Strawberries may be synonymous with summer, but eaten all year round they can prevent heart attacks, a study suggests.

Scientists found that three or more handfuls of strawberries or blueberries each week reduced the risk of heart attack in women by up to a third.

Both fruits contain specific kinds of flavonoid plant compounds that appear to combat blocked arteries, say the researchers.

strawberry heart attack

The study involved 93,600 participants in the Nurses' Health Study II, a major US investigation of women's health.

Women aged 25 to 42 completed questionnaires about their diet while their health was monitored over 18 years.

During the study, 405 heart attacks were recorded. Women who ate the most strawberries and blueberries were 32% less at risk than those who consumed the berries no more than once a month.

Even participants with diets rich in other fruits and vegetables were more likely to experience heart attacks if they avoided strawberries and blueberries.

Dr Eric Rimm, one of the senior study authors from the Harvard School of Public Health in Boston, said: "Blueberries and strawberries can easily be incorporated into what women eat every week.

"This simple dietary change could have a significant impact on prevention efforts."

See also:

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The findings appear in the American Heart Association journal Circulation.

Scientist believe the protective effect could be linked to anthocyanins, a type of flavonoid that may help open up arteries and counter the build-up of fatty deposits on blood vessel walls.

"We have shown that even at an early age, eating more of these fruits may reduce risk of a heart attack in later life," said nutritionist Dr Aedin Cassidy, from the University of East Anglia, who took part in the research.

The scientists took account of risk factors such as age, high blood pressure, body mass, lack of exercise, smoking, caffeine and alcohol consumption, and family medical history, that could have influenced the results.

Other foods may have similar benefits, say the researchers. Strawberries and blueberries were chosen for the study because they are the most commonly eaten berries in the US.

Victoria Taylor, senior dietitian at the British Heart Foundation, said: "This study found an association between a diet rich in red and purple fruits, such as blueberries, blackberries and strawberries, and a reduction in heart attack risk for young and middle-aged women.

"However, more research is needed to understand why this link between berries and better heart health exists. We would need to know more before we make specific recommendations about individual fruit and vegetables in relation to heart disease.

"But in the meantime, this is yet another good reason to make sure we get our five a day and enjoy the wide variety of fruit and vegetables available to us."

From carrots and kale to grapefruit and clementines, here are more top superfoods for January.

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  • Clementines

    <strong>Why we love them:</strong> Just one of these <a href="http://www.huffingtonpost.com/2012/01/06/orange-varieties_n_1190194.html">sweet citrus picks</a> contains 60 percent of your daily recommended intake of vitamin C. <strong>How to enjoy:</strong> These perfectly-portable fruits are easy to grab and go. Or try adding a few slices to your next winter salad. When paired with a dash of vitamin C, the iron in leafy greens like kale and spinach becomes <a href="http://www.huffingtonpost.com/2012/09/12/food-synergy-food-pairings_n_1874641.html#slide=1504290">easier for the body to absorb</a>.

  • Kale

    <strong>Why we love it:</strong> One of the first foods to come to mind when you think "superfood," kale has earned its reputation. It's rich in <a href="http://www.huffingtonpost.com/2012/06/29/healthy-food-healthiest-list_n_1636409.html#slide=1161890">vitamins A and C, iron, potassium and calcium</a>. <strong>How to enjoy:</strong> If you're going to enjoy it raw in a salad, be sure to add a little healthy fat, like olive oil, avocado or nuts, to <a href="http://www.huffingtonpost.com/2012/10/12/best-worst-salad-greens-health_n_1962626.html">help the body better absorb all those nutrients</a>. Sautéed kale is another tasty option, as are <a href="http://www.huffingtonpost.com/2011/10/27/kale-chips_n_1062534.html">kale chips</a> for a fun crunch that's low in calories, says Bauer.

  • Carrots

    <strong>Why we love them: </strong>These crunchy root veggies deserve their reputation for being good for your peepers -- a cup of chopped carrots contains <a href="http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2383/2">more than 400 percent of your daily recommended intake of vitamin A</a>, also found in the similarly-hued <a href="http://www.huffingtonpost.com/2012/06/28/foods-vision_n_1632176.html#slide=1155157">sweet potato</a>. Plus, the naturally-sweet taste may help someone with a sweet-tooth keep cravings at bay, says Bauer. <strong>How to enjoy:</strong> While they're perfectly good raw, they can also be pureed into a cozy <a href="http://www.huffingtonpost.com/2012/10/10/carrot-soup_n_1951262.html">winter soup</a> or <a href="http://www.epicurious.com/recipes/food/views/Herbed-Roasted-Winter-Vegetables-108829">roasted along with other root vegetables</a>.

  • Brussels Sprouts

    <strong>Why we love them:</strong> While these leafy greens sometimes get a bad rap for their taste, they're part of the <a href="http://lpi.oregonstate.edu/infocenter/foods/cruciferous/">cruciferous veggie family</a> -- the same group that boasts broccoli, cauliflower and other well-known superfoods that fight inflammation and seem to offer some protection against certain cancers. Brussels sprouts are also <a href="http://www.cookinglight.com/food/in-season/in-season-brussels-sprouts-00400000001701/">rich in fiber, potassium, vitamins A and C and iron, all for very few calories</a>. <strong>How to enjoy:</strong> Bauer swears by sautéing those Brussels with a little olive oil and garlic.

  • Grapefruit

    <strong>Why we love them:</strong> A well-known source of vitamin C, grapefruit is also <a href="http://www.huffingtonpost.com/2012/08/30/healthy-food-healthiest-list_n_1840547.html#slide=1446544">rich in fiber</a>, which can help keep you full and <a href="http://www.huffingtonpost.com/2012/11/30/high-fiber-diet-healthy-why_n_2221255.html#slide=1824749">lower cholesterol</a>, among other benefits. Grapefruit has also been found to aid in weight loss. In a 2006 obesity study, participants lost the most weight when they <a href="http://www.ncbi.nlm.nih.gov/pubmed/16579728">ate half a grapefruit before a meal</a>. It's also <a href="http://www.health.com/health/gallery/0,,20475957_11,00.html">90 percent (or more) water</a>, meaning it can help you stay hydrated. And the red variety is rich in lycopene, the famed antioxidant abundant in tomatoes, says Bauer, which may offer protection from certain cancers and skin damage from UV rays. Just be careful, as <a href="http://www.huffingtonpost.com/2012/11/26/grapefruit-drug-interactions-study_n_2193814.html">grapefruit is known to interact dangerously with certain medications</a>. <strong>How to enjoy:</strong> Broil a half <a href="http://www.huffingtonpost.com/2012/01/05/superfoods_n_1184465.html#s589628&title=Grapefruit">with cinnamon and honey for a tasty winter treat</a> or <a href="http://www.huffingtonpost.com/2012/01/19/grapefruit-recipes_n_1216204.html#s622605&title=Mixed_Green_Salad">try the slices as a salad topper</a>, to help with iron absorption.

  • Parsnips

    <strong>Why we love them:</strong> Another root veggie with a similar appearance to a carrot, parsnips add a <a href="http://www.cookinglight.com/food/in-season/in-season-parsnips-00400000033461/">"sweet, nutty flavor"</a> to winter soups and stews. They are <a href="http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2515/2">rich in fiber, vitamin C and potassium</a>. <strong>How to enjoy:</strong> Besides the afore-mentioned soups and stews, parsnips also go well with other roasted root veggies, or <a href="http://www.huffingtonpost.com/2011/10/27/potato-parsnip-mash_n_1057003.html">mashed for a less starchy potato-esque side</a>, says Bauer.