Blueberries – another superfood

26 July, 2010 by Neuschwanstein

Sales of blueberries have overtaken those of raspberries. But why have British fruit lovers developed such a taste for these little juicy gems?

Small, sweet yet tart, firm to the bite. And hailed as a superfood.

The same could be said of many native berries, which are better suited to the UK’s growing conditions and have a similar nutritional profile. Yet blackcurrants, gooseberries and blackberries struggle to find space on supermarket shelves, which are increasingly given over to blueberries.

Blueberries are literally bursting with nutrients and flavor, yet very low in calories. Recently, researchers at Tufts University analyzed 60 fruits and vegetables for their antioxidant capability. Blueberries came out on top, rating highest in their capacity to destroy free radicals.

An Antioxidant Powerhouse

Packed with antioxidant phytonutrients called anthocyanidins, blueberries neutralize free radical damage to the collagen matrix of cells and tissues that can lead to cataracts, glaucoma, varicose veins, hemorrhoids, peptic ulcers, heart disease and cancer. Anthocyanins, the blue-red pigments found in blueberries, improve the integrity of support structures in the veins and entire vascular system. Anthocyanins have been shown to enhance the effects of vitamin C, improve capillary integrity, and stabilize the collagen matrix (the ground substance of all body tissues). They work their protective magic by preventing free-radical damage, inhibiting enzymes from cleaving the collagen matrix, and directly cross-linking with collagen fibers to form a more stable collagen matrix.

blueberries

Blueberries

Cardioprotective Action
While wine, particularly red wine, is touted as cardioprotective since it is a good source of antioxidant anthocyanins, a recent study found that blueberries deliver 38% more of these free radical fighters. In this study, published in the Journal of Agriculture and Food Chemistry, researchers found that a moderate drink (about 4 ounces) of white wine contained .47 mmol of free radical absorbing antioxidants, red wine provided 2.04 mmol, and a wine made from highbush blueberries delivered 2.42 mmol of these protective plant compounds.

A Visionary Fruit

Extracts of bilberry (a cousin of blueberry) have been shown in numerous studies to improve nighttime visual acuity and promote quicker adjustment to darkness and faster restoration of visual acuity after exposure to glare. This research was conducted to evaluate claims of bilberry’s beneficial effects on night vision made by British Air Force pilots during World War II who regularly consumed bilberry preserves before their night missions.

Protection against Macular Degeneration

Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the Archives of Ophthalmology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.

In this study, which involved over 110,000 women and men, researchers evaluated the effect of study participants’ consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARMD, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men.

While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARMD, fruit intake was definitely protective against the severe form of this vision-destroying disease. Three servings of fruit may sound like a lot to eat each day, but by simply topping off a cup of yogurt or green salad with a half cup of blueberries, tossing a banana into your morning smoothie or slicing it over your cereal, and snacking on an apple, plum, nectarine or pear, you’ve reached this goal.

A Better Brain with Blueberries

In laboratory animal studies, researchers have found that blueberries help protect the brain from oxidative stress and may reduce the effects of age-related conditions such as Alzheimer’s disease or dementia. Researchers found that diets rich in blueberries significantly improved both the learning capacity and motor skills of aging animals, making them mentally equivalent to much younger ones.

Promotion of Gastrointestinal Health

In addition to their powerful anthocyanins, blueberries contain another antioxidant compound called ellagic acid, which blocks metabolic pathways that can lead to cancer. In a study of over 1,200 elderly people, those who ate the most strawberries (another berry that contains ellagic acid) were three times less likely to develop cancer than those who ate few or no strawberries. In addition to containing ellagic acid, blueberries are high in the soluble fiber pectin, which has been shown to lower cholesterol and to prevent bile acid from being transformed into a potentially cancer-causing form.

Protection against Colon Cancer

Laboratory studies published in the Journal of Agricultural and Food Chemistry show that phenolic compounds in blueberries can inhibit colon cancer cell proliferation and induce apoptosis (programmed cell death).

Extracts were made of the blueberry phenols, which were freeze-dried and further separated into phenolic acids, tannins, flavonols, and anthocyanins. Then the dried extracts and fractions were added to cell cultures containing two colon cancer cell lines, HT-29 and Caco-2.

In concentrations normally found in laboratory animal plasma after eating blueberries, anthyocyanin fractions increased DNA fragmentation (a sign that apoptosis or cell death had been triggered) by 2-7 times. Flavonol and tannin fractions cut cell proliferation in half at concentrations of 70-100 and 50-100 microg/mL, while the phenolic fraction was also effective, but less potent, reducing proliferation by half at concentrations of 1000 microg/mL. Bottomline: eating blueberries may reduce colon cancer risk.


Protection against Ovarian Cancer

Among their rich supply of phytonutrients, blueberries include a flavonoid called kaempferol. Research calculating flavonoid intake in 66,940 women enrolled in the Nurses Health Study between 1984 and 2002 revealed that women whose diets provided the most kaempferol had a 40% reduction in risk of ovarian cancer, compared to women eating the least kaempferol-rich foods. In addition to blueberries, foods richest in kaempferol include tea (nonherbal), onions, curly kale, leeks, spinach, and broccoli.

A significant 34% reduction in ovarian cancer risk was also seen in women with the highest intake of the flavone luteolin (found in citrus). Int J Cancer. 2007 Apr 30; Am J Clin Nutr. 2004 May;79(5):727-47.

Healthier Elimination

Blueberries can help relieve both diarrhea and constipation. In addition to soluble and insoluble fiber, blueberries also contain tannins, which act as astringents in the digestive system to reduce inflammation. Blueberries also promote urinary tract health. Blueberries contain the same compounds found in cranberries that help prevent or eliminate urinary tract infections. In order for bacteria to infect, they must first adhere to the mucosal lining of the urethra and bladder. Components found in cranberry and blueberry juice reduce the ability of E. coli, the bacteria that is the most common cause of urinary tract infections, to adhere.

Other benefits & facts: They keep you fresh, active, fit, sharp, close to nature and in a good mood, as they are very good anti depressants. You also need not spend a lot on medicines, neither are there any side effects. Remember, the deeper the color of the Blue Berries, the more they are rich in anti oxidants and other medicinal values.

Description

Blueberries are the fruits of a shrub that belong to the heath (Ericaceae) family whose other members include the cranberry and bilberry as well as the azalea, mountain laurel and rhododendron. Blueberries grow in clusters and range in size from that of a small pea to a marble. They are deep in color, ranging from blue to maroon to purple-black, and feature a white-gray waxy “bloom” that covers the berry’s surface and serves as a protective coat. The skin surrounds a semi-transparent flesh that encases tiny seeds. Cultivated blueberries are typically mildly sweet, while those that grow wild have a more tart and tangy flavor.


3 Comments »

  1. Neuschwanstein says:

    Results of a preliminary U.S. Department of Agriculture (USDA)-funded study with laboratory mice suggest that blueberries may help fight atherosclerosis, also known as hardening of the arteries.

    The research provides the first direct evidence that blueberries can help prevent harmful plaques or lesions, symptomatic of atherosclerosis, from increasing in size in arteries.

    Principal investigator Xianli Wu, based in Little Rock, Ark., with the USDA Agricultural Research Service (ARS) Arkansas Children’s Nutrition Center and with the University of Arkansas for Medical Sciences, led the investigation. The findings are reported in the current issue of the Journal of Nutrition.

    Atherosclerosis is the leading cause of two forms of cardiovascular disease–heart attacks and strokes. Cardiovascular disease is the number one killer of Americans.

    The study compared the size, or area, of atherosclerotic lesions in 30 young laboratory mice. Half of the animals were fed diets spiked with freeze-dried blueberry powder for 20 weeks; the diet of the other mice did not contain the berry powder.

    Lesion size, measured at two sites on aorta (arteries leading from the heart), was 39 and 58 percent less than that of lesions in mice whose diet did not contain blueberry powder.

    Earlier studies, conducted elsewhere, have suggested that eating blueberries may help combat cardiovascular disease. But direct evidence of that effect has never been presented previously, according to Wu.

    The blueberry-spiked diet contained 1 percent blueberry powder, the equivalent of about a half-cup of fresh blueberries.

  2. Neuschwanstein says:

    Start eating blueberries if you have atherosclerosis, for the humble fruit can actually help fight artery hardening associated with the disease, revealed a study with laboratory mice.

    The research provides the first direct evidence that blueberries can help prevent harmful plaques or lesions, symptomatic of atherosclerosis, from increasing in size in arteries.

    Principal investigator Xianli Wu, based in Little Rock, Ark., with the U.S. Department of Agriculture’s (USDA’s) Agricultural Research Service (ARS) Arkansas Children”s Nutrition Center and with the University of Arkansas for Medical Sciences, led the investigation.

    Atherosclerosis is the leading cause of two forms of cardiovascular disease–heart attacks and strokes. Cardiovascular disease is the number one killer of Americans.

    The study compared the size, or area, of atherosclerotic lesions in 30 young laboratory mice.

    Half of the animals were fed diets spiked with freeze-dried blueberry powder for 20 weeks; the diet of the other mice did not contain the berry powder.

    Lesion size, measured at two sites on aorta (arteries leading from the heart), was 39 and 58 percent less than that of lesions in mice whose diet did not contain blueberry powder.

    Earlier studies, conducted elsewhere, have suggested that eating blueberries may help combat cardiovascular disease.

    But direct evidence of that effect has never been presented previously, according to Wu.

    The blueberry-spiked diet contained 1 percent blueberry powder, the equivalent of about a half-cup of fresh blueberries.

    All mice in the investigation were deficient in apolipoprotein-E, a trait, which makes them highly susceptible to forming atherosclerotic lesions and thus an excellent model for biomedical and nutrition research.

    Wu”s group wants to determine the mechanism or mechanisms by which blueberries helped control lesion size.

    For example, by boosting the activity of four antioxidant enzymes, blueberries may have reduced the oxidative stress that is a known risk factor for atherosclerosis.

    In follow-up studies, Wu”s group wants to determine whether eating blueberries in infancy, childhood and young adulthood would help protect against onset and progression of atherosclerosis in later years.

    Early prevention may be especially important in light of the nation”s epidemic of childhood obesity. Overweight and obesity increase atherosclerosis risk.

    The findings are reported in the current issue of the Journal of Nutrition.

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