In the 2009 systematic review, researchers analyzed 13 different studies whose findings showed the heart health benefits of short-term walnut consumption on participant blood lipid profiles. Across more than 360 participants, those who ate a walnut-dense diet for anywhere between four weeks and 24 weeks experienced significant drops in LDL and total cholesterol levels compared to those who adhered to control diets.
While these may have been short-term trials, researchers from a 2021 study published in Circulation investigated the long-term health benefits of eating walnuts on a daily basis. The study team tracked over 700 healthy older adults in Spain and California, the majority of whom were women. The study findings revealed that adults who ate approximately ½ cup of walnuts every day for two years saw modest decreases in their LDL cholesterol levels compared to participants who ate no walnuts whatsoever during the course of the study. On average, participants who were eating walnuts on a daily basis saw a 4.3 milligrams per deciliter (mg/dL) decrease in their “bad” cholesterol after two years.
