Tomato

An annual or short-lived herb, 1–3 m tall, bushy or sprawling, covered in glandular hairs that release a characteristic smell. Leaves are irregularly pinnate with toothed and lobed leaflets, the petioles and veins hairy. Flowers are small, bisexual, five-petalled and yellow, borne in axillary cymes and largely self-pollinating. The fruit is a round to flattened berry, 1.5–10 cm across by cultivar, ripening red (some cultivars yellow, orange, pink, purple or blackish) and holding many flat, hairy seeds. Roots are shallow, concentrated in the top 20–30 cm.

According to Plants of the World Online (Kew), Solanum lycopersicum L. has a native range recorded as a "cultigen from Peru" — a domesticated plant originating in the Peruvian Andes, a scrambling subshrub of wet tropical habitats. The wild ancestors of the tomato are Andean species (Peru, Ecuador) and the Galápagos; the plant was domesticated in Mesoamerica (Mexico) and spread worldwide along trade routes. Today it is grown on every continent except Antarctica and often escapes into the wild; China, India, Türkiye and the USA are among the largest producers.

The ripe fruit is mainly water (about 94%) with carbohydrates (glucose, fructose and the organic acids citric and malic), fibre, protein and minerals (notably potassium), folate, vitamin C and beta-carotene (provitamin A). Its most prominent bioactive is lycopene (C40H56) — the red carotenoid pigment with strong antioxidant, anti-inflammatory and cardioprotective activity, concentrated in the fruit tissue and skin. The stems, leaves and green fruit also contain the glycoalkaloids tomatine and solanine at mild levels, along with volatile aroma compounds such as 2-isobutylthiazole and hexanal.

On uses and research, tomato is a staple food eaten fresh, in salads, sauces, paste, juice and canned products and as a seasoning. Lycopene is better absorbed when cooked with fat — products such as tomato sauce and paste deliver more usable lycopene than raw fruit. For health, several clinical trials have examined lycopene and prostate cancer: Chen et al. (2001) gave 32 patients about 30 mg lycopene/day from tomato sauce, and Grainger et al. (2008) found about 25 mg lycopene/day for eight weeks lowered PSA in 34% of participants (n=41). A 2025 meta-analysis of 121 studies (over 108,000 cancer cases) associated higher lycopene intake with lower prostate-cancer risk; the authors caution that more randomised controlled trials are still needed. Reviews published in 2026 (Anghel et al.; Benabdelmoumene et al.) reaffirm lycopene's antioxidant, anti-inflammatory, anticancer and cardioprotective effects.

On safety, ripe tomatoes are safe and nutritious for most people; by contrast the leaves, stems and green fruit contain tomatine and solanine — glycoalkaloids that can cause digestive upset if eaten in quantity, so stems and leaves are not used as food and green fruit should be limited. People with acid reflux should be mindful because tomatoes are acidic; tomato allergy is rare but possible. On conservation, this crop is ranked Least Concern (LC) and is not threatened; as a global crop its conservation value lies in cultivar diversity, maintained in seed banks and botanical gardens.