Purple Foods (Red + Blue = Purple)

Part of the mouth-watering experience of eating is what appeals to your color perception. Unless visually impaired, we see our food before we taste it. Aroma may precede that. What we anticipate enhances what we taste. The more colors there are on the plate, the more nutritious the tasting. Beyond the humdrum nature of tan, ecru, and washed-out pale, there is an array of colors that can arouse a more than casual interest in eating: blue, red, and purple.

The compounds that give fruits and vegetables their characteristic colors actually serve to improve the health of humans. Although artificial colors have their due place in new carpets and upholstery, they deserve no place in our foods, where they serve only to exacerbate existing health concerns and give rise to new ones, as in excitatory and unfocused behaviors. A press release on 15 August, 2011 by Ohio State University announced that anthocyanins, chemicals that offer red, blue and purple color to foods, are capable of inhibiting the growth of cancer cells while keeping healthy cells intact. Lead author of the study, Dr. Monica Giusti, commented, “These foods contain many compounds, and we’re just starting to figure out what they are and which ones provide the best health benefits.” In the tests, grapes, radishes, purple corn and purple carrots, bilberries and several other anthocyanin-rich fruits and vegetables were featured. Giusti added, “All fruits and vegetables that are rich in anthocyanins have compounds that can slow down the growth of colon cancer cells, whether in experiments in laboratory dishes or inside the body.” A welcome addition to her remarks is, “It is possible to use natural, anthocyanin-based food colorants instead of synthetic dyes…” (OSU Press Release. 8/15/2011: http://www.newswise.com/articles/view/532497/)

Good news needs to be spread, not restricted to the scientifically elite.  Some plants high in anthocyanins are also rich in the tannins that produce the gustatory sensation similar to the pucker afforded by a bitter cup of tea.  You might have noticed that purplish lettuces are bitterer than the pale ones.

Anthocyanins extracted from black chokeberries were used by scientists at the U of MD to study effects on normal and cancerous colon cells, finding that growth of the cancerous cells was inhibited by a factor of 60% when exposed to the extract.  (Malik. 2003)  Anthocyanin-rich extracts (ARE) were examined by a group from Ohio State in 2008, where findings indicated that purple corn, bilberries, purple carrots, grapes, radishes, and elderberries had similar impact on the same colorectal cancer line, where the ARE’s not only provided chemoprotection, but also demonstrated an additive interaction with the other phenolics present.  Purple corn was at the top of the list.  (Jing. 2008)

The antioxidant potency of anthocyanins was comparatively uncertain prior to 2001, when studies in the United Kingdom looked at their ability to donate electrons, the sign of antioxidant character.  Even in the absence of the fat-soluble antioxidant, vitamin E, AREs were able to repair oxidative damage done to laboratory animals made susceptible to such damage by antioxidant-deficient diets that were especially low in that specific vitamin.  (Ramirez-Tortosa. 2001)  An ARE used in these tests came from violets, which are edible flowers.

One of the favorite purples is grapes, both the fruit and the juice.  Purple grape juice acts as a liver-protective agent because of its anthocyanin content, although it is accompanied by other active flavonoids and phenolics that may yield an appreciated synergy.  Greater antioxidant potential was exhibited in test subjects exposed to organic grape juice than to conventionally-grown juice, as demonstrated by enhanced enzyme activity and reduced lipid peroxidation, but both juices did the job.  (Dani. 2008)  Applied to cardiovascular disease, purple grape juice protects against the oxidation of low-density lipoprotein (LDL), the “bad” cholesterol whose oxidation into foam cells is a factor in arterial blockage.  This suggests that grape juice—and red wine—are cardioprotective against atherosclerosis.  (Folts. 2005)  (Stein. 1999)  The antiplatelet and antioxidant benefits, and improved endothelial function, are consistently seen with routine grape juice consumption.

Purple barley and eggplant evince similar protective properties.  The bran fraction of purple barley has a significantly higher antioxidant activity than its paler cousins, by as much as six times.  (Bellido. 2009)  Eggplants, exceptionally rich in an anthocyanin called nasunin, protect us from lipid peroxidation (especially helpful to the brain).  (Noda. 1998)  Nasunin transcends the ordinary antioxidant by chelating iron molecules and inhibiting the production of free radicals.  A bonus is that it also stops tumors from making new blood vessels, thereby starving them.  (Matsubara. 2005)  Purple sweet potatoes have a more powerful antioxidant character than ascorbic acid, which is known better as vitamin C, as demonstrated by depressing the malevolent effects of chemical insults upon the liver.  (Kano. 2005)  Even the mundane plum has anthocyanin phenolic properties that rival vitamin C.  (Chun. 2003)

Maybe a purple fruit or vegetable merits its own TV show.

http://www.newswise.com/articles/view/532497/    PRESS RELEASE Compounds that Color Fruits and Veggies May Protect Against Colon Cancer Released: 8/15/2007 12:25 PM EDT Embargo expired: 8/19/2007 8:00 AM EDT Source: Ohio State University

http://extension.osu.edu/news-releases/archives/2011/february/2018anthocyanins-for-color-health2019-talk-by-osu-food-scientist-friday-2-18 ‘Anthocyanins for Color, Health’: Talk by OSU Food Scientist Friday (2/18) Feb 17, 2011

Malik M, Zhao C, Schoene N, Guisti MM, Moyer MP, Magnuson BA. Anthocyanin-rich extract from Aronia meloncarpa E induces a cell cycle block in colon cancer but not normal colonic cells. Nutr Cancer. 2003;46(2):186-96.

Jing P, Bomser JA, Schwartz SJ, He J, Magnuson BA, Giusti MM. Structure-function relationships of anthocyanins from various anthocyanin-rich extracts on the inhibition of colon cancer cell growth. J Agric Food Chem. 2008 Oct 22;56(20):9391-8.

Ramirez-Tortosa C, Andersen ØM, Gardner PT, Morrice PC, Wood SG, Duthie SJ, Collins AR, Duthie G G Anthocyanin-rich extract decreases indices of lipid peroxidation and DNA damage in vitamin E-depleted rats. Free Radic Biol Med. 2001 Nov 1;31(9):1033-7.

Dani C, Oliboni LS, Pasquali MA, Oliveira MR, Umezu FM, Salvador M, Moreira JC, Henriques JA. Intake of purple grape juice as a hepatoprotective agent in Wistar rats. J Med Food. 2008 Mar;11(1):127-32.

Folts JD. Potential health benefits from the flavonoids in grape products on vascular disease. Adv Exp Med Biol. 2002;505:95-111

Stein JH, Keevil JG, Wiebe DA, Aeschlimann S, Folts JD. Purple grape juice improves endothelial function and reduces the susceptibility of LDL cholesterol to oxidation in patients with coronary artery disease. Circulation. 1999 Sep 7;100(10):1050-5.

Bellido GG, Beta T. Anthocyanin composition and oxygen radical scavenging capacity (ORAC) of milled and pearled purple, black, and common barley. J Agric Food Chem. 2009 Feb 11;57(3):1022-8.

Noda Y, Kaneyuki T, Igarashi K, Mori A, Packer L. Antioxidant activity of nasunin, an anthocyanin in eggplant. Res Commun Mol Pathol Pharmacol. 1998 Nov;102(2):175-87.

Matsubara K, Kaneyuki T, Miyake T, Mori M. Antiangiogenic activity of nasunin, an antioxidant anthocyanin, in eggplant peels J Agric Food Chem. 2005 Aug 10;53(16):6272-5.

Kano M, Takayanagi T, Harada K, Makino K, Ishikawa F. Antioxidative activity of anthocyanins from purple sweet potato, Ipomoera batatas cultivar Ayamurasaki. Biosci Biotechnol Biochem. 2005 May;69(5):979-88.

Chun OK, Kim DO, Moon HY, Kang HG, Lee CY. Contribution of individual polyphenolics to total antioxidant capacity of plums. J Agric Food Chem. 2003 Dec 3;51(25):7240-5.