New evidence that caffeine is a healthful antioxidant in coffee

May 4, 2011

Scientists are reporting an in-depth analysis of how the caffeine in coffee, tea, and other foods seems to protect against conditions such as Alzheimer's disease and heart disease on the most fundamental levels. The report, which describes the chemistry behind caffeine's antioxidant effects, appears in ACS' Journal of Physical Chemistry B.

Annia Galano and Jorge Rafael León-Carmona describe evidence suggesting that coffee is one of the richest sources of healthful in the average person's diet. Some of the newest research points to caffeine (also present in tea, cocoa, and other foods) as the source of powerful antioxidant effects that may help protect people from Alzheimer's and other diseases. However, scientists know little about exactly how caffeine works in scavenging the so-called free radicals that have damaging effects in the body. And those few studies sometimes have reached contradictory conclusions.

In an effort to bolster scientific knowledge about caffeine, they present detailed theoretical calculations on caffeine's interactions with free radicals. Their theoretical conclusions show "excellent" consistency with the results that other scientists have report from animal and other experiments, bolstering the likelihood that caffeine is, indeed, a source of healthful antioxidant activity in coffee.

Explore further: Tea seen as healthier than water

More information: “Is Caffeine a Good Scavenger of Oxygenated Free Radicals?” Journal of Physical Chemistry B. DOI: 10.1021/jp201383y

The reactions of caffeine (CAF) with different reactive oxygen species (ROS) have been studied using density functional theory. Five mechanisms of reaction have been considered, namely, radical adduct formation (RAF), hydrogen atom transfer (HAT), single electron transfer (SET), sequential electron proton transfer (SEPT), and proton coupled electron transfer (PCET). The SET, SEPT, and PCET mechanisms have been ruled out for the reactions of CAF with •OH, O2•−, ROO•, and RO• radicals. It was found that caffeine is inefficient for directly scavenging O2•− and •OOCH3 radicals and most likely other alkyl peroxyl radicals. The overall reactivity of CAF toward •OH was found to be diffusion-controlled, regardless of the polarity of the environment, supporting the excellent •OH scavenging activity of CAF. On the other hand, it is predicted to be a modest scavenger of •OCH3, and probably of other alkoxyl radicals, and a poor scavenger of HOO•. RAF has been identified as the main mechanism involved in the direct ROS scavenging activity of CAF. The excellent agreement with the available experimental data supports the reliability of the present calculations.

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2 / 5 (1) May 04, 2011
I saw recently on Southeastern Louisiana University's local cable television channel that research by real health experts shows that anti-oxidants are harmful to the body and should be avoided.

Caffeine also causes headaches and hypertension.
1 / 5 (1) May 04, 2011
Caffeine also causes headaches and hypertension.

Caffeine withdrawal can cause a temporary (and easily treated) headache.

Is there a scientific study showing a correlation between caffeine and hypertension? I am not aware that there has been any association or causation found for caffeine and hypertension.
not rated yet May 05, 2011
Caffeine also causes headaches and hypertension.

Caffeine withdrawal can cause a temporary (and easily treated) headache.
Tell me about it!

Is there a scientific study showing a correlation between caffeine and hypertension? I am not aware that there has been any association or causation found for caffeine and hypertension.
There doesn't appear to a link between caffeine and hypertension, at least nothing like the link between hypertension and salt (in some individuals), but caffeine can cause an irregular heat beat in a few people. It's a mildly neuro-active drug, so you get a wide range of, on balance, subtle effects (irregular heartbeats among them). The evidence for positive effects against neuro-degenerative disorders are becoming more and more convincing with every passing year, however.
not rated yet May 05, 2011
To clarify: there is no known relation between caffeine and chronic hypertension as their is with long term salt intake and hypertension (more people thing of 'hypertension' as a chronic condition). As with caffeine intake and irregular heartbeats, however, a few people do appear to react to caffeine with a transient spike in blood pressure.
not rated yet May 05, 2011
To answer your question, dogbert, here is a page from the Mayo Clinic:
not rated yet May 05, 2011
Ah frak. Physorg generated the URL *with* the period at the end. Bad Physorg, bad! Please copy and paste the link into your browser and remove the period.

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