Background: The role of calcium in cardiovascular and metabolic risk is controversial.
Objective and hypotheses: To examine the effect of highly mineralized natural water in lowering body weight, blood pressure, cholesterol and blood sugar and to assess health behaviour of the staff of a pediatric hospital.
Method: Out of 650 pediatric hospital staff members, we examined 161 healthy subjects, aged 2864 years, 77.5% women, two drop-outs, in a randomized, placebo-controlled blinded trial. After randomization, 77 drank 1.5 l of mineral water (Ca 519, Mg 117, Sulfate 1445 and HCO3− 278 mg/l) and 82 natural water (40, 5, 6.2 and 10 mg/l, resp.) during 3 weeks. Before and at the end, we assessed nutrition and activity by standardized questionnaires, weight, height, blood pressure, waist and hip circumference, hydration by bioimpedance as well as fasting morning serum calcium, sodium, total-, LDL-, HDL-cholesterol, triglycerides, glucose, creatinine and calcium/creatinine ratio in the 2nd morning spot urine.
Results: BMI was 23.5±3.2 kg/m2, 26% were overweight and 6.8% obese (Swiss average of 33 and 11%, resp.) and did not change significantly, same as blood pressure, triglycerides, serum and urinary calcium. Most importantly, glucose (4.95±0.6) decreased by 10%, as did waist circumference, creatinine, total (5.4±0.95; 5.1±0.95) and HDL-cholesterol (1.73±0.45;1.62±0.4), although less markedly. Water intake (initially 0.8±0.3 l), BIA-phase-angle and LDL-cholesterol increased slightly, but significantly. Physical activity of 4.0 h/week was above national recommendation (3.5 h).
Conclusion: Pediatric staff participating in this RCT may be a particularly healthy role model population. While the higher mineral content of water did not induce significant changes during this study and the variations in cholesterol levels were unexpected, the decrease of waist circumference as well as of glucose levels points to favourable effects of drinking water. This is supported by epidemiological findings of higher type 2 diabetes prevalence in restricted fluid intake.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology