So the problem is actually lack of intake from the gut (malabsorption), not the blood. There is a problem with the intestinal crypt cells not uptaking fructose (my uptake of glucose is not at all impaired), and it bypasses the small intestine altogether and ends up in the large intestine, where sugar should never go... because when it ends up there, the bacteria have a hey day and make all sorts of byproducts such as gasses and so forth, causing all my misery. This condition is found in 40% of central europeans. All I know is that if I eat too many things with an overabundance of fructose, I am in complete pain and misery. When fructose is not absorbed, it causes an osmotic effect also, which means that things stay with it in the gut and down to the large colon, meaning that other things are not absorbed like amino acids and minerals and vitamins, which can lead to all sorts of other trouble. It's even been linked to depression (due to lack of absorption of tryptophan), anemia, osteoporosis and other things. Since I first thought of the possibility, I have eliminated fructose and fructans (wheat and onion family) from my diet and feel a million times better. It's utter hell for a vegetarian, and raw foodist. Utter hell. But I feel better! Not all fruits are high in fructose, just those that are mainly tropical... I have no tropical blood in my veins, so I'm not surprised. My ancestors are all Northern. Blueberries seem ok, and other lower sugar fruits... but mango, starfruit, and papaya just kills me. Fructose malabsorption... what a pain in the gut. Anyone else suffering from this problem?