Anti-nutrients in grains, beans, tomatoes, potatoes... play a major role in diseases.
Textbooks on antinutrients read like books on what not to eat- Neolithic foods are the most prominent. Professor Irvin Liener published one of the most famous of these books in 1980. In the first chapter he points out that when we started cooking inedible plants, new toxins entered the diet for the first time. Ironically, he wasn't trying to promote Paleolithic diets- his aim was to help agricultural scientists more safely feed the world on grains, beans and potatoes.
It's a technical subject, and I'll do my best to make it clear to you.
Consider our friend, the apple. When an animal eats an apple, it profits by getting a meal. It swallows the seeds and then deposits them in a pile of dung. With some luck a new apple tree might grow, and so the apple tree has also profited from the arrangement. In nature as in finance, it is good business when both parties make profit happily. Consider what would happen if the animal were greedy and decided to eat the few extra calories contained within the apple seeds- then there would be no new apple tree to continue on the good work. So, to stop this from happening, the apple seeds contain toxins that have multiple effects:
* firstly, they taste bad- discouraging the animal from chewing them
* secondly some toxins are enzyme blockers that bind up predators digestive enzymes- these also act as "preservatives" freezing the apple seed enzymes until sprouting- Upon sprouting of the seed, many of these enzyme blockers disappear.
* thirdly, they contain lectins- these are toxic proteins which have numerous effects. They act as natural pesticides and are also toxic to a range of other species including bacteria, insects, worms, rodents and other predators including humans .
Of course, the apple has other defenses- to start with it is high above the ground well out of reach of casual predators, and it also has the skin and flesh of the apple to be penetrated first. Above all though is the need to stop the seed from being eaten, so that new apple trees may grow.
Now, please consider the humble grain. Once again as a seed its duty is mission critical- it must perpetuate the life cycle of the plant. It is however much closer to the ground, on the tip of a grass stalk. It is within easy reach of any predator strolling by. It contains a good source of energy, like a booster rocket for the new plant as it grows. The grain is full of energy and in a vulnerable position. It was "expensive" for the plant to produce. It is an attractive meal. Its shell offers little protection. Therefore, it has been loaded with toxic proteins to discourage predators- grains are full of enzyme blockers and lectins. You may be surprised to learn that uncooked flour is very toxic- please don't try eating it as you become very sick. And yes, I don't recommend al dente pasta (if one must eat pasta at all).
Beans too are full of enzyme blockers and lectins. Potatoes contain enzyme blockers, lectins and another family of toxins called glycoalkaloids. Glycoalkaloids (GA) unlike lectins and enzyme blockers aren't destroyed by cooking, even deep-frying. GA are particularly high in green or injured potatoes, which must never be eaten even if trimmed heavily and well-cooked. Many people have told me that they eat small amounts of raw potato- this is a dangerous habit and it should be discouraged very strongly.
These toxins in foods are commonly referred to as antinutrients. Let's learn some more about them:
Enzyme Blockers: These enzyme blockers are abundant in all seeds including grains and beans, and also in potatoes, serving to hold them in suspended animation and also acting as pesticides. Most commonly they block the enzymes that digest protein (proteases), and are called "protease inhibitors". They can affect the stomach protease enzyme "pepsin", and the small intestine protease enzymes "trypsin" and "chymotrypsin". These small intestine enzymes are made by the pancreas (it does a lot of other important things besides making insulin). Some enzyme blockers affect the enzymes that digest starch (amylase) and are called "amylase inhibitors".
When GBP are cooked, most of the enzyme blockers are destroyed, but some are not. In human volunteers and in animal experiments high levels of protease inhibitors lead to increased secretion of digestive enzymes by the pancreas. This is because the body can sense that the enzymes have been knocked out and orders to pancreas to make more. Even if the effect of GBP based foods is only a small increase in pancreatic enzyme secretion, over many years it all adds up to a lot of extra work.
They are effective poisons- rats cannot gain weight if they have substantial amounts of enzyme blockers in the diet. As far as their preservative action is concerned, I need only to remind you that the potted grains in the tombs of the Egyptian pharaohs were still viable and sprouted after thousands of years locked away.
Grain eating birds have evolved digestive enzymes that are resistant to grain protease inhibitors. Lectins (Haemagglutins)................ Meet Hannibal
Lectins are natural proteins that have a large variety of roles. They are amongst the most fascinating and stimulating of all biological compounds, and I have no doubt that they play a major role in many "unexplained " diseases. I think of them as "Hannibal Lectins" as they remind of the devious criminal mastermind in the shock horror movie "Silence of the Lambs.' Lectins are like master code-breakers. The cells of our bodies are studded with receptors which are like code pads to ensure stimulation only under the correct circumstances. Lectins have the ability to crack these codes and stimulate the receptors causing a variety of responses- covering basically the full repertoire of the cell and even tricking the cell into doing things it normally cannot do.
They also have a knack for bypassing our defenses and "getting behind the lines", and then they can travel all over the body causing harm. They can, for example:
- strip protective mucus off tissues,
- damage the cells lining the small intestine- disrupting the microscopic fingers called villi and microvilli,
- get swallowed whole by the small intestine cells ("pinocytosis")
- bind to cells including blood cells causing a clot to form (hence they were initially called "haemagglutins")
- make a cell act as if it has been stimulated by a hormone-
- stimulate a cell to secrete a hormone
- promote cell division at the wrong time
- cause gowth or shrinkage of lymphatic tissue ("outposts" of white blood cells)
- cause enlargement of the pancreas
- cause cells to present codes (HLA's) that they normally should not use
- cause cell death (apoptosis)
Lectins break down the surface of the small intestine, stripping it of mucus and causing the cells to become irregular and leaky. Some lectins make cells act as if they have been stimulated by insulin. Others cause the pancreas to release insulin. Others cause immune cells to divide in the wrong way, causing growth of some white blood cells and breaking down the control of the immune system. Others cause cells to present the wrong codes (HLA's) on their surface, tricking the immune system into thinking that intruders have been found and activating the immune system inappropriately- thus leading to "autoimmune disease" where the body's tissues are attacked by its own immune system.
Autoimmune diseases are incredibly common and increase every year that a person gets older. A disordered immune system also has a much harder job recognizing and attacking the real intruders- invading germs and cancer cells (you may have heard that scientists think that most people generate many cancer cells in a life time but that the immune system cleans most of them up).
It is not known whether lectins can cause cancer- this is one of the most important questions in medicine today. They certainly affect colon cells in the test tube. I feel that they are likely candidates as they can stimulate abnormal cell growth and they also cause disorder in the immune system.
Lectins have many other roles besides defending seeds. For example in beans, lectins act like a glue to enable nitrogen-fixing bacteria to bind to the roots of the plant. Many important lectin families are found in animal tissues, but as we are carnivores, we have evolved to be able to deal with these- just as birds that live on grains have evolved to be resistant to grain lectins.
It is ironic that the lectins were discovered more than 100 years ago and yet so many questions remain unanswered- the same was true of the immune system until the 1980's. I hope that there is more research done into lectins as they hold a whole world of disease mechanisms of which most of the medical community is blissfully unaware.
Exorphins:
Exorphins are food chemicals that have morphine-like activity. They are found in dairy products and wheat. Our body has its own natural morphine like substances that are called endorphins. Endorphins work by stimulating a type of nerve cell surface receptor called endorphin receptors. Endorphins are very important in controlling pain and addictive behaviour.
Exorphins also act on endorphin receptors and may stimulate them or block them. It is logical that exorphins may therefore affect chronic pain and also affect addictive behaviour.
Hmmm, I'm sure intestinal parasites are delighted about this state of affairs.