When it comes to total cholesterol and low-density lipoprotein (LDL) or "bad" cholesterol, lower is better. However, having an elevated level of a certain type of cholesterol, high density lipoprotein (HDL), or "good" cholesterol, is protective against heart disease. HDL travels throughout the bloodstream, collecting cholesterol and carrying it back to the liver for breakdown and disposal. In addition to genetics and low exercise levels, not consuming enough beneficial foods can depress HDL levels.
Significance
Lipid disorders are significant, independent risk factors for the development of coronary artery disease (CAD). Prevention studies such as the Coronary Primary Prevention Trial and the Helsinki Heart Study have shown that lowering LDL and raising HDL cholesterol levels decreases the risk for developing heart disease.
According to the National Cholesterol Education Program (NCEP) guidelines, HDL cholesterol levels of less than 35 mg/dl are considered too low. The higher your HDL level, the more protection you have against heart disease. In addition, the ratio of total cholesterol to HDL-C (HDL cholesterol) is also important in determining risk for heart disease and, optimally. It should be less than 5. Many institutions recommend higher HDL levels for cardiovascular benefits (greater than 46 mg/dl).
Genetics---A Non-Modifiable Risk Factor
A genetic disposition toward low HDL cholesterol is a non-modifiable risk factor for heart disease. It is non-modifiable in that it is beyond your control. Lifestyle modification, such as good diet and exercise habits, are most important for those predisposed to low HDL cholesterol levels. According to an article published in the July 2007 issue of "Current Opinion in Cardiology," mutations of common variants of a gene known as the ABCA1 gene may play an important role in low HDL levels. In fact, as many as 20 percent of individuals with low HDL cholesterol levels may have this gene mutation (which interferes with HDL synthesis in the liver).
Consume More Omega-3 Fats
Omega-3 fats are one of the essential fatty acids. The 2 types of omega-3 fatty acids are known as docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA). Nuts (especially walnuts) and canola, flax seed, soybean, walnut and wheat germ oils are all rich sources of DHA. EPA is more potent as far as increasing HDL levels and is found in fatty, cold-water fish such as salmon, sardines, tuna, mackerel, halibut and trout. Those that do not eat fish and/or who consume diets low in omega-3 fatty acids are at a greater risk factor for developing cardiovascular disease, largely due to low serum levels of HDL cholesterol.
Eat the Right Fruits
Not all fruits are created equal when it comes to elevating HDL cholesterol levels. Citrus fruits are important for increasing HDL levels. They contain very powerful phytonutrient group (chemicals in plant foods that are responsible for the color of the fruit/vegetable and offer antioxidant benefits) known as flavanones. One of the phytonutrients within this group (known as hesperidin) may raise levels of HDL cholesterol. Other citrus fruits rich in hesperidin are red bell peppers, lemons and tangerines. The peel and the membrane of the citrus fruits offer the highest concentration of hesperidin.
Soy Products for Elevated HDL Levels
Soy foods are a beneficial double-edged sword in the fight against heart disease. Soy products, such as tofu, may decrease LDL cholesterol AND increase HDL cholesterol. Many soyfoods, in particular soybeans, offer appreciable amounts of cholesterol-lowering dietary fiber, and provide omega-3 fatty acids. Soy milk, tempeh and soynuts are other examples of beneficial foods in this category.
References
- Journal of Investigative Medicine; Cholesterol and coronary heart disease: predicting risks in men by changes in levels and ratios; B Kinosian, H Glick, L Preiss and KL Puder; Oct 1995
- European Heart Journal; The Helsinki Heart Study: basic design and randomization procedure; M Mänttäri, O Elo, MH Frick, et al.; Oct 1987
- Current Opinion in Cardiology; Genetic determinants of HDL: monogenic disorders and contributions to variation; KL Klos and IJ Kullo; July 2007
