Association between Micronutrients Intake/Status and Carotid Intima Media Thickness: A Systematic Review

BackgroundCarotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis and play a major role in the development of cardiovascular diseases (CVDs).ObjectiveThe primary aim of this review was to synthesize the evidence regarding the association between carotid IMT and selected micronutrients.MethodThe authors searched PubMed, Cochrane, and EMBASE databases from inception to June 2016 for selected micronutrients, CVD, carotid IMT, and antioxidants. Thirty-five original studies met the inclusion criteria and were reviewed following preferred reporting items for systematic review and meta-analysis guidelines.ResultsAlthough not all studies found consistent results, the weight of the evidence suggests that high intakes and/or circulatory levels of magnesium, as well as vitamin D and the vitamin B group, may be associated with lower carotid IMT or reduced progression of carotid IMT. The majority of studies did not find any significant association between vitamin E and C and carotid IMT. Less evidence was available for associations of retinol, zinc, and iron with carotid IMT.ConclusionsIn general, the current evidence concerning micronutrient intake and carotid IMT is largely inconclusive. Pragmatic clinical trials are required to determine whether dietary or supplemental intake of specific micronutrients alters carotid IMT, which is a surrogate measure of cardiovascular risk.