Fruit a day keeps muscles in top shape in old age Wednesday December 16 2020 older people who eat plenty of vitamin C - commonly found in citrus fruits, berries and vegetables - have the best skeletal muscle mass. PHOTO | SHUTTERSTOCK By SARAH OOKO Summary For physical strength and ability, the body relies on skeletal muscles, which exist throughout the body. These are the only type that people can voluntarily control. According to new research conducted by scientists from the University of East Anglia (UEA), older people who eat plenty of vitamin C - commonly found in citrus fruits, berries ...