How Blueberries Affect Your Health ~ Diet Digest

From research labs all across the country and the world, there is growing evidence that blueberries are an important part of a healthy diet.

Blueberries and Antioxidant Activity

Antioxidants are thought to help protect the body against the damaging effects of free radicals and the chronic diseases associated with the aging process. Fresh fruits, including blueberries, and vegetables contain many of these naturally occurring antioxidants such as Vitamins C and E. Blueberries contain 14 mg of Vitamin C and 0.8 mg Vitamin E per 1 cup of blueberries. In addition, blueberries contain anthocyanins and phenolics that can also act as antioxidants. Based on data from the USDA Human Nutrition Research Center on Aging (Boston, MA), blueberries are among the fruits with the highest antioxidant activity. Using a test called ORAC (Oxygen Radical Absorbance Capacity), researchers have shown that a serving of fresh blueberries provides more antioxidant activity than many other fresh fruits and vegetables.

Blueberries and Aging

In a USDA Human Nutrition Research Center laboratory, neuroscientists discovered that feeding blueberries to laboratory rats slowed age-related loss in their mental capacity, a finding that has important implications for humans.

In one study, Jim Joseph, director of the neuroscience laboratory in the USDA Human Nutrition Research Center (HNRC), fed blueberry extractions—the equivalent of a human eating one cup of blueberries a day—to mice and then ran them through a series of motor skills tests.

He found that the blueberry-fed mice performed better than their control group counterparts in motor behavioral learning and memory, and he noticed an increase in exploratory behavior. When he examined their brains, he found a marked decrease in oxidative stress in two regions of the brain and better retention of signal-transmitting neurons compared with the control mice.
The compound that appears responsible for this neuron protection, anthocyanin, also gives blueberries their color and might be the key component of the blueberry’s antioxidant and anti-inflammatory properties. Blueberries, along with other colorful fruits and vegetables, test high in their ability to subdue free radicals. These free radicals, which can damage cell membranes and DNA through a process known as oxidative stress, are blamed for many of the dysfunctions and diseases associated with aging.

These findings could become increasingly important as the U.S. population ages. It is projected that by 2050, more than 30% of Americans will be over 65 and will have the decreased cognitive and motor function that accompanies advanced age. Joseph is currently testing the effects of blueberries on humans. Preliminary results show that people who ate a cup of blueberries a day have performed 5–6% better on motor skills tests than the control group.

Blueberries and Health

Researchers at Rutgers University in New Jersey have identified compounds in blueberries called proanthocyanidins that promote urinary tract health and reduce the risk of infection by preventing bacteria from adhering to the cells that line the walls of the urinary tract.

Blueberries and Nutrition

Though blueberries themselves are not a cure-all, they contain a number of substances which are thought to have health benefits. These substances include, but are not limited to fructose, fiber, vitamins and antioxidants. Antioxidants thus far, seem to have the most conclusive role in the prevention/ delaying of such diseases as cancer, heart disease and the aging process however, a limited number of studies, especially long term and on human beings, are not available at this time.

One cup of blueberries contains 14% DV of fiber 2.41 g per 100g
Blueberries are a source of vitamins, minerals, dietary fiber, phenolics, and flavonoids
Blueberries are very low in fat and sodium

USDA National Nutrient Database For Standard Reference, Release 19 (2006)
Nutrient	unit	Blueberry (fresh) 1 c (148 g)	Blueberry (frozen, unsweetened) 1 c (155 g)
Energy	kcal	84	79
Protein	g	1.10	0.65
Fat	g	0.49	0.99
Carbohydrate	g	21.45	18.86
Fiber	g	3.6	4.2
Calcium	mg	9	12
Iron	mg	0.41	0.28
Magnesium	mg	9	8
Phosphorus	mg	18	17
Potassium	mg	114	84
Sodium	mg	1	2
Zinc	mg	0.24	0.11
Copper	mg	0.084	0.051
Manganese	mg	0.497	0.228
Selenium	mcg	0.1	0.2
Vitamin C	mg	14.4	3.9
Thiamin	mg	0.055	0.05
Riboflavin	mg	0.061	0.057
Niacin	mg	0.619	0.806
Panthothenic acid	mg	0.184	0.194
Vitamin B6	mg	0.077	0.091
Folate	mcg	9	11
Vitamin B12	mcg	0	0
Vitamin A	IU	80	71
Vitamin E	mg	0.84	0.74
Vitamin K	mcg	28.6	25.4

g=grams mg=milligrams kcal=kilocalories IU=International Units ug=micrograms ATE=alpha tocopherol equivalent

Other Substances Found in Blueberries

Blueberries contain a variety of compounds. These include: phenolics, anthocyanins, carotenoids, ellagic acid. The significance of their presence and modes of action continue to be explored.