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Beans, Beans, good for your heart…
To quote a favorite saying among male classmates when I was in second grade. This quote claims that beans are good for your heart, among other things.
Not that we can put any stock in a childhood saying, of course, but beans are generally considered a healthy food and when combined with rice, form a perfect protein for vegetarians. Yet, they’re not recommended on certain diets like Paleo and Keto and the contain controversial compounds called lectins.
Beans show up in some form in many different cultures and countries, though preparation methods vary vastly. Americans, for our part, get most of our bean consumption from soy and soy products.
Peanuts, technically also a legume and not a nut, also make up a substantial part of our bean consumption, and are also a rapidly rising allergy, especially among children.
What’s In A Bean?
Beans contain a lot of soluble fiber, protein, carbohydrates, folate and iron. They also contain Lectins, which are also present in high amounts in grains. Because of their protein content, beans (legumes) often get a primary role in the diet of vegetarians, though not without cost.
The lectins in legumes are an important protective measure for the bean plant, and a potentially harmful one for humans. Before the dawn of genetically modified disease resistant soybeans (gee, thanks Monsanto) and their corresponding toxic pesticides and herbicides, legume plants were actually quite able to defend themselves.
Benefits of Beans
Beans are a great source of fiber and plant-based protein. In general, beans are relatively low in fat and calories, making them a common recommendation in various diets including the Mediterranean diet and slow carb diet.
It also turns out that the second graders were right… beans may, in fact, be good for the heart.
A meta-analysis of research showed that regular consumption of beans can reduce LDL cholesterol and other risk factors for heart disease and stroke. Another study showed that eating beans may improve HDL numbers and lower inflammation.
But, before we all eat beans for every meal…
We need to understand the potential dark side of beans and how to mitigate it.
Let’s Talk About Lectins
Lectins are specific proteins that bind to carbohydrates, and exist in plants in varying levels as a protective mechanism. As Dr. Steven Gundry explains:
A lectin is a type of protein (susceptible to various diseases, bacteria, and viruses) that forces carbs (sugars, starches, and fibers) to clump together and even attach to certain cells in your body when you eat them.
In short, plants use lectins to protect themselves from being eaten. Or if, eaten, to protect their seeds (like beans) from digestion so they can live to sprout another day.
Problem with Lectins
At the extreme, lectins are potent enough to be a biological warfare agent as in the case of ricin. Ricin is a lectin isolated in the castor oil bean and it acts on certain protein cells, allowing the ricin to enter the cell and prevent protein synthesis, eventually leading to cell death.
Obviously, some lectins have more toxic effects than others, as evidenced by the example above, but all lectins have some effect on the body. This is the reason that grains, beans, and other lectin containing foods cannot be eaten raw. In fact, ingesting even just a few raw kidney beans can cause vomiting and digestive problems.
Lectins in the Intestines
Lectins are capable of harming the lining of the intestines, especially the microvilli. This happens when the lectins bind to the protein receptors in the intestinal lining, causing damage.
When the intestines are damaged, lectins, and the foods that they bind to, can pass through the intestinal wall and into the blood stream. These sticky molecules can then wreak havoc in the bloodstream.
Lectins and Insulin Resistance
Once lectins are floating around in the bloodstream, they can bind to any carbohydrate containing protein cells, including insulin and leptin receptors, desensitizing them. Without proper insulin and leptin function, problems like diabetes and metabolic syndrome can emerge. It is speculated that lectins may cause insulin and leptin resistance, two major factors in obesity and diabetes.
What is not so speculative is that once you’re leptin-resistant, you become obese and insulin resistant, and at that point you are intolerant to any type of carbohydrate. This may explain the efficacy of carbohydrate restriction in weight loss and improving general health.
Lectin may cause leptin resistance, affecting its functions (signal have high levels of leptin and several effects gathering to protect from lipid overload), as indicated by studies on effects of single nucleotide polymorphisms on the function of leptin and the leptin receptor.
Such leptin resistance may translate into diseases, notably it could be responsible for obesity in humans who have high levels of leptin.
Lectins and Autoimmune Disease
Lectins also have the potential to bind to any carbohydrate containing tissue in the body, from the thyroid to the heart. (Maybe beans aren’t so good for the heart after all!). My personal theory is that sticky particles and pre-digested food floating around in the bloodstream does much more to clog arteries than slippery saturated fats, which get the bad rap!
So, lectins can contribute to disease and obesity when they pass through the intestinal wall and float through our bloodstream with other parts of pre-digested food. Personally,I’m not a big fan of the idea of partially digested food floating around in my blood, so is there a solution?
How to Reduce Lectin in Beans and Grains
I certainly don’t want to let beans take all the heat here! Grains contain just as high of levels of lectins and can wreak just as much havoc, if not more.
All plants, in fact, contain lectins in varying amounts. Grains and beans (especially soybeans and peanuts) have especially high concentrations, along with nuts, pasteurized dairy, and genetically modified foods.
Use Traditional Cooking Methods
The harmful effects of lectins (and phytic acid) can be mitigated some by using traditional methods of perpetration, like sprouting, fermenting, and soaking, though even these do not remove the lectins completely. Unfortunately, these methods are rarely practiced anymore, and grains in the processed forms we typically consume are little lectin powerhouses.
Use a Pressure Cooker
Another easy way to reduce and almost completely eliminate lectins is to cook foods in a pressure cooker like an Instant Pot. This greatly reduces the lectin content of beans and is an easy and fast way to cook them.
I recommend soaking beans overnight in several changes of water and then pressure cooking according to the directions on the pressure cooker.
Buy Safe Brands
On a recent podcast episode, Dr. Gundry mentioned that Eden brand beans are pre-soaked and cooked in pressure cookers so they are a great brand to eat out of the can for convenience.
What Level of Lectin Consumption is Safe?
This is a difficult question with no single answer. Certainly, if foods containing high levels of lectins are going to be consumed, traditional methods like soaking, fermenting, and sprouting or pressure cooking should be used to minimize the lectin content.
But many foods contain lectins, not just beans and grains. We can’t avoid them completely. The key is finding a workable balance that minimizes the worst sources.
My personal recommendation is the get rid of the highest sources of lectins and reduce the other sources if possible. The highest sources are:
- Improperly prepared legumes, seeds and nuts (reduce by soaking, sprouting or fermenting and pressure cooking).
- Grains like barley, oats, and wheat
- Nighshade vegetables like tomatoes, potatoes, peppers and eggplant (can be reduced by peeling and pressure cooking)
Lectin Consumption: What I Do
Personally, I avoid the grains (and legumes unless properly prepared), soak nuts overnight, and trust that the much lower levels in other plants won’t harm my intestines too much. Removing all processed and commercially prepared foods will remove the worst offenders: grains and soy. When I was actively working to halt my autoimmune disease, I avoided lectins much more carefully.
If you are overweight or attempting to lose weight, a more stringent avoidance of lectins might be helpful. Since lectins can bind to leptin and insulin receptors, they can increase resistance to carbohydrates and cause weight gain or inability to lose weight.
For many, avoiding lectins, especially for a year or so, can help heal the intestinal lining, and facilitate weight loss, reduction of allergy symptoms, and other health improvements.
This article was medically reviewed by Dr. Lauren Jefferis, board certified in Internal Medicine and Pediatrics. As always, this is not personal medical advice and we recommend that you talk with your doctor or work with a doctor at SteadyMD.
Do you eat beans? If so, what kind(s)? Share below!