Blackcurrant has grown across temperate Europe and Northern Asia for centuries, used traditionally as both a food and a folk remedy for coughs, sore throats, and general vitality. Like rosehip, blackcurrant played a genuine wartime nutritional role — Britain organized large-scale blackcurrant cultivation during World War II because the fruit's exceptionally high vitamin C content could substitute for imported citrus, leading to the well-known blackcurrant cordial still sold in Britain today.
Modern research interest in blackcurrant centers on its distinctively high anthocyanin content, driving investigation into a specific, modern application — digital eye fatigue.
Blackcurrant has genuine, replicated human trial evidence for one modern and specific application: digital eye fatigue. An original pilot study found blackcurrant anthocyanin extract improved measures related to screen-induced visual fatigue, and this finding was independently replicated in a follow-up randomized, double-blind, placebo-controlled trial of 61 adult women, which found a statistically significant 29.9% reduction in blurry vision symptoms compared to placebo.
Separate, smaller trial evidence supports additional applications: a pilot RCT in 40 peri- and postmenopausal women found daily blackcurrant powder over 6 months significantly reduced bone mineral density loss at the higher tested dose. Given genuine, independently-replicated positive trials for a specific modern application (eye fatigue) plus additional small but real positive trials for bone health, "Limited-Moderate" is the accurate rating.
Berries eaten fresh, made into jam, cordial, or juice; traditionally used in syrups for coughs and sore throats.