Nutritional Composition and Bioactive Compounds in Tomatoes and Their Impact on Human Health and Disease: A Review

Abstract

Tomatoes are consumed worldwide as fresh vegetables because of their high contents of essential nutrients and antioxidant-rich phytochemicals. Tomatoes contain minerals, vitamins, proteins, essential amino acids (leucine, threonine, valine, histidine, lysine, arginine), monounsaturated fatty acids (linoleic and linolenic acids), carotenoids (lycopene and β-carotenoids) and phytosterols (β-sitosterol, campesterol and stigmasterol). Lycopene is the main dietary carotenoid in tomato and tomato-based food products and lycopene consumption by humans has been reported to protect against cancer, cardiovascular diseases, cognitive function and osteoporosis. Among the phenolic compounds present in tomato, quercetin, kaempferol, naringenin, caffeic acid and lutein are the most common. Many of these compounds have antioxidant activities and are effective in protecting the human body against various oxidative stress-related diseases. Dietary tomatoes increase the body's level of antioxidants, trapping reactive oxygen species and reducing oxidative damage to important biomolecules such as membrane lipids, enzymatic proteins and DNA, thereby ameliorating oxidative stress. We reviewed the nutritional and phytochemical compositions of tomatoes. In addition, the impacts of the constituents on human health, particularly in ameliorating some degenerative diseases, are also discussed.

Keywords: antioxidants; degenerative diseases; human health; nutrients; phytochemicals; tomatoes.

Figure 1

Summary of health benefits of tomato.

Figure 2

Summary of the effects of nutrients and bioactive compounds in tomato on cancer, diabetes mellitus and cardiovascular disease (CVD). UV: ultraviolet; DNA: deoxyribonucleic acid; RNA: ribonucleic acid; TGF-β1: transforming growth factor beta 1; CTGF: connective tissue growth factor; NF-kB: nuclear factor kappa-light-chain enhancer of activated B cells; p38 MAPK: p38 mitogen-activated protein kinase; JNK/SAPK: c-Jun N-terminal kinases/stress-activated protein kinases; TC: total cholesterol; TG: triglyceride; LDL-C: low-density lipoprotein cholesterol; NO: nitric oxide; HDL-C: high-density lipoprotein cholesterol.