Hypertension and drinking water constituents in Colorado

Assessment of dietary nitrate supplementation: prevalence of use, knowledge, attitudes and beliefs among active Australians

Introduction

Use of nitrate as a dietary supplement has gained popularity among athletes and recreationally active individuals to enhance exercise performance. However, the prevalence and patterns of use, and knowledge of nitrate as a dietary supplement are unknown.

Methods

Individuals (≥16y) completed a 42-item online questionnaire to collect (i) sociodemographic information; (ii) participation in activity and sport; (iii) nitrate supplementation use and reasons; (iv) attitudes and beliefs regarding information sources and the safety of nitrate as a dietary supplement; and (v) knowledge of dietary nitrate supplements.

Results

In total, 1,404 active adults (66% female) took part in the study. Only about one in 10 respondents (11.9%) reported they had consumed dietary nitrate ("users") in the past, most commonly as beetroot juice (31.3%). Over two-thirds (69.4%) of users could not correctly identify the correct timing of intake relative to performance time to best improve exercise performance, and most users (82.3%) were unsure of the contraindications to oral consumption of dietary nitrate supplements. Only 3.9% of users experienced adverse effects after ingesting dietary nitrate supplements. Among non-users, the most common reasons respondents selected for not using dietary nitrate supplements were "I do not think I need to" (70.2%) and "I have never thought about it" (69.2%).

Discussion

There is evidence to support the efficacy of dietary nitrate intake in improving exercise performance. However, findings from this study suggest dietary nitrate is under-utilized. Educational messages that target dietary nitrate consumption should be targeted toward nutritionists, coaches, and exercise physiologists to bridge the gap between knowledge-to-practice.

Review of epidemiological studies on drinking water hardness and cardiovascular diseases

BACKGROUND

Major risk factors do not entirely explain the worldwide variability of morbidity and mortality due to cardiovascular disease. Environmental exposures, including drinking water minerals may affect cardiovascular disease risks.

METHOD

We conducted a qualitative review of the epidemiological studies of cardiovascular disease and drinking water hardness and calcium and magnesium levels.

RESULTS

Many but not all ecological studies found an inverse (i.e., protective) association between cardiovascular disease mortality and water hardness, calcium, or magnesium levels; but results are not consistent. Some case-control studies and one cohort study found either a reduced cardiovascular disease mortality risk with increased drinking water magnesium levels or an increased risk with low magnesium levels. However, the analytical studies provide little evidence that cardiovascular risks are associated with drinking water hardness or calcium levels.

CONCLUSION

Information from epidemiological and other studies supports the hypothesis that a low intake of magnesium may increase the risk of dying from, and possibly developing, cardiovascular disease or stroke. Thus, not removing magnesium from drinking water, or in certain situations increasing the magnesium intake from water, may be beneficial, especially for populations with an insufficient dietary intake of the mineral.

An anthracene-based tripodal chemosensor for anion sensing

An anthracene-based tripodal ligand was synthesized from the condensation of tren with 9-anthraldehyde, and the subsequent reduction with sodium borohydride. The neutral ligand was protonated from the reaction with p-toluenesulfonic acid to give a triply charged chemosensor that was examined for its anion binding ability toward fluoride, chloride, bromide, sulfate and nitrate by the fluorescence spectroscopy in DMSO. The addition of an anion to the ligand resulted in an enhancement in fluorescence intensity at the excitation of 310 nm. Analysis of the spectral changes suggested that the ligand formed a 1:1 complex with each of the anions, showing strong affinity for fluoride and sulfate in DMSO. The unsubstituted tren was reacted with sulfuric acid to form a sulfate complex and the structure was determined by the X-ray crystallography. Analysis of the complex revealed that three sulfates are held between two ligands by multiple hydrogen bonding interactions with protonated amines.

Drinking-water nitrate, methemoglobinemia, and global burden of disease: a discussion

On behalf of the World Health Organization (WHO), I have undertaken a series of literature-based investigations examining the global burden of disease related to a number of environmental risk factors associated with drinking water. In this article I outline the investigation of drinking-water nitrate concentration and methemoglobinemia. The exposure assessment was based on levels of nitrate in drinking water greater than the WHO guideline value of 50 mg/L. No exposure-response relationship, however, could be identified that related drinking-water nitrate level to methemoglobinemia. Indeed, although it has previously been accepted that consumption of drinking water high in nitrates causes methemoglobinemia in infants, it appears now that nitrate may be one of a number of co-factors that play a sometimes complex role in causing the disease. I conclude that, given the apparently low incidence of possible water-related methemoglobinemia, the complex nature of the role of nitrates, and that of individual behavior, it is currently inappropriate to attempt to link illness rates with drinking-water nitrate levels.

Stroke-associated deaths in Washington county, Maryland, with special reference to water hardness

Deaths associated with strokes from 1963 to 1975 among 36,860 adult residents of Washington County, Maryland, were studied in relation to the hardness of drinking water at home, assessed on the basis of 1,569 water samples taken during this period. There was no satisfactory evidence that water hardness was related to stroke mortality. Age was a strongly related factor. There was little or no association with sex, marital status, socio-economic status as reflected by education or housing, smoking history, or frequency of church attendance.

Distribution of hypertension and renal disease in Oregon

Expecting to find agreement between the geographic distribution of hypertension and renal disease, we developed regional mortality rates for 1950-72 and prevalence rates for a Selective Service cohort born in 1939-41 and examined during 1957-69. For this purpose the State's counties were grouped into eight geographically homogeneous regions. The general decline in hypertension mortality was most pronounced in Portland, Oregon's major urban center. However, the decline halted during 1968-72 in the southern Cascade region which has become an area of relatively higher risk within the State. During these 23 years nephritis mortality fell, kidney infection mortality was stable, and both syndromes showed peak mortality in other, different regions of the State. The geographic pattern of hypertension prevalence among the draftee cohort resembled the 1963-67 hypertension mortality pattern, but more recent morbidity data are needed to confirm the southern Cascade region's recent change to a high-risk area. Of 529 draftees with diagnosed hypertension, only 35 percent of the cases were previously known, only 7 percent has had any previous treatment, and only 7 percent were associated with known renal conditions. Among 521 registrants with a history of renal disorders, the prevalence of hypertension was increased for all categories of renal disease but was significantly high only for those with a history of glomerulonephritis. To date in Oregon we have found no evidence that renal disorders are major determinants of hypertension morbidity or mortality.