This systematic review and meta-analysis aimed to assess the effect of reduced sodium intake on blood pressure, cardiovascular diseases, and potential adverse effects such as changes in blood lipids, catecholamine levels, and renal function. The study included 37 randomized controlled trials and 14 cohort studies in adults, and 9 controlled trials and 1 cohort study in children. The results showed that reduced sodium intake significantly reduced resting systolic and diastolic blood pressure in adults by 3.39 mm Hg and 1.54 mm Hg, respectively. In children, it reduced systolic and diastolic blood pressure by 0.84 mm Hg and 0.87 mm Hg, respectively. Reduced sodium intake had no significant adverse effects on blood lipids, catecholamine levels, or renal function in adults. In cohort studies, increased sodium intake was associated with an increased risk of stroke and fatal coronary heart disease. The evidence suggests that reducing sodium intake is likely to benefit most people, particularly in reducing blood pressure and associated cardiovascular risks.This systematic review and meta-analysis aimed to assess the effect of reduced sodium intake on blood pressure, cardiovascular diseases, and potential adverse effects such as changes in blood lipids, catecholamine levels, and renal function. The study included 37 randomized controlled trials and 14 cohort studies in adults, and 9 controlled trials and 1 cohort study in children. The results showed that reduced sodium intake significantly reduced resting systolic and diastolic blood pressure in adults by 3.39 mm Hg and 1.54 mm Hg, respectively. In children, it reduced systolic and diastolic blood pressure by 0.84 mm Hg and 0.87 mm Hg, respectively. Reduced sodium intake had no significant adverse effects on blood lipids, catecholamine levels, or renal function in adults. In cohort studies, increased sodium intake was associated with an increased risk of stroke and fatal coronary heart disease. The evidence suggests that reducing sodium intake is likely to benefit most people, particularly in reducing blood pressure and associated cardiovascular risks.