HEALTH NEWS\n\xa0\n\n\xa0\nRed onion helps prevent heart disease\nEnhanced tai chi program found to improve cognition, executive function in older adults with mild cognitive impairment\nX-rays raise childhood leukemia\xa0risk\nOmega-3 fatty acids show promise against liver disease\nProtein interaction causing rare but deadly vaccine-related clotting found\xa0\nImproving deep sleep may prevent dementia, study finds