Foods That Help Lower LDL or "Bad" Cholesterol
High LDL (low-density lipoprotein) or "bad" cholesterol levels are linked to the development of atherosclerosis, the underlying cause of coronary heart disease (CHD). Numerous clinical trials have shown that reducing LDL can lower CHD risk1. Furthermore, epidemiological and clinical studies indicate that a diet rich in fruits, vegetables, unrefined grains, fish and low-fat dairy products, and low in saturated fats and sodium lower the risk of CHD and hypertension2. There are some foods that contain ‘protective’ components, which are thought to reduce heart disease risk, primarily by acting on blood lipids. In this article, some of these foods/food components including soluble fiber, phytosterols, nuts, soy protein, and a few others will be discussed.
Foods That Help Lower "Bad" Cholesterol
- Soluble Fiber
- Plant Sterols and Stanols
- Soy Protein
- Dark Chocolate (needs more research)
- Fenugreek (needs more research)
- Cinnamon (needs more research)
- Black Tea (needs more research)
1. Soluble Fiber
Observational studies found that diets high in dietary fiber are associated with reduced CHD risk. Dietary fiber is a plant substance that does not get digested in the human small intestine. There are two types of fiber based on their solubility in water: soluble and insoluble fiber. Oats, psyllium, pectin, flaxseed, barley and guar gum are all common sources of soluble fibers. Cellulose, lignins, and wheat bran are insoluble fibers1. Dietary fibers are a safe and practical way to reduce cholesterol. Only soluble fibers can lower LDL cholesterol, whereas insoluble fibers do not have this effect. Studies have consistently shown that consumption of soluble fiber can modestly reduce LDL by about 5% to 7%. A meta-analysis of 67 trials demonstrated that intake of soluble fiber, 2-10 g/day, was associated with a small but significant 7% reduction in LDL. All types of fibers including oat, psyllium, pectin, and guar gum, could produce this effect. It is not fully understood how these different types of fibers produce their effects. One important mechanism is the binding of bile acids. This leads to heighten bile acid synthesis (which requires cholesterol), decrease in liver cholesterol content, increase in LDL receptors, and increased LDL clearance. Other potential mechanisms include fiber’s ability to increase the viscosity of the intestinal lumen and slow nutrient absorption, entrap cholesterol in the small intestine, and enhance satiety, resulting in lower energy intake1.
Foods High in Soluble Fiber
- Oatmeal Barley
- Kidney Beans
2. Plant Sterols and Stanols
All plants make sterol compounds, also called phytosterols, which are chemically related to cholesterol. The main natural source of plant sterols is vegetable oils such as tall pine-tree and soybean oil. It can also be found in various nuts. Phytosterols can be hydrogenated to give stanols. Both plant sterols and stanols can likely lower LDL to the same degree. There are now numerous studies demonstrating that plant sterols/stanols can decrease LDL by 6 to 15% taken at dosages of 2 to 3 g/day. A more recent meta-analysis of 84 trials reported that consumption of an average of 2.15 g/day of sterols reduced LDL by 8.8%. Mechanism-wise, phytosterols fight with cholesterol for space within bile salt micelles (small aggregates of bile salt, lecithin, cholesterol, that are involved in lipid transport and absorption) in the intestinal lumen, thus reduces cholesterol absorption. Another possible mechanism is that plant sterols likely interact with intestinal cell transporting proteins to direct cholesterol back into the intestinal lumen1.
There can be potential adverse effects of phytosterols in certain patients who are high absorbers, for instance in patients with sitosterolemia. This is a rare autosomal-recessive disorder, characterized by increased intestinal absorption and decreased biliary elimination of all sterols, including plant sterols as well as cholesterol. These patients have mutations in the transporter proteins, ABCG5 or ABCG8, which regulate the export of sterols from liver and intestinal cells. This condition leads to high blood levels of plant sterols and cholesterol, which can contribute to premature atherosclerosis. The role of dietary plant sterols in the development of atherosclerosis is unclear1.
Foods High in Plant Sterols and Stanols
- Promise Activ buttery spread
- Smart Balance Heart Right
- 1% low-fat milk
- Benecol margarine spread (1 to 2 tablespoons)
- BioBest probiotic yogourt with Plant Sterols (Canada)
Nuts are often considered unhealthy because of their high fat content. However, studies have shown that increased nut consumption is associated with a lower risk of heart disease. Nuts are rich in mono- and poly-unsaturated fatty acids, and also contain dietary fiber, phytosterols, and polyphenols. All these components likely combine to reduce LDL. A review of 23 clinical studies investigating the effects of nuts on cholesterol levels concluded that consuming roughly 50-100 g of nuts at least five times per week may reduce LDL between 2-19% in normal and individuals with high blood lipids2. Subjects in the studies consumed nuts (including almond, peanut, pecan nut and walnut) as part of a heart-healthy diet with 35% of energy from total fat content (a moderate fat diet), consisting of mainly monounsaturated and polyunsaturated fats. In a more recent meta-analysis of 13 trials, the authors found that diets consisting of walnuts (30–108 g/d) resulted in a 6.7% greater reduction in LDL compared with the control diet1. Trials using smaller amounts of walnuts demonstrated more modest lipid improvements. Taken together, there is considerable evidence supporting the LDL-lowering effects of nuts.
Nuts That Lower LDL
4. Soy Protein
Epidemiological studies from Asian nations showed that large consumption of soy products is associated with a lower incidence of high blood cholesterol and CHD. A meta-analysis of 38 controlled clinical trials in 1995 found that an average intake of 47 g/day of soy protein decreased LDL by 12.9% (1). The cholesterol lowering effect was greatest in subjects with the highest initial level of cholesterol in their blood. A more recent (2008) meta-analysis of randomized controlled trials in adults with normal or moderate high blood cholesterol confirmed that consuming modest amounts of soy protein, 25 g/day, can reduce total cholesterol and LDL. The percent LDL reduction is about 6% (2). The current data indicate that soy proteins can produce a small reduction in LDL. The mechanism by which soy decreases cholesterol is not fully understood. Soy contains phytoestrogens (isoflavones), which have weak estrogenic and antiestrogenic properties. In the past, scientists were not certain which of the soy components, the isoflavones or the soy protein, were responsible for the cholesterol-lowering effect. Recently, a study concluded that isolated isoflavones in capsules do not affect blood cholesterol. Thus, current evidence supports soy protein, rather than isoflavones, as the component responsible for lowering cholesterol. However, there may still be other active chemicals in soy waiting to be discovered.
Foods Containing Soy Protein
- Tofu firm (4 ounces of tofu has 9.4 grams of soy protein)
- Soy veggie burger
LDL Lowering Foods That Need More Research
5. Dark Chocolate
Cocoa, a food rich in flavonoid, may have a role in the prevention of cardiovascular disease (CVD). One study showed that cocoa power at doses from 13 to 26 g/day reduced LDL levels in subjects with a baseline LDL concentration ≥ 3.23 mmol/l (LDL levels that are near ideal)2.
Fenugreek is an herb that may help lower blood sugar levels in diabetics. One randomized controlled clinical trial showed that fenugreek seed reduced total cholesterol and LDL by 13.4% and 15.1%, respectively. Additional trials are needed to establish the safety and cholesterol-lowering efficacy of fenugreek products2.
Cinnamon, a popular spice, can decrease total cholesterol and LDL levels in diabetic individuals. Further trials are needed to confirm cinnamon’s ability to lower blood lipoprotein levels2.
8. Black Tea
Epidemiological studies suggest that regular tea consumption is associated with reduced risk of CHD. One small clinical trial showed that consuming five servings of black tea daily reduced total cholesterol and LDL by 3.8% and 7.5% respectively in adults with mildly high cholesterol levels2.
Food That Lower Total Cholesterol, but Not LDL
Since ancient times, garlic has been used medicinally to enhance physical and mental health. It is thought to have lipid-lowering properties by decreasing cholesterol absorption in the intestine, and inhibiting enzymes involved in cholesterol synthesis. Two meta-analysis of randomized controlled trials, done in 2000 and 2009, found that garlic can modestly decrease total cholesterol, without a significant effect on LDL levels2.
In summary, there is current and ample evidence indicating that soluble fiber, plant sterols, soy protein, and nuts definitely have a modest LDL-lowering effect. The FDA has allowed a health claim to be attached to these foods, declaring that they can reduce CVD risk through lowering LDL. The other foods, including dark chocolate, fenugreek, cinnamon and black tea, do not have substantial data supporting their ability to lower LDL and need further research. There is a lack of evidence backing up garlic’s ability to reduce LDL, but there is data indicating that it can modestly lower total cholesterol. Although some of these foods have weak evidence supporting their ability to lower LDL, it is still worthwhile to add them into your diet as they may have other health benefits in addition to their unconfirmed lipid-lowering effects. Besides, the majority of these foods are safe and do not appear to be unhealthy when consumed at moderate levels. It would not hurt to add them to a heart-healthy diet that is low in saturated and trans fats. Furthermore, a clinical trial showed that subjects on a low saturated fat diet consisting of a combination of plant sterols, viscous fiber, soy protein, and nuts had a mean LDL reduction of 28.6%, which was comparable to subjects on a low saturated fat diet taking lovastatin who had a mean LDL reduction of 30.9% (1). In conclusion, incorporating and combining all of the foods from above can potentially have a major lowering effect on LDL levels, and consequently may help prevent atherosclerosis and CHD.
The material presented in this article is only for your information. Before you make any changes to your diet and lifestyle, please consult your physician. Your doctor will be able to give you appropriate advice on what will help you manage your lipid levels.
- Nijjar PS, Burke FM, Bloesch A, Rader DJ. "Role of dietary supplements in lowering low-density lipoprotein cholesterol: A review." Journal of Clinical Lipidology. 2010;4(4):248-58.
- Sirtori CR, Galli C, Anderson JW, Sirtori E, Arnoldi A. "Functional foods for dyslipidaemia and cardiovascular risk prevention." Nutrition Research Reviews. 2009;22(02):244-61.
- "Adding Cholesterol Lowering Foods to Your Diet." Harvard University. May 15, 2012.
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.