Not all cholesterol is bad for you. Your LDL, or low-density lipoprotein, cholesterol is the bad guy, and your HDL, or high-density lipoprotein, benefits your health. HDL cholesterol circulates in the blood and picks up particles of LDL, returning them to the liver where they can be processed and removed from the body through the intestinal tract. This prevents LDL from clinging to the sides of your arterial walls where it can cause hardening of the arteries, blood clots, stroke and heart attack. The higher your HDL level, the lower your risk of stroke and heart attack.
Eat the Right Fats
Just as not all cholesterol is bad, not all dietary fat is bad, either. Monounsaturated fats -- MUFAs -- in particular can raise your HDL levels substantially, according to a study in a 2010 Canadian Medical Association Journal. Participants in the study who consumed high levels of monounsaturated fats for four weeks raised their HDL by 12 percent. Safflower oil, sunflower oil, olives and olive oil, avocados and nuts are examples of foods high in MUFAs.
At the same time, limit your intake of saturated fats and trans fats, found in fried foods and pastries. A report from the Harvard School of Public Health recommends replacing saturated fat, such as butter, with mono or polyunsaturated fat, such as olive oil. Increase your intake of omega-3 fatty acids, found in fresh fish such as salmon and mackerel, along with flaxseed and walnuts.
Watch Carbohydrate Intake
Carbohydrates are often rated by how fast they raise your blood sugar or cause insulin response. This is referred to as their glycemic index or GI. Processed carbs such as white breads or crackers are considered high GI, while whole grains, oats and sweet potatoes are examples of low-GI foods. Eating foods with a lower GI index may help increase your HDL levels, as will a low-carb diet, according to a review in the 2014 issue of Journal of Clinical Medicine Research. Authors of the study note that low-carb diets -- less than 45 percent of your daily caloric intake from carbs -- increase your HDL.
If you are overweight, shed some pounds, as weight loss can improve your HDL levels. A review in a 2007 Journal of Clinical Lipidology states that when combined with exercise and a healthy diet, weight loss can raise your HDL numbers by 10 to 13 percent. Losing weight by increasing your exercise may be even more beneficial, according to an article in a 2007 issue of Obesity.
Healthy Lifestyle Factors
Take a brisk walk, swim some laps or bicycle around the block. The type of exercise you choose to do is not important, but it is important to do something. Getting at least 120 minutes of aerobic exercise per week can increase your HDL levels, according to a study published in 2007 in Archives of Internal Medicine. While that time may be broken up into smaller sessions, the study points out that the longer your exercise sessions, the greater your HDL increase. The Centers for Disease Control and Prevention recommends 150 minutes of exercise per week. Speak to your physician before beginning an exercise program.
If you smoke, quit. Smoking not only lowers your HDL levels, it alters the ability of the HDL that you do have to work properly, according to a review in a 2013 issue of Journal of Cellular Biochemistry. When you quit, your HDL levels may improve in as early as three weeks.