Eating pure starch may not seem like the healthiest choice. However, resistant starch is an exception: it feeds gut probiotics, balances blood sugar, improves metabolism, and more. Read on to learn the health benefits and side effects of resistant starch. If you are interested in hacking your gut microbiome , this post is a must-read. Mechanisms
Potential health benefits of resistant starch stem from the following properties: By acting as a dietary fiber, resistant starch slows down digestion and absorption in the small intestine and bulks up the stool in the large intestine [ 1 ]
By supporting the production of short-chain fatty acids ( butyrate , acetate, propionate) and other beneficial metabolites in the large intestine [ 3 ]
Short-chain fatty acids support intestinal barrier function (i.e., help repair leaky gut), and healthy secretions of hormones and enzymes in the gut [ 3 ]
Resistant Starch and Metabolic Health
1) May Balance Blood Glucose
Supplementing the diet with resistant corn starch helped control blood glucose levels in overweight individuals [ 4 ].
One study found that consuming high-amylose maize resistant starch daily for six weeks improved glucose balance in 18 overweight adults. Glucose balance is the process of maintaining normal blood glucose levels [ 5 ].
According to preliminary research, there are many ways in which resistant starch may help normalize blood glucose, including: By activating glycogen synthesis genes, it causes the body to store more carbohydrates in our muscles and liver [ 6 ].
Insulin resistance occurs when cells fail to respond to insulin, leading to high blood sugar levels, and it is associated with a higher risk of developing type 2 diabetes and heart disease.
Resistant starch intake may improve insulin sensitivity and reduce the amount of insulin required to manage blood sugar in both animals and humans. It may help by: Increasing the excretion of certain bile acids into the gut, which helps decrease insulin resistance through GLP-1 [ 8 , 9 ].
Reducing fat tissue macrophages, which are immune cells that drive the development of insulin resistance [ 7 , 3 , 10 , 11 , 12 ].
Short-chain fatty acids (fermentation products of resistant starch) signal to the brain and liver to reduce glucose production, which may improve insulin sensitivity [ 13 ].
Increasing adiponectin , which improves insulin sensitivity by increasing fatty acid oxidation and inhibiting liver glucose production [ 14 ].
Increasing ghrelin , which inhibits glucose-stimulated insulin secretion from the pancreas [ 15 ].
Type 2 Diabetes
Resistant starch potentially reduces the risk of developing type 2 diabetes in animals and overweight adults by improving insulin sensitivity, reducing blood glucose, and reducing blood fat levels [ 16 , 4 , 12 ].
Supplementing the diet with resistant starch may prevent complications resulting from excess blood sugar in patients with type 2 diabetes. One study of 56 women with type 2 diabetes found that resistant starch improved blood glucose levels, reduced toxins released by bacteria, and increased antioxidants [ 17 , 18 ].
In diabetics, resistant starch consumption also protects the blood vessels from oxidative damage due to high blood sugar and improves endothelial function [ 19 , 18 ]. 2) May Improve Metabolic Syndrome
Metabolic syndrome is a group of factors that increase the risk of heart disease, diabetes, and stroke. These include large waistline, low HDL cholesterol, high blood pressure, high triglycerides , and blood sugar levels [ 20 ].
In one study of 20 healthy adults, resistant starch decreased the amount of insulin released after food intake, which makes it a promising complementary approach to metabolic syndrome [ 21 ].
Adding resistant starch to the diets of patients with metabolic syndrome improved cholesterol, triglyceride levels, and insulin sensitivity [ 22 , 10 ].
When added to standard treatment, resistant starch decreased LDL and total cholesterol levels while increasing HDL in 19 subjects with metabolic syndrome [ 23 ]. 3) Supports Heart Health
In a double-blind study of 86 individuals, resistant starch type 4 reduced abnormal fat levels in the blood [ 22 ].
The hardening of blood vessels is often a precursor to heart disease. Resistant starch potentially reduces the risk factors involved in the hardening of blood vessels in overweight individuals [ 4 ].Resistant starch reduced cholesterol and triglyceride levels in multiple animal studies [ 1 , 24 , 25 ]. 4) May Protect the Kidneys Supplementing the diet with resistant starch decreased toxic metabolite (indoxyl sulfate and p-cresol sulfate) levels in 56 patients on kidney dialysis [ 26 ].A diet with high-amylose maize starch slowed down chronic kidney disease (CKD) by decreasing oxidative stress , reducing inflammation, and preventing colon lining damage in rats [ 27 ]. 5) May Support Weight Control Please note that the effects of resistant starch on weight control stem from preliminary low-quality research. Although it may theoretically support metabolism and weight control in multiple ways, solid clinical evidence is lacking. Weight Gain and Metabolism In obesity-prone rats, dietary resistant starch and regular exercise prevented weight gain by reducing energy (food) requirements [ 28 ].It reduces fat accumulation and blood glucose levels and increases the breakdown of fat through fermentation in the intestines, thus potentially improving weight control [ 29 , 30 ].Resistant starch may stimulate fat burning by: Forcing the body to burn fat by lowering blood glucose [ 31 ]. Consuming dietary resistant starch increases the appetite-reducing hormone peptide YY ( PYY ), which promotes satiety and fullness [ 33 , 34 , 35 , 36 ].A study of 20 healthy adults found that consuming resistant starch over a 24-hour period significantly reduced the amount of food eaten. Although food intake was lower, there was no association between food consumption and how subjects rated their appetite [ 21 ]. Resistant Starch and Digestive Health 6) Acts as Prebiotic Prebiotics stimulate the growth of beneficial or probiotic gut bacteria .By increasing the number of good bacteria in the large intestine, resistant starches may offer several health benefits, such as […]