by Bonnie Bruce, DrPH, MPH, RD
Elevated blood glucose levels and water retention are just two of the possible side effects of glucocorticoid drugs that are related, to a greater or lesser degree, to food and nutrition. Glucocorticoids, also known as glucosteroids, corticosteroids, or just steroids, are powerful drugs used to treat many serious medical conditions, from asthma and allergies to inflammatory types of arthritis such as rheumatoid arthritis, systemic lupus erythematosus, and polymyalgia rheumatica. Examples of glucocorticoids are prednisone, hydrocortisone, and dexamethasone. The drugs also have many potential side effects besides the nutrition-related ones, ranging from mood swings and increased risk of cataracts and infections to easy bruising, osteoporosis, and muscle weakness. Some side effects are very common. Others are rare. Some are more serious than others, and some are less likely with short-term treatment at low doses. You may not be able to take action on your own to deal with many of the side effects of glucocorticoids, but there are practical strategies you can use when it comes to side effects related to nutrition.
The glucocorticoids you take as medicines are usually man-made versions of glucocorticoid hormones produced naturally in the body. The natural hormones help keep inflammation in check, and they dampen the body’s immune response. They also help control many other important functions in the body, among them how the body uses carbohydrates, fat, and protein and how it regulates the balance between salt, potassium, and water. When you take glucocorticoid medicines, the amount of the hormone circulating in the body is higher than usual, and not surprisingly, these functions are all affected. The drugs also often increase appetite, and they sometimes alter the way fat tissue is distributed in the body.
Glucocorticoids affect how the body processes carbohydrates, fat, and protein. In normal circumstances, the body breaks down into glucose the carbohydrates we take in when we eat. Glucose is a simple molecule used for energy in the body’s cells. It is carried around the body in the bloodstream and moves from there into the cells with the help of the hormone insulin. If, for whatever reason, the body isn’t getting the glucose it needs from carbohydrates, it will break down its own protein-containing tissues (muscles and other organs) and fat tissues to get it.
Glucocorticoids can affect this process in some important ways. For one, they can increase glucose levels in the body because of their effect on the liver and on muscle and fat tissue. For another, they can cause the body’s cells to become resistant to insulin, making it difficult for glucose to be transferred into them from the bloodstream. The result: an increased concentration of glucose in the blood. A high blood glucose level is a hallmark of diabetes, a serious condition that requires regular monitoring. The good news is that diabetes caused by glucocorticoids may be reversed after stopping treatment with the drugs.
Additionally, glucocorticoids’ effect on the breakdown of fat and muscle tissue has another unwanted effect: leftover fragments of fat and protein in the bloodstream. It’s the job of the kidneys to excrete the waste products of protein breakdown. If there is too much of these waste products, the kidneys can become overworked. The fragments of fat, known as triglycerides, can accumulate in the blood. High levels of triglycerides are a well-recognized risk factor for heart disease.
What you can do. If you already have diabetes and must take glucocorticoids, make sure that your doctor knows. Because of the effects of glucocorticoids on glucose levels, your doctor may want you to check your blood glucose levels more often and may change your diabetes drug and/or insulin regimen.
If you have diabetes, you most likely already know that there are some steps you can take to help manage your blood glucose levels. If you don’t have diabetes and are taking glucocorticoids, these same steps, discussed below, can help you stave it off. They are also helpful for managing triglyceride levels.
Try to keep your intake of carbohydrates to about 50% to 60% of your daily calories. Center your carbohydrate food choices around whole grains (like oats, whole wheat, and brown rice) and high fiber foods (like whole fruits, vegetables, nuts, and seeds). Choose fruits and vegetables with “strings, seeds, and skins,” like celery, cucumbers, apples, and grapes — they are nearly always good sources of fiber. Limiting consumption of sugary foods and sweets at the same time is also important. You don’t have to avoid these foods — just save them for special occasions (or try limiting yourself to one or two small servings a week). If you drink alcohol, be aware that alcohol can contribute to high triglyceride levels, as can a high intake of sweets and refined foods.
Glucocorticoids can cause your body to retain sodium, a major component of salt. When you retain sodium, you retain water. Besides causing weight gain, retaining water increases the risk of high blood pressure, which causes your heart to work harder and puts stress on arteries. About one in five people will develop high blood pressure from long-term use of glucocorticoids. Glucocorticoids will also cause you to excrete more of the mineral potassium. Potassium helps to maintain water balance in the body.
What you can do. Frequently, doctors recommend a “no added salt” diet for people on glucocorticoids to help prevent burdening the body with excess sodium. The average American eats about one to three teaspoons of salt every day, or about 2,400 to 7,200 milligrams (mg) of sodium. According to Dietary Guidelines for Americans, the recommended daily amount is no more than 2,300 mg (and no more than 1,500 mg for some specific groups: middle-aged and older people, African-Americans, and people with high blood pressure). About 30% of our sodium comes naturally from foods like meats, fish, and poultry; about 30% comes from sodium that is added in processing (as with luncheon meats, cheese, chips and crackers); and the remaining 40% comes from adding salt and other high-sodium condiments (like soy sauce) to our food.
Most foods in their natural or unprocessed state (like beef, pork, lamb, fish, fruits, and vegetables) have small amounts of sodium, so a “no added salt” diet does not mean being sentenced to a bland and uninteresting way of eating. It simply means that you should salt food only lightly during preparation and not add salt to food at the table. Save highly salted foods, like snack chips, salted nuts, and processed foods, for special occasions. Try some new flavors — lemon, lime, fruit-flavored vinegars, black and chili peppers, onion, and garlic. These are outstanding sodium-free flavorings and condiments, and there are also a number of excellent salt-free seasonings on the grocer’s shelves.
Try keeping the salt shaker off the table. If there are certain foods that you absolutely cannot eat without salting, taste first and then use salt sparingly. Interestingly, much of the time people actually find that they get used to using less salt and even come to prefer their food that way. Indeed, the preference for salt is a learned taste, not one with which we are born. Try going without extra salt for two weeks, and you will probably find that you prefer less salty foods.
To boost your potassium intake, fruits such as bananas, oranges, apricots, and raisins are the best sources. Vegetables such as avocado, winter squash, dry beans, peas, lentils, and spinach are also high in potassium. Something simple like eating half a banana or an orange each day (both great sources of potassium), in tandem with consuming less salt, can help to keep body fluid in balance and blood pressure low.
For many people, a dreaded consequence of glucocorticoid treatment is weight gain. Weight gain comes partly from water retention and partly from an increase in body fat. The increase in body fat is partly because glucocorticoids promote the body’s fat storage and partly because they often promote a ravenous appetite. Sometimes body fat is redeposited around the face (the “moon face” effect), the back, and the abdomen.
What you can do. Unfortunately, there is no magic bullet for dealing with increased appetite and weight gain. Besides stimulating appetite, glucocorticoids affect the emotions, and eating is a common way to deal with emotional highs and lows. It isn’t easy to cut back on food when you are taking glucocorticoids. However, there are weight management solutions, based on the principle that weight management is a behavior and a lifestyle issue, as well as a food issue.
In general, watching the number of calories you eat will help ward off weight gain. An easy way to get a ballpark estimate of your daily calorie needs is to multiply your current weight by a factor of 10, 11, or 12 (use 12 if you are physically active most days of the week, 10 if you are relatively inactive or want to try to lose weight). For example, if you are relatively inactive and weigh 150 pounds, you should aim for about 1,500 calories a day.
When you are struggling with an increased urge to eat, you might find it helpful to focus on the speed of eating. Choose foods that take longer to eat, like crunchy, hard vegetables or fruits and whole grains. Eating more slowly can help you to feel satisfied with less food. It takes the brain about 20 minutes to register that the stomach is full. Some people eat so fast that they take a second helping before the first has registered, thinking, “that must have been good — I need to go back for more…just to be sure.” If you find yourself having these kinds of thoughts, a way to slow things down is to take at least 10 minutes for your morning and noon meals and at least 20 minutes for your evening meal (or some other combination like this). Time yourself and wait 30 seconds or a minute in between bites of food. Alternatively, clock yourself and wait at least 20 minutes from when you began eating before you allow yourself to take seconds.
Strictly speaking, bone loss that leads to osteoporosis — one of the most common, serious, and often poorly treated complications of glucocorticoid treatment — is not a nutrition-related side effect. But calcium is a major constituent of bone and helps to maintain bone, and getting enough calcium plays a part in helping to stave off and treat osteoporosis.
Bone is a living tissue. Old bone is removed and replaced by new bone. In osteoporosis more bone is lost than can be replaced, and the bones become thinner and their structure weakens. This makes them more likely to fracture. According to the American College of Rheumatology (ACR), anyone taking glucocorticoids for more than 3 months is at increased risk for osteoporosis. In part this is because glucocorticoids can slow the rate at which bone is formed by acting directly on the bone cells. In part it is because they can increase the rate at which bone is lost by affecting levels of sex hormones and interfering with how the body handles calcium.
What you can do. The ACR recommends that people taking glucocorticoids also take 1,000 to 1,500 mg of calcium supplements and 400 to 800 International Units of vitamin D supplements daily to help restore the body’s normal calcium balance. (Vitamin D helps the body absorb the calcium.) If you’re taking glucocorticoids for more than a few weeks and aren’t taking anything for your bones, talk to your doctor about calcium and vitamin D supplements (and about other medicines that help protect bone).
People may feel emotions more strongly while they’re taking glucocorticoid drugs, and they may find themselves acting or eating in uncharacteristic ways. Loss of sleep and difficulty concentrating are common. Though these effects are generally mild, when combined with an increased appetite they can thwart even the best dietary intentions.
What you can do. To help you maintain control of your diet under these circumstances, you may find it helpful to monitor what you are eating by keeping a daily log or journal. It can take only a minute or two each day — one or two sentences — to jot down particular or specific differences in what or how much you are eating or to note that there are no changes (which is important, too). Or you can spend more time and detail everything you eat. Be sure to note when you are doing well or when you are successful at any changes you are trying to make. Some people even find it helpful to make a daily assessment by giving themselves a value from 1 to 10, with 10 meaning no problems or “doing great.” Of course, keep in mind this doesn’t always mean that changes you observe in your eating are due to glucocorticoid use or other medicines, but you will at least know that there are changes or that something is happening. In the long run, and on the positive side, conscious monitoring gives you valuable information that allows you to track your diet over time.
Last Reviewed October 19, 2011
Bonnie Bruce is a Senior Research Scientist in the Division of Immunology and Rheumatology in the Department of Medicine at Stanford University.
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