Flavonoids may lower the risk of fatal cardiovascular disease

Flavonoids may lower the risk of fatal cardiovascular disease

Even small amounts of flavonoids may offer positive health benefits.

Frontier Voice of Nutrition Remarks (April 11, 2012) Print PDF

NalinSiriwardhana, Ph.D., interviewed Dr. Marji McCullough, Ph.D., Strategic Director, Nutritional Epidemiology, Epidemiology Research Program, American Cancer Society.

A new study supports possible benefits of flavonoids against fatal cardiovascular diseases (CVDs). The study suggests that even small amounts of flavonoids may reduce the risk of CVD.

CVD is the leading cause of death in US and the same is true for the rest of the world. Center for Disease Control and Prevention (CDC) says that 1 in every 3 deaths in US is CVD related. With steadily growing advancements in prevention and treatment options available, CVD is still the number one cause of death in US. World Health Organization (WHO) estimates that by 2030, almost 23.6 million people will die from CVDs. CVDs are a group of disorders of the heart and blood vessels. WHO states that the major risk factors for CVD, primarily heart disease and stroke, are unhealthy diet, physical inactivity, tobacco use, and harmful use of alcohol.

Scientific evidence suggests that CVD risk can be greatly reduced simply by reducing harmful fats (such as trans fats), including beneficial fats (primarily omega 3 fats) and including various flavonoids in our daily diet. Flavonoids are multifunctional compounds that improve human health due to their promising effects against inflammation, cancer, diabetes, obesity, and other diseases, such as CVD. Various types of beneficial flavonoids are adequately present in fruits, vegetables, grains, roots, stems, flowers, tea, and wine.

In particular to CVD risk prevention, flavonoids can neutralize the harmful free radicals/oxidants and suppress the production of inflammatory molecules called pro-inflammatory cytokines. Free radicals and inflammatory mediators can damage endothelial cells that line the blood vesicles and lead to the formation of atherosclerotic lesions. Further, flavonoids can reduce the formation of plaques that block the blood vessels. Blocked blood vessels can cause stroke and heart attacks. Also, flavonoids can lower the bad cholesterol directly and help to reduce CVD risk. Dr. McCullough at the American Cancer Society has analyzed the relationship between CVD and flavonoid intake and showed that flavonoids even at relatively low levels can significantly reduce the risk of CVD. Nutrition Remarks interviewed Dr. Marji McCullough, Ph.D., the principle investigator of the study, and a simplified version of the conversation is given below:

Question from Nutrition Remarks: What are the most effective flavonoid classes against CVD?

Answer from Dr. McCullough: In our study, flavones were most strongly related to lower risk, primarily among women and primarily for ischemic heart disease. However, we also observed a lower risk of CVD in men and women combined with greater intakes of anthocyanidins, flavan-3-ols, flavonols, and proanthocyanidins as well as with all flavonoids combined.

Question: Your recent publication reported the total flavonoid intake of the study population. However, if the important individual flavonoids are concerned, what is the average daily intake of these highly promising flavonoids?

Answer: Median intakes reported in our study is men and women combined: median is perhaps better to use since mean can be influenced by more extreme values; we compared means with others’ because that was what they listed.

Median intake in mg/day

Total flavonoids – 201.9 (mean: 268)

Anthocyanidins – 9.8 (mean 12.2)

Flavan-3-ols – 16.8 (mean 29.9)

Flavone – 1.1 (mean 1.4)

Flavonol – 13.0 (mean 15.5)

Proanthocyanidins – 132 (mean 185.3)

**Important: These were calculated from a FFQ which is likely to underestimate intakes somewhat because not all flavonoid containing foods were on the questionnaire.

Question: What foods are the rich sources of these flavonoids?

Answer: As we showed in the Table 01 of our recent publication about Flavonoid intake and cardiovascular disease mortality in a prospective cohort of US adults in the “American Journal of Clinical Nutrition”, blueberries, red wine, and strawberries are rich sources of anthocyanidins. Apples, black tea, blueberries, chocolate, and red wine are rich sources of flavan-3-ols. Citrus fruit and juices, herbal teas are rich sources of flavanones. Celery, garlic, green peppers, and herbal tea are rich sources of flavones. Blueberries, garlic, kale, onions, spinach, tea, broccoli, redwine, cherry and tomatoes are rich sources of flavonols. Apples, black tea, blueberries, chocolate, mixed nuts, peanuts, red wine, strawberries, and walnuts are rich sources of proanthocyanidins. Soy products and peanuts are rich sources of isoflavones.

Question: What is the average daily intake (or average physiological concentrations) of those flavonoids in general population?

Answer: In 2007, Dr. Won O. Song and colleagues from the Department of Food Science and Human Nutrition, Michigan State University reported an estimated dietary flavonoid intake and major food sources in U.S. Adults. According to this report, in men and women aged 19-70+, mean intakes were: total flavonoids- 189.7 mg/day; anthocyanidins- 3.1mg/day; flavan-3-ols- 156.5mg/day; flavones 1.6mg/day, flavonols, 12.9mg/day (no proanthocyanidins). It is also worth noting that their estimates for isoflavones (main sources are soy foods), were 1.1, similar to ours (mean 0.7mg/day), because Americans in general eat little soy.

Note that researchers often combine different flavonoid subtypes together, and often use different databases, which make it harder to compare amounts of subtypes consumed

Question: What are the common/popular mechanisms mediated by flavonoids to suppress CVD risk?

Answer: Potential biological mechanisms include: anti-oxidant, anti-inflammatory, reduced LDL cholesterol oxidation, regulated endothelial nitric oxide synthesis and inhibition of platelet function.

Question: Your CVD data are very strong and promising due to the large sample size and have both male and female subjects. Can you also talk about the cancer prevention data from this study?

Answer: The study of flavonoids and cancer will be our next step.

This news release was based on the original scientific article published by Dr. McCullough in the American Journal of Clinical Nutrition. Additional general background information was acquired from PubMed and NIH sources.

Original work; McCullough et al., Flavonoid intake and cardiovascular disease mortality in a prospective cohort of US adults.Am J ClinNutr February 2012 ajcn.016634. J Am

Dr. Marji McCullough, Ph.D., is the Strategic Director, Nutritional Epidemiology, Epidemiology Research Program, American Cancer Society. Dr. McCullough is a leading scientist involved in researching, analyzing and translation of the effects of dietary bioactive compounds and obesity on cancer and cardiovascular diseases. She has published more than 130 peer-reviewed publications in related sciences.

Dr. McCullough would like to acknowledge funding provided by the American Cancer Society, and collaborators from Tufts University were supported in part with funds from the NIH and the USDA.

More about Dr. McCulloughand work

http://www.cancer.org/Cancer/News/ExpertVoices/page/Marji-McCullough-ScD-RD.aspx

http://www.sph.emory.edu/ih/TEST/mmcullough.html

Written by NalinSiriwardhana, PhD.

 

Copyright © 2012 Nutrition Remarks. All rights reserved

Lower Your Cholesterol With Strawberries

Lower Your Cholesterol With Strawberries

Written by Emily Creasy, MS, RD, LD, (Nutrition Remarks writer), Reviewed by Nalin Siriwardhana, Ph.D.

Health News Highlights (March 15, 2012) Print PDF

Adding strawberries to your diet may help to lower the unhealthy cholesterol levels. The bioactive compounds of strawberries can also help to reduce inflammation and risk for developing heart disease.

Cholesterol is a wax-like substance that is not always bad and is actually needed by our body to function properly. We normally produce enough cholesterol in our body. Well-known dietary sources of cholesterol include meat and dairy products. Our total cholesterol level is made up of two main types of cholesterol including low-density lipoproteins (LDL) and high-density lipoproteins (HDL). LDL cholesterol is most often referred to as bad cholesterol, while HDL cholesterol is considered to be good cholesterol. Consuming a diet high in cholesterol can lead to the accumulation of LDL cholesterol in the blood. Family history can also contribute to high cholesterol levels. If high cholesterol runs in your family, you may inherit certain genes, which cause your body to produce too much cholesterol. Over time, LDL cholesterol can slowly build up and possibly even clog the arteries supplying blood to the brain and heart resulting in heart attack or stroke. HDL cholesterol has been shown to help remove LDL cholesterol from the blood and protect your cardiovascular system. To boost your HDL levels, the American Heart Association recommends engaging in regular physical activity, and following a heart healthy diet rich in whole grains, vegetables, and fruits, such as strawberries.

A study by Dr. Basu and colleagues found that strawberries may be a simple, yet effective way to lower both total and LDL cholesterol levels. Twenty-seven participants were randomly assigned to consume either a prepared strawberry beverage, or a non-strawberry beverage, twice a day for eight weeks. The strawberry beverage contained the equivalent of three cups of fresh sliced strawberries. No other special diet or lifestyle changes were made. Following the study, those who consumed the strawberry beverage showed a significant reduction in both total cholesterol and LDL cholesterol levels. The addition of strawberry to the diet helped to decreased total cholesterol levels by 10% and decrease LDL cholesterol levels by 11%. The non-strawberry group showed a decrease in total cholesterol of 2% and no changes in LDL cholesterol levels.

Dr. Zunino and colleagues at the United States Department of Agriculture, Agricultural Research Service, noted that the addition of strawberries to the diet also helped to decrease the concentration of small HDL cholesterol particles in the blood. High levels of small HDL particles in the body are associated with increased coronary risk, as reported in a study by Dr. Benoit J. Arsenault and colleagues at the Hospital Laval Research Centre, Quebec, Canada.

The 2010 Dietary Guidelines for Americans recommends that adults consume at least 2 cups, or servings, of fruits each day. When prepared without added fats or sugars, fruit can be a heart healthy addition to your diet. Per cup, strawberries contain 53 calories, making up only 2.5 percent of a 2,000-calorie diet. Strawberries are also a rich source of vitamin C, fiber, and folate, all of which are needed for your body to stay healthy. The American Heart Association recommends keeping your total cholesterol level below 200 mg/dL. In addition, aim to keep your HDL cholesterol above 60 mg/dL and your LDL cholesterol less than 100 mg/dL.

References:

Basu A, Fu DX, Wilkinson M, Simmons B, Wu M, Betts NM, Du M, Lyons TJ.Strawberries decrease atherosclerotic markers in subjects with metabolic syndrome. Nutrition Research. July 2010.

Zunino SJ, Parelman MA, Freytag TL, Stephensen CB, Kelley DS, Mackey BE, Woodhouse LR, Bonnel EL.Effects of dietary strawberry powder on blood lipids and inflammatory markers in obese human subjects. The British Journal of Nutrition. November 2011.

Cheung MC, Brown BG, Wolf AC, Albers JJ.Altered particle size distribution of apolipoprotein A-I-containing lipoproteins in subjects with coronary artery disease. Journal of Lipid Research. March 1991.

Arsenault BJ, Lemieux I, Després JP, Gagnon P, WarehamNJ, Stroes ES, Kastelein JJ, Khaw KT, Boekholdt SM.HDL particle size and the risk of coronary heart disease in apparently healthy men and women: the EPIC-Norfolk prospective population study. Atherosclerosis. September 2009.

American Heart Association. You’re your Cholesterol Levels Mean. http://www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/What-Your-Cholesterol-Levels-Mean_UCM_305562_Article.jsp

American Heart Association. About Cholesterol. http://www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/About-Cholesterol_UCM_001220_Article.jsp

American Heart Association. Lifestyle Changes and Cholesterol. http://www.heart.org/HEARTORG/Conditions/Cholesterol/PreventionTreatmentofHighCholesterol/Lifestyle-Changes-and-Cholesterol_UCM_305627_Article.jsp

United States Department of Agriculture. Dietary Guidelines for Americans, 2010. http://www.cnpp.usda.gov/dietaryguidelines.htm

United States Department of Agriculture. National Nutrient Database for Standard Reference. Strawberry.

Copyright © 2012 Nutrition Remarks. All rights reserved