Blueberries have always been delicious, especially when those tiny black-blue gems are foraged for in the wild.
But in recent years the fruit of yogurt-topping and pie-filling have reached infamy as a superfood. The reason, as with so many superfoods, is their high antioxidant properties. Excellent at inhibiting free radicals, which damage cells, blueberries are also been found to have anti-inflammatory effects.
Additional research suggests that blueberries may help prevent some degenerative diseases and malignancies. Studies are being conducted on how blueberries may be beneficial in relation to blood pressure, eye health, neurodegeneration, improved memory, delay of cognitive aging, lowering the risk of cancer, and in the reduction of Parkinson’s Disease.
For more information on the beneficial effects of blueberries, all available research is listed below by topic.
Anthocyanidins, pterostilbene, resveratrol
There are no known contraindications and no known adverse reactions.
If you are taking blood thinners, consult a health care practitioner prior to use.
No known pregnancy and breastfeeding concerns.
In this study, researchers used samples from countries worldwide and assayed the samples for their total antioxidant content using a modified version of the FRAP assay. The researchers found that berries have high antioxidant values.
Carlsen, Monica H et al. “The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide.” Nutrition journal vol. 9 3. 22 Jan. 2010, doi:10.1186/1475-2891-9-3
In this study, a variety of wild berries (including blueberries) were tested to discover their oxygen radical absorption capacity (ORAC) in the raw berries. The research concluded that “Alaska wild berries (including blueberries) have extraordinarily high antioxidant levels.”
Rodgers Dinstel, Roxie, Julie Cascio, and Sonja Koukel. "The antioxidant level of Alaska's wild berries: high, higher and highest." International journal of circumpolar health 72.1 (2013): 21188.
Ten females consumed a blueberry smoothie or placebo of a similar antioxidant capacity five and 10 hours prior to and then immediately, 12 and 36 hours after exercise-induced muscle damage (EIMD). This study demonstrates that “the ingestion of a blueberry smoothie prior to and after EIMD accelerates recovery of muscle peak isometric strength.”
McLeay, Yanita et al. “Effect of New Zealand blueberry consumption on recovery from eccentric exercise-induced muscle damage.” Journal of the International Society of Sports Nutrition vol. 9,1 19. 11 Jul. 2012, doi:10.1186/1550-2783-9-19
Blueberries are a source of eight phenolic acids, which have antioxidant and anti-inflammatory effect. This report shows that chlorogenic acid was found to be the more predominant one.
Kang, Jie, et al. "Phenolic acids of the two major blueberry species in the US Market and their antioxidant and anti-inflammatory activities." Plant foods for human nutrition 70.1 (2015): 56-62.
Blueberries have been found to reduces inflammatory compounds in human subjects. This study shows that the inflammatory cytokines IL-1β and IL-6 were reduced in patients consuming a concentrated blueberry supplement.
Ono-Moore, Kikumi D., et al. "Postprandial inflammatory responses and free fatty acids in plasma of adults who consumed a moderately high-fat breakfast with and without blueberry powder in a randomized placebo-controlled trial." The Journal of nutrition 146.7 (2016): 1411-1419.
This study found that blueberries may reduce an inflammatory response in the colon. The anti-inflammatory effect is likely due to its antioxidant effect, the down-regulation of the expression of inflammatory mediators and inhibition of the nuclear translocation of NF-κB.
Pervin, Mehnaz, et al. "Preventive and therapeutic effects of blueberry (Vaccinium corymbosum) extract against DSS-induced ulcerative colitis by regulation of antioxidant and inflammatory mediators." The Journal of nutritional biochemistry 28 (2016): 103-113.
Blueberries have been found to be a good source of anthocyanidins which protect cells from oxidative damage.
Huang, Wuyang et al. “Effect of Blueberry Anthocyanins Malvidin and Glycosides on the Antioxidant Properties in Endothelial Cells.” Oxidative medicine and cellular longevity vol. 2016 (2016): 1591803. doi:10.1155/2016/1591803
There is ongoing research on the effects of blueberry as it relates to the following health concerns:
May help prevent some degenerative diseases and malignancies (ovarian, melanoma and cervical cell lines have been studied).
Diaconeasa, Zoriţa et al. “Antiproliferative and antioxidant properties of anthocyanin rich extracts from blueberry and blackcurrant juice.” International journal of molecular sciences vol. 16,2 2352-65. 22 Jan. 2015, doi:10.3390/ijms16022352
This double-blind, placebo-controlled human trial demonstrates that daily blueberry consumption may reduce blood pressure and arterial stiffness, possibly due to increased nitric oxide production.
Johnson, Sarah A., et al. "Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre-and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial." Journal of the Academy of Nutrition and Dietetics 115.3 (2015): 369-377.
Blueberry ingestion for six weeks increases NK cells (natural killer cells) and reduces augmentation index, aortic systolic blood pressure, and diastolic pressures in sedentary males and postmenopausal females, suggests this human study.
McAnulty, Lisa S., et al. "Six weeks daily ingestion of whole blueberry powder increases natural killer cell counts and reduces arterial stiffness in sedentary males and females." Nutrition research 34.7 (2014): 577-584.
This study examines how gallic acid, found in blueberries, is neuroprotective, prevents neurodegeneration and is an antioxidant.
Daglia, Maria, et al. "Polyphenols: well beyond the antioxidant capacity: gallic acid and related compounds as neuroprotective agents: you are what you eat!." Current Pharmaceutical Biotechnology 15.4 (2014): 362-372.
Blueberries may reduce the spread and growth of triple negative breast cancer cells, and may reduce inflammatory cytokines, according to this study’s findings.
Kanaya, Noriko, et al. "Whole blueberry powder inhibits metastasis of triple negative breast cancer in a xenograft mouse model through modulation of inflammatory cytokines." Nutrition and cancer 66.2 (2014): 242-248.
Evidence is accumulating that consumption of blueberries may be one strategy to prevent or even reverse age-related neuronal deficits.
Shukitt-Hale, Barbara. “Blueberries and neuronal aging.” Gerontology vol. 58,6 (2012): 518-23. doi:10.1159/000341101
Improves Eye Health
Pterostilbene, a naturally occurring compound in blueberries, has been studied in relation to how it helps to reduce oxidative damage in the cornea.
Li, Jin, et al. "Blueberry component pterostilbene protects corneal epithelial cells from inflammation via anti-oxidative pathway." Scientific Reports 6 (2016): 19408.
Anthocyanadins may help to decrease intraocular pressure in glaucoma and ocular hypertension, suggests this study.
Karhanová, M., et al. "ProVens® in the Therapy of Glaucoma and Ocular Hypertension." Ceska a slovenska oftalmologie: casopis Ceske oftalmologicke spolecnosti a Slovenske oftalmologicke spolecnosti 71.6 (2015): 288-292.
To evaluate the protective effect of blueberry anthocyanins on Retinal pigment epithelium (RPE) cells, in vitro cell models of replicative senescent and light-induced damage were established in the present study. These results demonstrate that “blueberry anthocyanins extracts are efficacious against senescence and light-induced damage of RPE cells.”
Liu, Yixiang et al. “Blueberry anthocyanins: protection against ageing and light-induced damage in retinal pigment epithelial cells.” The British journal of nutrition vol. 108,1 (2012): 16-27. doi:10.1017/S000711451100523X
In this study, researchers investigated the effects of daily consumption of wild blueberry juice in a sample in older adults with early memory changes. The findings of this preliminary study suggest that “moderate-term blueberry supplementation can confer neurocognitive benefit.”
Krikorian, Robert et al. “Blueberry supplementation improves memory in older adults.” Journal of agricultural and food chemistry vol. 58,7 (2010): 3996-4000. doi:10.1021/jf9029332
Delays Cognitive Aging
In this study, researchers fed regulated doses of blueberry supplements to rats. The experiment found that “phytochemicals present in antioxidant-rich foods such as blueberries may be beneficial in reversing the course of neuronal and behavioral aging.”
Joseph, J A et al. “Reversals of age-related declines in neuronal signal transduction, cognitive, and motor behavioral deficits with blueberry, spinach, or strawberry dietary supplementation.” The Journal of neuroscience : the official journal of the Society for Neuroscience vol. 19,18 (1999): 8114-21.
Lowers Risk of Cancer
This paper focuses on studies of “whole berries” such as berry extracts and purified fractions, juices, and freeze-dried powders. Potential mechanisms of anticancer action and bioavailability of berry phenolics, as well as gaps in knowledge and recommendations for future berry research, are also briefly discussed.
Seeram, Navindra P. "Berry fruits for cancer prevention: current status and future prospects." Journal of Agricultural and Food Chemistry 56.3 (2008): 630-635.
In this study, the researchers investigated whether blueberry extracts rich in anthocyanins, proanthocyanidins, or other polyphenols suppress the neurotoxic effects of rotenone in a primary cell culture model of Parkinson’s Disease (PD). Their findings suggest that “anthocyanin- and proanthocyanidin-rich botanical extracts such as blueberries, may alleviate neurodegeneration in PD via enhancement of mitochondrial function.”
Strathearn, Katherine E et al. “Neuroprotective effects of anthocyanin- and proanthocyanidin-rich extracts in cellular models of Parkinson׳s disease.” Brain research vol. 1555 (2014): 60-77. doi:10.1016/j.brainres.2014.01.047
In this patient trial, researchers examined whether higher intakes of total flavonoids and their subclasses, were associated with a lower risk of developing Parkinson disease. Their findings suggest that “intake of some flavonoids may reduce Parkinson’s Disease risk, particularly in men.”
Gao, X et al. “Habitual intake of dietary flavonoids and risk of Parkinson disease.” Neurology vol. 78,15 (2012): 1138-45.
AVAILABLE RESEARCH ON CONTRADICTIONS
This review of literature assesses the use and misuse of various dietary intakes, including blueberries.
Trumbo, Paula, et al. "Dietary reference intakes: vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc." Journal of the Academy of Nutrition and Dietetics 101.3 (2001): 294.