Heart Health & Cholesterol
Silk Soymilk® For Heart Health
Silk Soymilk can be a great addition to a heart-healthy diet. It contains only a fraction of the saturated fat found in dairy milk, and is 100% cholesterol-free. Silk is a good source of soy protein, which has been recognized by the FDA for its role in helping to reduce heart disease risk. Silk Soymilk also provides B vitamins and naturally-occurring omega-3 fats, both of which have been shown to offer heart health benefits. Best of all, Silk Soymilk is delicious, versatile and convenient, so incorporating it into your daily routine is as easy as opening a carton.
How the Heart Functions
Did you know that a healthy heart beats about 100,000 times a day? No wonder you need to take good care of it! About the size of a fist, the heart pumps blood through the arteries to deliver oxygen and nutrients to muscles and organs, and to pick up carbon dioxide and waste products for elimination. Like every other organ of the body, the heart itself needs oxygen and nutrients, which it receives through the coronary arteries.
Blood flow to the heart is impeded when cholesterol and other substances accumulate in the walls of the coronary arteries. These cholesterol deposits are called plaque. The disease of plaque formation and narrowing of the arteries is called atherosclerosis. As atherosclerosis progresses, the arteries also become less flexible, increasing your risk for heart disease.
Because cholesterol is best known as a harmful substance to be avoided, many people don’t realize that it actually has several essential functions in the body. It is part of cell membranes, and is a necessary building block used to produce certain hormones and vitamin D. However, because the liver and intestine can make all the cholesterol that the body needs, it is not necessary to take in more from the diet.
Cholesterol is ferried around in the bloodstream as part of a protein-cholesterol package called a lipoprotein. LDL-cholesterol – the “bad” cholesterol – is the lipoprotein most closely associated with atherosclerosis. HDL-cholesterol – or “good” cholesterol – is the lipoprotein involved in moving cholesterol to the liver for eventual elimination. High levels of HDL-cholesterol have been shown to help protect against heart disease.
If blood flow in the heart becomes restricted enough or blocked completely, a heart attack occurs. In the United States, someone has a heart attack every 20 seconds, and 2,500 people die from heart disease every day. Some people with atherosclerosis will experience shortness of breath or chest pain, but many people don’t feel any symptoms. A heart attack can often be the first warning that heart disease exists.
Reducing Heart Disease Risk
High levels of LDL-cholesterol are associated with a greater risk for heart disease. Although eating foods high in cholesterol raises blood cholesterol levels, the greater culprit is saturated fat, found in most animal foods such as beef, pork, poultry and full-fat dairy products.(1) Trans fats, found in hydrogenated products and many processed foods, also tend to elevate blood cholesterol levels.(2) However, the old advice about eating a low-fat diet to reduce heart disease risk is outdated. When eaten in moderation, fat is a necessary and beneficial part of the diet. The key is to replace detrimental saturated and trans fats with more healthful mono- and polyunsaturated fats. Choose foods rich in monounsaturated fats like olive and canola oil, nuts, peanuts, and avocado, as well as foods high in polyunsaturated fats like soymilk, tofu and other soyfoods.
Other diet components besides fat affect heart disease risk, too. Fiber – especially the soluble fiber found in whole oats, legumes and some fruits – helps reduce blood cholesterol levels.(3) So do certain proteins, including the protein found in soy foods.
Triglycerides are fats in the blood that may raise heart disease risk. Omega-3 fatty acids – found in certain fatty fish, walnuts, flax seed, and soyfoods – are linked to reduced triglyceride levels.(4) Omega-3’s may also have beneficial effects for those suffering from cardiac arrhythmias (irregular heart beats), which are a common complication of heart disease. Arrhythmias can lead to heart tissue damage, but studies have shown that consuming Omega-3 fatty acids may help prevent such damage from occurring.(5) (6)
Adequate intake of certain B vitamins – folic acid, vitamin B6, and vitamin B12 – reduces levels of homocysteine, an amino acid that is linked to increased heart disease risk.(7) Folic acid can be found in leafy vegetables and many fresh fruits. Eggs, many lean meats and whole wheat products are all good sources for vitamin B6. Silk Enhanced Soymilk, which contains folic acid, B6 and B12, is a convenient way to boost intake of all of these important nutrients.
Lifestyle factors influence heart health as well. Physical exercise can raise the levels of HDL-cholesterol and strengthen heart muscle,(8) while smoking promotes plaque buildup and is closely associated with increased heart disease risk.(9)
Soyfoods and Heart Disease
Soyfoods have a number of properties that may reduce risk for heart disease. Among the most interesting –and most studied – is the role of soy protein in reducing cholesterol levels. Studies showed this effect in humans nearly 40 years ago.(10) But it wasn’t until 1995 – when an evaluation of the clinical research on the cholesterol-lowering properties of soy was published – that the medical community became interested in soy as a heart-healthy food.(11) Four years later, the US Food and Drug Administration approved a health claim for soy protein and coronary heart disease.(12) This claim allows a food with at least 6.25 grams of soy protein per serving to include a statement on its product label about the role of soy protein in reducing heart disease risk. Similar claims exist in other countries as well.
Since 1995, many researchers have examined the cholesterol-lowering potential of soy protein. Their findings show that adding soy protein to the diet can reduce LDL-cholesterol levels by 3 to 5%.(13) (14) These beneficial effects appear to be independent of initial cholesterol levels and medical treatments. Even those on cholesterol-lowering drugs may experience an additional advantage from including soy protein in their diet.
While this is a modest reduction in cholesterol, it can have a significant impact on heart disease risk. Over a period of many years even a 3% reduction in LDL-cholesterol could reduce heart disease risk by as much as 10%.(15)(17)
In addition to helping lower LDL-cholesterol levels, soy protein may reduce heart disease risk in other ways. Soy protein has been shown to modestly lower levels of triglycerides (blood fats), and raise levels of HDL-cholesterol.(14) Also, soy protein may lower blood pressure(18) and make LDL-cholesterol less harmful.(19)
In addition to soy protein, soy foods also contain isoflavones – beneficial compounds that have been studied for many possible benefits including reduced risk for heart disease. Although it is too early to draw firm conclusions, several studies have shown that soy isoflavones directly improve the health of the arteries.(20) (23) A particularly compelling study examined 65,000 women in Shanghai, China. Results showed that women who consumed approximately 16 grams of soy protein per day (the amount found in about two cups of soymilk) were 86% less likely to have a heart attack than women who consumed relatively little soy protein.(24) Soy protein alone could not be responsible for such a large effect. The magnitude of this variance suggests that it is due to soy protein plus additional factors in soybeans such as isoflavones.
Finally, consuming more soy foods in place of animal products can reduce overall saturated fat and cholesterol in the diet, and increase intake of healthful unsaturated fats, omega-3 fatty acids, and fiber. The important role of soy foods in displacing higher-saturated-fat foods has been highlighted by the American Heart Association.(13)
1. Kris-Etherton PM, Krummel D, Russell ME, et al. The effect of diet on plasma lipids, lipoproteins, and coronary heart disease. J Am Diet Assoc 1988;88(11):1373-400.
2. Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC. Trans fatty acids and cardiovascular disease. N Engl J Med 2006;354(15):1601-13.
3. Erkkila AT, Lichtenstein AH. Fiber and cardiovascular disease risk: how strong is the evidence? J Cardiovasc Nurs 2006;21(1):3-8.
4. Lewis A, Lookinland S, Beckstrand RL, Tiedeman ME. Treatment of hypertriglyceridemia with omega-3 fatty acids: a systematic review. J Am Acad Nurse Pract 2004;16(9):384-95.
5. Brouwer IA, Katan MB, Zock PL. Dietary alpha-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: a meta-analysis. J Nutr 2004;134(4):919-22.
6. Lee KW, Hamaad A, MacFadyen RJ, Lip GY. Effects of dietary fat intake in sudden death: reduction of death with omega-3 fatty acids. Curr Cardiol Rep 2004;6(5):371-8.
7. Wald DS, Law M, Morris JK. Homocysteine and cardiovascular disease: evidence on causality from a meta-analysis. BMJ 2002;325(7374):1202.
8. Leon AS, Gaskill SE, Rice T, et al. Variability in the response of HDL cholesterol to exercise training in the HERITAGE Family Study. Int J Sports Med 2002;23(1):1-9.
9. Loew M, Hoffmann MM, Hahmann H, Marz W, Rothenbacher D, Brenner H. Smoking, apolipoprotein E genotype, and early onset of coronary heart disease. Eur J Cardiovasc Prev Rehabil 2005;12(3):268-70.
10. Hodges RE, Krehl WA, Stone DB, Lopez A. Dietary carbohydrates and low cholesterol diets: effects on serum lipids on man. Am J Clin Nutr 1967;20(2):198-208.
11. Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med 1995;333(5):276-82.
12. Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease. In: Federal Register: (Volume 64, Number 206)]; 1999:57699-733.
13. Sacks FM, Lichtenstein A, Van Horn L, Harris W, Kris-Etherton P, Winston M. Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee. Circulation 2006;113(7):1034-44.
14. Zhan S, Ho SC. Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile. Am J Clin Nutr 2005;81(2):397-408.
15. Holme I. An analysis of randomized trials evaluating the effect of cholesterol reduction on total mortality and coronary heart disease incidence. Circulation 1990;82(6):1916-24.
16. Law MR, Wald NJ, Thompson SG. By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? BMJ 1994;308(6925):367-72.
17. Law MR, Wald NJ, Wu T, Hackshaw A, Bailey A. Systematic underestimation of association between serum cholesterol concentration and ischaemic heart disease in observational studies: data from the BUPA study. BMJ 1994;308(6925):363-6.
18. He J, Gu D, Wu X, Chen J, Duan X, Whelton PK. Effect of soybean protein on blood pressure: a randomized, controlled trial. Ann Intern Med 2005;143(1):1-9.
19. Desroches S, Mauger JF, Ausman LM, Lichtenstein AH, Lamarche B. Soy protein favorably affects LDL size independently of isoflavones in hypercholesterolemic men and women. J Nutr 2004;134(3):574-9.
20. Cuevas AM, Irribarra VL, Castillo OA, Yanez MD, Germain AM. Isolated soy protein improves endothelial function in postmenopausal hypercholesterolemic women. Eur J Clin Nutr 2003;57(8):889-94.