Blueberries are an excellent source of nutrition and full of antioxidants. Long considered a superfood, they have free radical fighting properties as well as anti-cancer properties. They have a wide range of micronutrients, with notably high levels of the mineral manganese, vitamin B6, vitamin C, vitamin K and dietary fiber. They are also relatively low on the glycemic index, meaning they are absorbed slower and don't tend to spike blood sugar levels. A 100 gram serving size (about 75 berries) has only 57 calories. This serving has no fat, no cholesterol, and only 1 milligram of sodium. It does have 14 grams of carbs including 10 grams of sugar and 2 grams of fiber. In addition it provides 16% of your vitamin C needs and 2% of your iron requirement.
Blueberries are flowering plants of the genus Vaccinium with dark-blue, -purple or black berries. The flowers are bell-shaped, white, pale pink or red, sometimes tinged greenish. The fruit is a called a false berry, because part of the flower, the flared crown, is attached to the fruit. The berries are 5–16 mm in diameter; they are pale greenish at first, then reddish-purple, and finally blue on ripening. They have a sweet taste when mature, with variable acidity. The bushes typically bear fruit from May through June.
In commercial production, smaller fruit species are known as "lowbush" and synonymous with "wild" berries, and the larger fruit species as "highbush". Commercially offered "wild blueberries" are usually from species that naturally occur only in eastern and north-central North America.
Lowbush species are fire-tolerant and production often increases following a forest fire as the plants regenerate rapidly and benefit from removal of competing vegetation. "Wild" has been adopted as a marketing term for harvests of managed native stands of the low bush variety. The bushes are not planted or genetically manipulated, but they are pruned or burned over every two years, and pests are "managed".
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). One serving provides a relatively low glycemic load score of 4 out of 100 per day. Although most studies below were conducted using the highbush cultivar (V. corymbosum), content of polyphenol antioxidants and anthocyanins in lowbush wild (V. angustifolium) exceeds values found in highbush species. Especially in wild species, the berries contain anthocyanins, other antioxidant pigments and various phytochemicals possibly having a role in reducing risks of some diseases, including inflammation and certain cancers.
Researchers have shown that blueberry anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins inhibit mechanisms of cancer cell development and inflammation in vitro. Similar to red grape, some species contain in their skins significant levels of resveratrol, a phytochemical. Many of these chemicals are found in the skins of fruits to protect the fruits from pests, bacteria, viruses and parasites. By consuming the skins of fruits we can benefit from the protective properties found in the skins.
At a 2007 symposium on berry health benefits there were reports showing that the consumption of blueberries (and similar berry fruits including cranberries) may alleviate the cognitive decline occurring in Alzheimer's disease and other conditions of aging. Research at Rutgers has also shown that they may help prevent urinary tract infections.
Animal studies found that consumption lowered cholesterol and total blood lipid levels, possibly affecting symptoms of heart disease. Additional research showed that consumption in rats altered glycosaminoglycans which are vascular cell components affecting control of blood pressure.
Here is the complete nutritional value for raw blueberries. Nutritional value per 100 g (3.5 oz) Energy 60 kcal 240 kJ
Carbohydrates 14.5 g
- Dietary fiber 2.4 g
Fat 0.3 g
Protein 0.7 g
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%
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