INTRODUCTION
Several modifiable risk factors such as tobacco use, unhealthy diet, and
excessive alcohol intake are linked to the greater risk of
non-communicable diseases, some evidence suggests that adequate water
intake may improve health outcomes[1]. Adequate
hydration and water intake are necessary for critical physiological and
metabolic processes[2]. Using this framework
dietary guidelines recommended consumption of 2 and 2.5 L per day from
water for females and males respectively[3]. Low
fluid consumption and inadequate water intake may provoke dehydration.
This condition can lead to low-grade inflammation in the human body. It
should be noted that the low-grade inflammation in long-term was
associated with inanition and progression of some chronic
diseases[4], CVD[5], and
mortality[6]. Previous meta-analysis on the
association of specific beverages, such as tea[7,
8], coffee[9, 10], and
alcohol[11-13] with mortality reported inverse,
positive or null associations. Findings on the link between water intake
and longevity remain an unresolved question. While total water intake
from foods and beverages was associated with a lower risk of mortality
in some investigations[14] others failed to find
such evidence[15, 16]. No information is available
about the strength and shape of dose-response relation between water
intake and risk of mortality. On the other hand, understanding the
association between water consumption and mortality is important for
guiding consumers and prioritizing dietary guidelines to reduce the
risk. Therefore, in the current study, we conducted a systematic review
and dose-response meta-analysis of prospective cohort studies to
summarize the association between total water intake from foods and
beverages and drinking intake and risk of mortality from all causes and
CVD.