Type 2 diabetes is a growing epidemic both in the United States and around the world. Nearly 10 percent of American adults have type 2 diabetes, and 25 percent have prediabetes; these numbers are only continuing to rise, with a shocking one-third of U.S. adults projected to have diabetes by 2050. (1, 2, 3)
While type 2 diabetes was once considered a “disease of affluence,” its numbers are exploding in middle- and low-income countries, mainly due to the global spread of the nutrient-poor Western diet. (4) Type 2 diabetes is also no longer limited to middle-aged and older adults; children and young people are increasingly being diagnosed with type 2 diabetes, significantly increasing their risks of many other chronic diseases throughout their lifespans.
The conventional medicine approach for treating type 2 diabetes, long centered around a “wait and see” mentality and drug therapy, isn’t working to stem the tide of these epidemic numbers, nor are preventive strategies emphasized. Read on to learn why Functional Medicine, a science-based approach to preventing and treating disease that is focused on diet and lifestyle changes, is the most effective first-line strategy for managing type 2 diabetes.
- All about type 2 diabetes
- Type 2 diabetes and blood sugar
- The problem with the conventional medicine approach
- How does Functional Medicine treat type 2 diabetes?
- Nine functional foods
- Five nutrients and nutraceuticals
- Other ways to prevent or reverse type 2 diabetes
Type 2 diabetes is a chronic disease that affects the way the body metabolizes sugar. It is characterized by a progressive loss of sensitivity to insulin, the pancreatic hormone that regulates blood sugar levels. In the early stages of type 2 diabetes, the body produces more insulin to try to overcome reduced insulin sensitivity; however, in the long run, the pancreas can’t produce enough insulin to maintain blood sugar levels, resulting in high blood sugar, or hyperglycemia. Hyperglycemia induces oxidative stress which, in turn, contributes to many of the complications of type 2 diabetes, such as kidney, nerve, retinal, and vascular damage.
Want to learn how to address the root cause of type 2 diabetes using the Functional Medicine approach? Check out this article for tips on what to eat, the nutrients you need, and lifestyle changes that can help. #functionalmedicine #chriskresser #unconventionalmedicine
What Causes Type 2 Diabetes?
The question of why a person develops type 2 diabetes has been debated and explored for decades. For many years, dietary fats were blamed for causing the disease. Next, obesity was thought to be the culprit (obesity and diabetes share so many of the same underlying causes, they’re often referred to collectively as “diabesity”). However, it’s now clear that type 2 diabetes can occur in the absence of obesity. Today, we now understand that we cannot blame diabetes on any single factor. Rather, the disease process is driven by a complex network of diet and lifestyle factors, oxidative stress, and genetics.
The Western diet, full of refined carbohydrates, fructose, and industrial seed oils, is an established risk factor for type 2 diabetes. Wherever the Western diet goes, type 2 diabetes follows. For example, hunter–gatherer populations such as the Australian aborigines are typically healthy eating their traditional diets. When they are displaced and moved into urban environments, however, they replace their traditional diets with a Western one and develop diabetes at record speed. (5)
To successfully manage diabetes, it helps to have a basic understanding of the science behind blood sugar. When you eat carbohydrates, they are broken down in your intestine into monosaccharides, or simple sugars, the most basic unit of carbohydrates. One of these monosaccharides, glucose, is subsequently absorbed from your gut into your bloodstream, where it is shuttled to your cells by insulin. In type 2 diabetes, various factors have caused cells to become less sensitive to insulin, causing excessive glucose to accumulate in your bloodstream (the state of hyperglycemia, or high blood sugar). Blood sugar measurements are essential for assessing the progression and severity of type 2 diabetes.
Three Ways of Measuring Blood Sugar
Generally, practitioners rely on one or more of the following tests to assess blood sugar levels:
1. Fasting Blood Glucose (FBG)
This test measures blood sugar after an eight- to 12-hour fast. An FBG of 126 mg/mL indicates diabetes, and the upper limit of “normal” FBG is 99 mg/dL. Any value between 99 and 126 mg/dL is indicative of prediabetes. A drawback of this test is that it does not tell us how blood sugar responds to the foods we eat.
2. Oral Glucose Tolerance Test (OGTT)
This test involves consuming 75 g of pure glucose dissolved in water and then measuring blood glucose one and two hours later. If your blood sugar is higher than 140 mg/dL two hours later, you likely have prediabetes. If it is greater than 199 mg/dL two hours later, you may have type 2 diabetes. A drawback of this test is that the large dose of glucose delivered can cause severe symptoms in people with glucose intolerance. Furthermore, glucose in foods does not generally come in the isolated form used in this test, making the OGTT an inaccurate representation of how the body responds to carbohydrate-containing foods.
3. Hemoglobin A1c (HbA1c)
This test measures the percentage of hemoglobin to which sugar has bonded due to chronically elevated blood sugar. It reflects average blood sugar over the past three months. A healthy range for HbA1c is between 4.6 and 5.3 percent. Unfortunately, this test can be unreliable in individuals and should be compared with other biomarkers such as fasting insulin, fasting leptin, HOMA-IR, fructosamine, and triglycerides.
The conventional medicine approach to type 2 diabetes is fraught with problems.
Under the conventional system, practitioners wait until people have full-blown type 2 diabetes before initiating treatment. Little is done to alter the course of the disease in the prediabetic stage when the body is more responsive to diet and lifestyle changes.
The drugs used to treat type 2 diabetes have serious side effects. Sulfonylureas, biguanides, thiazolidinediones, and meglitinides are just a few of the classes of medications used to treat type 2 diabetes. They are associated with liver and kidney dysfunction, nausea, fatigue, dizziness, rashes, weight gain, and hypoglycemia (low blood sugar).
The conventional diet guidelines for diabetics are outdated. The American Diabetes Association’s dietary guidelines for type 2 diabetes have long promoted a relatively high intake of carbohydrates while demonizing dietary fats. Yet abundant research indicates that this dietary approach not only doesn’t work for type 2 diabetes but may actually make the condition worse.
In contrast to conventional medicine, the Functional Medicine approach emphasizes prevention and treatment through diet and lifestyle changes.
Adjust Your Carb Quantity and Quality
It is well established that a high-starch, low-fiber diet increases the risk of type 2 diabetes. (6) Despite this fact, conventional health experts continue to recommend a high-carbohydrate diet for type 2 diabetics to achieve better results. The Canadian Diabetes Association recommends that diabetics obtain 45 to 60 percent of calories from carbohydrates, while the American Dietetic Association has only recently rescinded its endorsement of high carbohydrate intake for diabetics and remains reluctant to recommend a low carb intake. (7)
Despite such foot-dragging, a growing body of scientific research indicates that low-carbohydrate diets are superior to high-carbohydrate diets for the treatment of type 2 diabetes. A recent systematic review and meta-analysis of 18 randomized controlled trials found that reducing dietary carbohydrates produces significant improvements in HbA1c, triglycerides, and cholesterol, while also lowering patients’ diabetes medication requirements. (8) Importantly, the definition of a “low-carbohydrate diet” varied across the studies included in the review; had the definition been stricter, a greater beneficial effect might have been observed.
How much do you need to reduce your carbohydrate intake to get type 2 diabetes under control? While the answer to this question varies from person to person, I’ve generally found that those with blood sugar regulation problems benefit from limiting carb intake to 10 to 15 percent of total calories.
In addition to adjusting carb quantity, you also need to change the quality of the carbs you consume. Instead of refined carbohydrates such as pasta and bread, eat moderate amounts of starchy tubers (sweet potatoes, cassava, beets, and rutabaga), plantains, whole fruit, and moderate amounts of full-fat dairy, if tolerated.
Determine Which Carbs Work for You
While the methods for measuring blood sugar in the clinical setting (see the earlier section in this article) have their place, they do not reflect how your body responds to glucose in foods. To better understand which carbohydrate-containing foods your body tolerates best and which ones cause unhealthy blood sugar swings, you’ll need to test your blood sugar at home.
The first step in testing your blood sugar at home is to buy a glucometer, such as the ReliOn Prime. You will also need to purchase glucose test strips. Once you have a glucometer and test strips, follow these steps to test your glucose tolerance in response to foods:
- Test your blood sugar first thing in the morning after fasting for at least 12 hours. Drink a little bit of water just after rising, but don’t eat anything or exercise before the test. The measurement you obtain at this point is your fasting blood sugar level.
- Test your blood sugar again just before lunch.
- Eat your typical lunch and test your blood sugar one hour, two hours, and three hours after. Do not eat anything during this three-hour post-lunch period.
- Record your blood sugar results, along with what you ate for lunch.
- Repeat this practice the following day. The blood sugar measurements you gather will tell you how the foods you usually eat influence your blood sugar levels.
- On day three, follow steps 1 and 2. However, at step 3, instead of eating your typical lunch, consume 60 to 70 grams of fast-acting carbohydrates, such as an eight-ounce boiled potato or a cup of cooked white rice. Fast-acting carbs quickly break down and release glucose into your system. For the purposes of this test only, avoid eating any fat or protein with the potato or rice because it will delay the absorption of glucose.
- After your carbohydrate-rich meal on day three, record your blood sugar results.
The goal here is to make sure that your blood glucose doesn’t consistently rise higher than 140 ng/mL an hour after a meal but does steadily drop to 120 ng/mL two hours after eating and returns to baseline three hours post-meal.
As for fasting blood sugar, measurements in the 80s are best. However, if you see some readings in the 90s, don’t panic. If all other biomarkers (fasting insulin, fasting leptin, fructosamine, and triglycerides) are normal, this isn’t cause for concern.
Age also needs to be considered when assessing blood sugar; an FBG in the 90s is relatively normal for a 70-year-old but may be more cause for concern when observed repeatedly in someone in their twenties.
For more information on measuring your blood sugar at home, see my blog post “How to Prevent Diabetes and Heart Disease for $16.”
Think about Going Keto
Increasing numbers of people are experimenting with the ketogenic diet for the treatment of type 2 diabetes, with some strongly positive results. The ketogenic diet is a very-low-carb, moderate-protein, high-fat diet that causes the body to rely on fatty acids and ketones for fuel, rather than glucose.
Studies indicate that a ketogenic diet has significant benefits for type 2 diabetics. A ketogenic diet has been found to improve HbA1c, promote weight loss, reverse kidney damage, and improve blood lipids and cardiovascular health in type 2 diabetics. (11) It has also proven more successful than a conventional low-carb diet for diabetes. (12) In fact, the benefits are so profound that an entire company, Virta Health, has made a ketogenic diet the cornerstone of their novel treatment approach for type 2 diabetes. (13)
Consider Getting Rid of Gluten
In recent years, multiple studies have examined the effects of gluten on type 2 diabetes. We know that celiac disease is more common in individuals with poorly controlled diabetes than in the general population; this finding suggests that gluten may contribute to the development and progression of diabetes. (14) Furthermore, animal models of type 2 diabetes indicate that a gluten-free diet increases the functional capacity of beta cells, the pancreatic cells responsible for making insulin, and improves glucose tolerance. (15)
How does gluten contribute to diabetes? The answer lies in the damaging effects of gluten on the intestinal barrier. Gluten increases intestinal permeability, causing leaky gut and systemic inflammation; these two factors have been found to precede type 2 diabetes. Removing gluten from the diet restores intestinal barrier integrity and reduces inflammation, thereby improving insulin resistance and potentially reversing the course of diabetes. (16)
Eat More Protein
Protein is a powerful tool for managing type 2 diabetes. Increasing protein intake improves blood sugar control and satiety (the feeling of fullness) and preserves lean body mass in diabetics. According to the research, a protein intake of 20 to 30 percent of total calories is best for optimizing type 2 diabetes management. (17)
There are still some concerns that a high protein intake can cause diabetic kidney disease. However, this myth has been disproven multiple times; a high protein intake does not compromise kidney function in people without preexisting kidney disease. (18)
Nature has provided us with a plentiful variety of Paleo-friendly foods that can help in the treatment of diabetes, proving that food can indeed serve as medicine.
Incorporating blueberries into your diet lowers the risk of type 2 diabetes, and for those who are living with diabetes, blueberries improve glucose control. (19, 20) The antidiabetic effects of blueberries are attributed to their high level of anthocyanins, chemical compounds that can exert anti-inflammatory effects in some fat cells and increase the body’s uptake and utilization of glucose.
If you have type 2 diabetes, dark chocolate should be your treat of choice! Animal studies have shown that eating dark chocolate after a meal lowers blood sugar levels, while human research shows that it promotes vasodilation, enhancing the delivery of glucose to muscle cells and alleviating hyperglycemia. (21, 22, 23)
3. Coffee and Tea
Extensive research shows that coffee may reduce the risk of type 2 diabetes by combating oxidative stress and through its beneficial impact on the gut microbiota. (24). As it turns out, coffee is the largest source of dietary antioxidants in the average American’s diet.
If you’re not a fan of coffee, then green tea, which contains some of the same antioxidant compounds, is an excellent alternative. (25)
4. Fermented Foods
Could fermented foods reduce your need for diabetes medication? Emerging research suggests that it could. Fermented foods including yogurt, kefir, and kimchi have been shown to improve glucose metabolism, reducing the risk of type 2 diabetes as well as enhancing glycemic control in those with existing diabetes. (26, 27, 28)
5. Nuts and Seeds
Nuts offer multiple health benefits for diabetics. Daily consumption of almonds for 24 weeks has been found to reduce waist circumference, serum triglycerides, LDL cholesterol, high-sensitivity C-reactive protein (a marker for inflammation), and hemoglobin A1c in adult diabetics. (29) Walnuts improve endothelial function in diabetics, thus reducing the elevated cardiovascular disease risk associated with the disease. (30) Chia seeds reduce blood pressure, C-reactive protein, and post-meal high blood sugar. (31, 32) When buying nuts, select raw or lightly roasted nuts and avoid the ones coated in industrial seed oils, such as canola oil.
6. Olive Oil
Extra-virgin olive oil consumption produces significant reductions in fasting blood glucose HbA1c. (33) It also improves the post-meal blood sugar response, which, as I mentioned earlier, is perhaps the best parameter for assessing glucose tolerance. (34)
7. Resistant Starch
Resistant starch is a type of dietary carbohydrate that is not digested in the small intestine; instead, it passes intact to the large intestine, where it promotes the growth of beneficial gut bacteria. Research has shown that resistant starch may improve insulin sensitivity and lower blood glucose. (35, 36, 37)
Fish and shellfish consumption, but not supplementation with isolated omega-3 fatty acids, is consistently associated with a reduced risk of type 2 diabetes. (38) Seafood may have a protective effect against diabetes due to its high level of omega-3 fatty acids, which modulate cellular insulin sensitivity, and its levels of other insulin-sensitizing nutrients, such as vitamin D, retinol, and selenium.
Spices don’t just liven up meals; they also offer significant health benefits for diabetics. The consumption of cinnamon in doses ranging from 120 mg/day to six g/day has been found to produce significant decreases in fasting blood glucose, LDL cholesterol, and triglycerides in type 2 diabetics. (39) Garlic reduces fasting blood glucose, fructosamine, and HbA1c and improves blood lipid profiles. (40) Curcumin, a constituent of turmeric root, has hypoglycemic effects and protects the renal and cardiovascular systems from diabetes-associated complications. (41)
Ensuring you get enough of these nutrients and nutraceuticals could prevent type 2 diabetes from developing.
1. Vitamin D
Vitamin D isn’t just crucial for maintaining healthy bones; it also regulates inflammation and insulin sensitivity. Low vitamin D is a risk factor for the development of type 2 diabetes, whereas vitamin D supplementation reduces inflammation and oxidative stress in diabetics. (42)
Magnesium is an essential cofactor for over 300 enzyme systems in the body, including several that regulate blood sugar. Magnesium insufficiency is associated with an increased risk of type 2 diabetes, whereas magnesium supplementation improves insulin sensitivity and blood sugar control. (43, 44) While magnesium is available in a variety of foods, including nuts, avocados, and dark chocolate, it can be difficult to obtain enough of the mineral from food to support optimal health. I recommend supplementing with 400 to 600 mg of magnesium, preferably chelated to glycinate or malate for optimal absorption.
3. B12 and Folate
Diabetic patients who have used the commonly prescribed antidiabetic medication metformin long term may benefit from supplemental folate and B12, as the drug depletes levels of these two B vitamins. Folate and B12 supplementation alleviate oxidative stress in diabetics, improving symptoms such as diabetic retinopathy. (45)
Berberine, a bitter compound with potent antidiabetic properties, can be found in Oregon grape, barberry, and goldenseal plants. It improves insulin resistance and insulin secretion, inhibits the generation of glucose in the liver, reduces the intestinal absorption of glucose, and promotes an anti-inflammatory gut microbiota. Interestingly, berberine works in the same way as the antidiabetic metformin. (46)
5. Alpha-Lipoic Acid
Alpha-lipoic acid is a sulfur-containing compound that acts as a powerful antioxidant in the body. By boosting the body’s endogenous antioxidant systems, alpha-lipoic acid alleviates oxidative stress, an underlying cause of type 2 diabetes; this helps reduce diabetic complications such as diabetic neuropathy. (47) Alpha-lipoic acid also activates AMPK, a protein with blood sugar-lowering effects. (48)
I’ve said it before: there’s really no replacement for a healthy, ancestral lifestyle when it comes to preventing chronic disease. Here are more tips on how to prevent or reverse type 2 diabetes through your lifestyle.
Improve Your Gut Health
Recent studies have identified a previously unrecognized effect of metformin on the gut microbiota: the drug increases levels of Akkermansia muciniphila, a commensal gut bacterium associated with reduced inflammation and improved metabolic health. This newly discovered effect of metformin indicates that the gut microbiota indeed plays a pivotal role in type 2 diabetes. (49, 50)
Several prebiotics and probiotics have been investigated for their gut health-promoting, antidiabetic effects:
- In animal studies, mannan-oligosaccharide, a prebiotic fiber found in mushrooms and konjac root, has been found to boost the blood sugar-lowering effects of metformin. (51) Inulin, a prebiotic in chicory, garlic, onions, leeks, and asparagus, reduces fasting blood glucose while also promoting a more metabolically healthy gut microbiota.
- Some probiotic strains also demonstrate antidiabetic effects. Supplementation with Lactobacilli and Bifidobacteria improves biomarkers of inflammation and oxidative stress in type 2 diabetics and lowers fasting blood sugar by promoting an anti-inflammatory gut microbiota. (52, 53) Anti-inflammatory gut bacteria, in turn, help correct underlying inflammation in diabetes and improve metabolic function.
One in four American adults sits for over eight hours every day, making us one extremely sedentary nation! (54) A sedentary lifestyle is a significant risk factor for type 2 diabetes, so exercise should be a central part of any treatment plan for the disease. (55)
Fortunately, you don’t have to become a marathoner to prevent or manage diabetes. Research indicates that walking for just 30 minutes a day reduces the risk of type 2 diabetes by approximately 50 percent. (56) High-intensity interval training (HIIT) also appears beneficial—it reduces fasting blood sugar, hemoglobin A1c, and cardiovascular complications in type 2 diabetes and is more effective than continuous aerobic activity (such as jogging) for improving blood sugar control. (57)
In addition to exercising more, reducing sedentary time in daily life is also essential. Alternate sitting with working at a standing desk or treadmill desk. Breaking up prolonged sitting with standing or walking has been shown to improve the post-meal blood sugar response in those at risk for diabetes. (58)
The dramatic increase in the incidence of type 2 diabetes over the past few decades has paralleled a progressive decrease in sleep duration reported by American adults. Is sleep loss related to diabetes? Research indicates that this is indeed the case: a short sleep duration, defined as sleeping less than seven to eight hours a night, has emerged as a major risk factor for type 2 diabetes. (59)
Sleep loss may promote type 2 diabetes by interfering with energy metabolism and increasing insulin sensitivity. (60) Sleep loss also impairs satiety, triggering cravings and overconsumption of sugary processed foods that increase the risk of diabetes.
Obstructive sleep apnea (OSA), a common cause of sleep loss, promotes type 2 diabetes by inducing hypoxia (when the body doesn’t get enough oxygen), which in turn impairs insulin production by pancreatic beta cells. (61) Strategies that correct OSA, such as the use of a continuous positive airway pressure (CPAP) machine and weight loss, reduce OSA severity and improve blood sugar control. (62, 63)
To improve blood sugar control, aim for seven to eight hours of sleep a night. Follow the circadian rhythm-normalizing tips below to enhance your sleep quality further.
Normalize Your Circadian Rhythm
Your circadian rhythm is a set of biochemical processes that occur in your body on an approximately 24-hour schedule and regulate many aspects of your behavior and physiology. Factors that disrupt the human circadian rhythm, such as jet lag, an erratic eating schedule, and blue light exposure at night, impair circadian-regulated pancreatic beta cell function and increase the risk of type 2 diabetes. (64)
While much of the research on circadian disruption and diabetes risk has been performed in animals, the substantially elevated risk of type 2 diabetes observed in night shift workers suggests that circadian disruption also promotes diabetes in humans. (65) If you are a type 2 diabetic and want to improve your health, normalizing your circadian rhythm is essential. If you currently work night shifts, you may need to reconsider whether your job is damaging your health. If so, can you avoid night shifts? If that is impossible and your health is in danger, it’s probably time to look for another job. You can also normalize your circadian rhythm by maintaining a regular sleep schedule, avoiding late-night eating, and limiting bright light exposure in the evening with the help of blue light-blocking glasses. (66, 67)
Reduce Your Stress Levels
Chronic stress is another overlooked but significant risk factor for type 2 diabetes. The hormonal changes that go hand in hand with chronic stress cause blood sugar imbalances. (68) High perceived stress is associated with insulin resistance and a significantly increased risk of type 2 diabetes in adults. (69, 70) The profound effect of stress on blood sugar is mediated by the HPA axis, the body’s stress-response system. Chronic HPA axis activation causes beta cell dysfunction, inhibiting the effects of insulin and inducing insulin resistance. (71)
Research indicates that reducing psychological stress can improve blood sugar management in type 2 diabetes. Meditation, yoga, and breathing exercises have been found to decrease fasting blood glucose and post-meal glucose in diabetics. (72) If you’re new to the concept of mindfulness, I recommend starting with an app such as Calm or Headspace, which offer guided meditations and breathing exercises that are simple and effective for alleviating stress.
Avoid Environmental Toxins
Environmental toxins have more recently gained attention for their potential role in the development of type 2 diabetes. Accumulating evidence suggests that BPA, phthalates, and persistent organic pollutants contribute to diabetes, which is why it makes sense to reduce your exposure.
BPA is a chemical found in polycarbonate water bottles, dental sealants, the lining of tin cans, and cash register receipts. BPA exposure contributes to diabetes by causing stress in pancreatic beta cells, impairing insulin secretion. (73, 74) It also decreases the levels of adiponectin, a protein hormone that regulates glucose levels, reducing insulin sensitivity in fat cells, skeletal muscle, and the liver. Importantly, BPS, a chemical alternative to BPA commonly used in “BPA-free” products, may not be any safer for the body. (75) For more information, see my article “Re-Examining the Evidence on BPA and Plastics.”
Phthalates are a type of common plasticizer found in children’s toys, vinyl, and personal care products. Phthalates exacerbate type 2 diabetes by disrupting the PI3K/AKT pathway, reducing the number of glucose receptors in the pancreas and inducing insulin resistance. (76) To reduce exposure to phthalates, avoid buying plastic products as much as possible and use only natural, plant-based shampoo, conditioner, lotion, and other personal care products.
Persistent organic pollutants (POPs), a category of environmental toxins that include organochlorine pesticides, PCBs, and fluorinated compounds, reduce insulin secretion from pancreatic beta cells, causing hyperglycemia. (77) The metabolic toxicity of POPs is enhanced when these compounds are combined. To reduce your exposure to POPs, buy organic produce and filter your water because conventionally grown produce and tap water are a significant source of persistent organic pollutants.
Now I want to hear from you. Do you have type 2 diabetes? Have you tried any Functional Medicine strategies for managing the disease? Let me know in the comments below.