Although not as commonly eaten as blueberries or strawberries, blackberries are rich in vitamins, minerals, and offer many health benefits. One cup of blackberries contains 62 calories, 2 g protein, 15 g carbohydrates, <1 g fat, and 8 g fiber. They are full of vitamin C, with 1 cup providing 50% of the recommended daily value. They are also packed with vitamin K and manganese, containing 36% and 47% of the recommended daily values, respectively [i].
Vitamin C and Cancer
Vitamin C, an antioxidant, plays a role in immune function and may be involved in cancer prevention and treatment. Many case-control studies have found intake of dietary vitamin C to be associated with decreased cancers including: breast, colon or rectum, esophagus, larynx or pharynx, lung, stomach, and oral cavity. Prospective cohort studies find inconsistent results, although in those that found significantly lower cancer risk, individuals had high intakes of dietary vitamin C (80-110 mg/day), near vitamin C tissue saturation (RDA for females is 75 mg, males is 90 mg) [ii].
Berries, Berry Extracts, and Cancer Risk
In a 2006 study on berry extracts and human cancer cells in vitro, six berry extracts were used, including blackberry. The berry extracts were evaluated for inhibiting growth of breast, colon, oral, and prostate cancer cells. Increased concentration of berry extracts was associated with increased inhibition of cell proliferation [iii]. In a 2016 review on berry intake and cancers, the authors concluded that berries show chemoprevention effects in cancers primarily of the GI tract. They also found these protective benefits in breast cancer, and to a lesser degree in liver, prostate, pancreatic, and lung cancers [iv].
Manganese and Health
Manganese is not a commonly mentioned mineral, though it has important functions in the body. Manganese is a cofactor for many enzymes, and thus aids in the metabolism of amino acids, lipids, glucose, and carbohydrates. It is involved in reactive oxygen species scavenging, bone formation, immune response, blood clotting, and reproduction [v].
Ways to Eat
Enjoy blackberries in a tri-berry fruit salad along with blueberries and strawberries for a bright, antioxidant-rich snack. Try them in Greek yogurt with cinnamon or in a salad with arugula, walnuts, and goat cheese. Top quinoa (a complete protein) with blackberries and add almond milk for a plant-based, protein and fiber-rich breakfast, and experiment with almond butter and blackberry toast for a creative PB&J alternative. Look out for our Savor Cooks article featuring blackberries, coming soon!
[i] Blackberries, raw. Retrieved from https://nutritiondata.self.com/facts/fruits-and-fruit-juices/1848/2
[ii] Vitamin C. Retrieved from https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#en2
[iii] Seeram NP, Adams LS, Zhang Y, Lee R, Sand D, Scheuller HS, Heber D, 2006. 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, 54(25):9329-9339. Retrieved from https://pubs.acs.org/doi/pdf/10.1021/jf061750g?rand=nh6h43wx
[iv] Kristo AS, Klimis-Zacas D, Sikalidis AK, 2016. Protective role of dietary berries in cancer. Antioxidants, 5(4):37. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187535/
[v] Manganese. Retrieved from https://ods.od.nih.gov/factsheets/Manganese-HealthProfessional/