Grape polyphenols and heart disease and diabetes
What it found
In people, grape polyphenols and grape products showed some benefits for blood pressure, blood lipids, oxidative stress and platelet clumping, but results varied.
For type 2 diabetes, the evidence is limited and inconsistent.
What they found
Studies in people
Blood pressure
Several human trials found that grape seed extract or grape-wine extract lowered systolic blood pressure by a few points, mostly in people with higher blood pressure. Some other trials found no change in blood pressure.
Blood lipids
Human studies with grape juice, grape extract or resveratrol showed mixed effects on cholesterol and triglycerides. Some found lower total cholesterol and LDL cholesterol, while others found no change or even higher triglycerides.
LDL oxidation
Many human studies found that grape products reduced oxidized LDL and increased the time before LDL oxidizes. A few studies found no change.
Platelet aggregation
Some human studies found that grape juice reduced platelet clumping, while others found increased or no effect, depending on the type of juice and the trigger used.
Diabetes and blood sugar
In people with type 2 diabetes or metabolic syndrome, grape polyphenols or resveratrol improved some markers like insulin sensitivity and HbA1c, but evidence is limited and inconsistent.
Gut bacteria
Small human studies found that grape seed extract or red wine polyphenols increased Bifidobacteria in the gut, but these studies lacked a control group for comparison.
What the authors conclude
“The results presented in this review supports the benefits of grape and wine polyphenols in CVD, namely in the areas of inhibition of platelet aggregation, decreased LDL oxidation, and reduction of oxidative stress.”
Also in their conclusions
- They say the results support benefits of grape and wine polyphenols in cardiovascular disease, namely in inhibition of platelet aggregation, decreased LDL oxidation, and reduction of oxidative stress.
- They note a paucity of information regarding the health benefits of grapes and grape constituents for management, treatment, or prevention of type 2 diabetes.
- They state that larger and better designed studies are required before any recommendations of intake quantity, period, and type of grape product can be made.
How it was done
The authors wanted to review the benefits of different grape polyphenols in living organisms and in lab tests related to cardiovascular diseases and diabetes.
They reviewed human studies, animal studies and lab studies on grape polyphenols, including grape juice, grape seed extract, red wine and resveratrol, and their effects on cardiovascular disease and diabetes.
What it can’t tell you
- Most studies in this review were done in people, but they used different grape products, doses and lengths of time, so it is hard to compare them directly.
- The review cannot show that grape polyphenols cause better health outcomes, because many studies were small or had conflicting results.
- For type 2 diabetes, there is not enough information to know if grapes or grape products help prevent or treat the disease.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Université de Bordeaux, France; Institut des Sciences de la Vigne et du Vin, France
The paper
- Title
- Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Rasines-Perea Z, Teissedre PL (2017). Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes. Molecules (Basel, Switzerland). doi:10.3390/molecules22010068Free full textPubMed 28045444DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error