Moderate alcohol consumption after a mental stressor attenuates the endocrine stress response.

Alcohol is often consumed to reduce tension and improve mood when exposed to stressful situations. Previous studies showed that moderate alcohol consumption may reduce stress when alcohol is consumed prior to a stressor, but data on the effect of alcohol consumption after a mental stressor is limited. Therefore, our objective was to study whether moderate alcohol consumption immediately after a mental stressor attenuates the stress response. Twenty-four healthy men (age 21-40 y, BMI 18-27 kg/m2) participated in a placebo-controlled trial. They randomly consumed 2 cans (660 mL, ∼26 g alcohol) of beer or alcohol-free beer immediately after a mental stressor (Stroop task and Trier Social Stress Test). Physiological and immunological stress response was measured by monitoring heart rate and repeated measures of the hypothalamic-pituitary-adrenal axis (HPA-axis), white blood cells and a set of cytokines. After a mental stressor, cortisol and adrenocorticotropic hormone (ACTH) concentrations were 100% and 176% more reduced at 60 min (P = 0.012 and P = 0.001, respectively) and 92% and 60% more reduced at 90 min (P < 0.001 and P = 0.056, respectively) after beer consumption as compared to alcohol-free beer consumption. Heart rate and dehydroepiandrosterone (DHEA) were not influenced by alcohol consumption. Plasma IL-8 concentrations remained lower during the stress recovery period after beer consumption than after alcohol-free beer consumption (P < 0.001). In conclusion, consumption of a moderate dose of alcohol after a mental stressor may facilitate recovery of the endocrine stress response as reflected by decreasing plasma ACTH and cortisol.

Determinants of skin sensitivity to solar irradiation.

BACKGROUND: Acute effects of UV irradiation include UV-induced erythema. Sunlight plays an important role in the development of skin cancer. Several predictive factors of UV-induced erythema could also be predictive for skin cancer. OBJECTIVE: Our objective was to quantitatively assess phenotypical and nutritional determinants of sensitivity to UV irradiation, as assessed by the minimal erythema dose (MED). DESIGN: We conducted a cross-sectional study among 335 volunteers. Sensitivity to UV irradiation was established through assessment of the MED. Phenotypical determinants, including skin melanin content, hair color and iris color were determined by skin reflectance spectrometry, a subjective questionnaire and an objective classification system, respectively. Furthermore, dietary exposure was measured by carotenoids, vitamin C, retinol and alpha-tocopherol in serum. RESULTS: Male subjects were found to be more sensitive to UV irradiation; that is, the MED was significantly lower compared to female subjects. Skin melanin content, which was positively associated with iris color in both sexes and with hair color in men, was the main phenotypical determinant of sensitivity to UV irradiation. No associations were found between serum carotenoids and MED in the total study group. Vitamin C was inversely associated with MED. However, associations between carotenoids concentrations and MED showed a positive trend in subjects with melanin values above and a negative trend in subjects below the median after adjustment for gender and total cholesterol. CONCLUSIONS: Skin melanin content and gender are important determinants of sensitivity to UV irradiation. No relation was found between serum carotenoids and MED in the total study group. The inverse association between vitamin C and MED was against our hypothesis. For the modifying effect of melanin on the association between carotenoids and MED, we do not have a clear biological explanation.