Cholesterol gets a bad rap. But the truth is, you need it to live, let alone lead a long, healthy life. Without this waxy, fat-like substance, you couldn't make sex hormones such as estrogen and testosterone, adrenal hormones that help regulate blood pressure and metabolism, or essential nutrients such as vitamin D.
Floating through your bloodstream, two different fat- and protein-containing carriers, called lipoproteins, carry cholesterol to and from your cells. At healthy levels -- ideally less than 100 milligrams per deciliter -- low-density lipoprotein, or LDL, delivers the cholesterol you need into your tissues for cell stability and healthy function. Meanwhile, high-density lipoprotein, or HDL, scavenges the excess cholesterol and carries it to your liver, which breaks down the cholesterol and removes it from the body, says Dr. Nauman Mushtaq, medical director of cardiology at Northwestern Medicine Central DuPage Hospital in Illinois. Hence the name "good cholesterol."
However, when HDL levels are low -- typically defined as less than 40 mg/DL -- LDL can build up in the blood vessels, earning it the reputation of "bad cholesterol." This buildup can cause plaque to form in the arteries, increasing your risk of heart attack or stroke.
Thankfully, research has shed new light on several lifestyle changes you can make to ensure your good cholesterol stays ahead of the bad. Here, experts share their top six methods for raising HDL levels and keeping your heart happy:
1. Be a cardio bunny. Cardiovascular exercise can help keep your weight down and HDL levels up. For instance, in one study published in the Journal of Sports Sciences, by walking or running 50 to 60 minutes per day, five days per week for 12 weeks, overweight men significantly decreased their body fat, insulin resistance, blood pressure and "bad cholesterol" levels while upping their "good cholesterol." Meanwhile, an analysis in the Archives of Internal Medicine found that moderate-intensity aerobic exercise (e.g., walking, cycling or continuous swimming for at least 15 minutes) consistently increases HDL levels.
Increase your HDL levels: Perform at least 20 to 30 minutes of moderate-intensity aerobic exercise daily, Mushtaq says. Examples include brisk walking or light jogging, swimming or cycling. On a scale of 1 to 10, you should feel like you're working at about 4 to 6.
2. Quit smoking. Smoking can do a number on more than your lungs, actually reducing the body's concentration of HDL cholesterol. Fortunately, it's never too late to quit: One review published in Biomarker Research concluded that HDL levels can rise by as much as 30 percent within three weeks of quitting.
Increase your HDL levels: Giving up cigarettes isn't easy, but it can be done. According to Mushtaq, quitting cold turkey is the most effective method. Research in the Annals of Internal Medicine found that people who quit abruptly were more likely to be smoke-free at four weeks than those who gradually cut back (49 percent versus 39.2 percent). Try nicotine patches and gum to help tamp down cravings.
3. Go nuts. Eating a small serving of almonds (about eight kernels) daily is enough to raise HDL levels by as much as 16 percent after 12 weeks, according to research published in the Journal of Nutrition . Researchers believe the nutrients in almonds help limit the amount of LDL cholesterol that the body absorbs from foods while increasing the amount expelled by the body.
Increase your HDL levels: Pair a small handful of almonds with a piece of fruit for a snack, add slivered almonds and berries to yogurt or use sliced almonds as a topping for green beans or grain salad, recommends registered dietitian nutritionist Libby Mills, spokeswoman for the Academy of Nutrition & Dietetics.
4. Stick to moderate amounts of alcohol. Higher alcohol consumption can drastically increase your risk of heart disease (not to mention other conditions), but drinking moderate amounts of alcohol has been shown to raise HDL. A study in PLoS One suggests that low-to-moderate alcohol consumption -- defined as one drink per day for women and two for men -- may help increase the transfer of proteins involved in moving HDL through the bloodstream.
Increase your HDL levels: If you don't drink, there's no need to start. However, if you do drink, keep yourself in check by limiting yourself to one drink per day if you're female and two drinks per day if you're male. One drink equals 12 ounces of regular beer, 5 ounces of wine or 1.5 ounces of distilled spirits.
5. Limit processed foods. The average American diet is rife with processed foods, which contain high amounts of trans and saturated fats. When consumed in excess, trans and saturated fats have a negative effect on cholesterol levels, according to Mills. Trans fats in particular have been shown to lower HDL levels.
Increase your HDL levels: Check food labels for hydrogenated and partially hydrogenated ingredients, which contain trans fats, Mills says. Cut back on prepared desserts, packaged snacks, fried foods and powdered creamers.
6. Get your fiber. Fiber does more than regulate bowel movements. According to a report published by the National Heart, Lung, and Blood Institute, once ingested, soluble fiber (which, unlike insoluble fiber, absorbs water during digestion) helps to block the absorption of cholesterol in the bloodstream. Unfortunately, the average American gets only about half the daily recommended intake of 25 to 30 grams.
Increase your HDL levels: According to Mills, some of the best cholesterol-lowering sources of fiber include beans, lentils, apples, blueberries, flax seeds and oatmeal. However, adding too much fiber too quickly can cause gastric distress (think: constipation or diarrhea). Mills recommends increasing your fiber intake slowly and drinking plenty of water to help keep your gut happy.
K. Aleisha Fetters, MS, CSCS, is a freelance Health & Wellness reporter at U.S. News. As a certified strength and conditioning specialist with a graduate degree in health and science reporting, she has contributed to publications including TIME, Women's Health, Men's Health, Runner's World, and Shape. She empowers others to reach their goals using a science-based approach to fitness, nutrition and health. You can follow her on Twitter or Instagram, find her on Facebook or the Web or email her at email@example.com.