      concerning is that the food choices made by Mexican immigrants, many of whom are of lower
      socio-economic status, are driven partly by their inability to procure and purchase healthy
      foods. The disparity in both food availability and purchasing power fuels a tendency to
      obtain and consume a low-cost, Western style diet. When this diet is superimposed on persons
      with a "thrifty genotype" who are evolutionarily adapted to diets high in legumes and complex
      carbohydrates, it may lead to an abnormal metabolic response that favors adipose deposition
      and numerous health risks. Thus, ancestral genetic characteristics likely have an important
      role in metabolic response to specific dietary patterns and subsequent health risks. This
      phenomenon may partly explain the tendency for Mexicans and other immigrants from the
      Americas to become obese after just one generation in the United States.
    

Intervention name(s): Mexican or American foods
Intervention type(s): Other
Intervention description(s): Participants will be randomized to an isocaloric Indigenous Mexican or a Western diet for 24 days. All foods and beverages will be prepared by the Human Nutrition Laboratory at the Fred Hutchinson Cancer Research Center. After a 4-week wash-out period, participants will cross over to the other arm and be given the alternate diet for 24 days. Blood and urine specimens will be collected before and after each feeding period to test baseline and post-intervention metabolic response as defined by various inflammatory and cancer susceptibility biomarkers including insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), leptin, adiponectin, interleukin-6 (IL-6), C-reactive protein (CRP) and SAA (serum amyloid-A). DNA extracted from whole blood will be used to test whether a panel of 128 Ancestry Informative Markers (AIMs) is associated with metabolic response to the diets and other phenotypic traits of obesity, which relate to breast cancer risk.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Keywords: Healthy