Salads could become more colorful and healthier- thanks to unusually red tomatoes colleagues at royal holloway college, London, have genetically engineered tomatoes so that they contain unusually large amounts of lycopene and B- carotene. These compounds are among a group of chemicals called antioxidants that are thought to mop up highly reactive compounds called free radicals inside cells. Left at large, free radicals can damage DNA, possibly leading to cancer-causing mutations. Free radicals are also believed to play a role in the development of heart disease, triggering reactions that lead arteries to fur up with fatty deposits.