Insulin’s Effects on Health

Let’s say you’ve gained a few pounds, primarily in your midsection. You’re also feeling more tired and fatigued than usual and find yourself craving sugar and anything sweet. The cause may be impaired insulin function, a key risk factor not only for diabetes but also for cardiovascular disease and polycystic ovary syndrome (PCOS).

What Is Insulin?

Insulin is one of many hormones that help control body functions. Like most hormones, insulin is a protein, based on a specific chain of amino acids. The pancreas secretes insulin along with many other enzymes used for digestion, as well as hormones.

Insulin is required for the absorption of any type of carbohydrates or sugar from food. After you eat, carbohydrates in food are broken down into glucose, the body’s main energy source. Without insulin, you could actually be in a state of starvation because each individual cell requires insulin to use carbohydrates for energy.

Most cells in the body have insulin receptors that hook up with carbohydrates in the form of glucose that circulates through the blood stream. Once insulin is attached to a cell, other receptors are activated to allow glucose to enter the cell. Health professionals often talk about insulin being the key that unlocks the door to each cell and allows carbohydrates in to provide fuel for the body.

Insulin Resistance

Sometimes the pancreas stops producing insulin. When that occurs, taking insulin will be required throughout life. But a more common situation is insulin resistance, the failure of cells to absorb glucose effectively. It’s not a case of insulin deficiency; insulin levels are often higher than normal in cases of insulin resistance. Cells in the muscles, liver, and fat tissue aren’t able to connect properly with insulin, causing the body to keep producing larger amounts of insulin. Because the glucose doesn’t get into the cells to provide energy, there are elevated levels of both glucose and insulin in the blood stream.

Insulin resistance is caused by three major factors: genes, fat, and an inactive lifestyle.

The Effect of Insulin Resistance on Health

Insulin resistance is responsible for at least three different health conditions: type 2 diabetes, metabolic syndrome, and PCOS. Since the symptoms of insulin resistance aren't always easily detected, people often don’t realize their health is at risk until they’ve had the condition for years.

Metabolic syndrome, a cluster of medical conditions that includes elevated blood fats (cholesterol and triglycerides), high blood pressure, and elevated blood glucose levels, puts your cardiovascular system at risk. It’s now known that insulin resistance is often the root cause of metabolic syndrome. Therefore, a coordinated approach to treatment, rather than targeting each of the conditions separately, is more effective.

PCOS affects 6% to 10% of women and is a leading cause of infertility. Both genetics and environment are thought to be responsible for this condition that currently has no cure but responds well to treatment and lifestyle changes that help improve insulin function. According to Angela Grassi, MS, RD, LDN, a specialist in PCOS and disordered eating, the main cause of PCOS is elevated insulin levels. She notes that elevated insulin levels cause the ovaries to produce increased amounts of testosterone, leading to an imbalance of other “female” hormones such as luteinizing hormone and follicle stimulating hormone. “The result,” she says, “is irregularity with menstrual cycles—very heavy periods, no periods at all, or skipped periods for months at a time—causing problems with infertility.”

How Do You Know if You Have Insulin Resistance?

The National Women’s Health Resource Center commissioned an online survey in 2006 to determine women’s knowledge of insulin resistance and its impact on overall health. According to Elizabeth Battaglino Cahill, RN, executive vice president of the center, the survey was commissioned “because so many women are at risk for heart disease and diabetes, they need to be aware of the signs and symptoms of impaired insulin function and have access to practical, actionable advice that will help them stay healthy. Creating awareness on this health topic and more importantly providing free information and resources is the reason behind the survey.”

While insulin resistance occurs in both men and women, the survey shows that 75% of women had no idea impaired insulin function is responsible for a variety of common symptoms, including carbohydrate cravings, excess weight in the midsection, and low energy levels. A family history of diabetes or heart disease and being 40 years of age or older increase the risk for insulin resistance.

Take Control of Your Insulin Health

Janis Roszler, RD, CDE, LD/N, an international speaker on diabetes and health and the coauthor of several books, including Diabetes on Your Own Terms, employs a variety of holistic approaches and lifestyle options to help people improve insulin function and decrease their risk of heart disease and diabetes. She emphasizes the importance of learning stress-reduction techniques to decrease fatigue and improve energy levels, increasing physical activity to improve insulin sensitivity and reduce weight, and routinely getting adequate sleep.

Roszler is a firm believer in taking small steps to meet larger health goals. To help her clients, she uses her Jump Start Pledge to encourage people to make a weekly commitment to one or two small yet ultimately significant lifestyle changes to improve their health. For example, you commit to walking for 10 minutes during a lunch break every day to increase physical activity or pledge to drink a glass of water before dinner every night to feel more full and eat less. At the end of the week, review your progress with this goal. What worked? Does anything need to be changed? Then either continue with the same goal for another week, change it slightly to better fit your needs, or add another goal. As Roszler says, “Small steps bring great rewards!”

So What Do I Eat?

What foods make up a healthy diet? If you list fruit, vegetables, whole grains, legumes, and lean sources of animal protein as the primary components of healthy food choices, you’re right on target. A study reported in the March 2007 issue of the American Journal of Clinical Nutrition indicates that women who routinely ate a healthier diet (compared with a typical Western diet high in refined grains, red meat, butter, processed meat, high-fat dairy products, sweets and desserts, hydrogenated fats, and soft drinks) had a lower risk of insulin resistance and metabolic syndrome. They also weighed less and exercised more—two key preventive factors to promote healthy insulin action.

Roszler encourages her clients to choose primarily whole foods that are minimally processed to improve carbohydrate metabolism. She notes that the typical American diet of junk food, processed food, and fast food can encourage undesired weight gain that makes it more difficult for insulin to work effectively. Choosing foods naturally high in fiber, such as whole grains, fruit, vegetables, and legumes, helps the body use insulin and can also improve cardiovascular health and assist with weight loss. Roszler uses the glycemic index to teach her clients about healthier food choices to promote weight loss and improved insulin effectiveness. Visit www.glycemicindex.com for more information.

However, Roszler does not recommend a generic low-carbohydrate meal plan, noting that adequate amounts of carbohydrates are crucial for optimum energy levels. Roszler encourages her clients to become more knowledgeable about carbohydrates in foods, use the glycemic index to make wise carbohydrate food choices, and choose minimally processed foods whenever possible. Grassi also recommends whole grains, with carbohydrates providing 40% to 50% of total calorie intake. Additional suggestions include eating small meals every three to five hours and including protein with each meal to help regulate insulin levels.

Move It or Lose It

We know that regular activity, especially aerobic exercise that gets our heart pumping, improves the ability of the muscles to use insulin and decreases insulin resistance. The American Heart Association recommends that everyone get at least 30 minutes of moderate-intensity activity most days of the week. According to the American College of Sports Medicine, moderate-intensity activities are those that raise heart rate slightly and cause you to start sweating yet allow you to carry on a conversation. Examples are brisk walking, light jogging, or even mopping the kitchen floor.

Frank Claps, MEd,CSCS, owner/operator of Fitness For Any Body, a personal training service in the Lehigh Valley area of Pennsylvania, stresses that the key for people with insulin resistance is consistency. He recommends some type of physical activity every day to reduce insulin resistance, often starting clients with 10 to 15 minutes of activity on a regular schedule. Claps notes that strength training is also helpful, especially that which involves the use of light weights and high repetitions to keep people moving.

A Role for Supplements

Elizabeth Sloan, PhD, president of California-based Sloan Trends & Solutions Inc describes four major trends in the supplement industry focused on insulin resistance. One group of products is designed to manage and prevent the risk factors and consequences of diabetes, such as vision and circulation problems. A second group focuses on insulin health, while a third offers products to help control blood glucose levels. The fourth group claims to block carbohydrate absorption to control weight. It’s important to note that not all of these supplements are backed by rigorous scientific research, and consumers should always consult a physician before taking any type of supplement.

However, there’s a growing body of research that points to the effectiveness and safety of one dietary supplement to reduce insulin resistance: chromium picolinate. Research beginning in the 1950s showed chromium’s role in metabolizing carbohydrates, protein, and fat. Chromium increases the number of insulin receptors on cells and also enhances cells’ ability to bind with insulin. The result is decreased insulin resistance.

USDA studies on chromium intake in the United States show very low levels through food sources, with 90% of people surveyed routinely consuming less than the adequate levels set: 35 micrograms daily for men and 25 micrograms for women. Food sources of chromium include brewer’s yeast, whole grains, cheese, liver, and meat; much chromium is lost through food processing.

Not all chromium supplements are equal. While chromium picolinate is the best absorbed form, chromium chloride, often found in multivitamin and mineral supplements, may not be absorbed at all. Other forms, such as chromium nicotinate or niacin-bound chromium, also have poor absorption.

In addition to the lifestyle changes, Roszler also advises her clients to take between 120 and 200 micrograms of chromium picolinate each day to improve insulin function, decrease carbohydrate cravings, and increase energy levels. Grassi recommends 500 to 1,000 micrograms of chromium picolinate, cinnamon (caplet or spice), 400 international units of vitamin D, and 3 to 5 grams fish oils per day to lower insulin levels and improve insulin resistance.

There are no known side effects associated with chromium picolinate supplementation. Roszler cautions that it may take two to four months of daily use before clients can expect to see an improvement in insulin action. Emerging research on vitamin D supplementation to improve insulin resistance is promising, and some research shows that cinnamon, either when added to foods such as oatmeal or consumed through concentrated caplets, may also reduce insulin resistance.

Prevention Is the Key

Cahill recommends that healthy eating and activity habits start with toddlers. And especially in light of the current obesity epidemic, adolescents and teens need to be aware of the symptoms of insulin resistance. Cahill encourages both men and women to discuss any signs and symptoms of impaired insulin function with a physician, to review family history, consider supplementation with chromium picolinate, and eat well and exercise to protect against heart disease and diabetes. “It is never to late to start,” he says.

— Lynn Grieger, RD, CDE, cPT