Blueberries have a diverse range of micronutrients, with notably high levels (relative to respective Dietary Reference Intakes) of the essential dietary mineral manganese, vitamin B6, vitamin C, vitamin K and dietary fiber (table).[19] One serving provides a relatively low glycemic load score of 4 out of 100 per day.
Nutrients and phytochemicals
Nutritional value per 100 g (3.5 oz) | |
---|---|
Energy | 239 kJ (57 kcal) |
Carbohydrates | 14.5 g |
Dietary fiber | 2.4 g |
Fat | 0.3 g |
Protein | 0.7 g |
Vitamin A | 54 IU |
- lutein and zeaxanthin | 80 μg |
Thiamine (Vit. B1) | 0.04 mg (3%) |
Riboflavin (Vit. B2) | 0.04 mg (3%) |
Niacin (Vit. B3) | 0.42 mg (3%) |
Pantothenic acid (B5) | 0.1 mg (2%) |
Vitamin B6 | 0.1 mg (8%) |
Folate (Vit. B9) | 6 μg (2%) |
Vitamin C | 10 mg (17%) |
Vitamin E | 0.6 mg (4%) |
Calcium | 6 mg (1%) |
Iron | 0.3 mg (2%) |
Magnesium | 6 mg (2%) |
Phosphorus | 12 mg (2%) |
Potassium | 77 mg (2%) |
Zinc | 0.2 mg (2%) |
manganese 0.3 mg | 20% |
vitamin K 19 mcg | 24% |
Percentages are relative to US recommendations for adults. Source: USDA Nutrient database |
Especially in wild species, blueberries contain anthocyanins, other antioxidant pigments and various phytochemicals possibly having a role in reducing risks of some diseases,[20] including inflammation and certain cancers.[21][22][23]
Research on the potential anti-disease effects of blueberries
Researchers have shown that blueberry anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins inhibit mechanisms ofcancer cell development and inflammation in vitro.[24][25][26][27] Similar to red grape, some blueberry species contain in their skins significant levels of resveratrol,[28] a phytochemical.
Although most studies below were conducted using the highbush cultivar of blueberries (V. corymbosum), content of polyphenol antioxidants and anthocyanins in lowbush (wild) blueberries (V. angustifolium) exceeds values found in highbush species.[29]
At a 2007 symposium on berry health benefits were reports showing consumption of blueberries (and similar berry fruits includingcranberries) may alleviate the cognitive decline occurring in Alzheimer's disease and other conditions of aging.[20]
A chemical isolated from blueberry leaves can block replication of the hepatitis C virus and might help to delay disease spread in infected individuals.[30]
Feeding blueberries to animals lowers brain damage in experimental stroke.[31][32] Research at Rutgers[33] has also shown that blueberries may help prevent urinary tract infections.
Other animal studies found that blueberry consumption lowered cholesterol and total blood lipid levels, possibly affecting symptoms ofheart disease.[34] Additional research showed that blueberry consumption in rats altered glycosaminoglycans which are vascular cell components affecting control of blood pressure.[35]
A study soon to be published in the Journal of Agricultural and Food Chemistry found that supplementation with wild blueberry juice enhanced memory and learning in older adults, while reducing blood sugar and symptoms of depression.[36]
Marketing of Blueberries as a Superfood (Anti-Oxidant Properties)
Based on the promising research discussed above, magazines and newspapers have recently begun to hail blueberries as a superfood. Example: an article in the July 2010 issue of Chatelaine magazine mentions the blueberry as a food that can increase the body's natural ability to heal.