The Effect of Berry Consumption on Oxidative Stress Biomarkers: A Systematic Review of Randomized Controlled Trials in Humans

Abstract

Bioactive compounds in berries may scavenge reactive oxygen and nitrogen species by donating electrons to free radicals, thereby protecting DNA, proteins, and lipids from oxidative damage. Evidence shows that berry consumption has beneficial health effects, though it remains unclear whether berries exert a significant impact on oxidative stress in humans. Thus, we performed a systematic review of randomized controlled trials (RCT) to examine the effects of non-acute (more than a single dose and ≥7 days) berry consumption on biomarkers of oxidative stress. Searches were conducted in PubMed, Cochrane Library, and Scopus; results were imported into Covidence for screening and data extraction. The literature search identified 622 studies that were screened, and 131 full-text studies assessed for eligibility. Ultimately, 28 RCTs met the eligibility criteria. Common biomarkers of oxidative stress (antioxidants, DNA damage, isoprostanes, malondialdehyde, and oxidized LDL) were systematically reviewed, and results were reported narratively. Of the approximate 56 oxidative stress biomarkers evaluated in the 28 RCTs, 32% of the biomarkers were reported to have statistically significant beneficial results and 68% of the biomarkers were reported as having no statistically significant differences. More well-designed and longer-term berry RCTs are needed to evaluate biomarkers of oxidative stress.

Underutilized Canadian wild berries as potential sources of lipophilic bioactive compounds with antihypertensive properties

“…Linoleic acid, abundant in superfruits such as berries, was linked to reduced cardiovascular disease risk but raised concerns about inflammation. 38 Studies suggested replacing saturated fats with MUFAs and PUFAs to lower the risk of type 2 diabetes and cardiovascular diseases. 9 When considering the grapes, the grape seeds’ oil content was identified in the 7 to 160 g per kg DW range, with linoleic acid, oleic acid, and palmitic acid as major constituents, comprising over 92–97% of total fatty acids.…”

Complementary Nutritional Improvements of Cereal-Based Products to Reduce Postprandial Glycemic Response

“…The long-term effects of these enriched products, characterized by lower GI and II, need to be tested to evaluate the full potential of these processed products with improved nutritional profiles in the prevention of cardiometabolic risk. The lower postprandial glycemic and insulin responses may be associated with additional metabolic effects provided by selected active compounds, mainly fibers and polyphenols, which are been shown to interfere with oxidative stress and inflammation processes and could influence gut microbiota composition and activity [19,[51][52][53]. Dietary fibers interfere with the digestive tract on digestion processes and can also play through influencing gut microbiota composition and activity [51,54].…”

The state of the science on the health benefits of blueberries: a perspective

“…Martini et al ( 9 ) conducted a systematic review encompassing 45 intervention studies and the consumption of blueberries had a positive impact on vascular function with mixed results for oxidative stress, inflammation, and blood pressure. Moreover, Stote et al ( 16 ) conducted a systematic review evaluating berries (including blueberries) and blood and urine biomarkers of oxidative stress (e.g., antioxidants, DNA damage, isoprostanes, malondialdehyde and oxidized LDL). A total of 56 different biomarkers of oxidative stress were evaluated and many were beneficially impacted by experimentally increasing berry intake.…”