The consumption of fruits, but not vegetables, was associated with a decreased risk of abdominal aortic aneurysm, especially the risk of rupture, according to results of a large database study of two prospective cohorts of Swedish men and women.
"The risk of AAA decreased with increasing consumption of fruit (P =.003), whereas no significant association was observed for vegetable consumption," wrote Dr. Otto Stackelberg and his colleagues at Uppsala (Sweden) University (Circulation 2013;128:795-802).
The study population in the final analysis consisted of 36,109 women from the Swedish Mammography Cohort (established between 1987 and 1990) and 44,317 men from the Cohort of Swedish Men (established in 1997).
Both cohorts responded in 1997 to extensive questionnaires – identical except for sex-specific questions – that included 96 food-item questions accompanied by other lifestyle factors. Results were linked to the Swedish Inpatient Register and the Swedish National Cause of Death register to follow outcomes of these patients.
National health coverage in Sweden has been nearly 100% since 1987. All cases of AAA were identified by clinical events, not by general screening. AAA repair was identified via the Nordic Classification of Surgical Procedures. To classify aneurysmal localization and rupture status of AAA repairs, the researchers linked the cohorts to the Swedish Registry for Vascular Surgery (founded in 1987, which accounted for 93.1% of all AAA repairs in Sweden).
Fruit and vegetable consumption was summed from results of the 96 food item questionnaire and converted to daily consumption categories ranging from never to greater than or equal to 3 times daily.
Covariates assessed included education, alcohol consumption, diet, physical activity, waist circumference, and smoking duration and amount. The study population was ethnically homogenous. History of cardiovascular disease, diabetes, hypertension, and hypercholesterolemia was obtained from the Swedish Inpatient Register, the Swedish National Diabetes Register, and the self-reported data from the questionnaire.
During 13 years of follow-up (1998-2010), the researchers found that there were 1,086 primary cases (899 in men; 83%) and 222 cases of ruptured AAA (181 in men; 82%). The mean age for nonruptured AAA was 74 years in men and 76 years in women. For ruptured AAA it was 76 and 78.5 years in men and women, respectively. Cox proportional hazard analysis was used to estimate hazard ratios.
Individuals in the highest quartile of fruit consumption (greater than 2 servings per day) had a 25% lower risk of AAA and a 43% lower risk of ruptured AAA, compared with those in the lowest quartiles of fruit consumption (less than 0.7 servings per day). No association was observed between vegetable consumption and AAA risk. There was no impact of smoking or sex of the individual on the fruit consumption–related AAA risk for both ruptured and nonruptured AAA.
Men and women with a high consumption of fruit and vegetables were more educated, consumed more fish, meat, and whole grains, and were more likely to be leaner and physically active, and less likely to be smokers, according to the researchers. In addition, high consumers of fruit consumed less alcohol, whereas the reverse was true of high consumers of vegetables.
"A diet high in fruits may help to prevent many vascular diseases, and this study provides evidence that a lower risk of AAA will be among the benefits," the researchers concluded.
The study was funded by grants from the Swedish Research Council and the Karolinska Institute. The authors reported they had no disclosures.