Insulin resistance is at the root of diabetes and prediabetes and affects more than 1 in 3 US adults. Even more shockingly, only 1 in 4 adults with diabetes knew they had the condition, and only 1 in 10 adults with prediabetes knew they were at risk for developing diabetes (1). While some people may experience no symptoms at all, the effects of insulin resistance can range from moderate to life-threatening. Read on to discover more about insulin, the symptoms of insulin resistance, and the best ways to naturally decrease insulin resistance and improve insulin sensitivity.
How does insulin work?
After eating, your body digests carbohydrates, and glucose increases in your bloodstream. To keep blood glucose (also called blood sugar) levels normal, your pancreas produces and releases a hormone called insulin. Insulin escorts glucose out of your blood and into your muscle, fat, and liver cells to be used as energy. Due to several lifestyle or genetic conditions, your body may begin to resist insulin, which prevents normal glucose absorption (2). This results in high blood sugar levels. Chronic insulin resistance and high blood sugar can lead to premature aging, diabetes, obesity, coronary heart disease, atherosclerosis, hypertension, stroke, and even Alzheimer’s disease. Beyond that, it can cause the following symptoms that can greatly interfere with your everyday life:
Extreme hunger or thirst
Increased or frequent urination
Dehydration, dry mouth
Tingling in hands and feet
Nausea and vomiting
How do you become insulin resistant?
Excess weight, lack of physical activity, high blood pressure, sleep apnea, a history of gestational diabetes, heart attack, or stroke, and being age 45 or older are all risk factors for insulin resistance (2). What actually causes its development is more complex. Excess fat, especially in the belly, pancreas, and liver, low activity levels, and low-grade or obesity-induced chronic inflammation are thought to contribute to insulin-signaling impairment, though this is still being researched (2,3). Environmental toxins are also thought to contribute to insulin resistance.
For those with diabetes from insulin resistance, taking medications or insulin may be necessary to keep blood glucose levels and symptoms under control. Regardless of the need for medications and insulin, lifestyle changes are highly recommended, and for some people, these changes can be effective enough that these treatments are no longer needed. Lifestyle changes include changing your diet, losing weight, adding in herbs and supplements to your daily routine, and beginning or modifying your exercise habits.
Changes in Diet
Because insulin resistance and obesity often coexist and even exacerbate each other, weight loss can be an important first step to improve the body’s insulin sensitivity (4). Furthermore, since an excess of visceral fat tissue is correlated with excess fat in the liver and increased inflammation (two underlying causes of insulin resistance), maintaining a healthy weight is all the more crucial in improving insulin sensitivity (5).
However, even if you are a healthy weight, shifting from a diet high in carbs and sugar can reduce insulin resistance. When we eat high carbohydrate diets for an extended period of time, it creates a near-constant demand on the body to produce insulin to move glucose from the blood, leading to lowered insulin sensitivity (2,4). So, switching to a diet that focuses on healthy proteins, fats, and vegetables can help alleviate some of this demand and create more balance. Some studies are even finding that a ketogenic diet can be 3 times more effective for weight loss and maintaining healthy blood sugar levels, which can bring a huge improvement in insulin resistance and its accompanying symptoms (4).
Omega-3 Fatty Acids
Another aspect of dieting to manage insulin resistance is combating inflammation (6). Dietary fats, especially omega-3 fatty acids, have the potential to increase insulin sensitivity and reduce inflammation (6). Diets high in healthy fats such as omega-3s (like the ketogenic diet mentioned above) are great because they often offer more satiety and thus are easier to stick to over time than low-calorie or low-fat diets. Omega-3 fatty acid fish oil supplements are a great way to get omega-3 acids, as well as consuming cold-water fatty fish, nuts, seeds, and plant oils (7).
Polyphenols are micronutrients that are known to help with insulin resistance, weight loss, diabetes management, and other metabolic and cardiovascular diseases (7). Foods such as green tea, cocoa, and citrus fruits are high in polyphenols and can lower your risk of many diseases. Studies have shown that green tea consumption is associated with lower rates of Type 2 diabetes, citrus can lower inflammation and the risk of cardiovascular disease and stroke, and cocoa can improve insulin resistance, hypertension, and metabolic syndrome (8).
Fiber has long been known to be a dieter’s friend in that it can lead to feeling fuller longer because it delays stomach emptying. While it aids in the weight loss that can be necessary to increase insulin sensitivity for some, it also directly helps control glycemic and insulin response in diabetic patients (9). A healthy diet with a high fiber intake is also linked to decreasing levels of low-grade inflammation across the body, making fiber a great three-pronged option to increase insulin sensitivity (10).
Herbs and Supplements
Many herbs have been used for centuries in Eastern medicine to treat insulin resistance, and are more commonly being recommended as potential treatment options by Western medicine as well. Not only can the herbs and supplements listed below enhance insulin sensitivity and lower both fasting and post-meal blood sugar, but they can also improve overall blood lipid metabolism, systemic metabolism, blood pressure, and overall body weight (10). Herbs that are widely accessible and easily added into your meals and teas include cinnamon, fenugreek, and ginseng. Herbs that are best taken as supplements include berberine, astragaloside, resveratrol, coptis, gymnema, mulberry, and salvia (11).
Probiotics can boost general gut health, immunity, and mental health, and the positive effects even extend to insulin levels. Studies have shown that probiotics can cause a significant increase in insulin sensitivity, better fasting glucose and insulin levels, and increased glucose uptake from the bloodstream into the body (12). Probiotic supplementation may even benefit inflammation and fat storage in the liver, both of which correlate with insulin resistance (12).
Vitamins and Minerals
Chromium, biotin, vanadium, and vitamin D all work to maintain healthy blood sugar and insulin levels. Chromium helps metabolize carbohydrates and fats and, when added regularly to your diet as a supplement, can have a beneficial effect on glucose, insulin, and cholesterol levels (13, 14). Biotin is well-known to help skin, nails, and hair by helping convert nutrients into energy the body can use. In studies done on diabetic patients, biotin also improved glucose and lipid metabolism (15). Vanadium is a mineral that can restore elevated blood glucose levels to healthy levels, as well as reduce the amount of insulin required to facilitate proper glucose absorption, otherwise known as increasing insulin sensitivity (16). Adequate intake of vitamin D is associated with a reduced risk of developing diabetes and obesity and can improve blood sugar and insulin sensitivity in both non-diabetic and diabetic people (17).
Dynamic Strength Training
Some good news for all those who hate cardio workouts: dynamic strength training, whether by lifting weights or engaging in high-intensity interval training (HIIT), is proven to be more effective at improving insulin sensitivity than cardio or endurance exercises (18). Regularly participating in HIIT workouts can improve glucoregulation during workouts and even afterward during rest periods (19). Beyond that, exercise can improve stress levels, stabilize energy and mood, and relieve depression symptoms. This is significant, given that people who have severe insulin resistance are more than twice as likely to have depression, anxiety, or other mood disorders as compared to the rest of the general population (20).
Creating a Lifestyle that Supports Healthy Insulin Sensitivity
If you have any of the symptoms listed above or are curious about being tested for insulin resistance, please reach out to us at TCIM to schedule an appointment. Our Functional Medicine Physicians and Functional Nutrition and Lifestyle Practitioners would be happy to help you manage and reduce insulin resistance, and lower your risk of developing diabetes. We are here to talk through the diets, supplements, and lifestyle changes available and help you create and incorporate a plan that brings you to ideal health. It is our joy to assist you in creating sustainable lifestyle changes that will bring you real health.
Jonathan Vellinga, M.D. is an Internal Medicine practitioner with a broad interest in medicine. He graduated Summa cum laude from Weber State University in Clinical Laboratory Sciences and completed his medical degree from the Medical College of Wisconsin.
Upon graduation from medical school, he completed his Internal Medicine residency at the University of Michigan. Dr. Vellinga is board-certified with the American Board of Internal Medicine and a member of the Institute for Functional Medicine.
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U.S. Department of Health and Human Services. (2018, May 1). Insulin Resistance & Prediabetes. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance.
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Hardy, O. T., Czech, M. P., & Corvera, S. (2012, April). What causes the insulin resistance underlying obesity? Current opinion in endocrinology, diabetes, and obesity. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4038351/.
Lepretti, M., Martucciello, S., Burgos Aceves, M. A., Putti, R., & Lionetti, L. (2018, March 14). Omega-3 Fatty Acids and Insulin Resistance: Focus on the Regulation of Mitochondria and Endoplasmic Reticulum Stress. Nutrients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872768/.
U.S. Department of Health and Human Services. Office of Dietary Supplements - Omega-3 Fatty Acids. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/.
Munir, K. M., Chandrasekaran, S., Gao, F., & Quon, M. J. (2013, September 15). Mechanisms for food polyphenols to ameliorate insulin resistance and endothelial dysfunction: therapeutic implications for diabetes and its cardiovascular complications. American journal of physiology. Endocrinology and metabolism. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073986/.
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