The British press seem to be all over this one. I can find The Mail, The Mirror and The Huffington Post, not to mention diet.co.uk and AOL Lifestyle UK. All of them witter on about the “Mediterranean” style diet – rich in fruit, vegetables and fish – that is the healthiest, and which seemed to have a level of protection against Parkinson’s. That’s all fine and dandy, but the research was done in Japan, and the abstract does not mention the Mediterranean at all. The healthier, allegedly protective, diet that the Japanese researchers tested against the Western menu and an intermediate style of eating was actually the traditional Japanese diet.
Maybe it does resemble the Mediterranean diet. But why call a spade a pickaxe? Continue reading
My last post looked at the rather pleasant idea that chocolate might contain something that helps Parkinsonism. It also touched upon the potential of more widespread benefits of chocolate that might help everyone. I linked to a report of a study at the University of Nottingham which suggested that high levels of flavanols in chocolate drinks can temporarily increase brain functionality. The abstract for that study can be found here.
Flavanols are an example of an antioxidant, and I must confess that that makes the alarm bells go off in my head, probably because of the amount of pseudoscience spouted by (among others) the vendors of dietary supplements on the subject of these chemicals.
The Antioxidant Myth
There is a medical myth surrounding antioxidants, nicely busted by Ben Goldacre in his fabulous book, Bad ScienceBad Science. There’s a good online article here, too – this one’s written by Professor D Colquhoun, FRS, a professor of Pharmacology at UCL (University College, London). Colquhoun includes a handy link to a PDF of a New Scientist article entitled “The Antioxidant Myth” (you would have to be a subscriber to read this article on New Scientist’s Web site).
The current view on antioxidants is that, packaged in a pill, they do no good at all, and may instead do harm, particularly in large quantities. Foods containing antioxidants may have some beneficial effects – but the reasons for this are unknown. One suggestion is that the fibrous nature of vegetables promotes a slow release of the antioxidants.
Personally, I remain sceptical. The study at Nottingham was exceedingly small (16 volunteers were involved), but did seem to point to the possibility of there being some benefits from cocoa with exceptionally high flavanol content. Something similar to this, incidentally, can be purchased online from Mars Botanical (disclaimer: I’m not saying that this does anything; just that it is there).
Other Chemicals in Chocolate
Chocolate – or, more accurately, the cocoa bean – is complex stuff. It contains hundreds of different chemicals, several of which are pharmacologically active. The following list is not exhaustive, but includes the most commonly mentioned chemicals.
Theobromine is the stuff that is toxic to dogs and other animals (technically, it is also toxic to humans, but we are larger and we metabolize theobromine faster than other animals). While it seems that data hs not been published on the toxicity of theobromine on birds, it is generally assumed that chocolate – more specifically theobromine – is poisonous to birds.
Caffeine. Does chocolate contain caffeine? The author of xocoatl.org (a fairly comprehensive site “all about chocolate”), claims that it does not, and that it is “persistent urban legend” that chocolate does contain caffeine. He says that theobromine is often confused with caffeine, and that some commercially produced chocolate has caffeine added to it. However, xocoatl is a lone voice; from what I read elsewhere, it seems likely that chocolate may contain small quantities of caffiene.
Anandamide. This substance resembles THC (tetrahydrocannabinol), a chemical found in marijuana. Both substances activate the same receptor and consequently cause dopamine to be released. In addition to its importance in Parkinson’s Disease, dopamine is well known for inducing a feeling of well-being, or even a ‘high’. Anandamide does break down rapidly, but chocolate also contains compounds that prevent the breakdown of anandamide, thus prolonging the good feelings.
Histamine. Histamine is important to our immune responses; it is also a neurotransmitter that regulates sleep. It’s inflammatory effect can be a problem in conditions such as hay fever. Chocolate reputedly contains high enough levels of histamine to trigger migraines.
Beta-phenylethylamine. Another substance that promotes the production of dopamine, phenylethylamine is actually available as a food supplement; as such, it is sold with claims that it promotes weight loss, longevity and improved brain functionality. It can also cause migraines, along with histamine, theobromine and caffeine.
Interestingly, it is stated in the Wikipedia article that:
phenethylamine is rapidly metabolized by the enzyme MAO-B, preventing significant concentrations from reaching the brain, thus contributing no perceptible psychoactive effect without the use of a monoamine oxidase inhibitor (MAOI)
Of course, to nudge this post slightly back on-topic, I am taking a monoamine oxidase inhibitor in the form of Rasagiline (brand name Azilect).
The Feel-Good Factor
Chocolate makes you feel good. It does, doesn’t it? More so than other sweet things, more so than other sources of caffeine. I don’t think that scientists have discovered the precise reasons for this, yet (but there are many theories involving several of the psychoactive compounds listed above), but if chocolate makes you feel good, then it certainly can’t all be bad.
I like chocolate. Who doesn’t? (Oh, there are a few strange folks who don’t, it’s true, but most people seem to like the stuff.)
It’s laden with fat and sugar, mind, and conventional dietary advice is that it’s not really very good for you (or me, for that matter).
However, every now and then (usually around Christmas time, as noted here), you find stories that supply vague, pseudo-scientific reasons why chocolate may be good for you.
a) People with Parkinson’s apparently eat more chocolate (neurologists at Dresden University of Technology published the results of a self-questionnaire on this topic – see the abstract here); and
b) There may be some subconscious urge (with a biological basis) causing this.
A Dutch psychiatrist, Walter van den Broek, blogging under the name Dr. Shock, discusses this result and hypothesizes on the possible reasons why chocolate is especially important to people with Parkinson’s. You can read his full post here. Van den Broek, who seems to have a special interest in chocolate, states:
Beta-phenyl-ethylamine is the only possible psychoactive substance in chocolate that passes the blood brain barrier. It is a direct dopamine releasing ingredient. Moreover, cocoa contains caffeine and it’s structural derivatives, these components can have antiparkinsonian effects.
As you may be aware, it is lack of dopamine that causes Parkinsonian symptoms (Parkinson’s Disease is a condition in which the brain does not make sufficient dopamine; dopamine itself will not cross the blood-brain barrier, and so several drug treatments for Parkinson’s utilise various precursors of dopamine – such as beta-phenyl-ethylamine).
More about the potential effects of caffeine later.
But in the meantime, consider this comment, made by Parkinson’s patient Vivien Ambler on the Web site Medical News Today:
I have discovered by chance that consuming chocolate improves my motor symptoms. my body just craved chocolate & after I ate a few small pieces I noticed my symptoms improved for the rest of the day.
Vivien was responding to an article posted on the site referring to a study made at the University of Nottingham in which the ‘brain boosting power’ of chocolate was investigated. No reference was made to Parkinson’s or to dopamine in this article; instead, it referred to flavanols (substances that occur naturally in chocolate, but which are sometimes removed in commercial confectionery due to their bitter taste) and their observed ability to “boost blood flow to key areas of the brain for two to three hours.” I suspect that the effect Vivien noticed was more likely to be due to the beta-phenyl-ethylamine noted by van den Broek.
The team at Dresden have themselves planned a clinical trial on the “Effects of Chocolate on Motor Symptoms of Parkinson’s Disease”. This was also reported by the Daily Mail in a health round-up article. It is possible that this trial is now complete, but I have not yet seen any reference to the results.
One final point: if it is possible to extract an anti-Parkinsonian substance from chocolate and package it up in a pill, would it be a good idea? Or would we rather eat the chocolate?
More good news about chocolate in the following post – this time for everybody, not just Parkinsonians!