Having high cholesterol puts you at risk for heart disease, a condition that caused the deaths of over 616,000 people in 2008, according to the Centers for Disease Control and Prevention. But not all cholesterol is created equal, and higher levels of the type of cholesterol known as HDL can actually promote heart health. One way to boost HDL levels is by focusing on beneficial foods, with herbs like dry coriander seeds showing promise as a natural dietary therapy.
Cholesterol and HDL
Cholesterol is a waxy material in your body that helps protect skin and nerve cells, detoxifies your bloodstream and helps synthesize several steroids. Too much cholesterol, however, has a negative effect. Your liver manufactures three-quarters of cholesterol, with the other 25 percent coming from your diet. HDL, which stands for high-density lipoprotein, is the "good" form of cholesterol that helps prevent the “bad” LDL, or low-density lipoprotein, cholesterol from clinging to the lining of your arteries. The American Heart Association considers an HDL reading of 60 mg/dL and above to be protective against heart disease. Although it's important to keep your HDL levels high and LDL levels low, your cholesterol ratios are also important. The AHA recommends keeping the ratio -- which you calculate by dividing your HDL number into your total cholesterol number -- at 5-to-1 or lower.
Coriander, also known by its scientific name of Coriandrum sativum, is an herb that belongs to the parsley or carrot family and is widely used in Middle Eastern, Mediterranean, Indian and Asian cuisines. Every part of the plant is edible, particularly the leaves -- more commonly called cilantro -- and the seeds extracted from the fruit of the plant that are dried and used as a spice. Coriander has also been used for centuries in traditional medical practice to treat diabetes in Europe and fight inflammation in India. More recent studies have focused on the effects dry coriander seeds and their oil have on lowering cholesterol and blood fatty acids called triglycerides.
In a study on rats at the University of Kerala in India, published in "Plant Foods for Human Nutrition" in 1997, scientists found that dry coriander seeds had a significant effect on lowering total cholesterol levels and triglycerides, while increasing levels of HDL cholesterol. The researchers concluded that coriander increased bile production in the liver, increasing the breakdown of cholesterol into other compounds. Subsequent research in 1999 at the same university found that a high level of antioxidant enzymes in dry coriander seeds contributed to coriander's ability to improve cholesterol and lipid levels. Another animal study, published in "European Food Research and Technology" in 2008, showed there was a remarkable decrease in total cholesterol and a significant increase in HDL in rats fed a high-cholesterol diet, supplemented with coriander seed oil.
Although dry coriander seeds are generally considered safe, rare allergic reactions can occur. Data is also lacking on the recommended maximum daily dose of dry coriander seeds. Due to the absence of research on coriander's effects on cholesterol levels in humans, do not rely on coriander seeds alone to raise your HDL levels. One of the best ways to lower your LDL cholesterol and improve your HDL levels is to lose weight and exercise at least 30 minutes a day. If lifestyle changes don’t bring your cholesterol levels under control, then your doctor may prescribe medications such as statins. The Mayo Clinic recommends you get a baseline cholesterol test at age 20, with follow-up tests at least once every five years.