Fructose is found in three forms in our diet—as free fructose (in fruits, honey, high fructose corn syrup, agave nectar, etc.), as part of table sugar (glucose+fructose), and in most vegetables and grains—along with chains of fructose molecules, known as fructans.
Modern fruits have been selectively cultivated to be much sweeter and lower in fibre than traditional fruits eaten by most primates in the wild. The very high fructose content in modern fruits causes monkeys in captivity to develop mental and physical health problems. As this knowledge has become more widely accepted, more and more zoos have stopped feeding monkeys fruit. For example, according to keepers at Paignton zoo, “… reducing the sugars in their diets has calmed them down and made their groups more settled”. Clinical trials on human primates indicates the same.
If you’ve ever had the chance to eat wild edible fruits, you will know that they are rarely found, and until agriculture, fruits that humans could eat, had always been rare in nature. They are strictly seasonal, smaller, more sour, more fibrous and contain more seeds than do cultivated modern fruits. We love sweet and juicy fruits, and healthy people with normally functioning livers can get away with eating a few pieces of fruit each day. However if your liver is not functioning properly, the fructose you eat in your foods can be causing you mental upset.
Fructose is metabolized in a two-step phosphorylation process using two enzymes (aldolase iso-A and aldolase iso-B), occurring firstly in the small intestine and then in the liver (and to a minor extent in the kidneys). Over-worked livers have difficulty producing adequate aldolase iso-B enzyme, and when this happens, the liver is unable to fully metabolise fructose (See here for more info on this ) which then re-circulates back into the blood stream, and ultimately accumulates in the brain. Even though our brains produce a small amount of aldolase iso-C enzyme in an attempt to buffer this, often it is not enough to denature all the fructose which then causes mental dysfunction—as parts of the brain close down. This illness is called Partial Fructose Intolerance.
We observe the mental disruption in our children when they come home from birthday parties, during which they have eaten too much sugar. Mental disruption also occurs in people who drink too much wine, beer, or fruit juices—and who eat too much fruit or dried fruit for their livers to cope. When the person’s liver is not functioning efficiently and they eat too much fructose, they are more prone to experience emotional fights, oscillations into depression and feelings of low self worth. When people are stressed and have eaten too much fructose, their short term memory is less efficient. When this happens, most people then turn to coffee, tea, drugs, more sugar, more alcohol etc, to combat this symptom. As a general rule people will feel mentally much better if they do intense exercise to ‘burn-off’ excess fructose.
Through our Health Ecology Solution and Healing from Cancer Programs we support people to reverse and recover from chronic illnesses. One of the things we do is to help our clients remove excess fructose from their diets to allow their immune system and liver to rest and recover. We also take our clients through a fructose challenge to fully understand and experience the exact effects that fructose specifically has on them, both physically and emotionally.