British study is first to test the healthful treat in people who are always tired
by Craig Weatherby
From Britain comes further evidence of the health benefits of extra-dark chocolate.
The flavanols abundant in raw cocoa powder and dark chocolate—dominated by some of the same catechin-class flavanols abundant in green and white tea—help protect cells from oxygen free radicals and reduce inflammation damage.
The new findings seem to extend their benefits far beyond the cardiovascular and anti-cancer benefits documented in numerous prior investigations.
The mystery and misery of chronic fatigue syndrome
Chronic Fatigue Syndrome (CFS) is characterized by exhaustion and extremely poor stamina, neurological problems (e.g. mental confusion), sleep disorder, and a variety of flu-like symptoms.
The degree of severity can differ widely, from getting very fatigued only after stressful events to being frequently bedridden.
Most patients recover three to six years after onset, but others may go a decade or more before being totally well again. Their symptoms tend to wax and wane over time, making it hard to know whether they've recovered or are just between cycles.
The causes of CFS remain unknown, but the possibilities include viruses, environmental toxins, genetic predisposition, or a combination of these.
Brits find extra-dark chocolate fights fatigue
Professor Stephen Atkin, MD of Hull York Medical School led a team of researchers at Hull and East Yorkshire Hospitals, who recruited a group of adults diagnosed with chronic fatigue syndrome.
(We should note that our information on the study comes from a hospital press release that did not say how many subjects were involved. The study has not been published in a peer-reviewed journal, but was placebo-controlled, so it carries some scientific credibility.)
The participants consumed 45 grams (1.6 ounces) of a specially formulated, extra-dark chocolate (85 percent cocoa solids) daily for eight weeks, stopped eating it for two weeks, and then consumed a simulated dark chocolate, low in polyphenols, everyday for another eight weeks.
They reported feeling less fatigue after eating the extra-dark chocolate, but began feeling fatigued again after they were switched to the placebo chocolate.
Interestingly, they didn’t experience any significant weight gain during the test, which attests to the relatively low-calorie nature of extra-dark chocolate, compared to milk chocolate.
(Our slightly less dark chocolate, which is 80 percent cocoa solids, contains 165 calories per ounce or 264 calories in 1.6 ounces. Thus, there would have been about 250 calories in the 1.6 ounces of slightly darker chocolate eaten daily by the test subjects.)
Impaired sleep is common among CFS patients, and one possible explanation for the symptom-relief experienced by the test subjects is that dark chocolate is known to increase brain levels of the relaxing, mood-lifting, sleep-enhancing neurotransmitter serotonin.
This hypothesis makes sense, since a recent clinical trial shows that CFS patients get relief from Prozac-type anti-depressants that raise brain serotonin levels (Thomas MA, Smith AP 2006).
We should note that our information on the study comes from a hospital press release that did not say how many subjects were involved. The study has not been published in a peer-reviewed journal, but was placebo-controlled, so it carries some scientific credibility.
- Atkin S et al. Health benefits of chocolate revealed. Hull and East Yorkshire Hospitals NHS Trust. Accessed online December 19 at http://www.hey.nhs.uk/pdf/media/chocolate.pdf.
- Thomas MA, Smith AP. An investigation of the long-term benefits of antidepressant medication in the recovery of patients with chronic fatigue syndrome. Hum Psychopharmacol. 2006 Dec;21(8):503-9.