Impacts of microalgae consumption on psychological stress and cardiovascular function

Abstract

Cardiovascular disease (CVD) is the leading cause of death in the United States, killing 702,880 people annually. Psychological (or mental) stress has gained attention as a modifiable risk factor for CVD, showing links to hypertension, dyslipidemia, insulin resistance, atherosclerotic CVD, and stroke. The extent of how stress translates to pathological changes which result in CVD is not fully understood. One potential approach to managing mental stress is through the gut-brain-axis. A limited body of research in humans and rodents suggests that dietary microalgae supplementation may reduce gastrointestinal (GI) inflammation, leading to improvements in stress via the gut-brain axis which may have implications for cardiovascular health. We performed a randomized, double-blind, placebo-controlled, parallel-arm clinical trial evaluating the efficacy of four weeks of daily supplementation with 250 mg microalgae extract from Tetradesmus obliquus Mi175.B1.a vs. placebo on stress and anxiety in healthy adults aged 18-55 years with mild to moderate GI distress. Fifty-six adults (age: 31.9±7.7 years; body weight: 71.8±12.6 kg; BMI: 24.6±2.8 kg/m2) were enrolled. Participants were administered subjective assessments of perceived stress, blood pressure responses to environmental stress (i.e., cold pressor test, CPT) were evaluated, and salivary cortisol concentrations were measured. After four weeks of microalgae supplementation, our results showed improved scores on Positive and Negative Affect Schedule questionnaires which may reflect improvements in mental stress. No major treatment effects were observed for blood pressure responses to CPT or salivary cortisol. Our results suggest daily microalgae supplementation may have implications to improved mental health; however, more evidence is needed to understand the mechanisms of microalgae on stress reduction and implications for cardiovascular health.