Berries aren’t called superfoods for nothing. A review covering 336 scientific articles on these fruits has shown that berry consumption can go a long way in preventing and managing Type 2 diabetes and its complications
From the hunter-gatherers of ancient times to modern humans, berries hold incredible health benefits that only get further proven and respected over time. Coming in different varieties and forms like raw, frozen and dried, these compact and versatile fruits can be easily incorporated into your diet year round.
They are deemed “promising functional fruits” for their distinct therapeutic contents of anthocyanins, flavonoids, flavanols, alkaloids, organic acids and more — polyphenols that may be beneficial for oxidative stress, obesity, high blood pressure and diabetes.[ii]
In studies, polyphenols along with other berry components such as fiber and micronutrients have been linked with better cardiovascular health.[iii] Each type of berry has its specific “superpower,” from cranberry’s efficacy in treating and preventing urinary tract infections to strawberry’s outstanding vitamin C content to black currant’s support for brain power and efficacy against rheumatoid arthritis.
Polyphenol-Rich Berries Deter Diabetes and Its Complications
An August 2020 review discussed how consuming berries can prevent diabetes and its complications.[iv] Analyzing the differences in glucose and insulin levels after food intake in diabetic subjects, the reviewed studies found that consuming berries can be a reliable method to prevent and manage hyperglycemic and hyperlipidemic states.
The researchers examined berry consumption and the management of Type 2 diabetes by searching various scientific databases using keywords such as “berry consumption and diabetes,” “berries and high-glycemic diets” and individual berry names. This yielded 336 articles deemed relevant for the review.
Various berries have been probed for their potential diabetes benefits, including blueberries, bilberries, cranberries, raspberries, mulberries, lingonberries, blackberries, strawberries, goji berries, acai berries, chokeberries, black currants and maqui berries. The review showed berries’ various mechanisms of action against diabetes, including the following:
- Anthocyanins promoted glucose uptake and metabolism as well as inhibited weight gain and pro-inflammatory responses
- Berry intake led to improvements in insulin sensitivity and lowering glucose
- Berry consumption favorably altered gut microflora, thus assisting in diabetes management
The primary potential health-promoting bioactive compounds in berries include the following:
What will it take to obtain the healthful effects? According to the reviewed papers, the daily recommended dose of whole berry varies from 200 to 400 grams (0.875 to 1.69 cups) of berries for a 70-kilogram (154 pound) middle-aged person.
It’s fairly established in studies that the body needs less insulin for sugar balance after a meal if berries are consumed as well. A Finnish study among healthy women found that adding berries to white and rye bread significantly reduced the post-meal insulin spike. Strawberries, bilberries, lingonberries and chokeberries were considered effective.[v]
Other Berry Benefits Worth Noting
Berries work their wonder not just on diabetes but also on a wealth of other health issues:
- Hair loss — Antioxidant-rich and anti-inflammatory foods may help reverse hair loss suffered by both men and women. Some of those with the highest antioxidant potential include Indian gooseberry, bilberries, fresh black currants, blackberries, cranberries, crowberries, goji berries, strawberries and red sour berries.[vi]
- Anti-aging and improved brain health — An analysis of data on berry intake showed that mental decline slowed for women over age 70 who regularly consumed strawberries or blueberries.[vii] Subjects who had greater intakes of the berries had slower mental decline, with the estimated effects translating to a delay in cognitive aging by about 1.5 to 2.5 years.
- Cardiovascular wellness — A study published in the Journal of the Academy of Nutrition & Dietetics involving postmenopausal women concluded that eating 22 g of blueberry powder every day for eight weeks reduced blood pressure and arterial stiffness.[viii] This was likely due to increased nitric oxide production.
- Oral cancer and colorectal cancer — Animal studies have suggested that black raspberries may inhibit the growth of oral cancers.[ix] In a study on patients with biopsy-confirmed oral squamous cell carcinomas, researchers confirmed that the fruit may be effective for oral cancer chemoprevention, reducing adverse gene expression of the condition. Black raspberry may also help colorectal cancer patients including by altering amino acid metabolism, energy and lipid metabolism.[x]
- Breast cancer — Previous studies have associated a high intake of fruit during adolescence with a lower risk of breast cancer.[xi] In separate research, anticancer activity and lack of toxicity against normal cells indicate a chemopreventive potential of Goji berries in breast cancer treatment.[xii]
[i] Gropper S et al. Advanced Nutrition and Human Metabolism. 4th Ed. Belmont, CA: Thomson Wadsworth; 2005.
[ii] Hameed A et al “Select Polyphenol-Rich Berry Consumption to Defer or Deter Diabetes and Diabetes-Related Complication” Nutrients. 2020 Aug 21 ;12(9). Epub 2020 Aug 21.
[iii] Basu A et al “Berries: emerging impact on cardiovascular health” Nutr Rev. 2010 Mar; 68(3): 168–177.
[iv] Hameed A et al “Select Polyphenol-Rich Berry Consumption to Defer or Deter Diabetes and Diabetes-Related Complication” Nutrients. 2020 Aug 21 ;12(9). Epub 2020 Aug 21.
[v] Törrönen R et al “Berries reduce postprandial insulin responses to wheat and rye breads in healthy women” J Nutr. 2013 Apr ;143(4):430-6. Epub 2013 Jan 30.
[vi] Carlsen, M. et al “The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide” Nutr J. 9(3), doi: 10.1186/1475-2891-9-3
[vii] Elizabeth E Devore et al “Dietary intakes of berries and flavonoids in relation to cognitive decline” Ann Neurol. 2012 Jul ;72(1):135-43. Epub 2012 Apr 26.
[viii] Johnson SA 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” J Acad Nutr Diet. 2015 March;115(3):369-377
[ix] Knobloch T et al “Suppression of pro-inflammatory and pro-survival biomarkers in oral cancer patients consuming a black raspberry phytochemical-rich troche” Cancer Prev Res (Phila). 2015 Dec 23. Epub 2015 Dec 23.
[x] Pan Pan et al “Beneficial Regulation of Metabolic Profiles by Black Raspberries in Human Colorectal Cancer Patients” Cancer Prev Res (Phila). 2015 Aug ;8(8):743-50. Epub 2015 Jun 8.
[xi] Farvid M et al “Fruit and vegetable consumption in adolescence and early adulthood and risk of breast cancer: population based cohort study” BMJ. 2016 ;353:i2343. Epub 2016 May 11.
[xii] Wawruszak A et al “Anticancer effect of ethanol Lycium barbarum (Goji berry) extract on human breast cancer T47D cell line” Nat Prod Res. 2015 Nov 2:1-4. Epub 2015 Nov 2.