Ast level was 8 (normal 15-37). all other blood results are normal. even heart enzymes. what can cause this?

Normal: Just because the normal range is listed as 15-37, an AST value of 8 is nothing to be concerned about. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, low fat milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.