This was a huge week for basic health news. My colleagues over at theHeart.org covered a number of interesting studies. If you havenâ€™t already, Iâ€™d take a look at their “prevention” tab. There is a provocative story challenging the use of drugs for mild high blood pressure; another that relates (ABO) blood type and the future risk of heart disease, and for statin followers, there is (good) news on the risk of diabetes with statin use.
These are all highly bloggable health topics.
But there was one better. Tonight, I’m talking about the most recent chocolate study.
You like chocolate, right? I mean, who doesnâ€™t?
After a weekend of hard training rides and then the usual life-sucking calorie-depleting Tuesday night world championships, few topics are more relevant to blog about on Wednesday than chocolate. Not only that, but you have also read that flavanols found in chocolate are anti-oxidant chemicals that may promote blood vessel health. It follows that eating chocolate may (might) indeed be healthy.
The most recent chocolate study, simply titled Effect of Cocoa on Blood Pressure, was published in the Cochrane Database of Systemic Reviews. Australian researchers reported a meta-analysis (an awful word that means a culling of numerous previous studies) that tentatively suggests flavanol-rich (ie dark) chocolate consumption lowers blood pressure. The study was scientifically weak. The primary issue was that blood pressure was only slightly lower in chocolate eaters, averaging just 2.77 mmHg less. Is there a meaningful difference in a BP of 132/80 vs 129/80? The other problem is that each of the studies reviewed had short follow-up periods (weeks, not years). Thatâ€™s an important weakness because we know the effects of high blood pressure occur over the long-term.
Okay, so the study has limitations. All studies do. Though I referred to the trial as â€œweak,â€ that doesnâ€™t mean it is worthless. On the contrary, taken together with other non-negative chocolate trials a picture begins to take shape. I see the image looking something like this: Dark chocolate consumption probably parallels red wine drinking. Those who consume chocolate in moderation and also live healthy lifestyles may enjoy a modest benefit from the tasty concoction. We can probably say modest dark chocolate eating isnâ€™t harmful.
This is the good news.
Letâ€™s be serious about the other side of the story.
Chocolate has some serious downsides. Topic one is the calories. The current trial studied the use of dark chocolate. Ingesting flavanoids from cocoa is much different than getting them from dairy-rich calorie-intensive milk chocolate, like M & Ms or chocolate cake. The extra calories from chocolate containing foods should not be ignored. Headline readers could easily be misled by search engine grabbers like this one from the UKâ€™s Mail Online, “Eating chocolate could be a tasty new way to lower blood pressure.”
Another important issue is that in some people, cocoa doesnâ€™t agree with them. I donâ€™t have studies to cite, but I can tell you from experience (as both doctor and patient) that chocolate can cause arrhythmia. Because I hate feeling my one and only heart flutter, I rarely eat chocolate. Iâ€™m not alone either. Chocolate-induced palpitations are extremely common. Donâ€™t misunderstand; Iâ€™m not saying chocolate causes serious arrhythmia, I am just saying that humans are diverse creatures that respond differently to foods and medicines.
Another problem with chocolate is that some individuals report insomnia after eating chocolate. Thatâ€™s also bad news. Itâ€™s not like we are a society of good sleepers.
The Mandrola bottom line:
Dark chocolate is probably a lot like red wine. If consumed in modest amounts and not accompanied by adverse effects, thereâ€™s probably no significant harmâ€”and perhaps a modest benefit.
It would be a huge error, however, to substitute dark chocolate as a healthy elixir that replaces the basics. Do not be fooled. Wellness comes not from special foods, or supplements, and surely not from medicines (not even a polypill). The healthy person moves a lot, eats a little and sleeps like a child.
Life is short. Go ahead; have a glass of wine or a chocolate bar. Just donâ€™t think doing so makes you healthy.