Association of dietary nitrate with atherosclerotic vascular disease mortality: a prospective cohort study of older adult women

Abstract

Background: Nitrate-rich vegetables lower blood pressure and improve endothelial function in humans. It is not known, however, whether increased consumption of nitrate-rich vegetables translates to a lower risk of atherosclerotic vascular disease (ASVD) mortality. Objective: The objective was to investigate the association of nitrate intake from vegetables with ASVD mortality. Design: A total of 1226 Australian women aged 70-85 y without prevalent ASVD and/or diabetes were recruited in 1998 and were studied for 15 y. We assessed demographic and ASVD risk factors at baseline (1998), and we used a validated food-frequency questionnaire to evaluate dietary intake. Nitrate intake from vegetables was calculated by use of a newly developed comprehensive database. The primary outcome was any death attributed to ASVD ascertained by using linked data that were provided via the Western Australian Data Linkage system. We used Cox proportional hazards modeling to examine the association between nitrate intake and ASVD mortality before and after adjustment for lifestyle and cardiovascular disease risk factors. Conclusions: Nitrate intake from vegetables was inversely associated with ASVD mortality independent of lifestyle and cardiovascular disease risk factors in this population of older adult women without prevalent ASVD or diabetes. These results support the concept that nitrate-rich vegetables may reduce the risk of age-related ASVD mortality. This trial was registered at www. anzctr.org.au as ACTRN12617000640303.

Dietary nitrate consumption and risk of CHD in women from the Nurses’ Health Study

“…Blekkenhorst et al (21) were the first to investigate prospectively the association of dietary nitrate (measured only at baseline) with atherosclerotic vascular disease (ASVD) mortality including ischaemic heart disease, heart failure, cerebrovascular disease (excluding haemorrhagic stroke) and peripheral arterial disease, in 1226 Australian women aged 70-85 years, followed up for 15 years. Finding from Blekkenhorst et al (21) indicated that participants in the highest (>76•4 mg/d) compared with the lowest (<52•7 mg/d) tertile of total vegetable nitrate intake had a lower risk of ASVD (21) . Within the same cohort, Bondonno et al (41) found that for every 1SD (31 mg/d) higher intake of total nitrate, there was an associated 18 % lower risk of 14•5-year ischaemic cerebrovascular disease events (P = 0•017).…”

Association of Dietary Nitrate Intake with the 15-Year Incidence of Age-Related Macular Degeneration

“…Another study also indicated a non-linear association between dietary nitrate and vascular disease mortality, with the largest benefits observed among those with moderate nitrate intakes which is consistent with our data. 13 Alternatively, the small number of incident AMD cases could have reduced power to detect a modest association at the highest intake quartiles. Moreover, we observed no significant associations with incidence of late AMD, again this is likely to be due to the small number of incident late AMD cases (~4%), compared to ~15% incidence of early AMD cases.…”

“…Additionally, we observed no significant associations between non-vegetable nitrate intake and incidence of early or late AMD, this is not surprising given that there is no clear consensus on the impacts on health after consumption of non-vegetable sources of dietary nitrate. 13 Inflammation, oxidative stress, and endothelial dysfunction are among the many factors that are hypothesized to influence the incidence and progression of AMD. 2,6 Given that nitrate intake, particularly from vegetable sources, was previously shown to improve endothelial function and minimize oxidative stress, 4 this is a potential pathway by which dietary nitrate intake could protect against early AMD.…”

Cruciferous and Allium Vegetable Intakes are Inversely Associated With 15‐Year Atherosclerotic Vascular Disease Deaths in Older Adult Women

“…We assessed overall diet quality using the Nutrient‐Rich Foods Index . This index was calculated using the Nutrient Reference Values for Australia and New Zealand based on adult women older than 70 years and has been previously described …”