This article was inspired by Black History Month, as African Americans have the highest rates of cardiovascular diseases (CVD). According to the Centers for Disease Control and Prevention (CDC), CVD affects 1 in 5 Americans, and statistics from the 2018 U.S. Department of Health and Human Services (HHS) show that African Americans are 30 times more likely to develop CVD than non-Hispanic whites. (1) A huge contributor to these disparities is residential segregation, allowing for differences in socioeconomic statuses, such as levels of education, income, occupation, and more factors, between ethnic groups.
Background of CVD
CVD is the leading cause of death in men and women mainly residing in Western/developed countries. (1) It is a term that defines conditions involving blood traveling through the circulatory system affecting the heart and blood vessels. Conditions include coronary artery disease (CAD), cerebral artery disease, peripheral artery disease (PAD), heart failure, dysfunctional heart valves and arrhythmias, rheumatic heart disease, congenital heart disease, and deep vein thrombosis.
Three main factors increasing the risk of cardiovascular diseases include high blood pressure (hypertension), high cholesterol in the blood (hypercholesterolemia), and smoking. Other factors are diabetes, being overweight, obesity, having an unhealthy diet, physical inactivity, and high alcohol consumption. CVD complications include myocardial infarction and stroke, which are closely associated with atherosclerotic, plaque-forming, conditions. Another complication of CVD is pulmonary embolism, related to deep vein thrombosis.
Diet and lifestyle choices help prevent about 80% of early cardiovascular diseases. (2)
Anthocyanins' Antioxidant Effect on CVD
Anthocyanins are pigments that give fruits, vegetables, flowers, and other tissues their orange, red, and blue colors (3), and protect them against environmental stressors such as UV light, cold temperatures, and drought through light absorption. (4) Commonly consumed fruits with high amounts of anthocyanins are blackberries, raspberries, strawberries, blueberries, red grapes, and cherries (3) with no unfavorable effects seen with high intakes. (5) Anthocyanins display protective properties on blood vessels such as antioxidant, anti-inflammatory, anti-atherogenic, and vasodilatory actions (3), helping prevent CVD.
One way anthocyanins prevent cardiovascular diseases is by protecting against oxidative stress (4). Examples of harmful oxidants are reactive oxygen species (ROS) and reactive nitrogen species (RNS). Interactions with these harmful oxidants have been shown to induce inflammation, lipid oxidation, and some neurodegenerative disorders. (6) Anthocyanins look to gather these injurious oxidants to prevent them from causing harmful actions. (5) Cyanidin-3-Ο- glucoside is the main anthocyanin distributed throughout the body responsible for hunting superoxide (7), another damaging oxidant that affects cellular function and life negatively. Cyanidin-3-O-glucoside was also seen to improve the function of the endothelial cells and repair the endothelium, (5) Studies show it can also lower LDL-cholesterol levels and serum triglycerides while increasing HDL-cholesterol levels through its antioxidant effect (7), and the association between LDL-cholesterol and inflammation is discussed in a bit more detail later in the article.
Another antioxidant effect of anthocyanins includes directly increasing the presence of nitric oxide. (2, 4) Nitric oxide is a signaling molecule that decreases the formation of atherosclerosis, a plaque-forming condition (explained in more detail in the next section), in the presence of inflammation through its various actions as an antihypertensive, antithrombotic, anti-atherogenic, and anti-smooth muscle proliferator. (4) The membranes lining the blood vessels, also known as the endothelium, can produce nitric oxide. (4) Nitric oxide functions to dilate (open) the blood vessels, allowing for increased blood flow, leading to decreased blood pressure. One study shares that anthocyanins can improve the function of the endothelium and the elasticity of the arteries. (7) This is important because stiffening of the arteries can lead to increased blood pressure or hypertension, a known risk factor for CVD. Overall, anthocyanins can raise nitric oxide production, increasing the likelihood of reducing the risk of developing CVD increases.
Anti-Inflammatory Effects of Anthocyanins on CVD
Anthocyanins’ anti-inflammatory effect can potentially improve conditions associated with atherosclerosis. Atherosclerosis is a condition involving fats like cholesterol building up in the walls of the arteries, causing most cases of CAD. Other examples of atherosclerotic conditions include hypertension, PAD, and stroke. A study found that increased amounts of “harmful” cholesterol, such as low-density lipoprotein (LDL-C) and triglycerides contribute to the atherosclerotic process (8) and also cause inflammation within the vessels. More specifically, it is oxidized LDL that causes the formation of atherosclerosis. (9) Chronic inflammation in the endothelium of medium and large-sized arteries seems to be associated with atherosclerosis. (5) Anti-inflammatory actions of anthocyanins have been shown to reduce the risk of developing conditions. Both animal and clinical studies have proposed the possibility of anthocyanins decreasing inflammation. (5)
Conclusion
Health education and literacy are necessary to understand and motivate health behavior changes to help prevent or treat health conditions such as CVD. The United States' history of segregation explains the reasons for health disparities in the country. Socioeconomic status plays a role in the development of diseases such as CVD because it ultimately dictates diet and lifestyle choices that affect the risks of a group. Knowing that anthocyanins decrease inflammation, eliminate dangerous oxidants, perform vasodilation, and reduce plaque buildup in the arteries, decreasing the risk of developing cardiovascular diseases is important when understanding the role of diet in health and using food as medicine. Studies have shown anthocyanins to improve the levels of harmful fats that contribute to inflammation within the vessels. Its antioxidant effect can increase the production of nitric oxide, a strong vasodilator, to improve the structure of the blood vessels, decreasing the risk of cardiovascular disease.
References
1. Centers for Disease Control and Prevention. About Heart Disease. U.S. Department of Health & Human Services. Accessed February 27, 2023. https://www.cdc.gov/heartdisease/about.htm.
2. Pokimica, B., Garcia-Conesa, M.T., Zec, M., Debeljak-Martačić, J.,Ranković, S., Vidović, N., Petrović-Oggiano, G., Konić-Ristić, A., Glibetić, M. Chokeberry Juice Containing Polyphenols Does Not Affect Cholesterol or Blood Pressure but Modifies the Composition of Plasma Phospholipids Fatty Acids in Individuals at Cardiovascular Risk. Nutrients. 2019; 850:1-20.
3. Kimble, R., Keane, K.M., Lodge, D.K., Howatson, G. Dietary intake of anthocyanins and risk of cardiovascular disease: A systematic review of meta-analysis of prospective cohort studies. Critical Reviews in Food Science and Nutrition. 2018:1-11.
4. Wallace, T.C. Anthocyanins in Cardiovascular Disease. American Society for Nutrition, Adv. Nutr. 2011; 2:1-7.
5. Mattioli, R., Francioso, A., Mosca, L., Silva, P. Anthocyanin- A Comprehensive Review of Their Chemical Properties and Health Effects on Cardiovascular and Neurodegenerative Diseases. Molecules. 2020: 25(3809); 2-24.
6. Speer, H., D’Cunha, N.M., Alexopoulos, N.I., McKune, A. J., Naumovski, N. Anthocyanins and Human Health- A Focus on Oxidative Stress, Inflammation and Disease. Antioxidants.2020;9(366):1-13.
7. Mozos, L., Flangea, C.; Vlad D.C., Gug, C., Mozos, C., Stoian, D., Luca, C.T., Horbańczuk, J.O., Horbańczuk O.K., Atanasov, A.G. Effects of Anthocyanins on Vascular Health. Biomolecules. 2021;11(811). 1-17.
8. Aboufarrag, H., Hollands, W.J., Percival, J., Philo, M., Savva, G. M., Kroon, P.A. No Effect of Isolated Anthocyanins from Bilberry Fruit and Black Rice on LDL Cholesterol or other Biomarkers of Cardiovascular Disease in Adults with Elevated Cholesterol: A Randomized, Placebo-Controlled, Cross-Over Trial. Mol. Nutr. Food. Res. 2022;66:1-9.
9. DiNicolantonio, J.J., O’Keefe, J.H. Omega-6 vegetable oils a driver of coronary heart disease: the oxidized linoleic acid hypothesis. Open Heart. 2018;5:1-6.
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