A Lifelong Approach to Cardiovascular Health With Nutrition
Have you ever calculated your 30-year risk of cardiovascular disease? What about your chance of having a heart attack in the next 10 years? Both tools use general demographic information combined with established risk factors such as smoking status, cholesterol levels and blood pressure to calculate the chance that an individual will develop heart disease or suffer a heart attack within a certain period of time. These tools are also used in the primary prevention of cardiovascular disease, as described recently by Leening, Berry and Allen in the Journal of the American Medical Association as part of their article on taking a lifespan approach to reducing cardiovascular risk.
Modifying certain risk factors by either medication or lifestyle interventions can have a beneficial effect on risk of disease. For example, lipid lowering medication reduces cardiovascular disease risk by about 25% (Taylor), and the Diabetes Prevention Program showed that modest weight loss as part of an intensive lifestyle intervention could reduce risk of developing type II diabetes in pre-diabetic subjects, and improved cardiovascular risk factors (Perreault et al.).
However, these interventions tend to start with adults who already have met certain criteria for cardiovascular disease, such as elevated cholesterol levels and blood pressure, or with glucose intolerance. By this stage, damage to the cardiovascular system has already occurred. While it is possible to reverse some of the damage done, for example, Grines reviews evidence that shows that atherosclerosis is reversed with intensive statin therapy, surely it is better to try to avoid behaviors associated with the development of arterial plaques in the first place?
A seminal article on the natural history of one of the key causes of heart disease, the development of atherosclerosis, found that the process of plaque development begins in early childhood when fatty streaks form on the inside surface of the arteries (Holman and co-workers). Even so, certain risk factors are associated with a reduction in plaque size even in adolescents and young adults. McGill and co-workers found that in people aged 15-34, well-known risk factors such as obesity, smoking, hypertension, and impaired glucose tolerance were associated with more extensive fatty streaks or arterial lesions. If people are able to reach the age of 50 with no established risk factors of cardiovascular disease, then their lifetime risk of cardiovascular disease will remain very low. For example, Lloyd-Jones and associates report that people with no risk factors at age 50 have a risk of cardiovascular disease of 5% in men and 8% in women, compared to people with two or more risk factors who had a lifetime risk of 69% for men and 50% for women. It seems logical that a pro-active approach to reducing risk of cardiovascular disease is a better strategy than only treating the risk factors once they reach a certain critical threshold.
How can nutrition help to reduce lifetime risk of cardiovascular disease? Nutrition is an important part of several strategies that together prevent heart attacks and stroke, the others being engaging in regular physical activity, reducing stress levels and not smoking. Daniels and co-workers discuss how cardiovascular risk factors can be reduced in children and adolescents. Nutrition has been shown to affect circulating cholesterol levels in different ways. A diet low in both saturated fat and cholesterol affects the production side of cholesterol, while dietary fiber from cereals or fruit and vegetables increases cholesterol excretion rates. Greater intakes of long chain omega-3 polyunsaturated fatty acids affect cholesterol metabolism and reduce levels of triglycerides, which also increase cardiovascular disease risk (summarized by Ito). Controlling overall calorie intakes so that they match energy expenditure is also important to maintain a healthy weight. Obesity is linked to high blood pressure, an unfavorable lipid profile and insulin resistance, and achieving a weight reduction through nutrition and lifestyle modifications can have a beneficial effect on overall health, including the heart and blood vessels.
Waiting for risk factors to become bad enough to be treated is a bit like waiting until you can’t see through your windscreen before you clean your car: it is better to make cleaning the windscreen as part of your regular maintenance, then you will never have a problem with visibility.
Leening MG, Berry JD, Allen NB. Lifetime Perspectives on Primary Prevention of Atherosclerotic Cardiovascular Disease. JAMA. Published online March 21, 2016. doi:10.1001/jama.2016.1654. http://jama.jamanetwork.com/article.aspx?articleID=2504298
Stephen R. Daniels, Charlotte A. Pratt, and Laura L. Hayman. Reduction of Risk for Cardiovascular Disease in Children and Adolescents. Circulation. 2011;124:1673-1686, doi:10.1161/CIRCULATIONAHA.110.016170 http://circ.ahajournals.org/content/124/15/1673.full
Grines CL. The role of statins in reversing atherosclerosis: what the latest regression studies show. J Interv Cardiol. 2006 Feb;19(1):3-9. http://www.ncbi.nlm.nih.gov/pubmed/16483333
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Lloyd-Jones DM, Leip EP, Larson MG, D'Agostino RB, Beiser A, Wilson PW, Wolf PA, Levy D. Prediction of lifetime risk for cardiovascular disease by risk factor burden at 50 years of age. Circulation. 2006 Feb 14;113(6):791-8. Epub 2006 Feb 6. http://www.ncbi.nlm.nih.gov/pubmed/16461820
McGill HC Jr, McMahan CA, Herderick EE, Malcom GT, Tracy RE, Strong JP. Origin of atherosclerosis in childhood and adolescence. Am J Clin Nutr. 2000 Nov;72(5 Suppl):1307S-1315S. http://www.ncbi.nlm.nih.gov/pubmed/11063473
Perreault L, Temprosa M, Mather KJ, Horton E, Kitabchi A, Larkin M, Montez MG, Thayer D, Orchard TJ, Hamman RF, Goldberg RB; Diabetes Prevention Program Research Group. Regression from prediabetes to normal glucose regulation is associated with reduction in cardiovascular risk: results from the Diabetes Prevention Program outcomes study. Diabetes Care. 2014 Sep;37(9):2622-31. doi: 10.2337/dc14-0656. Epub 2014 Jun 26. http://www.ncbi.nlm.nih.gov/pubmed/24969574
Taylor F, Huffman MD, Macedo AF, Moore TH, Burke M, Davey Smith G, Ward K, Ebrahim S. Statins for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2013 Jan 31;1:CD004816. doi: 10.1002/14651858.CD004816.pub5. http://www.ncbi.nlm.nih.gov/pubmed/23440795