Blueberry, Strawberry Intake Linked to Reduced Heart Attack Risk

Eating foods rich in anthocyanins, such as blueberries and strawberries, may reduce the risk for heart attack in women, according to a new study.

Anthocyanins, which are antioxidant compounds called flavonoids, are the pigments many plants produce in order to attract the birds and insects necessary for the dispersion of their seeds and pollination. Blueberries have high levels of anthocyanins and thus high antioxidant potential. Lowbush (wild) blueberries have higher levels of certain antioxidant compounds than highbush varieties. Strawberries are also rich in anthocyanins and other flavonoids.

In a new study, researchers analyzed data on 93,600 women 25-42 years-old from the Nurses' Health Study II to assess the potential relationship between the intake of anthocyanins and other flavonoids with the risk of heart attack. Data on flavonoid intake was collected via questionnaires every four years.

Throughout the 18 year follow-up period, 405 heart attacks were reported. The researchers found that higher intake of anthocyanins was related to a decreased risk of heart attack when compared to those with the lowest intake. Furthermore, when reviewing the effects of specific foods, eating a combination of blueberries and strawberries more than three times weekly was linked to a decreased risk of heart attack when compared to those eating less than three servings. The authors noted that a link between intake of other flavonoids and heart attack risk was lacking.

The authors concluded that eating foods rich in anthocyanins may reduce the risk of heart attack in women; however, additional research is needed to further evaluate these findings and to assess the potential effects of increasing intake of anthocyanin-rich foods.

For more information about blueberries or strawberries, please visit Natural Standard's Foods, Herbs & Supplements Database.

For more information about integrative therapies for heart attack prevention, please visit Natural Standard's Comparative Effectiveness Database.

Comments

[MS]

The authors did look at the impact of physical activity, smoking, alcohol use, family history of myocardial infarctions (MI), other comorbidities (such as diabetes and hypertension) on anthocyanin intake. They concluded that these factors did not have statistically significant impact on the occurrence of MI. I was surprised by this result a meta-analyses on the impact of anthocyanin and MI will be useful in better evaluating its addition as a possible supplement to vitamin enriched food such as juices and cereals. Also I would like to see the impact of anthocyanin in men.

[ML]

I have never heard of strawberries and blueberries having benefits in reducing heart attack risk. I wonder why these benefits are only in women, it will be interesting to see if the benefits will be seen in men too. I also wonder if the study used fresh blueberries and strawberries and what the amounts were. The follow-up is really long and the population size is large. I guess it does not hurt to eat the strawberries and blueberries if the patient already ingests it frequently. But, keep in mind that blueberries do have vitamin K and there are interactions with warfarin.

[AM]

I had actually come across this article while reading Time Magazine. I found it interesting that after researchers had adjusted for certain cardiovascular risk, such as smoking, obesity, and family history, that the positive effect of eating servings of berries at least 3 times a week was still effective. You would think that because of all of these risk factors, the effect of berries would counteract these variables. It just goes to show you that there are a multitude of approaches that you can take to reducing cardiovascular risk.

http://healthland.time.com/2013/01/15/berries-linked-to-lower-heart-disease-among-women/

[Sara Berg]

I don't really find this to be ground breaking news. Berries are known to be a wonderful source of vitamins and very good for people in general. More than likely, the people eating lots of berries in this study, also lead more healthy lifestyles.

[AM]

Blueberries, for a long time, have been known as a "superfood." It's great to see that they are getting objective data to prove this. I agree with previous posters saying that it's odd that they chose to enroll only women. I'd definitely like to see more studies on these done, in conjunction with healthy eating habits shown in each group.

[JS]

I wonder if other anthocyanin or flavonoid rich foods such as cranberries, acai, black berries or concord grapes could also lower the risk for heart attack? Also, recall bias could’ve played a major role in this study since the subjects were reporting their own berry consumption. I think a randomized controlled study with older subjects specifically studying heart attack risk reduction associated with consumption of anthocyanin rich foods should be done to confirm results. Even though this study may not have the best design, I probably will still eat more berries because even if they don’t reduce your risk for a heart attack a diet focusing on lots of fruits and vegetables is good for your health anyways.

[pc]

I agree that it is interesting that only women were assessed for heart attack risk. Despite this, I am glad to see these results from such a large scale and long term study, though I feel like this study should be either continued with these women as they get older or repeated in an older population. Such a young age group is at an already decreased risk of heart attack, so it would be interesting to see if these results can be reproduced in older people who are at a higher heart attack risk.

[af]

I wonder why heart attack risk was assessed only for women in this study? Because the average age of the study subjects was fairly young, it would probably be difficult to extrapolate the study’s findings to the female population at large. I found this to be interesting because I hate blueberries but love strawberries, and during the summer, my mom always insists on mixing the two as part of our dinner. It’s ironic how it is stated that eating a “combination of blueberries and strawberries” was linked to reduced heart attack risk. My mom was glad to hear this!...and maybe I should just force myself to eat blueberries in the future, since heart disease runs in my family.

[af]

What I like about studies like this is that they show meaningful (or statistically significant) health effects of foods like fruits and vegetables. We grow up learning what comprises the “healthy” food groups, but how often do we see the data and statistics when it comes to protecting health and affecting specific disease states in the way that we are constantly reading about these things for drugs, herbs, and dietary supplements? I know that my exposure to the health-related effects of natural products, including a wide variety of foods, has significantly grown since I began my Natural Standard student rotation, but it would be nice to learn about them in school as well, as understanding the evidence behind them translates to valuable knowledge, in my opinion.

[ac]

My first thought after reading this blog was did the participants have similar dietary intake other than strawberrys and blueberries? I would think that participants who were eating greater than 3 servings of these fruits per week would be more likely to have a well-balanced healthy diet vs. controls. Dietary differences at baseline would definitely have an effect on the risk of heart attack in participants.

[kl]

It would be interesting to see if these results could be reproducible in a well-designed prospective trial in a similar patient population. If so, this could be a very significant scientific finding! Consuming three servings of blueberries and/or strawberries weekly is so easy to do (especially in the summertime when these fruits are inexpensive and widely available in grocery stores). One of my favorite breakfast treats is a strawberry smoothie made from a cup of fresh or frozen strawberries, skim milk, and honey. Knowing that it could reduce my risk of heart attack would only make me drink it more!

[BC]

I agree that doing additional studies in a different study comparing physical activity, smoking status, and alcohol intake will be more interesting. I think it would also be a good idea to perform this study in a broader population, including men.

[sc]

After reading this study I wanted to know more about the women that were included in the study. I read the article and a table was provided that had characteristics of the participants. I think it would have been interesting if the authors had also compared physical activity, smoking status and alcohol intake to heart attack risk since they had already obtained the data.