Low-Risk Food Pattern May Reduce Risk for Diabetes 

Dietary patterns affect the risk for type 2 diabetes to a greater extent vs intake of specific food groups, according to findings from the Multi-Ethnic Study of Atherosclerosis (MESA), reported in the June 10 Online First issue of Diabetes Care. "Each nutrient or food is part of a larger pattern consisting of many nutrients and foods, and thus, characterization of multiple, concurrent dietary exposures has particular relevance to health," write Jennifer A. Nettleton, PhD, from the University of Texas Health Sciences Center in Houston, and colleagues. "Using data from the . . . MESA we evaluated the relations between type 2 diabetes risk and 1) PCA [principal components analysis]-derived dietary patterns and 2) a ‘low-risk’ food pattern score based on the intakes of foods previously associated with risk of type 2 diabetes."

At baseline, from 2000 to 2002, a total of 5011 participants in MESA completed food frequency questionnaires. The study cohort consisted of white, black, Hispanic, and Chinese adults, aged 45 to 84 years and without cardiovascular disease or diabetes at baseline. At 3 follow-up examinations (2002 – 2003, 2004 – 2005, and 2005 – 2007), incident type 2 diabetes was determined on the basis of fasting serum glucose levels of more than 126 mg/dL, self-reported type 2 diabetes, or use of diabetes medication.

The investigators studied 2 types of dietary patterns: 4 empirically derived from PCA as well as the "low-risk food pattern," defined as the weighted sum of whole grains, vegetables, nuts/seeds, low-fat dairy, coffee (positively weighted), red meat, processed meat, high-fat dairy, and soda (negatively weighted).

A PCA-derived dietary pattern characterized by high consumption of tomatoes, beans, refined grains, high-fat dairy, and red meat was associated with an 18% greater risk for diabetes (hazard ratio [HR] per 1-score SD, 1.18; 95% confidence interval [CI],1.06 – 1.32; P for trend = .004 ). In contrast, the PCA-derived dietary pattern characterized by high consumption of whole grains, fruit, nuts/seeds, green leafy vegetables, and low-fat dairy was associated with a 15% lower risk for diabetes (HR per 1-score SD, 0.85; 95% CI, 0.76 – 0.95; P for trend = .005).

Although the "low-risk food pattern" was also inversely associated with diabetes risk (HR per 1-SD score, 0.87; 95%CI, 0.81 – 0.99; P fortrend = .04), individual component food groups were not independently associated with diabetes risk. Sex and race/ethnicity did not affect the observed associations.

"Multiple food groups collectively influence type 2 diabetes risk beyond that of the individual food groups themselves," the study authors write. "These findings underscore the importance of the collective influence of multiple food groups in the development of type 2 diabetes and suggest that individuals wishing to decrease the risk of type 2 diabetes, regardless of their race/ethnicity, focus on increasing intake of several key food groups, including whole grains, low-fat dairy, fruits & vegetables, and nuts/seeds, while decreasing their intake of red/processed meats, high-fat foods, and sugared soda beverages."

Diet may reduce the risk for type 2 diabetes independent of body weight and other risk factors. Whole grains, nuts/seeds, coffee, low-fat dairy, and vegetables have been associated with a lower risk for diabetes, whereas processed meats, sugar-sweetened beverages, and white potatoes have been associated with an increased risk, but more information is needed on the association between diet patterns and diabetes risk in multiethnic populations.

This is a longitudinal cohort study (the MESA study) of a diverse group consisting of white, black, Chinese, and Hispanic adults in 6 US field centers to examine the risk for type 2 diabetes associated with dietary patterns distinguished with use of PCA and a "low risk" pattern score.

Practice Pearls

• The "Whole Grains & Fruit" food pattern is associated with a lower risk for type 2 diabetes, whereas the "Beans, Tomatoes & Refined Grains" pattern is associated with a higher risk for type 2 diabetes.
• Low-risk patterns of food for type 2 diabetes include high intake of grains; low-fat dairy; coffee; nuts/seeds; fruits and vegetables; and low intake of processed meats, white potatoes, and soda.

Diabetes Care. Published online June 10, 2008.