Tea consumption and the risk of abdominal aortic aneurysm

Background Tea has the potential to lower the risk of abdominal aortic aneurysm (AAA) owing to its high antioxidant capacity. AAA risk factors including smoking, hypertension, and hypercholesterolaemia, may modify this association. Methods The study population included 45 047 men in the Cohort of Swedish Men (COSM) and 36 611 women in the Swedish Mammography Cohort (SMC), aged 45-83 years at baseline. The COSM was established in 1997 with all men who lived in two central Swedish counties (Vastmanland and orebro), and the SMC was established in 1987-1990 with women residing in Vastmanland county. Tea consumption was assessed by means of food frequency questionnaires in 1997 and 2009. Results During 17.5 years of follow-up, 1781 AAA cases (1496 men, 285 women; 1497 non-ruptured, 284 ruptured) were ascertained via Swedish registers. Tea consumption was inversely associated with total AAA incidence in men and women. Women had a 23 (95 per cent c.i. 8 to 36) per cent lower risk of AAA per each cup per day increment, whereas men had a 9 (0 to 17) per cent lower risk (P-interaction = 0.029). Tea consumption was associated with a lower risk of both non-ruptured (hazard ratio (HR) 0.93, 95 per cent c.i. 0.85 to 1.01) and ruptured (HR 0.84, 0.71 to 0.98) AAA. Smoking status modified the association (P-interaction < 0.001), whereby tea consumption was associated with lower risk of AAA in ex-smokers (per cup per day, HR 0.89, 0.80 to 0.98) and in never smokers (HR 0.88, 0.77 to 1.00), but not in current smokers (HR 0.95, 0.84 to 1.06). Tea consumption was associated with a lower risk in participants with (HR 0.88, 0.80 to 0.98) and without (HR 0.93, 0.88 to 1.00) hypertension, and in those with (HR 0.82, 0.67 to 1.01) and without (HR 0.92, 0.86 to 0.98) hypercholesterolaemia. Conclusion Tea consumption was associated with a reduced risk of AAA. The association was more pronounced for ruptured than non-ruptured AAA, and in patients with hypertension and hypercholesterolaemia than those without. The association was also observed in ex-smokers and never smokers, but not in current smokers. The results of the study suggest that tea consumption may be associated with a reduced risk of abdominal aortic aneurysm (ruptured and non-ruptured) in men and women, in participants with and without hypertension and hypercholesterolaemia, and in never and ex-smokers but not in current smokers. Tea consumption has the potential for the prevention of abdominal aortic aneurysm and, in addition to quitting smoking, a healthy diet including tea could help reduce this risk.