Biological effects of drinking-water mineral composition on calcium balance and bone remodeling markers.

OBJECTIVE: To compare the effects of 2 drinking waters containing similar calcium (Ca) concentration in order to analyze the role of ions other than Ca on bone metabolism. These mineral drinking-waters differed by their mineral composition primarily concerning the concentration of bicarbonate (HCO3-), high in the HB, and sulfate, high in HS water. DESIGN: Of 60 included women, 39 completed the study. Patients were randomly assigned to an intake of 1 liter per day of mineral water HB or HS for 28 d, followed by cross-over to the alternative drinking-water for a further 28 d. At baseline and after each period of one month, Ca metabolism parameters, acid-base status, and bone remodeling markers were measured. RESULTS: Changes in Ca metabolism were significant in the HB group where the ionized Ca increased and the PTH decreased. Serum pH showed a similar increase whatever the used drinking water compared to baseline. In the HB group, significant increase in urine pH, and significant decrease in AT-HCO3- and NH4+ were observed. Bone resorption markers, urinary CTx/Cr, Pyr/Cr, and D-Pyr/Cr, significantly decreased in the HB group compared to baseline, and were not significantly modified in the HS group. CONCLUSIONS: These results showed a beneficial effect of the bicarbonaterich HB water on bone metabolism. This may account for a better bioavailability of the Ca, a greater alkalinization, and a larger decrease in PTH level secondary to a higher ionized Ca level. The higher content of silica in HB water may have also participated to the positive action on bone balance that was observed. In this short term study, these data underlined the potential role of the mineral drinking water composition on bone metabolism.

Influence of repeated consumption of beverages containing sucrose or intense sweeteners on food intake.

OBJECTIVE: To investigate the influence of ingestion of beverages with sucrose or with intense sweeteners on food intake (FI) and on hunger ratings in before and after a month of daily consumption of beverages. DESIGN: Experimental study. SETTING: Department of Physiology, University Hospital, Dijon, France. SUBJECTS: In all, 12 men and 12 women, aged 20-25 y. INTERVENTION: Four beverages contained either sucrose (E+:100 g/l, 1672 kJ) or intense sweeteners (E-: null energy content) and were flavoured with either orange (O) or raspberry (R). FI was measured in the lab during two 2-consecutive-day periods, carried out on 2 successive weeks (session 1). The subjects drank 2 l of either E+ or E- beverages on the first day of both weekly periods, according to a balanced randomised design. E+ was paired with O for 50% of subjects and with R for the other 50%. Subjects were then habituated over a 4-week period to both beverages, consuming 1 l of E+ beverage on odd days and 1 l of E- drink on even days. After this period, the measurements of session 1 were repeated (session 2, weeks 7-8). Finally, FI was measured for two more 2-day periods (weeks 9-10) after the association between flavour and energy content was reversed (session 3). RESULTS: The E- drinks were less palatable than the E+ drinks. Besides, we observed that FI was not reduced in response to a liquid extra caloric load and there was no change in hunger ratings after the beverages in any of the sessions. CONCLUSION: Ingestion of caloric beverages induced a positive energy balance and the continuous exposure phase to these beverages over 1 month did not improve FI adaptation in response to the extra energy provided by the beverages.

Magnesium bioavailability from mineral water. A study in adult men.

OBJECTIVE: To assess magnesium enteral absorption from a magnesium-rich mineral water. DESIGN: Experimental study. SETTING: Department of Nuclear Medicine, Brugmann Hospital, Brussels, Belgium. SUBJECTS: Ten healthy male volunteers in the age range 25-42 y. INTERVENTION: Each subject completed two sessions in a random order. At one session, they received an oral load of 300 ml of water (containing 1.2 mmol Mg), traced with (28)Mg, and at the other session they received an intravenous injection of (28)Mg, in order to take into account the metabolism of endogenous magnesium. The dietary consumption was further noted on a weekly diary. RESULTS: The mean bioavailability was 59.1% (s.d.+/-13.6). Magnesium absorption and age were significantly inversely correlated (r=-0.68, P=0.035). CONCLUSION: Magnesium-rich mineral water is a reliable source of magnesium. Our observation of decreased magnesium absorption with age deserves further investigations. SPONSORSHIP: The study was sponsored by SEV, Bourg la Reine, France.

Short-term effects of the flavour of drinks on ingestive behaviours in man.

To examine the influence of the oro-sensory properties of different beverages on spontaneous intake of drinks, and the consequence of the volume of fluid ingested on subsequent food intake, 24 subjects (12 men, 12 women), slightly dehydrated, had access ad libitum, during four different experimental sessions in a cross-over design, to one of four commercial beverages without any other drink. The four beverages differed in flavour and caloric content: mineral water; the same mineral water flavoured with orange and unsweetened; the same mineral water flavoured with orange and sweetened with 100 g/l sucrose; or equally sweetened with 50 mg/l aspartame. Ad libitum: lunch was served 15 min after the subjects had access to the beverages and dinner was served when they spontaneously requested it, about 6 h after the end of lunch. The nature of the beverage exerted a small but significant effect on the cumulative fluid intake of the subjects. They consumed slightly more of the two sweetened beverages than the mineral water, and slightly less of the orange-flavoured beverage. However, energy intake and macronutrient selection during lunch and dinner on the experimental days and on the following day did not differ significantly between the different conditions. This resulted in a significantly higher total energy intake when the imposed beverage contained sucrose. Moreover, in such experimental conditions, with only one type of beverage to drink, the flavour of this beverage had little influence on the amount of fluid consumed, and the volume consumed did not influence subsequent food intake. As a consequence, the energy provided by the sucrose-sweetened beverage was not taken in account in the overall energy balance by the subjects, at least in the short term.

Bioavailability of calcium of fresh cheeses, enteral food and mineral water. A study with stable calcium isotopes in young adult women.

True fractional Ca absorption from six foods was measured in twelve normal healthy women, aged 20-29 years. The tested foods were commercially available fresh cheese, fresh cheese prepared by new technology and rich in Ca, similar cheese with added Fe, enteral food, mineral water alone and combined with a spaghetti meal. The aim of the study was to investigate: (1) Ca absorption from a new Ca-rich fresh cheese and to compare it with that from the traditional commercial type of fresh cheese; (2) the effect of Fe enrichment of the new cheese on Ca absorption; (3) Ca absorption from the mineral water and the enteral product and to compare it with that from the dairy products; (4) the effect of a meal combined with the mineral water on Ca absorption. All test foods were consumed by all subjects according to a design with two Latin squares. Each treatment of 2 d was followed by a wash-out period of 2 weeks. Ca absorption was measured using a double stable-isotope (44Ca and 48Ca) extrinsic labelling technique. Mean fractional Ca absorption from the new fresh cheese was not significantly different from that from the traditional type (37.7 (SD 10.2)% v. 42.2 (SD 11.6)%). The addition of Fe to the new cheese did not significantly influence Ca absorption. Ca-absorption values from the mineral water (37.0 (SD 9.8)%) and from the enteral product (42.6 (SD 11.4)%) were not significantly different from those from the dairy products (37.7-42.2%, SD 10.2-11.6%). The co-ingestion of a spaghetti meal with the mineral water significantly enhanced Ca absorption from 37 (SD 9.8)% to 46.1 (SD 11.7)%. It is concluded that a new process leading to a fresh cheese with a higher Ca concentration does not alter Ca bioavailability compared with the standard technology and for a constant Ca supply. Thus this new fresh cheese would probably provide more Ca than the standard one. The fractional Ca-absorption values for mineral water and the enteral product indicate that these products can make an interesting contribution to Ca supply for populations with a low Ca intake and patients with specific diseases respectively.