Effects of Dietary or Supplementary Micronutrients on Sex Hormones and IGF-1 in Middle and Older Age: A Systematic Review and Meta-Analysis

Abstract

Observational research suggests that micronutrients may be protective for sarcopenia, a key health issue during ageing, potentially via effects on hormone synthesis and metabolism. We aimed to carry out a systematic review of RCTs investigating effects of increasing dietary or supplemental micronutrient intake on sex hormones and IGF-1 in individuals aged 45 years or older. We searched MEDLINE, EMBASE and Cochrane databases for RCTs reporting the effects of different micronutrients (vitamins A, C, D, or E; carotenoids; iron; copper; zinc; magnesium; selenium; and potassium) on sex hormones or IGF-1. Of the 26 RCTs identified, nine examined effects of vitamin D, nine of multi-nutrients, four of carotenoids, two of selenium, one of zinc, and one of vitamin E. For IGF-1 increasing vitamin D (MD: −0.53 nmol/L, 95% CI: −1.58, 0.52), multi-nutrients (MD: 0.60 nmol/L, 95% CI −1.12 to 2.33) and carotenoids (MD −1.32 nmol/L; 95% CI −2.76 to 0.11) had no significant effect on circulating concentrations. No significant effects on sex hormones of other micronutrients were found, but data were very limited. All trials had significant methodological limitations making effects of micronutrient supplementation on sex hormones unclear. Further high quality RCTs with physiological doses of micronutrients in people with low baseline intakes or circulating concentrations, using robust methodology, are required to assess effects of supplementation adequately.

The effects of lycopene supplementation on insulin‐like growth factor‐1 and insulin‐like growth factor binding proteins: A systematic review of randomized controlled trials

“…The overall conclusion presented herein is in accordance with the previous reviews that did not support the efficacy of lycopene in improving serum IGF‐1 levels (Janjuha et al, 2020; Xie & Yang, 2020); however, there are some concerns limiting the validity of their results. The meta‐analysis by Xie et al, missed three eligible well‐designed RCTs (Gann et al, 2015; Talvas et al, 2010; Voskuil et al, 2008) which caused a loss of 258 participants.…”

“…Moreover, two included studies did not provide sufficient data for pairwise comparisons (Biernacka et al, 2019; Walfisch et al, 2007), and the meta‐analysis did not provide any explanation on how to calculate the effect size of these studies. Another meta‐analysis (Janjuha et al, 2020) also missed three eligible studies in the analysis (Biernacka et al, 2019; Schwarz et al, 2008; Talvas et al, 2010).…”

“…However, human trials investigating the effects of lycopene supplementation on circulating components of the IGF system, have yielded equivocal results (Gann et al, 2015; Voskuil et al, 2008). A recent meta‐analysis found no important change in IGF‐1 after carotenoid supplementation (containing lycopene, plus phytoene, phytofluene, beta‐carotene, and alpha tocopherol) (Janjuha et al, 2020). However, the study was restricted to adults aged at least 45 years, limiting the generalizability of the results.…”

Exercise training and burdock root (Arctium lappa L.) extract independently improve abdominal obesity and sex hormones in elderly women with metabolic syndrome

“…A number of studies have investigated the effects of dietary supplements on sex hormones related to conditions of age as well as noncommunicable diseases, because nutrients have important roles for hormone metabolism in the endocrine system 46 . Furthermore, sex-related endogenous hormones are associated with adiposity in postmenopausal women with diabetes 47 .…”

“…All procedures and protocols performed in studies involving human participants were by the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and the 2010 Consolidated Standards of Reporting Trials statement 46 were approved by the National Bioethics Committee of Pusan National University (PNU IRB/2015_22). This trial was retrospectively registered in the University Hospital Medical Information Network Clinical Trial Registry (Japan, registration 15/04/2020 UMIN000040170).…”