New York, May 20 (IANS): Body builders have known for over eight decades that a diet rich in vitamin E can help build strong muscles, but scientists have only now figured out one important way the vitamin works.

One big problem for many cells, such as muscle cells, is that the plasma membrane, which essentially keeps a cell from spilling its contents and controls what moves in and out, tears just from being used.

Vitamin E helps repair these membranes and thus contributes to keeping muscles healthy, the findings showed.

"Every cell in your body has a plasma membrane, and every membrane can be torn," said corresponding author of the study Paul McNeil, cell biologist at the Medical College of Georgia at Georgia Regents University in the US.

"Part of how we build muscle is a more natural tearing and repair process -- that is the no pain, no gain portion -- but if that repair does not occur, what you get is muscle cell death. If that occurs over a long period of time, what you get is muscle-wasting disease," McNeil explained.

Good sources of vitamin E include vegetable oils; nuts; seeds such as sunflower seeds; green leafy vegetables; and fortified breakfast cereals, fruit juices, and margarine, according to the US National Institutes of Health.

For the new study, rats were fed either normal rodent chow, chow where vitamin E had been removed, or vitamin E-deficient chow where the vitamin was supplemented.

The researchers found vitamin E-deficient rats were generally deficient in their running ability compared with controls.

The scientists also administered a dye that could not permeate an intact plasma membrane and found it easily penetrated the muscle cells of vitamin E-deficient rats.

The study appeared in the journal Free Radical Biology and Medicine.