Types of Berries
Why use supplements when berries can do so much?
Rosie Schwartz
National Post
June 21, 2005
One of the simplest pleasures of summertime is a bowl of fresh berries. Local strawberries begin the season and will be joined by assorted luscious choices including blueberries, blackberries and raspberries as the summer progresses. While they're certainly palate-pleasing, they're also chock full of a wide array of health-promoting compounds. Though you may have your favourites, go for a variety to reap some of the unique benefits of each kind.
Berries have long been known to be rich sources of nutrients -- from B vitamins to C -- and packed with fibre. But it's their phytochemical content that seems to have intrigued scientists lately. These disease-fighting compounds appear to offer a defence against a range of illnesses including heart disease and stroke, certain cancers and even cognitive decline. And it's a list that keeps on growing.
As the interest has grown in how various phytochemicals such as antioxidants may protect against disease, so has the area of antioxidant testing. Using a test-tube analysis that measures the total antioxidant power of foods and other chemical substances called oxygen radical absorbance capacity (ORAC), scientists have started to assess assorted foods and supplements. The higher the ORAC score for a food, the greater its antioxidant capacity. Berries have been shown to be a super source of antioxidants, ranking near the top of plant sources. It's thought their antioxidant power is boosted by interactions between phytochemicals and the nutrients in the berries.
At the Agricultural Research Service's Human Nutrition Research Center on Aging (ARS) at Tufts University in Boston, scientists have also been testing food versus supplements. We've all seen the commercials suggesting that supplements can help cover any nutritional shortfalls when you're too busy to eat all those healthy foods. But when ARS scientists put some berry-based commercial preparations to the test because of the exceptional ORAC stores of berries, the results were quite surprising. When they measured the ORAC readings of the supplements, including bilberry, cranberry, chokeberry and elderberry extracts, they discovered that the total antioxidant capacity of 40 berry-based supplements tested varied greatly, ranging from just 16 to 3,985 ORAC units.
While various berries only rank between 1,200 and 2,500 units, eating the actual berries gives you a range of different benefits -- antioxidant power along with an assortment of other protective compounds. Because they are not regulated for quality, supplements might contain very little in the way of antioxidants or such protective substances.
In other words, a pill can't take the place of disease-fighting berries. And would you want it to?
Here's a roundup of some of the research on types of berries. And some of it may just send you out to the berry patch to get your fill.
BLUEBERRIES
With an ageing population, the research on the link between blueberries and protection against cognitive decline has certainly received much attention recently.
In one investigation published in the Journal of Neuroscience, Dr. James Joseph and his colleagues at ARS found that rats fed an extract of blueberries, strawberries and spinach daily showed improvements in short-term memory. But it was only the blueberry extract that improved balance and coordination.
In a later study, in older rats, age-related declines in the ability to do motor tasks were reversed after the animals were fed the human equivalent of half a cup of blueberries a day for two months. While the scientists are working to isolate the specific compounds responsible for blueberries' effects, their theories point to a type of flavonoid called anthocyanins, the pigments that give the fruit their distinctive colour. Another class of compounds called hydroxycinnamates may work together with the anthocyanins to improve both motor and cognitive functioning.
Further research by Dr. Joseph and his colleagues continues to provide promising results on how blueberries may work on the brain. According to their studies, the most potent effects are supplied by wild berries, which are more intensely coloured and contain significantly higher levels of anthocyanins.
Another perk of blueberries is that they contain the same phytochemicals that have made cranberry juice a folk remedy for preventing urinary tract infections. Proanthocyanidins, the compounds responsible for this effect, are found not only in the juice but also in fresh, frozen and dried cranberries and blueberries.
Considering the accumulating evidence on the health benefits of berries, it's wise to enjoy them all year long. When fresh ones aren't available or the price is out of sight, go for frozen or dried. They're also convenient to have on hand when time for shopping is short. But keep in mind that while blueberries are readily available all year in the freezer section in supermarkets, wild strawberries are generally a rare pleasure that you can only gather from the berry patch.
STRAWBERRIES
In a review of the potential impact of strawberries on human health, scientists from the University of Illinois gave these berries a stellar rating. Their rich phytochemical content provides a wide range of health perks. On the artery disease front, their potential action includes protection against the oxidation of LDL-cholesterol. Oxidized cholesterol is a form of cholesterol that is more likely to be deposited in artery walls. In addition, these berries decrease the likelihood of blood clots, which can lead to heart attacks or strokes. And their anti-inflammatory action may play roles in both keeping arteries healthy and decreasing the risk of certain cancers -- blocking the initiation of cancer and suppressing the growth of certain cancer cells.
While there's no doubt about the appeal of strawberry shortcake, consider adding these berries to savoury dishes such as spinach salad. Or drizzle an aged balsamic vinegar over sliced berries for a fabulous taste treat.
RASPBERRIES
Red, yellow or black, raspberries provide many of the same benefits as other berries, but research shows that the darker the berry, the greater the phytochemical content and the potential for disease-fighting effects. Studies on the ellagic acid found in these berries have shown it not only suppresses cancer cell growth but also causes cancer cell death. Among the cancers scientists have investigated are oral, esophageal, liver, bladder and colon cancer.
Raspberries also outrank many of their berry cousins in the fibre department. A cup of raspberries supplies more than eight grams of fibre -- over a quarter of the recommended daily intake of 25 to 30 grams.
© National Post 2005
