What is the Best Diet for Diabetes and High Cholesterol
Though the mere mention of the words cancer or AIDS continues to strike fear in the hearts of almost everyone, few of us react that way to diabetes. We tend to view a diagnosis of cancer or AIDS as a death sentence, while diabetes is regarded as just another chronic condition. The frequent urination, abnormal thirst, and weight loss that signal the onset of the disease are bothersome, but once you begin treatment, life goes on pretty much as always.
Or so it seems. In reality, the nearly 16 million Americans who have diabetes face the danger of several serious complications, including heart disease, kidney failure, blindness, and damage to their nervous system. Many others must undergo limb amputations as the disease plays havoc with their circulation. Clearly, diabetes is not the minor ailment some people imagine it to be.
In fact, according to the American Diabetes Association, the disease is the leading cause of kidney failure, adult blindness, and amputations in this country, while exacting a heavy financial toll. Estimates of treatment costs combined with lost productivity approach $100 billion annually.
Despite these disheartening statistics, there’s still room for optimism. In the early 1990’s a major 10-year study offered new hope for diabetics. The Diabetes Control and Complications Trial (DCCT) found that an intense, tightly orchestrated treatment plan can reduce the risk of long-term damage to the eyes, nerves, and kidneys by 50 percent or more. Better yet, a follow-up study of patients in the original trial found that those adhering to this strict regimen also have less plaque in their arteries, suggesting that they are less likely to develop heart disease, the other major complication of diabetes. And according to David Nathan, MD, the physician in charge of the investigation, the benefits of intensive therapy are greater in older patients—the very people at greatest risk of cardiovascular complications.
Researchers have also discovered that this approach helps all diabetics, whether or not they need regular doses of insulin. Although the DCCT results applied mainly to “type 1” diabetics (who produce virtually no insulin), a major new clinical trial called the United Kingdom Prospective Diabetes Study (UKPDS) has shown that intensive treatment also benefits the many “type 2” diabetics whose available insulin simply fails to do the job. When these diabetics took insulin or oral medications faithfully, their risk of eye complications dropped by as much as 50 percent, while incidence of stroke and early kidney damage was cut by a third.
There are, however, a few drawbacks to consider. The program can be expensive. It demands steadfast commitment. And it requires a basic understanding of how your body processes sugar. A preferable alternative would be to prevent the disease before it takes hold in the first place. And an important clinical trial reported by the American Diabetes Association suggests that’s now a distinct possibility for persons who are prone to type 2 diabetes.
Up to 20 percent of adults have prediabetes (an impaired ability to process blood sugar). When Finnish researchers placed a large group of these at-risk adults on an individualized diet and exercise program, they were able to cut the frequency of full-blown diabetes by more than 50 percent.
The program consisted of numerous consultations with a nutritionist; a weight-reduction program; reduced intake of total calories, total fat, and saturated fat; and an increase in dietary fiber. The exercise component of the regimen focused on muscle-strengthening exercises like weight lifting rather than aerobics.
Still, if you already have diabetes and are considering one of the intensive treatment plans used in the DCCT or UKPDS studies, you’ll need to weigh the benefits of this latest approach to diabetes against its demands. Here’s what you need to know.
Most of the energy our bodies need to keep running comes from the carbohydrates in our food. Carbohydrates come in two forms: starches and sugars. Starchy foods include potatoes, rice, bread, and pasta; among the sugars are honey, molasses, and table sugar (sucrose). Other sugars are found in a variety of foods, including milk (lactose) and many fruits (fructose).
The digestive system breaks down starches and most food sugars into glucose, the form of sugar that’s burned by our cells. The glucose is then absorbed into the bloodstream and carried to all the body’s organs and tissues, where it powers brain activity, muscle action, nerve transmission, and other life-sustaining functions.
If blood levels of this vital fuel drop too low, the organs—especially the brain—start to malfunction. By the same token, if there’s too much glucose in the blood, there are equally serious consequences, as we’ll see in a moment.
It takes an “orchestra” of hormones to keep blood sugar levels within normal range. One of the key members of this orchestra is insulin, a substance normally secreted into the bloodstream by the pancreas. By assisting in the transfer of glucose from the bloodstream to the cells, insulin assures the body of a steady supply of fuel while clearing the blood of excess amounts.
The Body’s Tiny, Vulnerable Insulin Factory
|Nestled just below the stomach at the upper end of the intestines (the duodenum), the pancreas plays two distinct roles, pouring digestive juices into the intestines while it secretes insulin into the bloodstream. The insulin is manufactured in little clumps of cells—the Islets of Langerhans—tucked within the tissue of the pancreas. If the body’s immune defenders mistake the Islets for invaders and destroy them, insulin production fails and Type 1 diabetes results. In Type 2 diabetes, the Islets survive and continue to produce; but for reasons we don’t fully understand, the body’s cells fail to use the insulin efficiently.|
One of two things happens in diabetes. In insulin-dependent diabetes—most often seen in children and young adults—the pancreas fails to do its job, producing little if any insulin. In non-insulin-dependent diabetes—most often found in the middle-aged and elderly—the pancreas continues production, but the body either requires more than it can make or fails to respond properly to the available supply—a condition called insulin resistance.
In either case, blood sugar levels continue to go up and up as the intestinal tract converts carbohydrates into sugar and pours it into the bloodstream. Without insulin to speed sugar into the cells, the body’s energy level declines, resulting in the tired, listless feeling that often marks diabetes. Then, as unused sugar continues to mount, it begins to “spill” out of the bloodstream into the urine.
Faced with a syrupy concentration of sugar, the kidneys draw extra fluid from the body to dilute the urine. Unfortunately, this only makes matters worse, leading to increasingly serious dehydration. As the situation continues to unfold, a complex series of biochemical changes takes over, causing a dangerous acid condition to develop in the body. Left unchecked, this condition leads to coma and death.
Although scientists understand a great deal about the way insulin- and non-insulin-dependent diabetes develop, they still don’t know the exact causes. Insulin-dependent diabetes (type 1) is thought to be the result of an autoimmune reaction in which the body mistakes its own tissues as foreign proteins and begins to attack them as if they were an invading bacteria or virus. In type 1 diabetics, the theory goes, the immune system misidentifies the insulin-producing cells of the pancreas as an invader and mounts an all-out attack, destroying the organ’s ability to produce insulin.
Recently, some researchers have proposed an astonishing explanation for this reaction: They think it may originate in an allergy to cow’s milk. Several clues support this suspicion. For starters, insulin dependent diabetes is more common in children who drink large amounts of milk. In addition, breastfed infants, who usually begin drinking cow’s milk later in childhood, are less likely to develop the disease than bottle-fed babies. (The earlier a child is exposed to a potential allergen, the more likely his immature immune system will adversely react to it.)
Even more compelling is evidence that some diabetes-prone animals and humans have high levels of antibodies to the proteins in cow’s milk. These antibodies appear to cross-react with the proteins found in the insulin producing cells of the pancreas. If this research is confirmed in clinical trials, it would mean that—in susceptible children—drinking cow’s milk triggers a series of events that eventually generates the autoantibodies responsible for damaging the pancreas.
The latest research lends support to this notion: The mothers of 207 newborns at risk for type 1 diabetes were asked to breast feed their babies for 3 to 4 months. The group was then divided into two, with half the babies allowed cow’s milk. The researchers found that the infants who avoided milk were 40 to 50 percent less likely to develop autoantibodies to their pancreatic cells. Based on these encouraging results, a much larger 17-country trial is being planned to see if a milk-free diet will actually prevent the disease.
As for type 2 diabetes, researchers suspect that the insulin resistance responsible for the disease probably results from a genetic flaw. However, they also believe that overeating and overweight are contributing factors. In fact, between 80 and 90 percent of type 2 diabetics are obese. It seems that the fat cells of an overweight person are not as sensitive to the insulin as they should be. That prevents cells from taking up sugar.
Until recently, type 2 diabetes was largely restricted to the group most prone to excess weight: middle-aged men and women. Now, with obesity among young Americans reaching epidemic proportions, experts fear a similar outbreak in children and teens. The American Diabetes Association estimates that up to 45 percent of newly diagnosed cases in children are type 2 (or what used to be called “adult onset”) diabetes. A little over ten years ago the figure was less than 4 percent.
Children at greatest risk are couch potatoes—physically inactive overeaters—who have a family history of the disease. What makes early onset of the disease so ominous for this group is the earlier attack of the complications that accompany it. In the past, type 2 diabetes typically emerged when a person was in his 40s, and serious complications didn’t develop until his 60s or 70s. If this epidemic of obesity in the young continues unabated, by the time susceptible teens reach their early 30s, they will face the same threat of amputations, blindness, kidney failure, and heart attacks that their parents escaped until their senior years.
If unusual thirst or hunger, frequent urination, fatigue, or muscle weakness lead you to suspect you have diabetes, your first move is to see a physician for a complete diagnostic workup. To determine whether you really have the disease, the doctor may measure your blood sugar levels after a short period without food, or order a glucose tolerance test. If you have to take the tolerance test, you’ll be asked to drink a sugar solution on an empty stomach. You’ll then have several blood samples taken (usually every hour for 2 or 3 hours) to see how your body handles the load. Ordinarily, your blood glucose level would rise quickly, then gradually drop to normal. If you are diabetic, however, the level will still be somewhat elevated at the end of the test.
If you do have diabetes, you have several options. The treatment plan used in the DCCT and UKPDS studies is one. Since it reduces long-term complications so dramatically, many diabetes specialists are extremely enthusiastic about it. Unfortunately, without the help of a team of specialists that includes an endocrinologist, nurse educator, nutritionist, and maybe even a behavioral psychologist, the program is hard to follow.
An insulin-dependent diabetic on this program usually must take 3 to 4 injections of insulin daily. Someone with the non-insulin-dependent form of the disease usually starts out with a special diet and exercise program plus either oral medicine or insulin injections. This approach also requires you to test your blood sugar levels several times a day with an electronic glucose meter, then carefully schedule meals and exercise based on the results of the tests.
The aim of this intensive program is to keep your blood sugar to near-normal levels, which range from 80 to 120 milligrams per deciliter on an empty stomach. At bedtime, the numbers to aim for are 100 to 140 milligrams per deciliter. (Unfortunately, with the effort to hold down blood sugar comes the danger of overshooting into hypoglycemia, or low blood sugar. Diabetics in both the DCCT and UKPDS studies experienced more episodes of this complication, which can cause dizziness, sweating, tremors, weakness, headache, and fainting.)
Diabetics on more traditional, less rigorous regimens may take only one or two insulin shots a day and test their blood sugar levels less frequently—if at all. In fact, some diabetics continue to rely on urine test strips to check their sugar levels instead of using a glucose meter. Most diabetes specialists advise against relying solely on urinary sugar testing, however, because it’s not sensitive enough.
Since the intensive program requires so much work, many people are choosing a middle ground between the DCCT approach and traditional care in the hope that they can still reduce the risk of chronic complications.
Regardless of which options you choose, one of the cornerstones of treatment for all diabetics is good nutrition. And that means more than a standard diabetic diet. What you really want is an individually tailored plan that explains what to eat, how much to eat, and when. Since a registered dietitian has the expertise to give you this information, you need to enlist one for planning your strategy. If your doctor has no dietitian on staff, you can contact the local affiliate of the American Diabetes Association or the national office of the American Association of Diabetes Educators for the name of a qualified consultant.
Even if you have the help of a dietitian, you and your families still need to understand the basic diet strategy. The latest nutrition guidelines from the American Diabetes Association (AOA) stress the importance of achieving reasonable weight. This is especially important for type 2 diabetics in whom excessive numbers of fat cells may be one of the sources of the problem.
As a rule of thumb, anyone who needs to shed unwanted weight can expect to lose about a pound a week by reducing his usual daily food intake by 500 calories. A weight-loss diet should not drop below 1,200 calories for women and 1,500 calories for men. Anything less than this could leave you with vitamin and mineral deficiencies.
The Bottom Line on Diet
Latest guidelines from the American Diabetes Association stress the same factors that everyone should watch for:
How you divide up these calories depends upon your treatment goals and any complications you may have. If you are seriously overweight, but otherwise healthy you should probably get about 20 percent of your calories from protein, less than 30 percent from fat, and about 50 percent from carbohydrates.
When choosing carbohydrate-rich foods, you don’t necessarily have to restrict simple sugars, according to the latest ADA guidelines. Researchers have failed to prove that sugar, when included as part of a “mixed meal,” is any more likely to raise blood sugar levels than are starches. This is true, in part, because the other elements of such a meal—protein, fat, starches, and fiber—blunt the effects of the sugar.
Dietary fiber, in particular, plays an especially important role, as demonstrated by a growing number of studies. For instance, when investigators followed large numbers of healthy middle-aged women over time, they found that those who consumed the least amount of fiber from cereal grains were significantly more likely to develop diabetes than those with the highest intake of cereal fiber.
Even more convincing are the results of a new clinical trial in which type 2 diabetics were given either the conventional diet recommended by the American Diabetes Association, which contains 24 grams of total fiber, or one with more than twice the fiber content (25 grams of soluble and 25 grams of insoluble fiber). Patients on the higher fiber diet saw greater improvements in blood and urine glucose levels, as well as better serum cholesterol and triglyceride readings.
That still doesn’t mean you can eat all the cake, candy, and ice cream you want. Adding sweets to a meal that already provides the right number of carbohydrate calories can raise blood sugar levels. (And, of course, the extra sugar raises total calories, making it that much harder to lose weight.)
It’s also important to keep in mind that while many diabetics now have some freedom with simple sugars, if you fall within a group considered “sugar-sensitive” you won’t have that luxury. Sugar-sensitive diabetics have to limit foods that rapidly enter the bloodstream, such as table sugar, honey, molasses, and candy. They may also need to cut down on fruit or eat it at the end of a meal; some diabetics may have to avoid fruit juices altogether because of their almost immediate impact on blood sugar.
How can you tell which foods work best for you? That takes a lot of experimentation and blood-sugar self-monitoring. The only sure-fire way to create a diet plan that keeps blood sugar at near normal levels is to get in the habit of testing your blood sugar both before and one to two hours after meals. By seeing how various foods affect these readings, you can adjust the timing and ingredients of your meals and snacks.
Your diet should also help control abnormal levels of fats in your blood, a common problem among diabetics. In practical terms, that means limiting your intake of saturated fat and cholesterol. Among the worst offenders are fatty cuts of beef and pork, egg yolks, whole milk, cheese, and baked goods made with coconut and palm oils. (For more information, see “What to Do About Fat.”)
Regardless of the type of diet you need, you shouldn’t try to change all your eating habits at once—or get discouraged if it seems like you’re taking two steps forward and one step back. Almost everyone finds it difficult to give up deeply ingrained habits.
It helps to try to understand as much as you can about why you eat what you do. Many of us harbor subtle, often half-unconscious attitudes toward food that can hinder our ability to adapt to a new diet. Uncovering these attitudes can help you stay on course. (For tips on analyzing your approach to food, see “Fitting Health into Your Everyday Meals.”)
Even if you find it relatively easy to master the basics of your new diet, there are still a lot of details to consider. For instance, is it okay to drink alcohol? Should you take vitamin or mineral supplements? Are there any advantages to replacing sugar with artificial sweeteners?
The American Diabetes Association says that moderate use of alcohol should not create any problems for most diabetics, assuming their blood sugar levels are under control. That means no more than two drinks a day for men and one for women. (A drink is defined as a can [12 ounces] of beer, a glass [5 ounces] of wine, or one and one-half ounces of 80-proof hard liquor.)
This advice comes with several caveats: You should only drink alcohol with a meal; it can cause low blood sugar in a person who has fasted for more than 5 hours. The risk is even greater for anyone taking insulin or oral drugs that lower blood sugar levels, such as Orinase or Tolinase.
And people who have had a problem with alcohol abuse, as well as those with pancreatitis, gastritis, certain forms of kidney and heart disease, frequent bouts of low blood sugar, and neuropathy—a form of nerve damage common in many diabetics—should probably not include alcohol in their diets at all.
Unfortunately, there’s no simple answer to that question. A lot depends on your body’s reserves. For instance, studies have shown that if you have a deficiency of the trace element chromium, your body will have a harder time handling sugar. Although there is no hard evidence, researchers suspect that chromium deficiency may be more of a problem among the elderly and the poor than among other diabetics. Good sources of chromium include whole-grain breads, brewer’s yeast, and cheese.
A few recent studies also suggest that chromium tablets may help improve sugar metabolism in type 2 diabetics and those in danger of developing the disease—the obese and those who have a family history of diabetes. For instance, one experiment involving women with gestational diabetes—the kind that develops during pregnancy—found that chromium picolinate improved the way the body handled glucose, while lowering the excessive insulin levels commonly found in these women.
Experts caution, however, that people with diabetes should discuss chromium with their doctor before they begin taking it. Those on insulin or oral diabetes drugs may need to have their dosage lowered to compensate for the effect of the supplement.
There is more evidence to suggest that some diabetics need extra magnesium. Experts say magnesium deficiency in diabetics is probably due to loss of the mineral in the urine. A lack of magnesium may contribute to insulin resistance, making it harder for the body’s cells to take up sugar.
The threat of magnesium deficiency is greatest among pregnant women, those with congestive heart failure, and anyone taking diuretics, digoxin, or a group of antibiotics called aminoglycosides (gentamicin, streptomycin, tobramycin).
Before considering a magnesium supplement, however, you should talk with your doctor. High doses can be harmful in anyone with abnormal kidney function—a common problem for those with diabetes.
Among patients taking certain kinds of water pills (diuretics), the drug may flush so much potassium out of the body that supplements become necessary. Once again, you should consult your doctor before taking extra potassium because, in some circumstances, you may actually need less rather than more of the mineral. Potassium-restricted diets are sometimes needed for diabetics with kidney problems that cause the body to hold too much potassium—a condition referred to as hyperkalemia. Also in danger of hyperkalemia are those taking one of the blood-pressure drugs known as ACE inhibitors.
Studies have also shown that the levels of zinc in a diabetic’s blood are generally lower than normal. If you develop diabetic leg ulcers, zinc supplements may help to heal them.
Since the American Diabetes Association guidelines no longer limit dietary sugar, there’s less need to be concerned with sugar substitutes. But because there are now so many of these products, and so many conflicting claims about their value, you still might want to review their advantages and disadvantages.
The sweeteners sorbitol, mannitol, and xylitol (called sugar alcohols) all contain calories, which means they have to be counted toward your carbohydrate allowance. The good news is that they don’t raise blood sugar levels as much as sucrose (table sugar) and most other sugars. Keep in mind, though, that too much of these sugar alcohols can cause diarrhea.
The advantage of sweeteners such as aspartame (NutraSweet) and saccharin, is that they do not add calories to the diet. Nor do they affect blood sugar levels. Some research suggests, however, that they may produce side effects.
The Food and Drug Administration has received hundreds of complaints about aspartame saying that it causes headaches, anxiety, depression, irritability, insomnia, dizziness, abdominal pain, diarrhea, and rash. Careful scientific studies, however, have failed to verify any of these claims beyond a reasonable doubt. Some experts want saccharin banned because in animal studies it appears to have caused cancer of the bladder. Others point out that the doses used in the studies were huge—much higher than a normal person would ever consume. Whatever the truth is, the specter of cancer, plus the fact that saccharin can reach a developing baby, has prompted some experts to urge pregnant women to avoid it.
While adjusting your diet is a crucial part of your treatment for diabetes, it won’t be very effective without enough physical activity. Exercise can help lower your blood sugar levels by making the cells more responsive to insulin and by increasing the number of calories your body burns. Aerobic exercise is most effective because it has the greatest impact on overall blood sugar control. If possible, you should exercise at least 3 days a week for at least 20 minutes a day.
Regular exercise is also an indispensable part of any weight loss plan and allows you to be a little more liberal with your diet. But remember: In order to determine how much liberty to take, you need to test your blood sugar levels before and after exercising.
For a diabetic, it’s especially important to get a complete physical before starting an exercise program. Because diabetes can be accompanied by so many complications, your doctor will have to determine whether there are any signs of heart, eye, kidney, or nerve disease. If there are, you may have to modify the type, duration, and intensity of activity.
Someone with eye disease, for example, needs to avoid exercises that raise blood pressure, which can further damage the eyes. That means replacing sit-ups, calisthenics, and weight lifting with low-impact aerobics and non-jarring activities such as walking. (See “Exercise: The Other Half of Weight Control,” for more information.)
Diabetes is clearly a more dangerous problem than some imagine it to be. If ignored, it can cause serious, and sometimes life-threatening consequences. But if you follow a basic healthy diet, watch your sugar levels, exercise, and take medication as prescribed, you can do much more than cope with the disease: You can feel better and be healthier than ever.