These Are Some Of The Best Fruits For Heart Health, New Study Shows
Diet plays a profound role in preventing heart disease. A diet rich in fruits, vegetables, whole grains, healthy fats, and quality proteins is beneficial, but research shows that certain foods may have especially protective effects. Cue deeply hued fruits.
Researchers of a new systematic review published in Nutrients investigated the impacts of grapes blueberries and cardiovascular health markers. Here's what they found.
About the study
Researchers conducted a comprehensive search of the scientific literature, pulling together 37 studies including 17 meta-analyses and systematic reviews and 20 randomized controlled trials.
The review focused on grapes, blueberries, and their key bioactive compounds:
- Polyphenols
- Anthocyanins (the pigments that give these fruits their deep color)
- Resveratrol (a compound found primarily in grape skins)
Cardiovascular outcomes examined included blood pressure, blood vessel function, cholesterol levels, inflammation, and oxidative stress.
Blood vessel health showed the most consistent benefit
The analysis showed that grape and blueberry compounds produced modest but consistent improvements in cardiovascular risk markers. The most reliable effects were seen in how well blood vessels dilate and relax, a key indicator of cardiovascular health.
- Blood vessel function: Multiple high-quality trials found improvements in how well blood vessels dilate and relax. In one six-month trial, one cup of blueberries daily significantly improved this measure and reduced arterial stiffness.
- Blood pressure: Several reviews found meaningful reductions in systolic blood pressure with grape polyphenols and red wine polyphenols. One meta-analysis of 30 randomized controlled trials linked whole grape products to a systolic blood pressure reduction of about 3 mmHg.
- LDL cholesterol and blood lipids: Grape products were linked to reductions in total cholesterol, LDL cholesterol, and triglycerides across multiple reviews, with effects most pronounced in people with elevated cholesterol at baseline.
- Inflammation: Higher-dose grape polyphenols (above 500 milligrams per day) taken as a supplement for 12 or more weeks were linked to significant reductions in C-reactive protein, a key marker of inflammation.
- Who benefits most: Effects were consistently stronger in people with existing cardiovascular risk factors, including those with high blood pressure, high cholesterol, metabolic syndrome, or excess weight.
Why polyphenols seem to protect the heart
The cardiovascular benefits of grapes and blueberries come down to their rich polyphenol content, a broad category of plant compounds that work through several overlapping pathways in the body:
- Polyphenols and nitric oxide: Polyphenols appear to boost the availability of nitric oxide, a molecule that signals blood vessels to relax and widen.
- Reducing LDL oxidation: Grape polyphenols may help prevent LDL cholesterol from becoming oxidized, a process that contributes to plaque buildup in arteries.
- Dialing down inflammation: Polyphenols suppress the expression of inflammatory markers in the body. As chronic low-grade inflammation is a driver of cardiovascular disease over time, calming inflammation is crucial for prevention.
- The gut connection: Emerging research suggests that anthocyanins, the pigments responsible for the deep blue, red, and purple hues in these fruits, may be broken down by gut bacteria into compounds that could further support cardiovascular function.
- Resveratrol's role: Resveratrol, found primarily in the skins of dark grapes, supports heart tissue health through its effects on cellular signaling and may help prevent oxidative stress within heart tissue itself.
The takeaway
All fruits support heart health, but deeply colored grapes and blueberries may be especially worth prioritizing thanks to their concentrated polyphenols. Adding a cup of blueberries or a handful of dark grapes to your day is a simple, heart-healthy addition to your routine. Or, whip up these blueberry oat muffins for a slightly sweet (but still nourishing) snack.