Brazil nut supplementation does not affect trimethylamine‐n‐oxide plasma levels in patients with coronary artery disease

Abstract

The purposes of this study were to assess the effect of Brazil nut supplementation on trimethylamine N‐oxide (TMAO) levels and glutathione peroxidase (GPx) activity in patients with coronary artery disease (CAD). Patients with CAD were randomly assigned to two groups, Brazil nut group (23 patients, 48% male, 62.7 ± 6.8 years, 29.4 ± 5.8 kg/m2), which received one Brazil nut per day for 3 months, and the control group (14 patients, 43% male, 63.7 ± 8.7 years, 28.4 ± 4.2 kg/m2) who did not receive any supplementation. After 3 months, TMAO levels and their precursors did not change in either group. Although not significant, GPx activity increased by 41% in the Brazil nut group. TMAO levels were negatively associated with total fiber intake (r = −0.385 and p = .02). A 3‐month Brazil nut supplementation did not change TMAO levels and GPx activity in CAD patients. Practical applications Trimethylamine N‐oxide (TMAO) has been associated with oxidative stress and cardiovascular disease risk. Thus, the increase in antioxidants enzymes production could be a promising strategy to reduce TMAO‐mediated oxidative stress. In this context, nutritional strategies are well‐known as activators of cellular antioxidant responses. As Brazil nuts have a known role in reducing oxidative stress by increasing glutathione peroxidase (GPx) activity (a selenium‐dependent antioxidant enzyme), this study hypothesized that Brazil nuts could be a strategy that, via antioxidant capacity, would reduce TMAO plasma levels. Although no changes in TMAO levels and GPx activity can be observed in this study, it is believed that other results can be obtained depending on the dosage used. Thus, this study can open new paths and direct other studies with different doses and treatment times to evaluate the effects of Brazil Nuts on TMAO levels.

Selenium supplementation provides potent neuroprotection following cerebral ischemia in mice

“…Both the tMCAO and tMCAO þ Se groups performed significantly worse than the sham group (Figure 3(f)). However, the number of shock zone entries for the tMCAO þ Se group was significantly lower than that of the tMCAO group (Figure 3(f); 11.17 AE 1.353 vs. 16.83 AE 1.637; P ¼ 0.0173), indicating a long-lasting beneficial effect of selenium supplementation.…”

“…This observation is in agreement with the results of a recent clinical study which showed that 3 months of selenium supplementation (via the consumption of Brazil nuts) did not reduce the levels of plasma TMA or TMAO in patients with coronary artery disease. 16 Hence, we propose that under an ischemic attack, selenium directly reduces the magnitude of the brain insult, thereby indirectly decreasing stroke-induced TMAO production. Whether inhibition of Enterobacteriaceae leads to a direct reduction in circulating TMAO remains unknown, and the causal relationship with stroke outcomes requires further investigation.…”

“…11 Alterations in gut microbiota have also been associated with ischemic stroke pathogenesis, with recent clinical studies finding an association between circulating trimethylamine N-oxide (TMAO), the most well-studied gut microbiota-derived metabolite, and adverse stroke outcomes. [16][17][18] Interestingly, selenium has recently been shown to have a positive effect on gut dysbiosis in mice. 19,20 However, whether it can protect against stroke-induced gut dysbiosis remains unknown.…”