High cholesterol has long been known to raise the risk of heart and blood vessel disease in people with diabetes and without. Unfortunately, it’s very common among Americans generally, including those with diabetes. The good news is that there’s a lot you can do to lower your cholesterol and, consequently, lower your risk of heart disease. Making the effort to lower blood cholesterol is especially important for people with diabetes — Type 1 or Type 2 — who have a higher risk of heart disease than the general public.
The bad guy: LDL
Your LDL, or “bad,” cholesterol is the culprit when it comes to raising the risk of heart disease. LDL stands for low-density lipoprotein, and if you have too much of it in your blood, it can build up along the insides of your artery walls, leading to the formation of fatty deposits called plaque. Plaque makes it harder for blood to flow through your arteries, which means that less blood can get to vital organs, such as your heart and brain. Sometimes this can lead to a heart attack or a stroke. Plaque can also rupture, triggering the formation of blood clots, which can also block the arteries, leading to a heart attack or stroke.
So it makes sense to keep your LDL level low. For most people with diabetes, the goal is an LDL cholesterol level below 100 mg/dl. If you have heart disease already, your doctor may want you to keep it below 70 mg/dl. If you’re not sure what your LDL is or what your target is, ask your health-care provider, and make sure you get your LDL checked every year.
Some of the steps you can take to help lower your LDL cholesterol level include reducing your intake of saturated fat, dietary cholesterol, and trans fat (which is present in foods that contain partially hydrogenated oils), maintaining a healthy weight, and engaging in regular physical activity.
The good guy: HDL
HDL, or high-density lipoprotein, is known as “good” cholesterol. HDL is like the body’s drain cleaner, scooping up the LDL-ridden plaque in the arteries and bringing it to the liver for disposal. The higher your HDL level, the greater your protection against heart disease. If you’re a woman, aim for an HDL of 50 mg/dl or higher; men should keep their HDL at 40 mg/dl or higher. Quitting smoking, losing excess pounds, and getting regular exercise are proven ways to raise your HDL cholesterol.
Another player: triglycerides
There’s another player to consider when it comes to heart health, and that’s triglycerides. Triglycerides are a kind of fat found in your blood and also stored in the body for fuel. But, as with LDL cholesterol, if you have too high a level of triglycerides in your blood, your heart disease risk goes up. The goal for triglycerides is less than 150 mg/dl.
Lifestyle and dietary measures that can help to lower triglycerides include losing excess weight, exercising regularly, avoiding refined carbohydrates such as white flour, lowering saturated fat intake, and increasing your intake of omega-3 fatty acids and fiber.
When you have your cholesterol checked, your lab report may also have your total cholesterol number, which is made up of your LDL, HDL, and triglycerides. The goal for total cholesterol is a number less than 200 mg/dl.
Many people with high cholesterol are prescribed one or more medicines to lower their LDL cholesterol and/or triglycerides or to raise their HDL cholesterol. Statins are one of the more common types of medicines used, but there are others that work well, too, including bile acid resins and niacin. Fibrates are a type of medicine that can help lower triglycerides and raise HDL cholesterol. There’s also a medicine that blocks the absorption of cholesterol in the intestines.
However, as with all drugs, side effects can occur, although most are not usually serious. Statins, for example, may cause muscle pain and, of more concern, liver damage. Fibrates can cause gastrointestinal upset and may increase the risk of gallstones. If you experience side effects when taking a cholesterol drug, always call your health-care provider for advice, rather than stopping the medicine on your own.
Nature’s cholesterol reducers
There’s strong evidence that making dietary changes — including lowering saturated fat and dietary cholesterol intake — and staying physically active can help with cholesterol management and lower the risk of heart disease. For many people, though, these changes aren’t enough to bring lipid levels into their target range. That’s where medicines can help, but some people are reluctant to take medicines or wonder whether there is anything else they can do on their own before — or in addition to — starting medicines. And in fact, there may be.
Any number of magazine or online articles and advertisements tout supplements that can lower cholesterol without harmful or unpleasant side effects. Some of them may indeed work, while others remain unproven or appear to be ineffective.
Here are some of the more popular supplements and food items for which cholesterol-lowering claims have been made. Of those that may have a positive effect, some may help to lower LDL cholesterol more, while others may have more of an effect on triglycerides. Keep in mind that any decisions about taking cholesterol-lowering supplements or making significant dietary changes should be made with the knowledge of your health-care team, who can best guide you toward the therapies that are likely to help and caution you about any possible side effects.
When most people think of fiber, they think of a bowl of bran cereal or a slice of whole wheat bread. These foods are high in insoluble fiber, the type of fiber that helps to move food through the intestinal tract and prevent constipation. But insoluble fiber is not the only kind of fiber found in food.
Soluble fiber, or viscous fiber, is found in certain foods, including oatmeal, oat bran, and other oat products, dried beans and peas (black beans, chickpeas, lentils), barley, flaxseed, nuts, apples, oranges, prunes, carrots, Brussels sprouts, and psyllium (seed husks found in some fiber supplements and bran cereals). Soluble fiber works a little differently from insoluble fiber: It takes up water in the digestive tract, forming a gummy, gel-like substance. While it, too, may help prevent constipation, a unique feature of soluble fiber is that it can help lower LDL cholesterol by binding to cholesterol in the intestines. The evidence for soluble fiber’s cholesterol-lowering abilities is pretty strong and is supported by fairly extensive research.
How much soluble fiber does one need to lower LDL? Aiming for 7–13 grams of soluble fiber each day helps. And consuming adequate insoluble fiber can help, too: Eating a total of 20–35 grams of fiber (both insoluble and soluble) each day can lower total cholesterol by 2% to 3% and LDL cholesterol by up to 7%. One way to get that much fiber in your meals is to eat at least 5 servings of fruits and vegetables a day, as well as 6 servings of grains.
Taking psyllium-based fiber supplements or beta glucan supplements (beta glucan is found in barley and oats) may also help lower LDL, particularly if you’re unable or unwilling to eat a lot of foods high in soluble fiber. But fiber supplements can cause gassiness, bloating, cramps, and diarrhea and may decrease the absorption of the fat-soluble vitamins A, D, E, and K. Also, some people may be allergic to psyllium, so caution is necessary; the incidence of psyllium allergy appears to be higher among health-care workers. Signs of psyllium allergy may include rash, itching, and shortness of breath.
Distant cousins to cholesterol (they share a similar chemical structure), phytosterols, or plant stanols and sterols, are natural substances found in plant cell membranes that compete with cholesterol for absorption in the intestinal tract. What this means is that if you consume enough of them, your total cholesterol and LDL cholesterol may decrease (but not if you eat a double cheeseburger with fries along with them). In fact, you can lower your LDL cholesterol by up to 15% by consuming at least 2 grams of phytosterols every day.
The evidence for phytosterols is strong enough for the National Cholesterol Education Program to have added the recommendation to consume at least 2 grams per day if one’s cholesterol is high. The Food and Drug Administration (FDA) also allows the following health claim on foods that meet the criteria:
“Foods containing at least 0.65 gram per serving of vegetable oil plant sterol esters, eaten twice a day with meals for a daily total intake of at least 1.3 grams, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
Natural sources of plant stanols and sterols include fruits, vegetables, vegetable oils, nuts, legumes, and whole grains. However, it would be difficult to consume much more than 500 milligrams (mg) of phytosterols daily from these food sources.
Food manufacturers have also fortified a number of foods with phytosterols, including certain brands of vegetable oil spread, juice, yogurt, soy milk, rice milk, snack bars, and even chocolate. Over-the-counter phytosterol supplements are also available.
Plant stanols and sterols are quite safe: There are no known harmful side effects of consuming them, and they can be taken or eaten along with a statin or a fibrate for an even greater LDL reduction.
Back in the 1990’s, researchers thought that soy was another tool in the cholesterol-buster’s arsenal. At the time, a meta-analysis of 38 studies appeared to show that consuming at least 25 grams of soy protein daily could help lower total and LDL cholesterol and triglycerides.
But in 2006, a second look at the research cast doubt on the magnitude of soy’s benefit in this area. The American Heart Association announced that eating soy had much less of an effect on LDL than previously thought, lowering it only by about 3%. The other catch is that most Americans don’t eat that many soy foods on a daily basis, so few are likely to consume 25 grams of soy protein per day. However, the evidence of some benefit is still there, so if you’re willing to eat a few soy-based meals a week, soy may be of some help in lowering your LDL.
Soy protein is found in tofu, tempeh, miso, edamame (green soybeans), soy nuts, soy milk, soy cheese, and soy-based meat substitutes (such as veggie burgers, soy hotdogs, and “bacon” strips).
Soy foods are generally considered to be safe, but another component of soy, called isoflavones, are natural, estrogen-like substances that may reduce thyroid function in some people (although these findings are not consistent). Women who have had estrogen-sensitive breast cancer and are taking either a selective estrogen receptor modulator (such as tamoxifen [brand name Nolvadex], raloxifene [Evista], or toremifene [Fareston]) or an aromatase inhibitor (such as anastrozole [Arimidex], exemestane [Aromasin], or letrozole [Femara]) should probably not eat soy foods until treatment has been completed.
Niacin, or nicotinic acid, is a B vitamin that the body needs to help turn food into fuel. The recommended dietary allowance (RDA) for niacin for men is 16 mg per day, and for women, 14 mg per day. The Upper Tolerable Limit (UL) for niacin is 35 mg per day if niacin is consumed either in supplement form or in niacin-fortified foods. Key food sources of niacin include dairy foods, lean meat, poultry, fish, nuts, and eggs.
Niacin is also sometimes prescribed in much larger doses — up to 2,000 mg, or 2 grams, taken two to three times a day — to increase HDL cholesterol (by 15% to 35%), with secondary effects of lowering LDL and triglycerides. Prescription niacin can be taken along with a statin or a bile acid resin for further LDL reduction. Some common brand names of prescription niacin are Niacor, Niaspan, and Slo-Niacin.
While consuming the RDA for niacin in foods or vitamin supplements is safe (but will likely have no effect on your HDL cholesterol level), you should never take large doses of niacin on your own without checking first with your doctor. Side effects of prescription-strength niacin can include flushing (redness of the face and neck), stomach upset, itching, high blood glucose, and liver damage.
Red yeast rice
Red yeast rice is a fungus that grows on rice. It’s been used in Asian countries both as a medicine (for various ailments) and as a food coloring (for Peking duck, for example) for hundreds of years.
Interest in red yeast rice in the United States has grown in recent years because of its ability to block the production of cholesterol by the liver. This ability is due, in part, to a substance called monacolin K, which is a “natural” form of lovastatin, a prescription drug used to lower LDL cholesterol. Red yeast rice is essentially a lower-dose type of statin. As a result, many people who either cannot tolerate the side effects of prescription statins or who do not want to take them for other reasons have turned to red yeast rice.
A study published in 2009 in the Annals of Internal Medicine showed that people who were unable to tolerate statins because of muscle pain were able to tolerate 1800 mg of red yeast rice twice daily for 24 weeks, with an average drop in LDL of 35 mg/dl. A study done in China showed that red yeast rice lowered heart disease risk by 30% after study subjects took the supplement for about 4 1/2 years.
The catch is that red yeast rice is sold as a dietary supplement in the United States, not as a drug. That means that the FDA does not regulate it for quality, safety, or effectiveness. An analysis of 10 brands of red yeast rice capsules done by ConsumerLab.com in 2008 found that there was wide variation in red yeast rice content from brand to brand. And given the fact that red yeast rice is essentially a low-dose statin, possible side effects are similar to those of statins, including muscle pain or tenderness that can lead to kidney damage, flulike symptoms, dark-colored urine, difficulty with urination, upset stomach, bloating, and headache.
In 2007, the FDA asked the manufacturers of three red yeast rice supplements — Red Yeast Rice, Red Yeast Rice/Policosanol Complex, and Cholestrix — to withdraw their products from the US market, citing them for containing “unauthorized” lovastatin. However, people are still able to obtain this supplement with smaller amounts of the “natural” lovastatin.
As tempting as it can be to take something that’s natural and effective, it’s wise not to take this supplement without first talking with your doctor. People who decide to take red yeast rice should have their liver enzymes checked about six weeks after starting it and then every six months thereafter. If any of the side effects listed above occur, anyone taking red yeast rice should call his doctor.
Policosanol is a fatty compound that can be derived from sugar cane, beeswax, wheat germ, and rice bran. Initial studies with this supplement indicated that it may be just as effective as statins at lowering LDL. But those studies were almost all conducted by a single research group in Cuba and were sponsored by a Cuban company that markets policosanol. A study conducted in Germany using Cuban sugar cane–derived policosanol at four different doses found no benefit to taking policosanol (results were published in The Journal of the American Medical Association in 2006). Subsequent studies by a variety of researchers similarly failed to show any lipid-lowering effect of policosanol.
Side effects of policosanol are mild and consist primarily of rash, fatigue, headache, weight loss, and insomnia. Policosanol may increase the blood-thinning effects of aspirin, warfarin (Coumadin) and clopidogrel (Plavix). It may also increase the effects of levodopa, a drug used for Parkinson disease.
Guggulipid is a supplement derived from the resin of the mukul myrrh tree. It contains compounds called guggulsterones, which initially were shown to lower LDL cholesterol and triglycerides in both human and animal studies done in India. In these studies, guggulipid lowered LDL cholesterol by 12% and triglycerides by 15%.
However, in another study, published in The Journal of the American Medical Association in 2003, 85 otherwise healthy men and women were given either a placebo, 1,000 mg of guggulipid three times a day, or 2,000 mg of guggulipid three times a day. At the end of the study, LDL cholesterol actually increased by 5% in the 1,000-mg group and by 7% in the 2,000-mg group. However, triglyceride levels dropped by about 14% in the subjects with the highest LDL levels. Additionally, C-reactive protein (CRP), a marker of inflammation, dropped by 28% in the group receiving the highest dose of guggulipid.
Since the study was published, there has been little enthusiasm to continue researching guggulipid. Side effects include nausea, vomiting, and diarrhea. It is not recommended for people with liver disease, kidney disease, or inflammatory bowel disease.
Garlic has long been believed to help lower cholesterol. However, a study published in Archives of Internal Medicine in 2007 tested raw garlic and two brands of garlic supplements in adults with high LDL, and none of the forms lowered their cholesterol after six months. Previous research indicated that garlic did cause a drop in LDL, but only temporarily.
On the plus side, garlic may offer some benefit in reducing the risk of heart disease by means other than lowering cholesterol. For example, it’s been shown to slightly lower blood pressure. It may also lower the risk of some types of cancer. Fortunately for garlic lovers, side effects are few. However, those who take blood-thinner medicines such as aspirin, warfarin, or clopidogrel are at increased risk for bleeding if they also take garlic.
Ginger has been used for centuries in traditional medicine in Asia and India, primarily to treat digestive disorders, arthritis, and heart conditions. It’s currently used in modern medicine to treat nausea associated with chemotherapy, motion sickness, and even morning sickness during pregnancy. Ginger may also help fight heart disease and lower cholesterol.
A small study published in the journal Saudi Medical Journal in 2008 looked at the effects of taking 3,000 mg per day of ginger for 45 days in people with high cholesterol. The results were promising: Total cholesterol dropped by 13 mg/dl, and triglycerides dropped by 9.5 mg/dl. However, the authors of the study point out that this was a small study and that the effects of ginger on blood lipids should be confirmed in a larger study.
A study published in The American Journal of Clinical Nutrition in August 2009 may cast new light on flaxseed. Ground flaxseed has already earned its position as a plant source of omega-3 fatty acids, helping to lower LDL cholesterol and triglycerides and promoting healthy digestion. In the study, researchers in China analyzed results from more than 28 studies involving whole flaxseed and flaxseed oil. The findings? Eating one tablespoon per day of whole flaxseed lowered total and LDL cholesterol, but not HDL cholesterol, in postmenopausal women and men, especially in those who had higher cholesterol levels. Until now it’s been thought that flaxseed must be ground up to be digested and yield health benefits, but it may be that the whole seed can also offer lipid-lowering benefits.
Flaxseed is quite safe, although nausea, bloating, and diarrhea are possible side effects. It’s best to take flaxseed separately from any medicines to prevent drug absorption problems: Flaxseed can slow the movement of food (and medicines) from the stomach to the intestines.
Heart-healthy eating overall
Following a heart-healthy eating plan is one of the best ways to help you reach your blood lipid goals. A heart-healthy plan has the following characteristics:
- It is low in saturated and trans fat. This means limiting fats that are solid at room temperature such as butter, some stick margarines, shortening, and lard, and consuming less red meat, cheese, whole milk, and fast food.
- It contains heart-healthy fats, such as olive, peanut, canola, corn, and sunflower oils; trans-fat–free tub vegetable oil spread; nuts and seeds; and omega-3 fatty acids, which are found in fatty fish, walnuts, and flaxseed.
- A heart-healthy plan is rich in both soluble and insoluble fiber from fruits, vegetables, whole-grain breads, cereals, and pasta, and dried beans and peas.
- It contains no more than 2400 milligrams of sodium daily, primarily for blood pressure control. Canned or processed foods, such as canned soups and vegetables, frozen meals, fast foods, and lunch meats tend to be high in sodium. Eating less of such foods and seeking out low-sodium (containing no more than 140 mg sodium per serving) or “no salt added” varieties of them can help you cut back on your sodium intake.
(Click here for more information about choosing foods that can help you lower your cholesterol.)
A registered dietitian can help you develop an individualized eating plan that’s good for both your heart and your blood glucose control. If you choose to try dietary supplements to lower your cholesterol — or for any other reason — tell your health-care provider, and keep him updated on your usage from one appointment to the next.