While the main goal of managing diabetes is optimizing blood sugar levels, there is much more to it than that.
People with diabetes are at higher risk of developing chronic high blood sugar complications, such as cardiovascular (heart disease). In fact, people with diabetes may be two to four times more likely to develop heart disease and have a heart attack than people without diabetes.
One of the risk factors for heart disease is high cholesterol. Cholesterol is a waxy, fat-like substance that is necessary for our bodies to function. Cholesterol helps produce essential hormones as well as vitamin D and is found in all of the cells in the human body.
The body produces about 80% of the cholesterol in the bloodstream, while the other 20% comes from diet. Animal products contain cholesterol, such as egg yolks, meat, and dairy products. Cholesterol isn’t obtained from eating plant foods, though plants do make very small amounts of cholesterol.
Cholesterol is reported in terms of total cholesterol and is then further broken down into the two main types of cholesterol. High-density lipoproteins (HDL) and low-density lipoproteins (LDL) are the two main cholesterol levels in the blood.
People with diabetes are encouraged to manage their cholesterol levels to reduce their risk of developing heart disease and related complications. Because those with diabetes are more likely to have unhealthy cholesterol levels, it’s imperative to address them. In this post we look at the relation between diabetes and cholesterol as well as the best low cholesterol diabetic diet.
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Cholesterol and diabetes
People with diabetes tend to have dyslipidemia, a term for unhealthy cholesterol and fat levels in the blood. This happens often enough that the term is called diabetic dyslipidemia. One of the main reasons for this connection is thought to be due to insulin resistance.
Insulin is the hormone necessary for blood sugar levels to be lowered. When the body doesn’t respond to insulin the way it should, the pancreas produces more insulin to counteract the high blood sugar levels. Over time, this can cause the pancreas to lose some of its ability to produce insulin. Insulin resistant cells tend to have more fatty acids and cholesterol. This increase in fatty acids prompts the liver to produce more cholesterol.
Diabetes tends to lower HDL levels or “good” cholesterol and raise LDL, or “bad” cholesterol. High LDL cholesterol levels increase the risk of plaque building in the arteries, while high HDL cholesterol levels help fight off inflammation and counteract the adverse effects of LDL cholesterol. For example, having high LDL cholesterol and high HDL cholesterol is less of a risk factor than having high LDL cholesterol and low HDL cholesterol.
Another aspect of dyslipidemia is the triglyceride level. Triglycerides are fats in the bloodstream and are often reported in a lipid blood test along with total cholesterol, LDL cholesterol, and HDL cholesterol. Elevated triglyceride levels, especially when coupled with low HDL and high LDL, increases the risk of heart attack, stroke, and peripheral artery disease (PAD). PAD is a narrowing of the peripheral arteries providing blood to the legs, stomach, arms, and head.
Elevated cholesterol levels can lead to a buildup of plaque, a waxy substance, in the arteries. Over time, plaque can build up so much that it forms a blockage and restricts blood flow. If the artery is blocked, the organ receiving blood from that artery will suffer. A blockage to the heart results in a heart attack, while a blockage to the brain results in a stroke.
Cholesterol level guidelines
Cholesterol targets will vary based on the individual risk for atherosclerotic cardiovascular disease (ASCVD), which can be calculated by your healthcare professional. This is often referred to as the ASCVD risk score. (“Atherosclerotic” refers to the buildup of plaque and cholesterol in the arteries.)
Similar to blood pressure guidelines and other health indicators, cholesterol goals have been updated over time based on new research, which is always changing. The general goals for cholesterol levels are as follows for adults over the age of 21:
Total cholesterol: Less than 200 mg/dL.
LDL (“bad”) cholesterol: less than 70 mg/dL for those with heart disease or at very high risk of heart disease;
- less than 100 mg/dL for those at high risk of heart disease;
- less than 130 mg/dL for all other people.
HDL (“good”) cholesterol: greater than 45 mg/dL (the higher, the better); women tend to have higher levels of HDL than men.
Healthy eating guidelines
Healthy lifestyle habits are one of the main ways to help combat high cholesterol levels. Eating a healthy diet as well as being physically active can help reduce bad cholesterol and raise good cholesterol numbers.
Some of the main aspects of healthy eating in regards to improving cholesterol include:
Cholesterol in foods:
This is one of the most talked-about aspects of diet in regards to cholesterol levels. All animal products contain cholesterol, and foods like eggs, organ meats, and shellfish are particularly high in cholesterol.
The recommendations behind diet and cholesterol seem to change often, which can be confusing for both people with high cholesterol and healthcare providers. The bottom line is that if you have high cholesterol, it’s probably a good idea not to eat large amounts of foods high in cholesterol on a regular basis. Aim for a balance, with some cholesterol-containing foods and plenty of plant foods free of cholesterol to balance them.
Sugar plays a large role in blood sugar levels but can also impact cholesterol. Studies have found that a high intake of sugar, especially in the form of refined and added sugars, can lower good cholesterol, raise bad cholesterol and increase triglycerides levels.
Type of fats:
Saturated fat tends to raise both LDL and HDL cholesterol levels. You can find saturated fat in animal products like meat, full-fat dairy, and some plants, such as coconut. Saturated fat is fine to eat, but it should be in moderation. If you have high cholesterol and eat a large amount of saturated fat, it may be beneficial to try cutting back to see if it helps improve cholesterol levels.
Trans fats, on the other hand, are considered the least heart-healthy of the fats and should always be avoided. They can raise LDL cholesterol and lower HDL cholesterol. Trans fat primarily comes from processed foods, such as those with partially hydrogenated oils. In 2018, the Food and Drug Administration (FDA) banned the use of trans fats in products, which has been effective since May 2019.
Unsaturated fats, such as monounsaturated and polyunsaturated fats, are considered the most heart-healthy and have been associated with a reduced risk of heart disease. When used to replace saturated fats, unsaturated fats have a favorable effect on cholesterol levels. Omega-3 fatty acids are a type of unsaturated fat and are also considered heart-healthy through reducing inflammation. Sources of unsaturated fats include nuts, seeds, plant oils, avocados, and fatty fish like salmon.
It’s important to note that the ketogenic diet, or keto diet, might not be ideal for promoting healthy cholesterol levels. The keto diet is a very low carbohydrate and high-fat diet gaining popularity in recent years. Ketogenic diets tend to be higher in saturated fat and can be lower in fiber as well.
People with diabetes might be curious if the ketogenic diet can help them manage their blood sugars. There isn’t enough long-term research on the impacts of a keto diet on cholesterol levels, so people with diabetes should discuss their dietary choices with their healthcare providers. If cholesterol levels increase while following a ketogenic diet, it would be advisable to consider another dietary approach to improve them.
Dietary fiber is found in plant foods such as fruits, vegetables, nuts, seeds, whole grains, and legumes. There are two types of fiber: soluble and insoluble. Soluble fiber, such as the kind found in oats, legumes, flax seeds, apples, berries, and broccoli, is especially helpful for lowering cholesterol levels. Some people prefer to get their daily soluble fiber intake through a fiber supplement such as psyllium fiber.
Plant sterols and stanols:
Sterols and stanols are substances found in plants that help block cholesterol absorption. Some products have sterols, and stanols added through fortification, and some foods contain them naturally. Studies find that intakes up to approximately three grams per day of plant sterols and stanols can lower LDL cholesterol by an average of 12%.
The Mediterranean Diet
The Mediterranean diet is one of the healthiest eating styles to help lower cholesterol is a Mediterranean-style eating pattern. A Mediterranean diet is associated with a reduced risk of developing type 2 diabetes. Some studies found an 83% reduction in diabetes risk when a Mediterranean diet was followed.
The Mediterranean diet emphasizes plant-based foods as the backbone of the diet. Fruits, vegetables, whole grains, legumes, nuts, and seeds are abundant in this style of eating, as are healthy plant-based fats such as olive oil and avocados. Meat, dairy, processed foods, and refined sugar are avoided, and the emphasis is put on whole foods. While sugary drinks are avoided, moderate amounts of alcohol such as red wine are included, but of course, this is entirely optional.
The different types of foods in a Mediterranean-style diet include:
- Vegetables: Tomatoes, broccoli, kale, spinach, onions, cauliflower, carrots, Brussels sprouts, cucumbers, etc.
- Fruits: Apples, bananas, oranges, pears, strawberries, grapes, dates, figs, melons, peaches, etc.
- Nuts and seeds: Almonds, walnuts, macadamia nuts, hazelnuts, cashews, sunflower seeds, pumpkin seeds, etc.
- Legumes: Beans, peas, lentils, pulses, peanuts, chickpeas, etc.
- Tubers: Potatoes, sweet potatoes, turnips, yams, etc.
- Whole grains: Whole oats, brown rice, rye, barley, corn, buckwheat, whole wheat, whole-grain bread, and pasta.
- Fish and seafood: Salmon, sardines, trout, tuna, mackerel, shrimp, oysters, clams, crab, mussels, etc.
- Poultry: Chicken, duck, turkey, etc.
- Eggs: Chicken, quail, and duck eggs.
- Dairy: Cheese, yogurt, Greek yogurt, etc.
- Herbs and spices: Garlic, basil, mint, rosemary, sage, nutmeg, cinnamon, pepper, etc.
- Healthy Fats: Extra virgin olive oil, olives, avocados, and avocado oil.
Foods not eaten on a Mediterranean diet include:
- Added sugar: Soda, candies, ice cream, table sugar, among many other types of added sugar. The American Heart Association recommends that women consume no more than 6 teaspoons of added sugar per day (24 grams) and men consume no more than 9 teaspoons of added sugar per day (36 grams).
- Refined grains: White bread, pasta made with refined wheat, etc.
- Refined oils: Soybean oil, canola oil, cottonseed oil, and others.
- Processed meat: Processed sausages, deli meats, hot dogs, etc.
- Highly processed foods: Packaged foods with a long list of ingredients.
Managing cholesterol and diabetes
Along with healthy eating, medications may be recommended to treat high cholesterol in people with diabetes. Statins are the class of medications used to help lower high cholesterol. They are classified by their intensity level or ability to lower cholesterol.
Statins work by blocking certain liver enzymes responsible for manufacturing cholesterol. Statins tend to lower LDL and raise HDL levels, which is ideal. They do come with possible side effects, so they are prescribed when the benefit is believed to be greater than the risks of side effects.
- High-intensity statins can lower LDL cholesterol by approximately 50% or more. Atorvastatin (Lipitor) at 40-80 mg daily and Rosuvastatin (Crestor) at 20-40 mg daily are both examples of high-intensity statins.
- Moderate-intensity statins can lower LDL cholesterol by approximately 30-50%. Lipitor and Crestor at lower doses are considered moderate-intensity. Simvastatin (Zocor) at 20-40 mg daily, Pravastatin (Pravachol) at 40-80 mg daily, Lovastatin (Mevacor) at 40 mg daily, and Fluvastatin at 40 mg twice daily are other examples.
- Low-intensity statins include lower doses of many of the moderate-intensity statins.
Other aspects of managing high cholesterol in diabetes include:
- Physical activity: Being active can help boost HDL cholesterol levels, as well as reducing blood sugar levels. The American Diabetes Association recommends daily exercise and a weekly goal of 150 minutes of physical activity per week. The ADA also recommends not going longer than two days without being active. Strength training is also recommended to help control blood glucose levels. Muscles take up extra glucose for energy, which may help reduce insulin resistance, a driving force behind high cholesterol.
- Stop smoking: Smoking can lower HDL cholesterol and raise LDL. Quitting smoking not only reduces heart disease risk but can help improve cholesterol, which impacts overall heart health.
- Natural vitamins and supplements: Niacin (vitamin B3) and red rice yeast are popular natural supplements for lowering cholesterol. Some people prefer to try these before starting a statin. As always, it’s best to have a conversation with your healthcare provider about your risk factors and treatment options for high cholesterol, including the use of supplements.
- Monitoring and follow-up: Patients with diabetes should follow-up with their healthcare provider on a regular basis and have a lipid panel blood test at least once a year. If cholesterol levels are very high, your healthcare provider may want to recommend treatment and re-check sooner than one year to reassess.
Heart disease risk increases the longer someone has diabetes. Suppose someone is newly diagnosed with diabetes and is also found to have high cholesterol. In that case, their healthcare provider may be comfortable trying lifestyle changes first before starting a cholesterol-lowering medication. On the other hand, if someone has had diabetes for years and their blood sugars are uncontrolled, cholesterol-lowering medication is more likely to be recommended.
People with diabetes are at increased risk of abnormal cholesterol levels, which is a risk factor for complications such as heart disease, heart attack, and stroke. High cholesterol can be managed with both lifestyle changes and medication use. Management of high cholesterol will depend on the individual and should be monitored and re-evaluated regularly with their healthcare provider.