The city is offering local seniors an opportunity to gain some tips on staying healthy. The Council on Aging is holding its annual health fair Thursday from 10 a.m. to 1 p.m. at the Connolly Center, 90 Chelsea St. A variety of health organizations, agencies, and private practitioners, including Mystic Valley Elder Services, the Red Cross, and the US Food and Drug Administration, will be on hand to provide information on elder health care topics. Included in this year’s fair will be a number of new participants, including the YMCA, the Middlesex County sheriff’s office, and the MSPCA-Angell. There will also be bone density testing, free massages, and free food samples from Whole Foods Market. The fair is free and open to all. For more information, contact Dale Palma, director of the city’s Council on Aging, at 617-394-2323, or Ida Reppucci at 617-394-2260.