Ensuring that you eat certified organic foods is very important. Another are very seldom inspected is how well is your central nervous system working. So many times an organ will degenerate and that organ will be inspected but the nerves leading to the affected organ are forgotten. The brain controls the involuntary actions of the body, for example the heart beat, breathing, digestion of food, etc. The next priority is ensuring the body can absorb your food.
Healthy intestines play an important role here.
If they are blocked or contain molds, parasites and bad bacteria, the chances of your getting your food into your blood without the poisons these things create are very slim. If one has a body that is a self-poisoning system even where the poisons are being produced on a cellular level, it is very difficult to improve health or for that matter the quality of life. For this reason make sure you clean out this area, and then work towards greater intestinal health. Another thing is building the body's ability to fight back. One can do this through nutrition and through the use of herbal remedies.