Insulin is an essential hormone that controls your blood sugar levels.
It's made in your pancreas and helps move sugar from your blood into your cells for storage. When cells are insulin resistant, they can't use insulin effectively, leaving your blood sugar high.
When your pancreas senses high blood sugar, it makes more insulin to overcome the resistance and reduce your blood sugar.
Over time, this can deplete the pancreas of insulin-producing cells, which is common in type 2 diabetes. Also, prolonged high blood sugar can damage nerves and organs.
You're most at risk of insulin resistance if you have prediabetes or a family history of type 2 diabetes, as well as if you are overweight or obese.
Insulin sensitivity refers to how responsive your cells are to insulin. Improving it can help you reduce insulin resistance and the risk of many diseases, including diabetes.
Here are 14 natural, science-backed ways to boost your insulin sensitivity.
A good night's sleep is important for your health.
For example, one study in nine healthy volunteers found that getting just four hours of sleep in one night reduced insulin sensitivity and the ability to regulate blood sugar, compared to getting eight and a half hours of sleep (4).
Fortunately, catching up on lost sleep can reverse the effects of poor sleep on insulin resistance (5).
Summary: A lack of sleep can harm your health and may increase insulin resistance. Making up for lost sleep may help reverse its effects.
Regular exercise is one of the best ways to increase insulin sensitivity.
It helps move sugar into the muscles for storage and promotes an immediate increase in insulin sensitivity, which lasts 2–48 hours, depending on the exercise (6).
For example, one study found that 60 minutes of cycling on a machine at a moderate pace increased insulin sensitivity for 48 hours among healthy volunteers (7).
Resistance training also helps increase insulin sensitivity.
For example, a study of overweight men with and without diabetes found that when participants performed resistance training over a three-month period, their insulin sensitivity increased, independent of other factors like weight loss (11).
Summary: Aerobic and resistance training can help increase insulin sensitivity, but combining them in your workouts seems most effective.
Stress affects your body's ability to regulate blood sugar.
It encourages the body to go into "fight-or-flight" mode, which stimulates the production of stress hormones like cortisol and glucagon.
These hormones break down glycogen, a form of stored sugar, into glucose, which enters your bloodstream for your body to use as a quick source of energy.
Unfortunately, ongoing stress keeps your stress hormone levels high, stimulating nutrient breakdown and increasing blood sugar (18).
This process may have been useful for our ancestors, who needed extra energy to perform life-sustaining activities. However, for people today who are under chronic stress, reduced insulin sensitivity can be harmful.
Summary: Ongoing stress is linked to a greater risk of insulin resistance. Meditation, exercise and sleep are great ways to help reduce stress.
Excess weight, especially in the belly area, reduces insulin sensitivity and increases the risk of type 2 diabetes.
Belly fat can do this in many ways, such as making hormones that promote insulin resistance in the muscles and liver.
Fortunately, losing weight is an effective way to lose belly fat and increase insulin sensitivity. It may also reduce your risk of type 2 diabetes if you have prediabetes.
For example, a study at Johns Hopkins University found that people with prediabetes who lost 5–7% of their total weight over six months reduced their risk of type 2 diabetes by 54% for the next three years (27).
Luckily, there are many ways to lose weight through diet, exercise and lifestyle changes.
Summary: Excess weight, particularly in the belly area, reduces insulin sensitivity. Weight loss may help increase insulin sensitivity and is linked to a lower risk of diabetes.
Fiber can be divided into two broad categories — soluble and insoluble.
Insoluble fiber mostly acts as a bulking agent to help stool move through the bowels.
For example, a study in 264 women found that those who ate more soluble fiber had significantly lower levels of insulin resistance (32).
Foods that are rich in soluble fiber include legumes, oatmeal, flaxseeds, vegetables like Brussels sprouts and fruits like oranges.
Summary: Eating soluble fiber has many health benefits and has been linked to increased insulin sensitivity. It also helps feed the friendly bacteria in your gut.
In particular, colorful fruits and vegetables are rich in plant compounds that have antioxidant properties (37).
Antioxidants bind to and neutralize molecules called free radicals, which can cause harmful inflammation throughout the body (38).
When you're including fruit in your diet, stick to normal portion sizes and limit your intake to two pieces or less per sitting and 2–5 servings per day.
Summary: Colorful fruits and vegetables are rich in plant compounds that help increase insulin sensitivity. But be careful not to eat too much fruit in a single sitting, as some types are high in sugar.
Herbs and spices were used for their medicinal properties long before they were introduced into cooking.
However, it wasn't until the past few decades that scientists began examining their health-promoting properties.
- Fenugreek seeds: They're high in soluble fiber, which helps make insulin more effective. Eating them whole, as an extract or even baked into bread may help increase blood sugar control and insulin sensitivity (43, 44, 45).
- Turmeric: Contains an active component called curcumin, which has strong antioxidant and anti-inflammatory properties. It seems to increase insulin sensitivity by reducing free fatty acids and sugar in the blood (46, 47).
- Ginger: This popular spice is linked to increased insulin sensitivity. Studies have found that its active component gingerol makes sugar receptors on muscle cells more available, increasing sugar uptake (48).
- Garlic: In animal studies, garlic has appeared to improve insulin secretion and have antioxidant properties that increase insulin sensitivity (49, 50, 51, 52).
These findings for herbs and spices are promising. However, most research in this area is recent and was conducted in animals. Human studies are needed to investigate whether herbs and spices do indeed increase insulin sensitivity.
Summary: Garlic, fenugreek, turmeric and ginger may help increase insulin sensitivity. The research behind them is recent, so more studies are needed before strong conclusions can be made.
Cinnamon is a tasty spice that's packed with plant compounds.
It's also known for its ability to reduce blood sugar and increase insulin sensitivity (53).
For example, one meta-analysis found consuming 1/2–3 teaspoons (1–6 grams) of cinnamon daily significantly reduced both short and long-term blood sugar levels (54).
Summary: Cinnamon could help increase insulin sensitivity by increasing glucose transport into cells and may even mimic insulin to increase sugar uptake from the bloodstream.
Green tea is an excellent beverage for your health.
It's also a great choice for people with type 2 diabetes or those who are at risk of it. Several studies have found that drinking green tea can increase insulin sensitivity and reduce blood sugar (59, 60).
For example, an analysis of 17 studies investigated the effects of green tea on blood sugar and insulin sensitivity.
It found that drinking green tea significantly reduced fasting blood sugar and increased insulin sensitivity (61).
Summary: Drinking more green tea could help increase your insulin sensitivity and overall health. The increase in insulin sensitivity associated with green tea could be due to the antioxidant epigallocatechin gallate.
Vinegar is a versatile liquid. You can clean with it or use it as an ingredient in foods, in addition to many other uses.
It's also a key ingredient in apple cider vinegar, an extremely popular beverage in the natural health community.
It also appears to delay the stomach from releasing food into the intestines, giving the body more time to absorb sugar into the bloodstream (67).
One study found that consuming apple cider vinegar increased insulin sensitivity by 34% during a high-carb meal in people who were insulin resistant and by 19% in people with type 2 diabetes (68).
Summary: Vinegar could help increase insulin sensitivity by improving insulin's effectiveness and delaying food release from the stomach to give insulin more time to act.
Carbs are the main stimulus that causes insulin blood levels to rise.
When the body digests carbs into sugar and releases it into the blood, the pancreas releases insulin to transport the sugar from the blood into the cells.
Reducing your carb intake could help increase insulin sensitivity. That's because high-carb diets tend to lead to spikes in blood sugar, which put more pressure on the pancreas to remove sugar from the blood (69, 70).
Spreading your carb intake evenly throughout the day is another way to increase insulin sensitivity.
Eating smaller portions of carbs regularly throughout the day provides the body with less sugar at each meal, making insulin's job easier. This is also supported with research showing that eating regularly benefits insulin sensitivity (71).
The type of carbs you choose is also important.
Low-glycemic index (GI) carbs are best, since they slow the release of sugar into the blood, giving insulin more time to work efficiently (72).
Carb sources that are low-GI include sweet potatoes, brown rice, quinoa and some varieties of oatmeal.
Summary: Eating fewer carbs, spreading your carb intake throughout the day and choosing lower-GI carbs are smart ways to increase insulin sensitivity.
If there's anything worth removing from your diet completely, it's artificial trans fats.
Evidence on the effects of high trans fat intake on insulin resistance appears to be mixed. Some human studies have found it harmful, while others haven't (75).
Because the findings are mixed for human studies, scientists can't clearly say that eating artificial trans fats increases insulin resistance. However, they are a risk factor for many other diseases, including diabetes, so they are worth avoiding.
Foods that typically contain artificial trans fats include pies, doughnuts and fried fast foods. Artificial trans fats are typically found in more processed foods.
Fortunately, in 2015 the US Food and Drug Administration (FDA) declared trans fats unsafe to eat. It gave food manufacturers three years to either gradually remove trans fats from their food products or apply for special approval (79).
Summary: The link between artificial trans fats and insulin resistance is stronger in animal studies than human studies. Nevertheless, it's best to avoid them since they increase the risk of many other diseases.
There's a big difference between added sugars and natural sugars.
Natural sugars are found in sources like plants and vegetables, both of which provide lots of other nutrients.
Conversely, added sugars are found in more highly processed foods. The two main types of sugar added during the production process are high-fructose corn syrup and table sugar, also known as sucrose.
Both contain approximately 50% fructose.
The effects of fructose on insulin resistance also appear to affect people who don't have diabetes, as reported in an analysis of 29 studies including a total of 1,005 normal and overweight or obese participants.
The findings showed that consuming a lot of fructose over less than 60 days increased liver insulin resistance, independent of total calorie intake (84).
Foods that contain lots of added sugar are also high in fructose. This includes candy, sugar-sweetened beverages, cakes, cookies and pastries.
Summary: High intakes of fructose are linked to a higher risk of insulin resistance. Foods that contain high amounts of added sugar are also high in fructose.
The idea of taking natural supplements to increase your insulin sensitivity is fairly new.
- Chromium: A mineral involved in carb and fat metabolism. Studies have found that taking chromium picolinate supplements in doses of 200–1,000 mcg could improve the ability of insulin receptors to reduce blood sugar (85, 86, 87, 88).
- Magnesium: A mineral that works with insulin receptors to store blood sugar. Studies have found that low blood magnesium is linked to insulin resistance. Taking magnesium may help increase insulin sensitivity (89, 90, 91, 92).
- Berberine: A plant molecule extracted from a variety of herbs including the plant Berberis. Its effects on insulin are not exactly known, but some studies have found it increases insulin sensitivity and lowers blood sugar (93, 94, 95, 96).
- Resveratrol: A polyphenol found in the skin of red grapes and other berries. It may increase insulin sensitivity, especially in those with type 2 diabetes, but its function is poorly understood (97, 98).
As with all supplements, there is a risk they may interact with your current medication. If you are ever unsure, it's best to check with your doctor before you start taking them.
Summary: Chromium, berberine and magnesium supplements are linked to increased insulin sensitivity. Resveratrol appears to increase insulin sensitivity, particularly among people with type 2 diabetes.
Insulin is an important hormone that has many roles in the body.
When your insulin sensitivity is low, it puts pressure on your pancreas to increase insulin production to clear sugar from your blood.
Low insulin sensitivity may also result in chronically high blood sugar levels, which are thought to increase your risk of many diseases, including diabetes and heart disease.
Fortunately, there are many things you can do to naturally increase your insulin sensitivity.
Try some of the suggestions in this article to increase your insulin sensitivity and lower your risk of disease.