When you think about “starch”, what comes to mind? Most likely, you think about foods like potatoes, breads, beans, rice and pasta and fruits like bananas and plantains. Perhaps you think about your shirts being laundered or that box of potato or corn starch you saw your grandmother take out of the cupboard to add to recipes. And if you’re old enough, you probably remember being told to avoid starchy foods because they can make you gain weight. But in reality, that old diet mentality couldn’t be farther from the truth.
Most unprocessed, whole plant food carbohydrates in our diets are starches. Starches are long chains of glucose found in grains, potatoes, legumes, seeds and other foods. Over the past several years, numerous studies have shown a correlation linking imbalances or disturbances of our gut bacteria to a wide range of diseases, including obesity, insulin resistance, inflammatory bowel conditions, and even depression and anxiety. One of the best ways to establish and maintain a healthy gut bacterial environment is to provide the right foods for your gut bacteria. These foods are called prebiotics.
Not to be confused with probiotics (good bacteria like acidophilus), prebiotics are indigestible carbohydrates that are not digested in the stomach or small intestine and reach the colon intact. They feed many strains of beneficial bacteria. Generally, prebiotics are classified into three different types: soluble fiber (like psyllim husks), non-starch polysaccharides (such as inulin) and something called resistant starch. Each of these types of prebiotics feed different species of gut bacteria, and among them, resistant starch is turning out to be quite beneficial and unique.
Resistant starch “resists” digestion–it reaches the colon intact and we therefore don’t see spikes in insulin or blood glucose after eating this type of starch. We also don’t obtain significant calories from resistant starch since it passes through relatively undigested while providing a lovely meal for our gut bacteria.
There are four types of resistant starch:
Type 1 starch is physically inaccessible, bound by indigestible plant cell walls; found in beans, grains, seeds and legumes.
Type 2 starch is intrinsically indigestible in it’s raw state due to its high amylose content; found in potatoes, bananas and plantains. Heating these foods causes changes in the starch making it digestible to us, thereby removing the resistant starch.
Type 3 retrograded starch is created after Type 1 or Type 2 resistant starches are cooked and then cooled. These foods can be reheated at low temperatures (less than 130 degrees) and still maintain the resistant starch benefits. Heating at higher temperatures again converts the starch into a form that is digestible to us rather than to our gut bacteria. This category includes cooked and cooled potatoes, legumes and rice.
Type 4 industrial resistant starch–this type doesn’t occur naturally and has been chemically modified. It’s not recommended to be included in our diet. A common example is “hi-maize resistant starch.”
It appears that resistant starch has several beneficial effects that may contribute to weight loss, including increased satiety and decreased appetite, decreased fat storage in fat cells and decreased blood insulin spikes after meals. Resistant starch also shows considerable health benefits. The good bacteria that feed on resistant starch produce short chain fatty acids through fermentation. One of these fatty acids, butyrate, has beneficial effects on the colon and overall health. Butyrate is the preferred energy source of the cells lining the colon and it also plays roles in increasing metabolism, decreasing inflammation and improving resistance to stress.
Resistant starch improves the integrity and function of the gut, inhibits endotoxins from getting into circulation and reduces leaky gut which can lead to allergies and autoimmune conditions. It is also associated with decreased risk of colorectal cancer. There is preliminary evidence that resistant starch may treat small intestinal bacterial overgrowth by flushing the bad bacteria out in the feces. And finally, resistant starch increases dietary magnesium absorption, most likely because it improves gut function and integrity.
Hopefully I’ve convinced you to add this superfood to your eating plan. Or perhaps you’re grinning from ear to ear because you already eat resistant starch daily. If so, keep up the good work. And even if you’re on a low carbohydrate diet, you can still add resistant starch to your diet without adding digestible carbohydrates.
There are two ways to add resistant starches to your eating plan: either get them from foods or supplement with things like raw potato starch, corn starch, cassava starch or garden pea meal. Bob’s Red Mill Unmodified Potato Starch is one of the best sources of resistant starch and is generally well tolerated even by those who react adversely to nightshades. Plantain flour and green banana flour are also great sources of resistant starch. Try alternating sources for greater benefit. You can add these to soups, salads and smoothies. Start with small doses of about 1/4 teaspoon once daily and very gradually increase the amount as tolerated.
Some common food sources of resistant starch include green, un-ripened bananas and plantains. Cooked and cooled rice and barley, legumes (lentils and beans) and potatoes are also a good source. Corn products such as cooked and cooled corn, corn tortillas and hominy grits are full of resistant starch. Try adding cashews and raw oats to a recipe for extra resistant starch.
Still resistant to adding this kind of starch to your eating plan? Think yummy starchy foods, weight loss, better health, lower blood sugar and improved digestion. What are you weighting for?
Posted by Julie M Simon, MA, MBA, LMFT, psychotherapist and life coach, certified personal trainer, founder and director of The 12 Week Emotional Eating Recovery Program and author of The Emotional Eater’s Repair Manual and When Food Is comfort. If you have a question or topic you’d like to see addressed in this blog, go to https://overeatingrecovery.com.