Overview

• Experts recommend about 75–100 grams per day as the sweet spot to gain cardiovascular, digestive and cognitive benefits without digestive upset.
• Testing highlights frequent residues: the Environmental Working Group detected pesticides in 90% of U.S. samples, and the Niedersachsen food-safety authority found residues in 68% of tested berries in Germany, reinforcing a preference for organic or vetted sources.
• Year-round supply leans on long-distance imports, especially from South America, which increases transport emissions and water use, so seasonal regional purchases can shrink the footprint.
• Wild blueberries deliver higher levels of anthocyanins and polyphenols than many cultivated varieties; forest-picked berries should be heated to at least 60 °C to eliminate the small fox tapeworm risk.
• Very high intakes may cause laxative effects, bloating or blood-sugar swings, and people with fructose intolerance, salicylate sensitivity or those taking blood thinners should take care.