Phytochemicals in Raspberries and Blackberries
Besides containing proteins, fats, carbohydrates, vitamins, and minerals, raspberries and blackberries contain several extremely important phytochemicals (naturally occurring chemicals from plants) Many of these substances are classed as phenolic compounds. The table below shows some of the healthful effects that have been determined for this group of chemicals found in fruits.
|
Type of Phenolic compound |
Mode of action |
|
Flavonoids Anthocyanins Cyanidin-3-glucoside Pelargonidin-3-glucoside Flavonols Kaempferol Quercetin Myricetin Flavan-3-ols Catechin |
Antiangiogenic and antiproliferative properties (prevents blood vessel, cancer growth); prevent oxidation of LDL (low density lipoprotein); prevent platelet aggregation; anti inflammatory
Antibacterial; prevent cancer initiation; capillary protectant; antioxidant
Prevent platelet aggregation, cancer initiation and growth; antioxidant |
|
Proanthocyanidins (condensed tannins; polymers of flavan-3-ols or flavanols) Monomer, dimer, trimer Polymeric (4 and above) (ellagitannins) |
Provide capillary strength; inhibit plasma oxidation (antioxidant)
|
|
Simple Phenolics Hydroxybenzoic acids (ellagic, gallic) Hydroxycinnamic acids (caffeic, coumaric, chlorogenic) |
Prevent esophageal cancer; prevent LDL oxidation Prevent oxidative stress, anti inflammatory |
As the table shows, one important function of this chemicals is as antioxidants. One of the overall measures of antioxidant potency is called ORAC, or “Oxygen Radical Absorbance Capacity.”Antioxidants inhibit oxidation, which is known to have a damaging effect on tissues. Studies now suggest that consuming fruits and vegetables with a high ORAC value may slow the aging process in both body and brain. Antioxidants are shown to work best when combined; the presence of fiber and other plant compounds enhance the health benefit. For this reason, a nutraceutical (healthful food) source is a more viable antioxidant option than is a dietary supplement.
When the ORAC of 27 different fruits was tested, blackberries and raspberries were in the TOP FIVE. (Wu et al., 2004)
|
|
Average |
Range (uM TE/g) |
|
Black raspberry |
117.0 * |
100.3 – 146.0 * |
|
Blueberry |
52.3 * |
18.6 – 130.7 * |
|
Blackberry |
46.4 * |
26.7 – 70.6 * (two 22.3 – 96.1 studies) |
|
Red raspberry |
18.15 |
15.9 – 20.0 |
|
Strawberry |
25.7 |
15.5 – 37.2 |
From the research papers
“Findings suggest that an active black raspberry fraction may be a promising complementary cancer therapy. It is natural and potent enough for manageable dosing regimens. These extracts contain multiple active ingredients that may be additive or synergistic in their antiangiogenic effects. These observations warrant further investigations in animals and human trials.” Liu, et al, J Agric Food Chem. 2005 May 18. Abstract
“Black raspberries are a rich natural source of chemopreventive phytochemicals. Recent studies have shown that freeze-dried black raspberries inhibit the development of oral, esophageal, and colon cancer in rodents…” Han, et al., Nutr Cancer. 2005. Abstract
“The findings … suggest that the content of individual health-promoting compounds varies significantly in raspberry, due to both developmental and genetic factors. This information will assist in the future development and identification of raspberry lines with enhanced health-promoting properties.” Beekwilder, et al. J Agric Food Chem. 2005 May 4. Abstract
“Berries and their phenolics [mostly ellagitannins] selectively inhibit the growth of human pathogenic bacteria…..these compounds would be of high interest for further evaluation of their properties as natural antimicrobial agents for food and pharmaceutical industry.” Puupponen-Pimia, et al. J Appl Microbiol2005;98(4):991-1000. Abstract
“Scientific research would suggest that the colorants called anthocyanins in strong-coloured berries like red berries, blueberries and blackcurrants may have a role in preventing heart disease.” More information on this study from Finland
“Juice from strawberry, blueberry, and raspberry fruit significantly inhibited mutagenesis caused by both carcinogens.” Hope Smith, et al. J Med Food. 2004 Winter;7(4):450-5. Abstract
