You’ve likely heard of insulin—that all-important hormone that helps blood sugar (glucose) enter your cells so that it can be used for energy. In a perfect world, your pancreas produces just enough insulin to balance the amount of glucose in your blood at any given time. But some people don’t respond well to the effects of insulin—a condition known as insulin resistance.
An estimated 40 percent of all Americans are insulin resistant. And that number just keeps rising, largely because of our modern dietary and lifestyle choices. Over time, the condition increases the odds of type 2 diabetes and a number of cardiovascular risk factors. But, because insulin resistance has no symptoms, it’s often hard to spot—until it’s too late.
What Is Insulin Resistance?
When you’re insulin resistant, your muscle, fat, and liver cells can’t easily absorb glucose from the bloodstream. This lack of insulin sensitivity creates a demand for higher and higher amounts of insulin in an effort to shove glucose into the resistant cells. The pancreas tries to keep up with this increased demand for insulin by producing even more. But eventually, the pancreas can’t keep up with the body’s need for the hormone, and excess glucose builds up in the bloodstream. But glucose may not be the only thing flowing through your veins. Many people with insulin resistance have high levels of both blood glucose and insulin circulating in their blood at the same time.
Testing 1, 2, 3
So how do you find out if you’re insulin resistant? No single test will give you a definitive answer. Instead, your health-care provider will likely conduct a physical exam and order several blood tests, such as:
- Fasting plasma glucose test, which measures your blood sugar levels after fasting for at least eight hours;
- Oral glucose tolerance test, which measures your glucose levels two hours after drinking a sugary solution;
- Hemoglobin A1C (HbA1c) test, which shows your average blood sugar level for the past three months;
- A lipid panel to measure your total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
If these blood tests show that you have high blood sugar, high triglycerides, high LDL (“bad”) cholesterol, and low HDL (“good”) cholesterol, your health-care provider may determine that you have insulin resistance.
Reversing Insulin Resistance
If you’ve been diagnosed with insulin resistance—or even if you’re simply at an increased risk for developing insulin resistance—there’s plenty you can do to reverse the condition or lower your risk. Since a poor diet and lifestyle can set you on a path toward insulin resistance, adopting healthier eating habits is a great first step.
Weight loss is an important factor for improving insulin sensitivity and reversing insulin resistance in those who are overweight. But it’s not the only factor. Studies show that what you eat is as important as how much you consume. Adopting a low-carb, protein-rich diet like the Paleo diet enhances insulin sensitivity, improves blood sugar control, and fosters weight loss. One recent randomized, crossover trial that appeared in the journal Nutrients found that overweight women who ate a high-protein diet experienced better insulin sensitivity than those eating a Mediterranean diet.
When you eat also matters. Time-restricted eating, also known as intermittent fasting, can be an effective way to lose weight and improve how well your cells respond to insulin. In one five-week clinical trial involving prediabetic men, those who stuck to a 6-hour eating window that ended no later than 3:00 p.m. had better insulin sensitivity, pancreatic function, and blood pressure than those with a 12-hour eating window. Want to try this for yourself? Start slowly by fasting for 12 hours and allowing yourself a 12-hour eating window. Over the course of several weeks, gradually increase the time you’re fasting and decrease your eating window until you are fasting for 18 hours per day with a 6-hour eating window.
Hack Your Habits
Along with diet, one of the most effective ways to prevent or improve insulin resistance is with exercise. In one analysis of 50 studies, British researchers found that engaging in regular high-intensity interval training (HIIT) reduced insulin resistance. And compared to steady-state exercise, HIIT also improved HbA1c and weight loss. But you don’t need to go full-on beast mode to experience benefits. Other studies show that moderate-intensity exercise can also increase insulin sensitivity. Simply walking for 30 minutes can improve insulin sensitivity and insulin resistance while also supporting a healthier BMI. And don’t forget resistance training. Whether you use weights or your own bodyweight, resistance workouts are just as effective as aerobic exercise for boosting insulin sensitivity. Plus, you’ll build muscle in the bargain.
Sleep is also important. While it’s common knowledge among researchers that a lack of sleep, as well as oversleeping, contributes to obesity, one 2018 study found that people who routinely slept for more than nine hours were more prone to insulin resistance. Instead of sleeping in, aim to stick to a consistent sleep schedule that provides seven to nine hours of sleep nightly.
And since research suggests that chronic stress may contribute to insulin resistance, seeking out ways to manage the pressures of daily life may also help to reduce your risk. Try to lower your stress levels with breathwork, meditation, or yoga.
Supplements for Better Insulin Sensitivity
Supplements can help reverse insulin resistance, too. Here are three of the most effective:
Berberine. This alkaloid compound found in herbs including barberry, goldenseal, and Oregon grape is one of the best tools for supporting healthy blood sugar levels. Used for centuries in Ayurvedic and Chinese medicines, a growing number of studies report that berberine is a safe and effective way to improve insulin sensitivity and balance insulin production. In one analysis of 46 clinical trials, researchers found that berberine improved insulin resistance by lowering fasting blood insulin, reducing the amount of glucose in the blood, and fostering weight loss. Another human study of berberine’s effect on insulin resistance found that, compared to a placebo, the compound increased insulin sensitivity while also decreasing waist circumference, blood pressure, and triglyceride levels. Plus, berberine has also been shown to improve unhealthy cholesterol levels, keep inflammation in check, and reduce oxidative stress. But to make sure you’re getting all the benefits berberine has to offer, look for a supplement that’s derived from Indian barberry (Berberis aristata) bark and root extract.
Fish Oil. The omega-3 fatty acids in fish oil have long been used to support brain and heart health. But it turns out, these healthy fats can also help prevent and reduce insulin resistance. In one randomized, double-blind, placebo-controlled study of people with abdominal obesity, researchers found that a daily dose of fish oil significantly reduced fasting insulin and insulin resistance. Other studies clearly show that supplementing with fish oil boosts insulin sensitivity, even in those with metabolic syndrome.
But before adding fish oil to your supplement plan, be aware that there are some poor-quality products on the market. To avoid rancidity and less than optimal absorption, seek out a fish oil supplement that delivers pure omega-3s sourced from Atlantic salmon. And check the label to ensure that it is formulated with phospholipids for enhanced absorption, as well as peptides, which researchers have found to reduce oxidative damage.
Hintonia. When you become resistant to the effects of insulin, glucose can build up in your bloodstream. Over time, high levels can damage your organs. This means that, along with increasing insulin sensitivity, it’s also important to control the amount of glucose flowing through your veins. Hintonia, a botanical from Central and South America, contains a polyphenol called coutareagenin that safely helps lower blood sugar levels. This was seen in an open, prospective clinical study of 41 diabetic patients. After six months of supplementing with hintonia, both fasting and post-meal blood sugar levels dropped. Plus, the participants’ HbA1c levels declined significantly without driving blood sugar levels too low. Just be sure to choose a bark extract supplement that provides 20 mg of polyphenols for best results.
Are You at Risk?
Anyone can become resistant to insulin. But some people are more likely to develop the condition. Specifically, people who are overweight or obese are at an increased risk. In fact, experts believe obesity is the main cause of insulin resistance, especially in those who carry too much fat in the abdominal area and around the internal organs (called visceral fat). A waist measurement of 40 inches or more for men and 35 inches or more for women is linked to insulin resistance.
Other risk factors include:
- African, Latino, or Native American heritage
- Being over the age of 45
- Certain drugs like anti-psychotics, HIV medication, and steroids
- Diet high in ultra-processed food
- History of heart disease or stroke
- Lack of exercise
- Some existing medical conditions including fatty liver disease, hypothyroidism, obstructive sleep apnea, and polycystic ovarian syndrome (PCOS)
Insulin resistance also tends to run in families. So if one of your parents or a sibling has the condition, your chance of developing the condition is higher.