A New Way to Tend Your Ticker

Cranberries are rich in a variety of phytonutrients including proanthocyanidins, anthocyanins, and flavonols, and contain concentrations of other health-promoting phytonutrients rarely found in other foods. Together, these compounds exert powerful anti-inflammatory and antioxidant effects in the body.¹ When it comes to cardiovascular health, cranberry may be the underdog that’s comparable to fish oil, CoQ10, vitamin D, and magnesium.

A 2022 double-blind, placebo-controlled study found that taking 9 grams of freeze-dried cranberry powder daily for one month (equivalent to about one cup of fresh cranberries) resulted in significant improvements in heart and blood vessel function, and ultimately helped reduce the risk of cardiovascular disease (CVD) compared to those taking a placebo.^{2 3} The study summarized, “Those consuming cranberry had a significant improvement in flow-mediated dilation (FMD), which signals improvement of heart and blood vessel function. FMD is considered a sensitive biomarker of cardiovascular disease risk and measures how blood vessels widen when blood flow increases.”⁴

Furthermore, Dr. Ana Rodriguez-Mateos, Senior Lecturer in Nutrition at the Department of Nutritional Sciences at King's College London and senior author of the study, said "The increases in polyphenols and metabolites in the bloodstream, and the related improvements in flow-mediated dilation (FMD) after cranberry consumption, emphasize the important role cranberries may play in cardiovascular disease prevention.”^{5 6}

Blood Sugar Out of Control? Cranberry Steps Up to the Challenge

There are a lot of factors to blame when it comes to our blood sugar being out of whack (a lack of fruits and vegetables and quality protein in the diet, too much sugar, refined carbs, and processed foods, and a sedentary lifestyle) which can ultimately lead to age-related diseases, obesity, and type-2 diabetes. But, where excess sugar in the bloodstream is our foe, cranberry supplementation is our friend. In fact, studies show that cranberry powder has beneficial effects on diabetic-related metabolic conditions, including lipid profiles, serum insulin and glucose levels, insulin resistance, as well as biomarkers of oxidative stress.⁷

The declining function of pancreatic beta-cells (β-cells)—the cells in the pancreas responsible for making and secreting insulin—as we age can negatively affect how our body responds to glucose. Preserving the health of these cells helps maintain healthy glucose balance and can offer significant protection against type-2 diabetes.^{8 9} In a study to evaluate the effectiveness of a cranberry-rich diet on the aging of pancreatic beta-cells, 24 aging rats consumed a diet that was supplemented with 2% cranberry powder or a standard, cranberry-free diet for 16 months (the equivalent of 12 grams daily for a 154-pound human).^{10 11} The rats fed the cranberry-supplemented diet showed a delayed decline in β-cell function and improved β-cell glucose responsiveness compared to the rats on the standard diet. This slowing down of the decline of β -cell function by means of cranberry supplementation is promising for protecting against type-2 diabetes.

Cultivate Gut, Liver, & Metabolic Health with Cranberry

In another study, researchers sought to determine if cranberry extract could reverse obesity and its associated metabolic disorders, such as fatty liver, in diet-induced obese mice. Mice were given a high-fat, high-sucrose diet for 13 weeks to induce obesity, and then were fed the high-fat, high-sucrose diet plus cranberry extract for eight weeks (the dose was equivalent to about 1 gram/day for a 154-pound human). After eight weeks, the cranberry extract had fully reversed fatty liver in the mice and reduced liver inflammation, as well as improved glucose tolerance and normalized insulin sensitivity.¹²

In the same study, the cranberry extract also triggered a bloom of a species of gut bacteria called Akkermansia muciniphila (A. muciniphila), which has been strongly correlated with healthy and lean bodies. In fact, a 12-week study showed that A. muciniphila was inversely related to fasting glucose, waist-to-hip ratio, and subcutaneous adipocyte diameter (the fat between your skin and muscles). Subjects with higher A. muciniphila abundance in the gut exhibited the healthiest metabolic status, particularly in fasting glucose, triglycerides, and body fat distribution.^{13 14}

Polyphenols, like those found in cranberry, have the potential to increase growth of this special bacteria that studies show has a direct association with better glycemic control, as well as a marked decrease in fat mass and healthy metabolic function, improved intestinal barrier (leaky gut), and mucus layer thickness. In summary, “Cranberry extract can fully reverse a high fat-high sucrose, diet-induced insulin resistance and fatty liver, while triggering A. muciniphila blooming in the gut microbiota, thus underscoring the gut-liver axis as a primary target of cranberry polyphenols.”^{15 16 17 18}

Cranberry Helps Keep Your GI Tract Intact

The inner lining of the gastrointestinal tract (the intestinal epithelium) acts as a barrier that protects the body from potentially toxic substances that move through the GI tract. The phytochemicals in cranberry provide protection to this important lining. Cranberry supports production of secretory IgA (SIgA), a key component of the gut’s mucosal lining, which serves as the first line of defense in protecting the intestinal epithelium from toxins and pathogenic microorganisms.¹⁹  Cranberry proanthocyanidins also interfere with colonization of the gut by pathogenic Escherichia coli (E. coli) and reduce gut-barrier dysfunction caused by a diet high in processed carbohydrates, added sugar, and even nutrient deprivation.²⁰

Studies have repeatedly identified polyphenol-rich compounds as promoters of gut microbial diversity.^{21 22} A 2022 study illustrated the synergy between cranberry’s proanthocyanidins and gut microbiota: Over a three-week period, a freeze-dried cranberry powder was shown to enhance short-chain fatty acid production (used by intestinal epithelial cells as an energy source) and lower the abundance of pathogenic bacteria.^{23 24 25}

Cranberry Benefits to Sink Your Teeth Into

A surprising health benefit of drinking cranberry juice, taking cranberry chews, or even using cranberry-infused floss is its ability to prevent cavities and periodontal (gum) disease. Exposing the mouth and teeth directly to the bioactives in cranberry ensures its anti-adhesive and anti-microbial properties are directly felt on the teeth themselves. In fact, the phenomenal polyphenol compounds in cranberry inhibit the production of organic acids and the formation of cavity-producing bacteria, such as Streptococcus mutans and Streptococcus sobrinus.³³  Additionally, cranberry polyphenols may reduce inflammation, as well as the production and activity of enzymes contributing to the destruction of the extracellular matrix in gum disease.³⁴

The Very “Brainy” Cranberry

Why is it a good idea to take cranberry now more than ever? Because the health of your brain depends on it! Polyphenol-rich fruits have long been recognized for their protection against age-related neurodegeneration and several studies back this up, proving that compounds in cranberry support cognitive function and brain health.

A May 2022 randomized, placebo-controlled study published in the journal Frontiers in Nutrition aimed to determine the impact of cranberry supplementation specifically on cognitive function in adults 50–80 years old. Dr. David Vauzour, Ph.D., leading researcher of the study and a senior research fellow in Molecular Nutrition at Norwich Medical School University of East Anglia (UK) said, “Past studies have shown that higher dietary flavonoid intake is associated with slower rates of cognitive decline and dementia. And foods rich in anthocyanins and proanthocyanidins, which give berries their red, blue, or purple color, have been found to improve cognition.”²⁶

In the study, 60 adults took either 9 grams (split into two 4.5-gram sachets) per day of cranberry powder, equivalent to a cup of fresh cranberries, or a placebo, for 12 weeks. Memory and executive function assessments, including processing speed, working memory, episodic memory, and special navigation, as well as neuroimaging and blood samples, were conducted before and after to determine the impact of cranberry consumption on cognition and brain function.

Results showed that subjects taking the cranberry powder saw “significant improvements” in memory of everyday events, neural functioning, and delivery of blood to the brain during the course of supplementation.^{27 28 29}

The Benefits of Cranberry + Propolis Are Not to be Missed!

Propolis is a resin that honeybees produce to protect and provide structural support to their hives.⁴⁷ It’s been used for thousands of years for its medicinal properties as an antimicrobial, anti-inflammatory, antioxidant, and immunomodulatory agent.⁴⁸ Greeks used it to treat abscesses, Assyrians put it on wounds and tumors to fight infection and help the healing process, and Egyptians used it to embalm mummies.⁴⁹ Today, it’s used to fight infections, heal wounds, treat candida, eliminate cold sores, fight cancer, and more.

Researchers have identified more than 300 compounds in propolis, many of which are forms of polyphenols that help modulate inflammation and immune responses in the body. Propolis has been shown to increase the number of immune cells, boost immune cell activities, enhance antibody production, activate macrophages (increasing numbers, responsiveness, and bacteria killing abilities), and increase natural killer cell activity.⁵⁰

One study that included young children indicated that propolis extract may naturally prevent, as well as shorten the duration, of the common cold. In the study, an aqueous propolis extract was given to a group of preschool and young school-aged children for the entire duration of a year’s cold season. The children treated with propolis had fewer colds with acute or chronic symptoms.⁵¹

Coupling cranberry’s immune system benefits with propolis’ may provide synergistic benefits: Propolis has been shown to increase cranberry’s effectiveness in reducing urinary tract infections by amplifying cranberry’s proanthocyanidins, preventing bacteria adhesion, bacterial replication, and degree of bacterial infection.⁵²

Immune System Superhero

Vitamins A, C, and E are just a few of the well-known vitamins and minerals for immune health—and cranberries contain them all and more. They’re even packed with super nutrients like lutein, zeaxanthin, folate, potassium, and manganese.³⁰ That’s a lot of superpowers in just one tiny cranberry, and they all work together to supercharge your immune system.

Studies investigating the effects of cranberry supplementation on immune health help solidify its ability to ward off cold and flu symptoms, perfect for the change in seasons and even year-round. In a randomized, double-blind, and placebo-controlled study, 10 weeks of consumption of a beverage containing cranberry powder resulted in a fivefold increase in the production of T-cells, a 30% increase in natural killer (NK) cell proliferation, and a 20% reduction in pro-inflammatory cytokine interleukin (IL)-17 secretion—all vital to the function of a healthy immune system.³¹

In another study, researchers discovered that cranberry extract inhibited both influenza A and B virus replication. Interestingly, the same anti-adhesive activities of cranberry against bacteria in the urinary tract, may also help it prevent viral attachment to healthy cells within the body.³² With these cutting-edge findings, cranberry is literally packing a one-two punch on the bacterial and viral fronts, making it a fantastic supplement to kick unwanted pathogens to the curb. Stay well year-round and seasonally with cranberry!

Wherever you are on your journey to health, cranberry can help catapult you into the best version of yourself. It might just be the tiny, mighty cranberry that could.

Cancer + Cranberry… A Dose of Hope?

Data from preclinical studies show that cranberry-derived constituents, such as ursolic acid and proanthocyanidins successfully decrease cancer cell density, viability, proliferation, adhesion, inflammation, and oxidative stress.³⁵ In fact, a significant amount of research shows cranberry inhibits the growth of 17 different cancers, including breast, colon, cervical, glioblastoma, leukemia, lung, melanoma, oral cavity, prostate, ovarian, esophageal, and renal cancer cell lines.^{36 37 38 39 40} When investigating cranberry and colon cancer, for example, researchers wrote, “several cranberry extracts inhibit the viability of colon cancer cell lines, including an organic-soluble cranberry extract, cranberry juice extract, cranberry proanthocyanidins, a flavonoid-rich fraction, a total polyphenolic fraction, and ursolic acid.”^{41 42 43 44 45 46}

References

1. Blumberg J.B., Camesano T.A., Cassidy A., Kris-Etherton P., Howell A., Manach C., Ostertag L.M., Sies H., Skulas-Ray A., Vita J.A. Cranberries and Their Bioactive Constituents in Human Health. Adv. Nutr. 2013;4:618–632. doi: 10.3945/an.113.004473. 
2. BSc, Atli Arnarson. “Cranberries 101: Nutrition Facts and Health Benefits.” Healthline, Healthline Media, 15 Feb. 2019, https://www.healthline.com/nutrition/foods/cranberries.
3. “Cranberry (Poly)Phenol Consumption on Vascular Function - Full Text View.” Full Text View - ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT02764749.
4. Heiss, Christian, et al. “Daily Consumption of Cranberry Improves Endothelial Function in Healthy Adults: A Double Blind Randomized Controlled Trial.” Food & Function, The Royal Society of Chemistry, 22 Mar. 2022, https://pubs.rsc.org/en/Content/ArticleLanding/2022/FO/D2FO00080F.
5. King's College London. “100g Of Cranberries a Day Improves Cardiovascular Health.” King's College London, King's College London, 22 Mar. 2022, https://www.kcl.ac.uk/news/100g-cranberries-day-improves-cardiovascular….
6. “100g Of Cranberries a Day Improves Cardiovascular Health, Study Finds.” ScienceDaily, ScienceDaily, 22 Mar. 2022, https://www.sciencedaily.com/releases/2022/03/220322111245.htm.
7. Blumberg J.B., Camesano T.A., Cassidy A., Kris-Etherton P., Howell A., Manach C., Ostertag L.M., Sies H., Skulas-Ray A., Vita J.A. Cranberries and Their Bioactive Constituents in Human Health. Adv. Nutr. 2013;4:618–632. doi: 10.3945/an.113.004473. 
8. Kim, Mi Joung, et al. “Effects of Cranberry Powder on Biomarkers of Oxidative Stress and Glucose Control in DB/DB Mice.” Nutrition Research and Practice, U.S. National Library of Medicine, Dec. 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865264/.
9. Rorsman, Patrik, and Frances M Ashcroft. “Pancreatic β-Cell Electrical Activity and Insulin Secretion: Of Mice and Men.” Physiological Reviews, U.S. National Library of Medicine, 1 Jan. 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5866358/#:~:text=The%20pan….
10. Zhu, Min, et al. “Effects of Long-Term Cranberry Supplementation on Endocrine Pancreas in Aging Rats.” The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, U.S. National Library of Medicine, Nov. 2011, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3193520/.
11. Reagan-Shaw S, Nihal M, Ahmad N. Dose translation from animal to human studies revisited. FASEB J. 2008;22:659–661.
12. Anhê, Fernando F, et al. “A Polyphenol-Rich Cranberry Extract Reverses Insulin Resistance and Hepatic Steatosis Independently of Body Weight Loss.” Molecular Metabolism, U.S. National Library of Medicine, Dec. 2017, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5699918/.
13. Le Chatelier E., Nielsen T., Qin J., Prifti E., Hildebrand F., Falony G. Richness of human gut microbiome correlates with metabolic markers. Nature. 2013;500:541–546.
14. Dao M.C., Everard A., Aron-Wisnewsky J., Sokolovska N., Prifti E., Verger E.O. Akkermansia muciniphila and improved metabolic health during a dietary intervention in obesity: relationship with gut microbiome richness and ecology. Gut. 2016;65:426–436.
15. Anhe FF, Roy D, Pilon G, et al. A polyphenol-rich cranberry extract protects from diet-induced bobesity, insulin resistance, and intesitnal inflammation in association with increased akkermansia spp. Population of the gut microbiota of mice. Gut. 2014; 64: 872-83
16. Anhê, Fernando F, et al. “A Polyphenol-Rich Cranberry Extract Reverses Insulin Resistance and Hepatic Steatosis Independently of Body Weight Loss.” Molecular Metabolism, U.S. National Library of Medicine, Dec. 2017, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5699918/.
17. Everard A., Belzer C., Geurts L., Ouwerkerk J.P., Druart C., Bindels L.B. Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity. Proceedings of the National Academy of Sciences of the United States of America. 2013;110:9066–9071.
18. Shin N.R., Lee J.C., Lee H.Y., Kim M.S., Whon T.W., Lee M.S. An increase in the Akkermansia spp. population induced by metformin treatment improves glucose homeostasis in diet-induced obese mice. Gut. 2014;63:727–735.
19. Mantis, N J, et al. “Secretory Iga's Complex Roles in Immunity and Mucosal Homeostasis in the Gut.” Nature News, Nature Publishing Group, 5 Oct. 2011, https://www.nature.com/articles/mi201141#:~:text=Secretory%20IgA%20(SIg….
20. Meagher, David, et al. “Carbohydrates: A Nutritional Insult?” Healthy Eating and Active Living 2017, 21 Nov. 2017, https://ctlsites.uga.edu/heal2017/carbohydrates-a-nutritional-insult/#:….
21. Le Roy C., Wells P., Si J., Raes J., Bell J., Spector T. Red Wine Consumption Associated With Increased Gut Microbiota α-Diversity in 3 Independent Cohorts. Gastroenterology. 2019;158:270–272.e2. doi: 10.1053/j.gastro.2019.08.024
22. Zhernakova A., Kurilshikov A., Bonder M.J., Tigchelaar E.F., Schirmer M., Vatanen T., Mujagic Z., Vila A.V., Falony G., Vieira-Silva S., et al. Population-Based Metagenomics Analysis Reveals Markers for Gut Microbiome Composition and Diversity. Science. 2016;352:565–569. doi: 10.1126/science.aad3369.
23. Khoo, Christina, et al. “A Freeze-Dried Cranberry Powder Consistently Enhances SCFA Production and Lowers Abundance of Opportunistic Pathogens in Vitro.” Biotech (Basel (Switzerland)), U.S. National Library of Medicine, 6 May 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9264401/.
24. David L.A., Maurice C.F., Carmody R.N., Gootenberg D.B., Button J.E., Wolfe B.E., Ling A.V., Devlin A.S., Varma Y., Fischbach M.A., et al. Diet Rapidly and Reproducibly Alters the Human Gut Microbiome. Nature.
25. Filippo C.D., Cavalieri D., Paola M.D., Ramazzotti M., Poullet J.B., Massart S., Collini S., Pieraccini G., Lionetti P. Impact of Diet in Shaping Gut Microbiota Revealed by a Comparative Study in Children from Europe and Rural Africa. Proc. Natl. Acad. Sci. USA. 2010;107:14691–14696. doi: 10.1073/pnas.1005963107.
26. “How Cranberries Could Improve Memory and Ward off Dementia.” Go to University of East Anglia, https://www.uea.ac.uk/news/-/article/how-cranberries-could-improve-memo….
27. Krawiec, Sebastian. “Cranberry Powder Supplementation May Support Cognitive Health in Aging Populations, Says Recent Study.” Nutritional Outlook, Nutritional Outlook, 20 May 2022, https://www.nutritionaloutlook.com/view/cranberry-powder-supplementatio….
28. Krawiec, Sebastian. “Cranberry Powder Supplementation May Support Cognitive Health in Aging Populations, Says Recent Study.” Nutritional Outlook, Nutritional Outlook, 20 May 2022, https://www.nutritionaloutlook.com/view/cranberry-powder-supplementatio….
29. Flanagan, Emma, et al. “Chronic Consumption of Cranberries (Vaccinium Macrocarpon) for 12 Weeks Improves Episodic Memory and Regional Brain Perfusion in Healthy Older Adults: A Randomised, Placebo-Controlled, Parallel-Groups Feasibility Study.” Frontiers in Nutrition, Frontiers Media S.A., 19 May 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9160193/#B2.
30. Cranberries - WHFOODS. https://whfoods.com/genpage.php?tname=foodspice&dbid=145.
31. Nantz, Meri P, et al. “Consumption of Cranberry Polyphenols Enhances Human Γδ-T Cell Proliferation and Reduces the Number of Symptoms Associated with Colds and Influenza: A Randomized, Placebo-Controlled Intervention Study.” Nutrition Journal, U.S. National Library of Medicine, 13 Dec. 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3878739/.
32. Luganini, Anna, et al. “The Cranberry Extract Oximacro® Exerts in Vitro Virucidal Activity against Influenza Virus by Interfering with Hemagglutinin.” Frontiers in Microbiology, Frontiers Media S.A., 7 Aug. 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6090095/.
33. Yamanaka A, Kimizuka R, Kato T, Okuda K. Inhibitory effects of cranberry juice on attachment of oral streptococci and biofilm formation. Oral Microbiol Immunol. 2004;19(3):150-4.
34. “Cranberry Polyphenols: Potential Benefits for Dental Caries and Periodontal Disease.” Jcda, https://jcda.ca/article/a130.
35. Hanahan D., Weinberg R.A. Hallmarks of cancer: The next generation. Cell.
36. Weh, Katherine M, et al. “Cranberries and Cancer: An Update of Preclinical Studies Evaluating the Cancer Inhibitory Potential of Cranberry and Cranberry Derived Constituents.” Antioxidants (Basel, Switzerland), U.S. National Library of Medicine, 18 Aug. 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5039576/.
37. Neto C.C., Krueger C.G., Lamoureaux T.L., Kondo M., Vaisberg A.J., Hurta R.A.R., Curtis S., Matchett M.D., Yeung H., Sweeney M.I., et al. Maldi-TOF MS characterization of proanthocyanidins from cranberry fruit (Vaccinium macrocarpon) that inhibit tumor cell growth and matrix metalloproteinase expression in vitro. J. Sci. Food. Agr. 2006;86:18–25. doi: 10.1002/jsfa.2347.
38. Kondo M., MacKinnon S.L., Craft C.C., Matchett M.D., Hurta R.A., Neto C.C. Ursolic acid and its esters: Occurrence in cranberries and other vaccinium fruit and effects on matrix metalloproteinase activity in DU145 prostate tumor cells. J. Sci. Food Agric. 2011;91:789–796. doi: 10.1002/jsfa.4330.
39. Murphy B.T., MacKinnon S.L., Yan X.J., Hammond G.B., Vaisberg A.J., Neto C.C. Identification of triterpene hydroxycinnamates with in vitro antitumor activity from whole cranberry fruit (Vaccinium macrocarpon) J. Agric. Food Chem. 2003;51:3541–3545.
40. Chatelain K., Phippen S., McCabe J., Teeters C.A., O’Malley S., Kingsley K. Cranberry and grape seed extracts inhibit the proliferative phenotype of oral squamous cell carcinomas. Evid. Based Complement. Altern. Med. 2011:1–12. doi: 10.1093/ecam/nen047. 
41. Seeram N.P., Adams L.S., Zhang Y.J., Lee R., Sand D., Scheuller H.S., Heber D. Blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts inhibit growth and stimulate apoptosis of human cancer cells in vitro. J. Agric. Food Chem. 2006;54:9329–9339. doi: 10.1021/jf061750g.
42. Boivin D., Blanchette M., Barrette S., Moghrabi A., Beliveau R. Inhibition of cancer cell proliferation and suppression of TNF-induced activation of NFKB by edible berry juice. Anticancer Res. 2007;27:937–948.
43. Vu K.D., Carlettini H., Bouvet J., Cote J., Doyon G., Sylvain J.F., Lacroix M. Effect of different cranberry extracts and juices during cranberry juice processing on the antiproliferative activity against two colon cancer cell lines. Food Chem. 2012;132:959–967. doi: 10.1016/j.foodchem.2011.11.078.
44. Seeram N.P., Adams L.S., Hardy M.L., Heber D. Total cranberry extract versus its phytochemical constituents: Antiproliferative and synergistic effects against human tumor cell lines. J. Agric. Food Chem. 2004;52:2512–2517. doi: 10.1021/jf0352778.
45. Liberty A.M., Neto C. Cranberry PACs and triterpenoids: Anti-cancer activities in colon tumor cell lines. Acta Hortic. 2009:61–66. doi: 10.17660/ActaHortic.2009.841.4.
46. Ferguson P.J., Kurowska E.M., Freeman D.J., Chambers A.F., Koropatnick J. In vivo inhibition of growth of human tumor lines by flavonoid fractions from cranberry extract. Nutr. Cancer. 2006;56:86–94. doi: 10.1207/s15327914nc5601_12.
47. “Propolis.” Wikipedia, Wikimedia Foundation, 3 May 2022, https://en.wikipedia.org/wiki/Propolis.
48. V;, Orsi RO;Sforcin JM;Funari SR;Bankova. “Effects of Brazilian and Bulgarian Propolis on Bactericidal Activity of Macrophages against Salmonella Typhimurium.” International Immunopharmacology, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/15652765/
49. Goldman, Rena. “Propolis: Benefits, Uses, and More.” Healthline, Healthline Media, 29 Sept. 2018, https://www.healthline.com/health/propolis-an-ancient-healer#healing-co…
50. Al-Hariri M. Immune's-boosting agent: Immunomodulation potentials of propolis. J Family Community Med. 2019 Jan Apr;26(1):57-60. doi: 10.4103/jfcm.JFCM_46_18
51. Crişan I, Zaharia CN, Popovici F, Jucu V, Belu O, Dascălu C, Mutiu A, Petrescu A. Natural propolis extract NIVCRISOL in the treatment of acute and chronic rhinopharyngitis in children. Rom J Virol. 1995 Jul-Dec;46(3-4):115-33. PMID: 9179964
52. Ranfaing, Jérémy, et al. “Propolis Potentiates the Effect of Cranberry (Vaccinium Macrocarpon) against the Virulence of Uropathogenic Escherichia Coli.” Nature News, Nature Publishing Group, 16 July 2018, https://www.nature.com/articles/s41598-018-29082-6