High doses of vitamin C plus E reduce strength training-induced improvements in areal bone mineral density in elderly men.

ABSTRACT

PURPOSE: Resistance training is beneficial for maintaining bone mass. We aimed to investigate the skeletal effects of high doses of antioxidants [vitamin C + E (α-tocopherol)] supplementation during 12-week supervised strength training in healthy, elderly men METHODS: Design: double-blinded randomized placebo-controlled study. Participants followed a supervised, undulating periodic exercise program with weekly adjusted load 3 sessions/week and 3-15 repetitions maximum (RM) sets/exercise. The control group (CG, n = 17, 67 ± 5 years) received placebo and the antioxidant group (AO, n = 16, 70 ± 7 years) 1000 mg vitamin C + 235 mg vitamin E, daily. Areal bone mineral density (aBMD) at whole body, lumbar spine (L1-L4), total hip, and femoral neck were measured by dual energy X-ray absorptiometry and muscle strength by 1RM. Serum analyses of bone-related factors and adipokines were performed. RESULTS: In the CG, total hip aBMD increased by 1.0% (CI 0.3-1.7) versus pretest and lumbar spine aBMD increased by 0.9% (CI -0.2 to 2.0) compared to the AO. In the CG, there was an increase in serum concentrations of insulin-like growth factor 1 [+27.3% (CI -0.3 to 54.9)] and leptin [+31.2% (CI 9.8-52.6)) versus pretest, and a decrease in sclerostin [-9.9% (CI 4.4-15.3)] versus pretest and versus AO. Serum bone formation markers P1NP and osteocalcin increased in both groups, while the bone resorption marker CTX-1 remained unchanged. CONCLUSION: High doses of antioxidant supplementations may constrain the favorable skeletal benefits of 12 weeks of resistance exercise in healthy elderly men.