I agree with this. My teacher, Doctor Buteyko taught us that refined products have no B-vitamins and this suppresses normal work of mitochondria and cellular respiration causing tissue hypoxia.
Meanwhile, one may have a best diet, but breathe 2-3 times more air than the medical norm and, hence, suffer from over-breathing and resultant hypoxia due to lifetysle factors, which we see only in sick people: breathing through the mouth, sleeping on one's back, talking too much, poor posture, nutritional deficincies, overeating, etc.
Curiously, people can breathe 3-4 times the norm and believe that their breathing is easy! But this will be enough to make tumours grow!