Lectins – Decomplexicating Equine Nutrition Part 11 of 12

This Is Really New Stuff

The things I will be writing about here is mind blowing - and very new. I am excited about this information for a lot of reasons but the most important for horse owners is that lectins are, for the most part, not good. For example, about 5 and 6 years ago a Nobel prize was awarded for research of lectins as a cause for making insulin ineffective. Can anyone say insulin resistance (again)?

Lectin is a new word for many of you but scientists have known about them for a while. A lectin is a protein made by plants. OK so far? Let’s start by telling you what lectins do.

We all know about the immune system within ourselves that defend against attacks by bacteria, viruses and other bugs trying to take over our bodies but did you know that plants also have a system to prevent attacks? Further, did you know that many plants do not want to be eaten? This especially applies to their “babies” or what we non-botanists call seeds. During the 100,000 to 200,000 years humans have been Homo sapiens (modern humans), and I assume horses too, we have learned to live with certain plants willing to become our food without the predator becoming sick or dying from them. This is usually because of a win-win relationship. For instance the horse eats the grass and then they defecate on the grass which in turn fertilizes the grass to help it grow. In addition, as they walk they knock off the seed heads and carry them on their wet legs which helps to spread the seeds.

Examples of defenses made by plants to prevent their demise from predators includes thorns (cactus, roses), irritating substances (poison ivy), and toxins (rhubarb leaves, belladonna). But they also can be more subtle in their attack. One of the most notorious lectin is gluten which slowly causes illness in humans especially susceptible people with celiac disease. Gluten is by far not the most offensive of subtle lectins. There are worse and we are just learning about them.

Remember that anything you place into your mouth and swallow is NOT inside of you. The food you eat (raw material) feeds the bacteria living in your gut creating the fuels (glucose and short chain fatty acids) that allows the mitochondria to make the energy to run the cells. When some new raw material is introduced to the gut that has a new foreign protein (a lectin), an alert is sent out to our immune system. The first line of defense is the slippery and sticky mucous covering the gut lining which binds to these foreign proteins and escorts them out of the gut without damage. This includes the mouth and nasal passages too. Ever get a stuffed up nose when eating something spicy? That is the response to a lectin.

The mucous is actually a mucopolysaccharide. Polysaccharide is a string of sugar molecules and “muco” means it is made by the mucous membranes that line the gut. The sugar (polysaccharide) binds to these lectins. As a side note, guess what a chondroitin is in the joint supplements you feed your horse? It is an oligosaccharide which is a sugar that binds to the lectins that cause joint inflammation. These supplements work in the gut and not in the joint. But guess what? If you produce enough mucous, it will also do this job making the chondroitin supplementation unnecessary.

But when there are 1) a lot of these many different lectins and 2) a lot of dead good bacteria (lipopolysaccharides) from the high carbohydrate feedings, then damage to the gut lining occurs and mucous production is reduced or overwhelmed. The end result is a leaking gut due to the breakdown of the tight junctions as well as a breakdown of the primary defense system against lectins. Of course this leads to a horse that is less then perfect in all aspects of health.

Where Did The Bad Lectins Come From?

Humans found that we could grow grains and store them making them available for use in winter when food was scarce. It is interesting to note that there is no evidence of osteoarthritis in bones found in archeological sites until the Egyptians and the Pharos. And guess who ate more grains than any other human on Earth? Yup - the Egyptians. The development of grains as a crop started about 8000 years ago in the “fertile crescent” of land between the Tigris and Euphrates Rivers in the land now know as Iran. The Egyptians further developed the use of grains, especially wheat, and became the leaders in its use to store this raw food for eating through the dormant months or droughts. It is the development of grains and grain storage that directly led to the expansion of civilizations (Egyptian, Greek, Roman, Mongolian, Viking etc) and the movement of exploration of man across the globe (Columbus et al). The diseases of man today including osteoarthritis, atherosclerosis and diabetes are seen in the mummified Egyptian remains but not in remains of man prior to 10,000 years ago.

The lectins of wheat are now well known including the common gluten and the more destructive cousin Wheat Germ Agglutinin (WGA). Then explorers such as Columbus brought back with him new foods such as tomatoes, squash, cucumbers, peppers and eggplant with lectins that are particularly destructive. Yes, only 500 years ago our gut bacteria were introduced to the lectins of these plants from the group of plants called nightshades (by the way, they are NOT vegetables but actually fruits) and their associated destruction of our gut lining and subsequent disease effects such as insulin resistance, diabetes and obesity soon followed.

Horses became domesticated about 4000 years ago because our expansion of civilizations, wars against neighbors and exploration of far away lands required their use. Feeding them grains seemed logical as horses were often kept in places without pasture such as boats for ocean crossings or fenced in areas for ever-ready use against enemies. Making hay was not efficient as hay farming techniques and the shipment of hay are recent developments.

The Damage Of Lectins

The direct damage to the tight junctions of the gut lining caused by the invading foreign proteins creates a space between the cells where more lectins can move right into our body. The term describing this is leaking gut and lectins have been shown to be a primary cause of leaky gut syndrome. The more damage, the more foreign invaders, the more inflammatory immune response, the more disease and ultimately, the fewer number of these animals eating the plant and therefore the better chance for the plant to survive.

In horses, the introduction of grains as a popular feed for all horses everywhere is only at most 50 years old. In 1973 as a stall mucker I would go to the railroad yard with the other workers and unload a box car full of high quality oats. It was a tough day and it was certainly harder than the ability of you today to pick up the phone and order a few bags of that fancy feed with the pretty pictures, catchy name and a back panel filled with unpronounceable words - and STACKED IN YOUR FEED ROOM by the strong delivery person! Add to this the increasing cost of hay and the decreasing availability of pasture. Grain is becoming a more cost effective option and a more efficient way to feed the horse. But this is from the human perspective. But from the perspective of the gut microbes of the horse, it is becoming lethal.

An important fact about lectins is that they are found in the outer layers of grains. This is why the white breads of sourdough, French baguettes and Italian bread have the least amount of lectins. They use the wheat that has the outer layer removed. This outer layer is the bran and middlings that are collected and fed to your horses. Did you know that back in medieval times the wealthy noblemen ate white bread while the poorer peasants not affording the process of stripping off the outer layers to make white bread were left to eat the whole grain bread? These peasants historically had more diseases. Rice is also a grain and their lectins are also in the outer layer. Most people in the Asian countries where rice is the main starch remove this outer layer before eating their rice. This may make you pause the next time you order brown rice or feed your horse a mix with rice bran in it.

Most people don’t feed the nightshade fruits to their horses, but it is interesting to know that every good Italian removes the skin and seeds of the tomato before eating them. They learned a long time ago that removing these lectin laden parts ended their illnesses caused from eating this new food that Columbus brought back from the new world.

Lectins and Disease in Horses

Most of the diseases so popular today in horses were uncommon back before grain became abundantly available. In fact, reading the vet texts written in the late 1800’s you will find little of what we see today in the form of illness. While not the only changes, the most common and persuasive change seen throughout this country in the care of the horse is the introduction of abundant and readily available grain with their associated foreign lectin proteins and high carbohydrate (starch) content. Please understand that this is only a hypotheses based on human research but for me and what I am seeing around the country, it explains why so many horses that are removed from grain show such positive improvements. At the very least, they seem calmer and more willing to do their jobs and exist in the human world we have created for them.

What about whole grains like the race horse oats that we fed 45 years ago? While a no-grain approach is the safest, if you just can’t stop feeding grain (extreme weather for instance), first go no-grain for at least 6 weeks to allow the full healing of the gut and the reestablishment of the good gut bacteria. Then, if you are looking for something to add, try adding extra protein if it is a top line or a better hoof you are looking for. Then, for added fat, go with the whole grains such as oats. Use only enough whole grains to meet a need and stop feeding it when that need is no longer necessary such as the availability of spring pasture. In my experience though the results from a no grain diet will stop you from ever feeding grain again in almost all circumstances. (See the article in “The Horse” titled “Racing Standardbreds on an all forage diet”).

Remember, almost every grain mix sold today is filled with byproducts with the lectin WGA ladened wheat middlings the most prevalent. All the byproducts including all the brans (wheat, rice) and hulls (oat, soy) and pulp (sugar beets) are the outer layers where the lectins are most abundant. In other words, feeding byproducts is feeding concentrated lectins. In addition, other soft seeds are also fighting for survival agains predators eating them. Soft seeds include all grains but don’t forget sunflower seeds, flax seeds and any other seed in grain mixes. These too will have lectins that may be disrupting the gut lining. While there is no scientific evidence of this yet, why feed something to your horse he would never eat (at least continually) in the wild?

As a comparison, an example of a hard seed is a peach. When the fruit becomes ripe, 3 things happen. First, the color of the skin changes and this is most likely what we developed color vision. Second, the lectins in the skin that make the fruit bitter are removed by the plant allowing our taste buds to accept the fruit. Third, the glucose within the fruit is converted to fructose which is a better sugar to create fat on our bodies. In addition, fructose is less stressful on insulin which is beneficial to that system, but fructose is more efficient in adding fat. Anybody want a glass of orange juice??? The benefit of eating the ripe hard seed is that we become fatter for the upcoming winter and the seed is thrown away which perpetuates the peach tree. Win - win.

There are no hard seeds for horses to eat and this is the reason, possibly, for them not having good color vision. There may be an exception and this would be coconut. The meal made from the meat of the coconut has been shown to be beneficial and noninflammatory in humans and may even be a prebiotic for the good gut bacteria. It is commercially available for horses and I recommend coconut meal for horses needing a source of noninflammatory food. An example would be for a horse 25 to 30 years old that when grain is removed their bodies seem to not respond right away. Coconut meal adds the food needed to add condition to these elder horses.

What we know is absolutely safe for horses is simply feeding them what grazers were made to eat - grass and plants low to the ground. If they consumed their seeds it was only for a short time of the year. The concentrated feeding of wheat, oats and other grains was not an option until humans harvested them and fed only the seeds to the horse. The remaining straw (oat straw, wheat straw, rye straw) are not preferred by the horse and are only eaten when there is no pasture or grass hay available.

This information is well ahead of most articles on equine nutrition. It is only about 5 years old in human nutrition. In horses, the discussion on the gut microbiome has started and at some point it will expand to lectins. Until then, if you remain skeptical about the effects of lectins it’s OK. Removing grain and grain byproducts to reduce the effects of carbohydrate dependency is good enough. But as you remove these you are also removing the lectins. I’m good with that.