Sweet basil has been cultivated in India for thousands of years before spreading to the Mediterranean and eventually becoming a defining ingredient in Italian and broader European cuisine. It's worth distinguishing clearly from holy basil (Ocimum tenuiflorum) — a related but genuinely distinct species with its own separate traditional use and research base, despite the similar common name.
Sweet basil's modern research profile remains considerably smaller than its more extensively studied cousin, holy basil, though real human trial interest has begun to emerge.
Sweet basil has one genuinely notable positive human trial: a randomized, placebo-controlled trial of 60 patients with major depressive disorder found basil syrup produced significant reductions in both anxiety and depression scores compared to placebo over four weeks. The study authors appropriately called for "further studies with larger" samples, since this represents a single trial rather than replicated, meta-analysis-level evidence.
Beyond this one anxiety-focused trial, sweet basil's other traditional claims have considerably less standalone human research behind them, with most available evidence being laboratory-based or drawn from its more heavily-studied relative, holy basil. Given one genuine positive human RCT for anxiety, but a thin evidence base overall, "Limited" is the accurate rating.
Fresh or dried leaves used extensively in cooking; occasionally brewed as tea or prepared as syrup for medicinal use.