The invention provides a composition comprising methylphosphonic acid or a salt thereof for human consumption. The invention also provides a method for treating aging and/or improving health in a human. Methods of the invention involve providing or administering methylphosphonic acid or a salt thereof to a human in need thereof for consumption. The invention provides nutritional and pharmaceutical compositions and articles containing such compositions including, for example, a nutritional supplement, a beverage, a food substance, a prepackaged food or meal, or a nutraceutical, as well as a pharmaceutical.