 Researchers found the secret to being healthy at age 70. I'm Cooper Lawrence, health and wellness expert, and this is All Well and Good. We all want to age with grace, but a new study found that fewer than 1 in 10 people were able to live disease-free and maintain good physical, cognitive, and mental health by age 70 and beyond. The study suggests that sticking to a healthy diet in midlife could increase your chance of achieving healthy aging.