Eating a small or medium handful of raw walnuts might give older adults a quick boost in natural antioxidants that help protect their body's proteins from damage caused by stress and aging.

What we've found so far suggests that eating walnuts may have short-term antioxidant effects in older adults, but not necessarily long-term increases in overall antioxidant levels. Our analysis of the available research shows that consuming a small or medium handful of raw walnuts might provide a quick boost in natural antioxidants [1]. These antioxidants could help protect the body’s proteins from damage linked to stress and aging. This effect appears to happen soon after eating walnuts, based on what the evidence indicates. However, when it comes to daily walnut consumption over time, the picture changes. We reviewed findings showing that eating walnuts every day for six weeks does not seem to raise overall antioxidant levels in healthy older adults who already follow a nutritious diet [2]. This suggests that while walnuts may offer a temporary boost, they may not build up antioxidant capacity in the body over weeks, at least in people who are already eating well. The evidence we’ve reviewed leans toward a distinction between immediate, short-lived effects and longer-term outcomes. We see support for walnuts playing a role in delivering antioxidants quickly, but not for them significantly changing the body’s total antioxidant levels with regular use in healthy individuals. It’s important to note that our current analysis is based on a narrow set of findings—just two assertions, each supported by 64.0 studies—and we cannot yet say how walnuts might affect those with different diets or health conditions. Practical takeaway: If you're a healthy older adult, eating a handful of walnuts might give your body a brief antioxidant boost, but don’t expect daily walnut eating to noticeably raise your overall antioxidant levels over time.