There are different types of resistant starch in foods. Amylose and amylopectin are examples. It is starch that is tightly packed in a stable crystalline form within foods, making it difficult to digest. The more resistant starch that reaches the colon undigested, the less calories we absorb from that food. When resistant starch reaches the colon, the bacteria there use it for fuel. The resistant starch is also, therefore, a prebiotic, meaning it serves to fuel the growth of beneficial bacteria in the colon.
This process of degrading these starches by bacterial action is called fermentation, and it produces a type of fat called short-chain fatty acids (SCFAs). In other words, the resistant starch does not even get converted to a simple sugar; it gets converted into a simple fat. Only a small percent of these calories are absorbed by the body, but they are highly beneficial. So calories from resistant starch are listed on the food labels but almost 90 percent of those calories do not get absorbed and they do not raise blood sugar at all. Resistant starch is especially associated with one type of SCFA called butyrate.
Now here’s the fascinating part: even though only a small amount gets absorbed, butyrate offers a wide array of health benefits, including strong protection against colon cancer. It protects our bodies in lots of other ways too, namely by enhancing the absorption of beneficial minerals like calcium and magnesium and so, importantly, improving insulin sensitivity. It has the opposite effect of eating sugary or high-glycemic starches. It actually improves diabetic glucose numbers the day after it’s eaten.
Most importantly, these SCFAs slow down glycolysis in the liver, thus delaying hunger, and they increase the breakdown of body fat as a source of energy, facilitating weight loss. As you recall, glycolysis is the breakdown of the stored glycogen back into glucose for use by the body. The small amount of SCFAs that are absorbed increases fat oxidation, meaning your body burns fat for energy more efficiently, encouraging weight loss.
When you eat a meal of mostly green vegetables, eggplant, onions, mushrooms, and a cup of beans, biochemical events occur that work medicinally; they repair the biochemical defects that would lead to diabetes. In fact, in direct contrast to meat and potatoes, just one additional serving of green vegetables in a diet has been demonstrated in a meta-analysis to offer significant diabetes protection independent of the effects on weight reduction. The authors of the study speculate these profound benefits were due to the high levels of beneficial micronutrients in greens. Then you add beans, and more magic happens.
Beans store well and are inexpensive, highly nutritious, and entertaining.
Let’s review some of the benefits of eating greens and beans, instead of bread, rice, and potatoes:
- Increased nutrients, SCFAs, bacterial activity, and fiber, which lower cholesterol and triglycerides
- A sensation of fullness or satiety, leading to meal satisfaction even though fewer calories are consumed
- Lower glucose level and improved insulin sensitivity, aiding in the reversal of diabetes
- Promotion of good bacteria, which aid nutrient absorption; suppression of bad bacteria and their toxic products
- Bowel regularity, preventing constipation
- Efficient removal of cholesterol and other unhealthful fats
- Less fat stored after meals
- Increased fat breakdown
- Slowed glycogen utilization in the liver, which delays hunger and promotes a lower calorie intake
- Protection against colon cancer development
Beans are the very best source of resistant fiber. Although the types of beans and preparation methods cause varying amounts of resistant starch (canned beans are more glycemic), in general, the starch in beans is about evenly divided between slowly digested starch and resistant starch. Note, though, that taking products such as Beano to increase digestibility of beans will also increase the digestibility of resistant starch and enhance its caloric absorption. Instead, it is better to allow the body to adjust to the use of beans in the diet over time, then, gradually, favorable bacteria will increase in number in the digestive tract, which will facilitate the digestion of the resistant starch in the beans.
Black beans, for instance, contain the highest amount of total dietary fiber at 43 percent, and 63 percent of their total starch content is resistant starch. Cereal grains, especially barley and corn, follow legumes in their percentages of resistant starch that reach the colon, but they drop off significantly in fiber content. Heavily processed flours and grain-based products have a very low resistant starch content with a range of 1.7 percent in white flour to about 4.6 percent in pasta. The point here is that the major source of carbohydrates in the diabetic diet should be beans, not grains or root vegetables like potatoes. I sometimes call my diabetic diet recommendations the greens and beans diet.
The resistant starch found in beans powerfully reduces hunger and, thus, food consumption over many hours, coinciding with the fermentation that takes place in the large intestine hours after eating the beans. So eating beans with lunch will reduce your hunger and appetite for dinner many hours later, overall lowering the amount of calories you desire for the day. For diabetics, beans are critical for lowering the insulin requirement for starch digestion. They also supply amino acids that complement the other vegetables, nuts, and seeds to enhance the biologic value of the protein in the diet, without raising IGF-1.
Refer to the food data chart. If you add up the percent of resistant starch (RS) (90 percent of which is unabsorbed) and fiber (which also is not absorbed) and make comparisons with other starches, you will see why beans are the preferred starch for diabetics. The RS + fiber is a handy measurement to illustrate the favorable effects of beans for diabetics compared to other high-carbohydrate foods, and certainly it is a much more critical measurement than the glycemic index for diabetes management and weight loss.
Let’s not forget that the ANDI scores of beans are high as well. They have been found to contain significant levels of polyphenols, which have anticancer effects. Red and black beans have been found to produce apoptosis (cell death) of colon cancer cells. This means the compounds in beans and those produced in the digestion of beans have beneficial effects to fortify cells against cancer. They also cause cells that have become precancerous or cancerous to die off before they can actually multiply into cancerous tumors. They protect people against colon cancer—the exact opposite of what red meat does. The Polyp Prevention Trial demonstrated that beans provide more protection against advanced adenomas of the colon than any other food does, with a 65 percent reduction of adenomas in participants in the highest quartile of dried bean intake. And people who eat beans merely twice a week were found to have about a 50 percent reduction of colon cancer. Imagine the protection we would achieve if we ate beans almost every day in conjunction with other well-investigated cancerfighting foods.
Other sources tout beans’ life-lengthening benefits too. The conclusions of an important longitudinal study show that a higher legume intake is the most protective dietary predictor of survival amongst the elderly, regardless of their ethnicity, in multiple populations studied. The study found that legumes were associated with long-lived people in various food cultures including Japanese (who eat beans in the form of soy, tofu, natto, and miso), Swedish (brown beans and peas), and Mediterranean (lentils, chickpeas, and white beans) diets. Beans and greens are the foods closely linked in the scientific literature with protection against cancer, diabetes, heart disease, stroke, and dementia.
We are not done with beans yet. Because beans contain so much resistant starch, as much as 20 grams in each cup of navy beans (4 calories per gram), and because they contain amylase inhibitors that resist the digestion of their starch, a decent percentage of the calories that are listed on the food label do not actually come into the bloodstream as glucose or even as calories. This is complicated, but remember that when the resistant starch hits the colon, it is acted on by bacteria and transformed into SCFAs. That transformation results in only about 2 calories per gram. The fermentation occurs so low down in the digestive track that very little of it gets absorbed. This resistant starch, as well as most of the other fibers that are not assimilated, are counted as a part of the 200 to 300 calories per cup in the nutritional info. But the bottom line is that even though a cup of cooked beans may be listed as 225 calories, they actually give you much fewer calories per cup, a higher percent of protein, and fewer carbohydrates than show up in their analysis. All those listed 225 calories are setting off caloric and nutrient receptors in the stomach and small intestines, registering satiation and telling you that you have eaten enough. And here’s the amazing thing, because of the presence of the amylase inhibitors and the resistant starch, maybe a quarter of those carbohydrate calories don’t even get absorbed.
EDAMAME, A SUPER BEAN
Edamame beans are young green soybeans that are boiled in the pod and served hot or cold. They are usually served in the pods, but you squeeze them out of the inedible pods to eat them. They are available in supermarkets, mostly in the frozen vegetable section, both shelled and in the pods. Young green soybeans are an unprocessed, natural food that is rich in minerals, calcium, and omega-3 fats and extremely high in protein. Frozen pods can be boiled for five minutes or just defrosted overnight in the refrigerator. They are a unique bean because they are so low in carbohydrates. They are a great food for diabetics and a delicious addition to a salad or vegetable dish. Multiple scientific studies have demonstrated that unprocessed soy beans have dramatic health benefits. Besides lowering cholesterol and blood glucose, they also prevent breast cancer.
So when you make beans your favored carbohydrate source, you:
Get high-quality protein
Get a powerful anticancer food
Get more satiation that turns off your desire to eat more food
Burn more fat, helping you get rid of your diabetes
Have better digestion
A healthy pantry needs to contain a stock of dried beans and canned beans. If your local market doesn’t have unsalted canned beans, you can usually find them in a health food store. If you have no other option but salted canned beans, rinse them before using to remove about half the excess salt.
Dried beans that are first soaked overnight and then cooked are the best way to use beans. They don’t have to be soaked in advance, but it speeds up the cooking time. Dried beans are the most economical high-nutrient food. You save money on food when you use lots of dried beans in your cooking. Also, sprouted whole beans and grains offer great nutrition and save money on your food bills. Soak beans overnight in a jar, and then rinse and drain the water out every day for the next four to six days, and you will have bean sprouts to use in your salad or in a vegetable dish.
Split peas, squash (butternut, acorn, or winter), corn, wild rice, quinoa, and wheat berries are healthy high-carbohydrate foods that contain a moderate to intermediate amount of resistant starch but are still fairly nutrient-rich foods. Dark or black wild rice is more fibrous and higher in resistant starch compared to ordinary brown rice. Note that wheat berries and coarsely ground sprouted wheat are more favorable than whole wheat flour, especially whole wheat pastry flour. The more finely ground the grain, the higher its glycemic load, and the more it is cooked, the more diabetic unfavorable it becomes.
Avoid anything that is white—white flour, white pasta, white potatoes, and white rice. Other carbohydrate-rich foods can be used in moderate quantities depending on body weight and diabetic parameters.
When looking at a choice of various high-carbohydrate plant foods, as a diabetic, consider:
- The fiber content
- The percent of slowly digestible starch
- The percent of resistant starch
- The micronutrient content
- The caloric density
- The beneficial qualities of other foods in the menu that may have to be eliminated or reduced to allow room for this food
There is a nutritional hierarchy of carbohydrate-rich plant foods. Beans, cauliflower, and other more nutritious high-carbohydrate foods are most heavily emphasized because of their micronutrient density, fiber, low GL, slowly digestible starch, and resistant starch content. Interestingly and conveniently, the micronutrient density of high carbohydrate plant foods parallels their fiber and resistant starch content.
The GL is also an important component to consider in creating the best diet for those with diabetes or prone to it. As we discussed, diets containing large quantities of high GI foods are associated with the risk of diabetes, heart disease, multiple cancers, and overall chronic disease. GL may not be the main thing, but it should not be completely ignored. It is likely the main reason why white potatoes have been linked to a worsening of glycemic control in diabetics. In fact, when 84,555 women aged thirty-four to fifty-nine were tracked for twenty years in the Nurses’ Health Study, researchers found that regular potato and French fry consumption was significantly associated with increased risk of diabetes; substituting a whole grain for a serving of potato per day lowered risk of diabetes by almost 30 percent.
Examining the glycemic effects of various carbohydrate choices enables us to modify food choices for improved glycemic control and enhanced weight loss.
GLYCEMIC LOAD OF COMMON HIGH-CARBOHYDRATE FOODS (1 CUP)
|Red Kidney Beans||7|
|Black Eyed Peas||14|
|White Bread (2 slices)||20|
|Cola (16 ounces)||32|
It is reasonable to limit white flour, white potato, and rice intake considering the large variety of carbohydrate-rich plant foods (beans, intact whole grains, cauliflower, peas, squash, and other starchy vegetables) to choose from that are more nutrient dense and without such a high GL. In general, I recommend diabetics avoid regular and liberal consumption of foods with a GL above 15, at least until their diabetes is in better control and their weight has dropped significantly. Remember, intact whole grains refers to most grains that are not ground into flour. If you want to eat a food made from flour, like pasta, use an alternative like black bean pasta or lentil pasta. You will be amazed by its taste.
My results with thousands of clients and patients indicate that excessive consumption of white potatoes (even prepared healthfully) and white rice may be problematic due to their high GL, especially in overweight individuals and those with diabetes and prediabetes. With some consideration of the factors discussed here, diabetics can remedy their challenges such as residual body fat, high triglycerides, suboptimal lipid profiles and nonoptimal fasting glucose levels. They also glean other benefits, especially heightened protection against cancer due to the inclusion of more cancer-protective micronutrients in the nutritarian diet.
So for maximizing weight loss and reversing diabetes, the trick is to use beans as your primary starch source. Eat some beans in a salad or soup with lunch and again with a green vegetable for dinner. Eat other non-bean, starchy foods such as squash, green or split peas, water-cooked steel-cut oats, black (wild) rice, or wheat berries in small amounts with breakfast or as part of a dinner vegetable casserole, but do not eat them as the main volume of food with the meal. Remember, incorporate these whole grains only in a limited amount in the diet until weight loss and glucose readings are under control.
THE BEST FOODS TO EAT TO REVERSE DIABETES
Raw greens, Tomatoes
Cooked greens, Cauliflower
Eggplant Nuts, Seeds
Onions, Lower-sugar fruits such as berries and kiwi
What About the Gas?
The body can learn to adjust the bacteria in the digestive tract to better digest beans and avoid gassiness. It just takes some time. Start out with a tablespoon of beans, chewed well, at each meal. In other words, have beans all the time, but begin with a nonthreatening amount so you do not become a gas factory. In a few weeks, you will be able to gradually increase the amount without experiencing digestive difficulty. Lentils, split peas, and garbanzo beans are less gassy because they have less resistant starch. So start with those first and gradually move up to red and black beans that are even more favorable for diabetics. Do not take digestive enzymes or Beano; instead take a probiotic such as lactobacillus acidophilus. Don’t forget to chew the beans very well, as most gas production comes from poorly chewed food.
Most people on my antidiabetic diet enjoy a salad and a bean-based vegetable soup for lunch. The beans used are the dry beans that have been cooked in the soup base. For dinner you can toss some beans on top of your salad or mix them into a cooked green vegetable dish. Beans offer a wide variety of flavors and textures and also make great dips, sauces, and chewy bean burgers.