Eating Nuts May Boost Your Serotonin Levels, Study Finds

Some of the participants were given pretzels and others were given a mix of tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios, and walnuts). At the end of the study period, the researchers analyzed fecal and blood plasma samples to better understand the effects of the different snacks.