1.
Time-restricted feeding influences immune responses without compromising muscle performance in older men.
Gasmi, M, Sellami, M, Denham, J, Padulo, J, Kuvacic, G, Selmi, W, Khalifa, R
Nutrition (Burbank, Los Angeles County, Calif.). 2018;:29-37
Abstract
OBJECTIVE This study examined the effect of 12 wk of time-restricted feeding (TRF) on complete blood cell counts, natural killer cells, and muscle performance in 20- and 50-year-old men. METHODS Forty active and healthy participants were randomly divided into young experimental, young control, aged experimental, and aged control group. Experimental groups participated in TRF. Before (P1) and after (P2) TRF, participants performed a maximal exercise test to quantify muscle power. Resting venous blood samples were collected for blood count calculation. RESULTS No changes were identified in muscle power in all groups after TRF (P > 0.05). At P1, red cells, hemoglobin, and hematocrit were significantly higher in young participants compared with elderly participants (P < 0.05). At P2, this age effect was not found in red cells between the young experimental group and the aged experimental group (P > 0.05). At P1, white blood cells and neutrophils were significantly higher in young participants compared with elderly participants (P < 0.05). At P2, only neutrophils decreased significantly (P < 0.05) in experimental groups without significant (P > 0.05) difference among them. Lymphocytes decreased significantly in the aged experimental group at P2 (P < 0.05), whereas NKCD16+ and NKCD56+ decreased significantly in experimental groups at P2 (P < 0.05). TRF had no effect on CD3, CD4+, and CD8+ levels (P > 0.05). CONCLUSION TRF decreases hematocrit, total white blood cells, lymphocytes, and neutrophils in young and older men. TRF may be effective in preventing inflammation by decreasing natural killer cells. As such, TRF could be a lifestyle strategy to reduce systemic low-grade inflammation and age-related chronic diseases linked to immunosenescence, without compromising physical performance.
2.
Higher DHEAS Levels Associated with Long-Term Practicing of Tai Chi.
Lai, HM, Liu, MSY, Lin, TJ, Tsai, YL, Chien, EJ
The Chinese journal of physiology. 2017;(2):124-130
Abstract
Tai Chi has many benefits for middle-aged/older individuals including improvements to muscle strength and various body lipid components. DHEAS and testosterone have anti-obesity/anti-aging characteristics and also improve libido, vitality and immunity levels. Thus, the aim of the present study was to investigate the differences between middle-aged Tai Chi practitioners (n = 17) and sedentary individuals (n = 17) in terms of leg strength, blood levels of cholesterol, triglyceride, HDL, as well as DHEAS, testosterone and cortisol. Unpaired t-tests were used to identify significant differences between the two groups. There were no significant differences in body composition, leg strength, blood lipid components and testosterone. However, the Tai Chi practitioners had higher levels of DHEAS (P < 0.01) and lower levels of cortisol (P < 0.05). Thus, Tai Chi practitioners have a higher ratio of DHEAS to cortisol, which might have potential benefits in terms of improving an individual’s health-related quality of life during the aging.