Effects of grape products on inflammation and oxidative stress: A systematic review and meta‐analysis of randomized controlled trials

Abstract

This systematic review and meta‐analysis of randomized controlled trials (RCTs) were conducted to determine the effects of grapes and grape products on inflammation and oxidative stress among adults. PubMed, Scopus, ISI Web of Science, and Cochrane Library databases were searched up to July 2020 to identify RCTs investigating the effects of grape and grape products on inflammatory and oxidative stress markers. Weighted mean differences (WMD) were pooled using a random‐effects model. Of the 8,962 identified studies, 24 RCTs (27 arms) were included in the statistical analysis. Grape products significantly reduced serum C‐reactive protein (CRP) levels (WMD: −0.35 mg/L; 95% CI: −0.62, −0.09, p = .008), but they had no significant effect on serum tumor necrosis factor‐alpha (TNF‐α) (WMD = −1.08 pg/ml; 95% CI: −2.29, 0.11, p = .07), interleukin‐6 (IL‐6) (WMD = 0.13 pg/ml; 95% CI: −0.35, 0.60, p = .60), total antioxidant capacity (TAC) (WMD = 0.15; 95% CI: −0.35, 0.65, p = .54), or malondialdehyde (MDA) (WMD = 0.14; 95% CI: −0.64, 0.92, p = .72). The analysis indicated possible decreasing effects of grapes and grape products on CRP, but they might not be able to change IL‐6, TNF‐α, TAC, and MDA concentrations. Nonetheless, further studies are warranted before definitive conclusions may be reached.

The Effect of Grape Seed Extract on the Alveolar, Jaw, and Skeletal Bone Remodeling: A Scoping Review

“…22 23 The proanthocyanidins exerted an antioxidant and anti-inflammatory effect by inhibiting the production of a pro-inflammation cytokine through the inhibition of nuclear factor kappa B (NF-kB) 24 and the C-reactive protein (CRP). 25 26 Recent research also provided that the supplementation of GSE containing high proanthocyanidins has great benefits for humans by providing antioxidative stress and anti-inflammation, 27 improving bone health such as preventing bone loss, 28 inhibiting bone resorption by inhibiting osteoclastogenesis through NF-kB and c-Jun N-terminal kinase (JNK) signaling, 29 inhibiting advance glycation end product, 30 increasing bone formation by increase bone mineral and density, 31 upregulating bone growth factors, such as bone morphogenetic protein 7 (BMP-7), 30 and increasing implant osseointegration. 28 On the other hand, the GSE also provides a protective effect against osteoarthritis in the knee.…”

The effect of grape products on liver enzymes: A systematic review and meta‐analysis of randomized controlled trials

“…There is ample evidence that certain foods and nutrients have good effects on the liver (Abbasnezhad et al, 2019; Asbaghi, Ghanbari, et al, 2020; Asbaghi, Kashkooli, et al, 2021; Asbaghi, Naeini, et al, 2021; Mousavi et al, 2021; Yousefi Rad et al, 2019). Grapes, a group of fruits with high polyphenol content, have been shown to exert several antioxidants, antiinflammatory, and anti‐diabetic properties (Asbaghi, Nazarian, et al, 2020; Ghalishourani et al, 2021; Moodi et al, 2021; Ramchandani, Chettiyar, & Pakhale, 2010), and are widely consumed around the world. The results of a meta‐analysis study including randomized controlled trials (RCTs) by Asbaghi, Nazarian, et al (2020) showed that administration of grape seed extract (GSE) significantly lowered C‐reactive protein (CRP) levels as a marker of acute phase inflammation produced by the liver.…”