It is generally stated that drinking plenty of water has a positive influence on skin condition. However, there is no published scientific study that has investigated this matter. The aim of our exploratory 'before-after' study was to evaluate the in vivo influence of drinking more than 2 L of mineral water or ordinary tap water per day on skin physiology. Ninety-three healthy subjects were included in our prospective study. After an initial run-in phase of 2 weeks to monitor individual drinking habits, subjects had to drink 2.25 L day(-1) of either mineral water (n = 53) or tap water (n = 40) for 4 weeks. Bioengineering in vivo measurements on the volar forearm included sonographic evaluation of skin thickness and density, determination of skin surface pH, assessment of skin surface morphology, and measurement of finger circumference. Eighty-six subjects completed the study. In the mineral water group measurements revealed a statistically significant decrease in skin density. Skin thickness increased slightly, albeit not at a statistically significant level. However, when separately analysing those individuals from the mineral water group, who had routinely drunken comparably little before the start of the study, their skin thickness increased at a statistically significant level. Skin surface pH remained almost unchanged in the physiologically optimal range. In the tap water group, skin density increased significantly, while skin thickness decreased significantly. Skin surface pH decreased at a statistically significant level. While in the mineral water group finger circumference decreased significantly, measurements in the tap water group revealed a statistically significant increase. Objective skin surface morphology did not change in any group. In summary, drinking more than 2 L of water per day can have a significant impact on skin physiology. The exact effects within the skin seem to differ depending on the nature of the water ingested. Randomized, controlled, double-blind follow-up trials are warranted to confirm the findings of our exploratory pilot study.

Although many schemes recommend the administration of emollients prior to UV therapy, there have also been calls for caution, as an uncritical application may interfere with such treatment. We showed that the emulsifying ointments tested exhibited no photoprotective potential and thus are suitable for the pretreatment of psoriasis prior to phototherapy. It has long been discussed whether the effects of emollient pretreatment on response to UV occur only in psoriatic skin or also in healthy skin. Our results indicated that stratum corneum rehydration did not result in a significantly increased erythema response of healthy skin to UVB exposure. With regard to the use of rehydrating cosmetics in everyday life, the outcome of our pilot study is reassuring, as we could not confirm with our experimental design that well-hydrated healthy skin is more prone to actinic damage.

A total of 155 high yielding dairy cows were used to study the effect of dietary beta-carotene (carotene) on fertility. The diet of group 1 was supplemented with 69 mg retinyl acetate per cow daily before calving and 96 mg retinyl acetate after calving: diet of group 2 was supplemented with 500 mg carotene per cow before calving and 96 mg retinyl acetate after calving; and that of group 3 with 500 mg carotene before and 700 mg after calving. Conception rates were 53.9, 42.2, and 27.9% for cows of groups 1, 2, and 3. Days open were 110 and 112 for young (second and third lactation) and old (fourth and later lactations) cows of the group 1; 130 and 129 for young and old cows of group 2; and 133 and 166 for young and old cows of group 3. Number of inseminations per conception was 1.8 and 1.8, 2.2 and 2.2, and 2.5 and 3.4 for the same groups, respectively. Within group 3 the percent of cows pregnant 120 d after calving was 57 and 20 for the young and old cows. Correlation coefficients between plasma carotene of 53 old cows of all groups 4 and 8 wk after calving, and the number of open days and the number of inseminations per conception were significant. The intake of high carotene may have adverse effects on the fertility of dairy cows.

No abstract

No abstract