Comparison of 3 methods for identifying dietary patterns associated with risk of disease

Abstract

Reduced rank regression and partial least-squares regression (PLS) are proposed alternatives to principal component analysis (PCA). Using all 3 methods, the authors derived dietary patterns in Costa Rican data collected on 3,574 cases and controls in 1994-2004 and related the resulting patterns to risk of first incident myocardial infarction. Four dietary patterns associated with myocardial infarction were identified. Factor 1, characterized by high intakes of lean chicken, vegetables, fruit, and polyunsaturated oil, was generated by all 3 dietary pattern methods and was associated with a significantly decreased adjusted risk of myocardial infarction (28%-46%, depending on the method used). PCA and PLS also each yielded a pattern associated with a significantly decreased risk of myocardial infarction (31% and 23%, respectively); this pattern was characterized by moderate intake of alcohol and polyunsaturated oil and low intake of high-fat dairy products. The fourth factor derived from PCA was significantly associated with a 38% increased risk of myocardial infarction and was characterized by high intakes of coffee and palm oil. Contrary to previous studies, the authors found PCA and PLS to produce more patterns associated with cardiovascular disease than reduced rank regression. The most effective method for deriving dietary patterns related to disease may vary depending on the study goals.

Figure 1.

Main factor loadings for patterns derived using principal component analysis (PCA), partial least-squares regression (PLS), and reduced rank regression (RRR) that were significantly associated with myocardial infarction in a case-control study of first incident myocardial infarction (n = 3,574), Costa Rica, 1994–2004. Abbreviations for food groups used in dietary pattern analyses: SG, sugar; RM, red meat; PM, processed meat; CH, chicken with skin and fat; L CH, lean chicken; FR, fruit; FJ, fruit juice; HD, high-fat dairy foods; HE, high-energy drinks; LQ, liquor; WB, wine and beer; CO, coffee; YV, yellow vegetables; CV, cruciferous vegetables; GV, green leafy vegetables; OV, other vegetables; TM, tomatoes; RG, refined grains; LG, legumes; CF, condiments, fresh; C, condiments; DE, desserts; SNX, snacks; PO, palm oil; SO, soybean oil; OO, other oil.