WHAT THEY’RE SAYING
Certain fruits and vegetables, particularly those that are high in compounds called flavonoids, may be better for vascular health than those that are low in flavonoids.
WHAT WE KNOW
Numerous large epidemiologic studies indicate that diets high in fruits and vegetables (F&Vs) are associated with a reduced risk for cardiovascular disease (CVD).1,2 However, the number of portions and types of F&Vs that provide the most protection against CVD are not known. Flavonoids are compounds that are found in a variety of F&Vs including berries, citrus, onions, grapes, peppers, broccoli, and various herbs.3 Many studies that have evaluated flavonoids in isolation (that is, consumed as a supplement or in powder form, not as a whole food) suggest that flavonoids may protect the cardiovascular system by lowering blood lipids and blood pressure, as well as acting as antioxidants and anti-inflammatory agents.4 Despite studies that show cardiovascular benefit from consuming specific flavonoids in isolation, data are lacking to indicate whether consuming a diet high in flavonoid-rich F&Vs improves vascular health more so than eating F&Vs lower in flavonoids .
HOW DO WE KNOW THIS?
In a recent study,5 154 adult men and women who ate a diet low in F&Vs and were at an elevated risk for CVD were randomized to one of three groups: a control group who maintained their diet; a low-flavonoid F&V group; or a high-flavonoid F&V group. Those in the low- or high-flavonoid groups increased their intake by 2,4, and 6 portions/day every 6 weeks above their usual F&V intake. All F&Vs were sent to participants’ homes and included fresh, canned, and frozen varieties. At the end of each 6-week period, measures of blood vessel function were assessed and blood was analyzed for inflammation and blood vessel damage. After each 6-week phase, men in the high-flavonoid F&V group showed improvements in the ability of the artery to dilate as well as some reductions of inflammation and blood vessel damage compared to those in the low-flavonoid F&V and control groups. These results were not seen in the women. Perhaps these findings could be explained by slightly higher F&V intake in women at baseline or women may have not eaten as many servings as men throughout the study, though the authors provide no information on gender differences in intake.
The results from this trial indicate that eating a diet high in flavonoid-rich fruits and vegetables may reduce risk of CVD by improving the ability of the artery to dilate, an essential aspect of vascular health, and by improving some biomarkers of CVD, particularly in men. While it’s unclear why high-flavonoid fruit and vegetable intake had more robust effects in men than women in this trial, other studies have shown a beneficial impact of flavonoid intake on cardiovascular risk factors in both men and women.6,7 Thus, we recommend everyone eat a variety of flavonoid-packed fruits and vegetables every day such as apples, onions, berries, citrus, grapes, peppers, and broccoli. And remember: all forms of fruits & veggies including fresh, frozen, or canned, are beneficial! Check out the Top 10 Ways to Enjoy Cherries or a delicious, unique way to enjoy apples with our Stuffed Apples Recipe. For a beautiful, flavonoid-packed breakfast or snack, check out the Beet + Raspberry Smoothie. Your heart and blood vessels will thank you!
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