Resistant Starches for Hormone & Gut Health
Have you noticed the ever-expanding flour varieties in the grocery aisle, particularly with green banana and plantain flours? Yep, fruit flours everywhere, and they’re gaining popularity as a gut-friendly carbohydrate due to their high resistant starch content. Basically, resistant starches are a type of fiber—they “resist” digestion in the small intestine. Normally, carbohydrates are broken down by enzymes into glucose, absorbed into the small intestine, and out into the blood stream. With fiber, such as resistant starch, they make it all the way into the colon where healthy gut bacteria feed on it (aka prebiotic) and slowly ferment it into short-chain fatty acids (SCFA).
Types of Resistant Starches
There are four types of resistant starches, and some foods contain multiple types.
Type 1: digestive enzymes can’t physically break them down. Examples include beans, uncooked whole grains (oats, barley), and seeds.
Type 2: contains high amounts of amylose, a starch that is more difficult to digest simply due to its structure. Examples include raw potatoes, lentils, beans, plantains, and green bananas (ripe bananas increase in sugar as they age, hence the sweeter taste).
Type 3: foods that have higher resistant starch after they’ve been cooked, then cooled. Examples include potatoes and rice.
Type 4: man-made, chemically modified. Found in synthetic, processed foods.
Benefits
Many of us are familiar with the benefits of fiber. Fiber-rich foods such as vegetables, fruits, beans, lentils, nuts, seeds, and whole grains are known to promote blood sugar balance, improve insulin resistance and cholesterol levels, and protect against cardiovascular disease. Fiber also adds bulk to stool, keeping bowels regular and reducing risk factors for irritable bowel syndrome, diverticular disease, colon cancer, and other bowel disorders.
But the gut-loving magic doesn’t stop there. Fiber feeds healthy gut bacteria and produces SCFAs. That feed-fermentation process allows healthy gut bacteria to thrive, which creates a domino effect of improved health throughout every major system in the body. The gut houses a large portion of our immune system, produces happy neurotransmitters for mental health, helps convert thyroid hormones for better metabolism, and more. So a healthy, well-fed gut makes for happy hormones (thyroid, adrenals, and sex), improved mental health, less inflammation, robust immunity, improved detoxification, and even vitamin production. Ummm… yes please!
Boost Your Fiber Intake
In general, aim to have ~40 grams of fiber per day. Luckily, you don’t need to spend your money on fancy fruit flours to have a healthy gut. Fiber-packed foods include vegetables, fruits, beans, lentils, nuts, seeds, and whole grains. Ideas to incorporate more fiber, including resistant starch, into your meals includes:
Breakfast: cold overnight oats with berries, yogurt, nuts, and/or seeds
Lunch: large leafy green and veggie salad with 1 serving of canned (or soaked and cooked) white beans or lentils, ½ sliced green banana, ½ avocado, and extra virgin olive oil dressing
Dinner: protein of choice, roasted veggies, and cold potato salad with olive oil
When it comes to increasing fiber, go easy and drink at least half of your weight in ounces of water daily. Adding too much fiber at once can overwhelm those little guys and their fermentation process. Also, pay attention to how you feel. Every body is different, and what works for one person may not work for another.
Now it’s your turn, please comment below with one way you’ll incorporate more fiber in your diet? If you thought this blog was helpful or know someone who would enjoy it, please like it and share it with them.
With love, Steph
References:
Gentile, C. L., Ward, E., Holst, J. J., Astrup, A., Ormsbee, M. J., Connelly, S., & Arciero, P. J. (2015). Resistant starch and protein intake enhances fat oxidation and feelings of fullness in lean and overweight/obese women. Nutrition Journal, 14, 113-123. doi: 10.1186/s12937-015-0104-2.
Hald, S., Schioldan, A. G., Moore, M. E., Dige, A., Laerke, H. N., Agnholt, J., … & Dahlerup, J. F. (2016). Effects of arabinoxylan and resistant starch on intestinal microbiota and short-chain fatty acids in subjects with metabolic syndrome: a randomized crossover study. PLoS One, 11(7), 159223-159241. Doi: 10.1371/journal.pone.0159223.
Laffin, M. R., Khosroshahi, H. T., Park, H., Laffin, L. J., Madsen, K., Kafil, H. S.,… & Vaziri, N. D. (2019). Amylose resistant starch (HAM-RS2) supplementation increases the proportion of faecalibacterium bacteria in end-stage renal disease patients: microbial analysis from a randomized placebo-controlled trial. Hemodialysis International, 23(3), 343-347. doi: 10.1111/hdi.12753.
Vital, M., Howe, A., Bergeron, N., Krauss, R. M., Jansson, J. K., & Tiedje, J. M. (2018). Metagenomic insights into the degradation of resistant starch by human gut microbiota. Applied Environmental Microbiology, 84(23): 1562-1575. doi: 10.1128/AEM.01562-18
Zhu, R., Fan, Z., Han, Y, Li, S, Li, G., Wang, L., Ye, T. & Zhoa, W. (2019). Acute effects of three cooked non-cereal starchy foods on postprandial glycemic responses and in vitro carbohydrate digestion in comparison with whole grains: a randomized trial. Nutrients, 11(3), 634-648. doi: 10.3390/nu11030634