Walnuts

Walnuts are nutritionally unique among tree nuts: they are the only nut with significant alpha-linolenic acid (ALA), the plant-based omega-3, at approximately 2.5g per ounce. They also contain ellagitannins, polyphenols that gut bacteria convert to urolithins — molecules that reduce intestinal inflammation and have shown preliminary anti-cancer activity in human trials. The WAHA trial (Walnuts and Healthy Aging) — a 2-year RCT in 636 older adults — found daily walnut consumption (approximately 14 walnuts) reduced LDL cholesterol by 4.4% and inflammatory adhesion molecules associated with cardiovascular disease. The portion that matters: one ounce (28g, approximately 14 halves) daily. More does not produce proportionally more benefit. Walnuts oxidize quickly — buy in shell or from bulk bins with high turnover, and store in the refrigerator.