In this large cohort study of women, we derived two major dietary patterns. Greater adherence to the prudent pattern, characterized by a high intake of vegetables, fruit, legumes, fish, poultry, and whole grains, was related to a lower risk of cardiovascular and total mortality. In contrast, greater adherence to the western pattern, reflecting a high intake of red and processed meat, refined grains, french fries, and sweets and desserts, was linked to a higher risk of cardiovascular, cancer, and total mortality.
The relation of overall dietary patterns with mortality due to CVD or other chronic diseases has not been widely examined. Similar to our study, the “prudent” pattern (characterized by a frequent intake of fruits, vegetables, and wholemeal bread) was associated with a decreased risk of cardiovascular mortality in Danish women.8
In recent studies including Asian populations, a “vegetable-rich” pattern10
and a pattern characterized by a frequent consumption of vegetables, fruit, soy products, seaweeds, and fish9
were inversely related to cardiovascular mortality, whereas a pattern characterized by a frequent consumption of meat and butter was directly related to this outcome.9
The results of the present study for the association between patterns and the major cause of other mortality, i.e. diseases of the respiratory system, are in line with previous findings on dietary patterns and nonmalignant respiratory outcomes.30,31
Further, several previous studies have examined the relation between overall dietary patterns and all-cause mortality. In a Japanese cohort study, a dietary factor reflecting a frequent intake of plant foods such as green-yellow vegetables, fruit, soybean products, seaweeds and potatoes was inversely related to all-cause mortality.14
Among Danish men and women, the “prudent” pattern was associated with a decreased risk of total mortality.8
In an U.S. study, a lower risk of total mortality was observed for the “fruit-vegetables-whole grain” pattern among men.12
In different European elderly populations, a plant-based dietary pattern was linked to a reduced risk of all-cause mortality13,17,18
and in German elderly men and women, a pattern reflecting high intakes of all types of meat, condiments, butter, and eggs was related to an increased risk of all-cause mortality.15
Among British women, a reduced risk of total mortality was observed for a pattern defined by frequent intakes of fruit, salad, vegetables, and brown bread, whereas an increased risk was found for a pattern characterized by frequent intakes of chips, crisps, fried food, processed meat, and soft drinks.16
Despite these positive results, other findings did not indicate a significant association between dietary patterns and all-cause mortality.8,11,32
These inconsistent results may be due to specific population characteristics such as gender or prevalent diseases. Further, inconsistencies may be explainable by differences in dietary assessment methods. For example, in a Danish study,8
the “western” pattern was based on 28 assessed food items compared to at least 116 items that were classified into 37 to 39 food groups in our study.
The results of the present study are supported by previous analyses of the association between dietary patterns and chronic diseases and biomarkers among women of our or a similar cohort, respectively. In particular, the prudent pattern was favorably associated with the risk of coronary heart disease,33
and plasma concentrations of markers of inflammation and endothelial dysfunction,35
which could have contributed to the observed inverse relation of the prudent pattern to cardiovascular mortality in the present study. Conversely, the western pattern showed a positive association with the risk of coronary heart disease,33
type 2 diabetes,37
and concentrations of inflammatory and endothelial markers.35
However, the prudent diet was not significantly related to the risk of postmenopausal breast cancer,22
or pancreatic cancer,39
which are among the main causes of mortality from cancer in women. Thus, it is not surprising that we found no significant association between the prudent pattern and cancer mortality after accounting for potential confounders in the present study. However, the western pattern was directly related to the risk of colon cancer in a previous study38
and directly associated with cancer mortality in the present study. The different associations between the patterns and specific diseases and causes of death may be due to different effects of characteristic pattern components on specific outcomes. Thus, a high consumption of fruit and vegetables, two main components of the prudent pattern, has been shown to be linked to a decreased risk of CVD,40,41
whereas the evidence from prospective studies for a reduced risk is limited for most cancer sites.42
The results of our study are further strengthened by distinctive nutrient compositions of the prudent and the western pattern. For example, the intake of trans-fatty acids - a recognized risk factor for CVD1
- was inversely associated with the prudent pattern and the intake of fiber and folate - which have been shown to be associated with lower CVD risk1
- was directly related to the prudent pattern, whereas an opposite trend in nutrient intake was evident for the western pattern (see ).
The large size of the cohort and long duration of follow-up provided adequate power for the analyses of cause-specific deaths and for the stratified analyses. The prospective design and the high rate of follow-up minimized the possibility of recall and selection biases. Another unique feature of this study is the existence of repeated measures of diet, which allowed us to calculate cumulative averages of dietary intakes to best represent long-term diet and reduce measurement errors.
Several limitations of this study need to be acknowledged. The dietary patterns identified by factor analysis represent existing eating habits of the study population, but do not necessarily reflect optimal diets with the greatest impact on mortality. In addition, factor analysis involves the subjectivity in selecting and grouping the food items, choosing the method of factor rotation, and determining the numbers of patterns to be retained.43
Variations in these criteria may induce variations in the composition of identified patterns and in the observed diet-disease associations. However, we defined the food groups and patterns using a standard method applied in numerous previous studies. Further, dietary patterns may represent a lifestyle in general43
and even though we carefully adjusted for known and suspected confounder variables, residual confounding cannot be ruled out due to the observational nature of this study. Finally, our study population was rather homogenous in terms of occupational class, ethnic group, and gender, which reduces residual confounding, but limits the generalizability of results.
In conclusion, in this large cohort study we found that women with higher prudent pattern scores had a lower long-term risk of cardiovascular and all-cause mortality, whereas women with higher western pattern scores had a higher long-term risk of cardiovascular, cancer, and all-cause mortality. These data highlight the importance of health professionals' and public health efforts that help to adopt healthy overall dietary patterns including high intakes of plant foods such as vegetables, fruit, legumes, and whole grains, high intakes of fish and poultry, and low intakes of red and processed meat, refined grains, french fries, and sweets.