Tea and cocoa share antioxidants believed to reduce risk factors for cardiovascular disease, dementia, and other health problems related to free radicals
by Craig Weatherby
Red wine, green tea, raw cocoa, and most berries are high in polyphenol antioxidants called flavanols, which have been shown to exert anti-inflammatory effects that help optimize the performance of artery linings (Sacanella E et al 2007).
This effect is one key to the links between all four foods and increased cardiovascular health, as seen in many studies and in preliminary clinical trials.
However, as the authors of a new study on red wine wrote, “Current evidence supports a contribution of [wine and tea] polyphenols to the prevention of cardiovascular disease, but their mechanisms of action are not understood.”
Late last year, these researchers tested the effects of red wine in 10 women, to look for impacts that would help explain its apparent heart benefits.
Red wine protects dietary fats from oxidation
Israeli scientists at the Volcani Center in Bet Dagan conducted a randomized, crossover study, designed to examine the effects of red wine consumption on dietary fat.
One undesirable byproduct of fat digestion—called malondialdehyde (MDA)—is known to increase the risk of cardiovascular disease and other conditions.
MDA is created when dietary fats get oxidized by free radicals, and it goes on to damage cells in the arteries and elsewhere.
So, the Israelis decided to look for the effects of red wine on creation of MDA after eating a fatty food.
They served 10 female volunteers dark (fatty) turkey meat, in three different contexts:
- Dark turkey meat (nine ounces) plus water to drink (control meal).
- Dark turkey meat soaked in red wine after heating, plus a 200 ml (6.7 oz) glass of red wine.
- Dark turkey meat soaked in red wine prior to heating plus a 200 ml (6.7 oz) glass of red wine
Each of 10 healthy volunteers sampled each of the meals at different times, and their urine was tested for levels of MDA before and after every meal.
After the “control” meal of plain turkey cutlets plus drinking water, the volunteers’ MDA levels increased.
In stark contrast, meal B produced a 75 reduction in the blood levels of MDA.
Best of all, meal C—turkey soaked in red wine before heating, plus a glass of red wine—totally prevented any rise in blood levels of MDA.
Similar results were seen in urine levels of MDA.
As they wrote, “Our study suggests that red wine polyphenols exert a beneficial effect by the novel new function, absorption inhibition of the lipotoxin MDA. These findings explain the potentially harmful effects of oxidized fats found in foods and the important benefit of dietary polyphenols in the meal” (Gorelik S et al 2007).
Green tea review puts beverage in similar heart-health position
Last August, researchers at Oklahoma State University published the results of their review of the extant evidence concerning tea and heart health.
This is what they concluded:
- “Epidemiological observations in Southeast Asian countries indicate an inverse correlation exists between habitual consumption of green tea beverages and the incidence of cardiovascular events.”
- “Green tea, rich in antioxidant and anti-inflammatory catechins, especially epigallocatechin gallate (EGCG), has been shown to reduce surrogate markers of atherosclerosis and lipid peroxidation, particularly LDL oxidation and malondialdehyde concentrations, in several in vitro [test tube], animal, and limited clinical studies.
It seems inarguable that the flavanols—especially the catechins and procyanidins—shared by green tea, cocoa, and red wine help prevent oxidation of dietary fats, with beneficial implications for heart health.
- Abu-Amsha Caccetta R, Burke V, Mori TA, Beilin LJ, Puddey IB, Croft KD.Red wine polyphenols, in the absence of alcohol, reduce lipid peroxidative stress in smoking subjects.Free Radic Biol Med. 2001 Mar 15;30(6):636-42.
- Basu A, Lucas EA.Mechanisms and effects of green tea on cardiovascular health.Nutr Rev. 2007 Aug;65(8 Pt 1):361-75. Review.
- Djoussé L, Ellison RC, McLennan CE, Cupples LA, Lipinska I, Tofler GH, Gokce N, Vita JA.Acute effects of a high-fat meal with and without red wine on endothelial function in healthy subjects.Am J Cardiol. 1999 Sep 15;84(6):660-4.
- Gorelik S, Lapidot T, Shaham I, Granit R, Ligumsky M, Kohen R, Kanner J.Lipid peroxidation and coupled vitamin oxidation in simulated and human gastric fluid inhibited by dietary polyphenols: health implications.J Agric Food Chem. 2005 May 4;53(9):3397-402.
- Sacanella E, Vázquez-Agell M, Mena MP, Antúnez E, Fernández-Solá J, Nicolás JM, Lamuela-Raventós RM, Ros E, Estruch R.Down-regulation of adhesion molecules and other inflammatory biomarkers after moderate wine consumption in healthy women: a randomized trial.Am J Clin Nutr. 2007 Nov;86(5):1463-9a