Spinach may prevent heart attacks in diabetics, a new study shows.[Agencies]

Diabetics may soon be encouraged to take a leaf out of Popeye's book and chow down on more spinach or become happy little Vegemites with the news folic acid may help protect them from heart attacks.

Tests on lab rats by researchers in NSW and China have uncovered a new and potentially vital therapeutic role for folic acid in protecting the heart muscle from the onslaught of high glucose levels experienced by diabetics.

Folic acid is best known as a supplement taken by pregnant women to protect unborn babies from developing neural tube defects like spina bifida.

But the team conducted experimental trials on diabetic rats and found that the vitamin has a new role - significantly reducing the rate of cardiac cell death.

The 11-week course of supplements also enhanced the expression of cell-death-prevention genes and suppressed cell-death-inducing genes in heart muscles, said lead researcher Professor Lexin Wang, of Charles Sturt University.