The farmers who harvest cocoa beans for a few cents in the Ivory Coast never tasted chocolate. Watch their faces when they eat it for the first time.
For us westerners chocolate is just one more thing. It’s inconsequential. We like to eat it, sometimes we get delighted by it for a minute. But more often than not it’s just one more snack to stuff our fat faces with. We don’t think about it and the incredible effort and resources that are required to make it. We take it for granted along with the other billion foods and the other billion other technologies and privileges we didn’t fight for.
Came across this funny article. It drew my attention because of my interest in chocolate. It seems from this research that their are three kinds of chocolate eaters: “fast chewers”, “thorough chewers” and “suckers”. The thorough chewers take a significant time for chewing on the chocolate and chew a lot more than the other two groups. Fast chewers keep the chocolate in their mouth for a much shorter time with a significant higher chew rate. Suckers are those that suck on the chocolate rather then chew on it, they also take more time for consuming the chocolate. They chew less but they score high on the swallowing. These findings were independent of the kind of chocolate. The researchers used two kinds of chocolate. I’m afraid I’m a fast chewer, that’s why I need more chocolate. So what kind of chocolate eater are you?
What can you evaluate when eating chocolate?
hardness at first bite (force to bite into chocolate with front teeth), speed of melting (measure of time taken to become molten chocolate), smoothness (of bolus, as opposed to gritty/grainy), thickness (perceived viscosity of molten chocolate) and mouthcoating (extent to which residue coats the mouth after swallowing).
How was this study done?
The objective of this study was to employ EMG and EEG to investigate variation in the individual eating behaviour of chocolate and to determine if changes in eating behaviour relate to observed textural differences between two chocolate samples.
Why is this important?
Characterization of chocolate eating behaviour is important as it will help understand its influence on consumer perception of its texture and flavour. Moreover, it’s possible that chocolate eating behaviour could impact on consumer liking levels and the amount of chocolate eaten, and by association weight gain.
Previous investigations have shown that consumer preferences for biscuits may be related to the way a sample breaks downs in mouth whilst chewing, chewing and swallowing influences the sensory perception of food, ‘Slow’ eating has also been shown to decrease food intake and result in increased satiety.
Carvalho-da-Silva, A., Van Damme, I., Wolf, B., & Hort, J. (2011). Characterisation of chocolate eating behaviour Physiology & Behavior, 104 (5), 929-933 DOI: 10.1016/j.physbeh.2011.06.001
To my astonishment the relation between the exposure of unhealthy snack foods in a supermarket and eating behavior is hardly a topic of research. Read this in a recent study about the relationship between a greater variety of chocolates in supermarket and consumption of chocolates. In this Australian study they used data from 1007 women in 35 neighborhoods with their local supermarkets. They examined the associations between the number of different varieties of chocolate and confectionery items stocked in local supermarkets and consumption of these foods over and above what would be expected based on demographic and socioeconomic characteristics.
In this study no relationship was found. The variety of these snack food items in local neighborhood supermarkets was not associated with women’s confectionery and chocolate consumption. In this cohort women ate either chocolate or confectionery once a week or less in 75% and 82% cases, only 5% ate chocolate on a daily bases.
This could be true but as the authors state, other factors were not included in their analyses. Important possible other factors for snack eating behaviors could be: shelf space occupied by these snacks, promotion of these products, the relative proportion compared to healthy products, product placement, and the presence at check out.
Since the biased publications on this blog about the healthy influences of dark chocolate the result at first seemed promising but most amazing is the probable lack of research. Will chocolate still stand as not very inviting on supermarket shelf space?
Thornton, L., Cameron, A., Crawford, D., McNaughton, S., & Ball, K. (2011). Is greater variety of chocolates and confectionery in supermarkets associated with more consumption? Australian and New Zealand Journal of Public Health, 35 (3), 292-293 DOI: 10.1111/j.1753-6405.2011.00706.x
In this video you can see how the Mast Brothers in NYC make their own chocolate. It’s one of the very few places that craft bean-to-bar chocolate. They also have a blog. Be careful what kind of chocolate you buy, let them help you choose the right chocolate bar. If your not keen on very dark chocolate you could end up disappointed as this dude was.
Two recent large epidemiological studies again suggest a beneficial effect of chocolate consumption on cardiovascular disease. One study was a prospective study in 1216 women with a follow up of 9,5 years. The frequency of chocolate consumption was categorized in three groups”: < 1 serving per week, 1-6 servings and 7 or more. Outcome was defined as plaque thickness in the carotid artery and hospitalization or death at follow up as clinical outcome.
Not only were carotid plaques less prevalent in those women eating more chocolate but also those who ate more chocolate were less frequently hospitalized or death from ischemic heart disease.
In a large German study with middle aged participants of both sexes without cardiovascular disease at inclusion also an inverse relationship between chocolate consumption (at the time of enrollment in the study) and cardiovascular disease risk (myocardial infarction and stroke over the following 8 years) could be found.
in the quartile characterized by the lowest chocolate consumption (1.7 g/day) 106 myocardial infarctions and strokes occurred, whereas only 61 events occurred (combined relative risk of 0.61) in the quartile with the highest chocolate consumption (7.5 g/day). In the latter group, both systolic and diastolic blood pressure were found to be 1 mmHg lower as compared with the referent low chocolate consumption quartile.
In our quest for the optimal chocolate dose this last research adds another probable dosage that benefits our cardiovascular system namely 7,5 g/day.
Nevertheless, the problem with these large studies is the proof of a correlation, unfortunately no causation. These studies cannot provide direct proof for the existence of a cause and effect relationship. These two studies add up with two other large epidemiological studies. One in elderly Dutch men (Zutphen Elderly Study) and one in post-menopausal American women (Iowa Women’s Health Study).
Another problem is specificity. Cocoa contains other bioactive substances. Until now the beneficial effect of chocolate is attributed to it’s flavanol content. Moreover, participants might derive flavanols from other food substances such as vegetables, tea or fruit.
Originally, the positive effects of cocoa were found among the Kuna Indians living longer on islands off the coast of Panama than the mainland Panama population. But these Indians drank a cocoa drink that is consumed many times a day. This drink is something completely different from our chocolate. It’s low in calories and contains the unadulterated, unstripped cocoa, its bitterness tempered by sugar. Tried to find it’s recipe on the Internet but without any luck. Recipe anyone?
Buijsse, B., Weikert, C., Drogan, D., Bergmann, M., & Boeing, H. (2010). Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults European Heart Journal, 31 (13), 1616-1623 DOI: 10.1093/eurheartj/ehq068 Emma Wilkinson (2009). CardioPulse Articles European Heart Journal, 30 (24), 2951-2961 DOI: 10.1093/eurheartj/ehp485 Heiss, C., & Kelm, M. (2010). Chocolate consumption, blood pressure, and cardiovascular risk European Heart Journal, 31 (13), 1554-1556 DOI: 10.1093/eurheartj/ehq114 Lewis JR, Prince RL, Zhu K, Devine A, Thompson PL, & Hodgson JM (2010). Habitual chocolate intake and vascular disease: a prospective study of clinical outcomes in older women. Archives of internal medicine, 170 (20), 1857-8 PMID: 21059981
They tested the protection of epicatechin on heart infarct size in mice. Epicatechin is a flavinoid and a major component of dark chocolate. It has antioxydant effects associated with a lower risk of stroke and heart failure. Epicatechin can bind to opiod receptors that can induce heart protection, moreover it can induce cardiac protection from ischemia-reperfusion injury with a heart attack.
What they did was treat mice with epicatechin and naloxone alone and a combination of both. Naloxone is an opiod antagonist. Infarct size was significantly reduced in the epicatechin group, this effect was attenuated when administered together with naloxone. These data suggest that the protective efect of epicatechin is mediated by the opiod receptor.
This is the first demonstration of a receptor-mediated mechanism for epicatechin-induced cardiac protection.
And for our ongoing discussion on dark chocolate dosage:
Studies show that 6.3 g (30 kCal) per day of dark chocolate containing 30 mg of polyphenols are sufficient to reduce blood pressure in hypertensive patients
Panneerselvam, M., Tsutsumi, Y., Bonds, J., Horikawa, Y., Saldana, M., Dalton, N., Head, B., Patel, P., Roth, D., & Patel, H. (2010). Dark chocolate receptors: epicatechin-induced cardiac protection is dependent on -opioid receptor stimulation AJP: Heart and Circulatory Physiology, 299 (5) DOI: 10.1152/ajpheart.00073.2010
In my quest to the right chocolate dose recently discovered a letter in the BMJ about this subject. The authors did a meta analysis. Their results suggest that dark chocolate is superior to placebo in reducing blood pressures of more than 140 mm Hg systolic or more than 80 mm Hg diastolic.
Daily flavanol dosages ranged from 30 mg to 1 g (equivalent to 6.3 g to 100 g of milk or dark chocolate), and interventions ran for two to 18 weeks. Data were insufficient to provide confident answers on optimal dosage and time frame.
However, they question the practicability as a long term treatment. Can you imagine that? They found that 50 g daily of chocolate was significantly less acceptable to participants as a long term treatment for high blood pressure than one capsule daily of placebo or tomato extract (73% v 100%).
At first Dr Shock was baffled. Mixing precious chocolate with chemicals? What a waste. Apparently cocoa has about 52 mg of GABA per 100 gram cacao. GABA is the major inhibitory neurotransmitter in the brain, that can also be found in rustgevende middelen, and it has been shown to have an acute psychological stress-reducing effect in humans and a tranquilizing effect on sleeplessness, depression and autonomic disorder observed during the menopausal or presenile period. Because cacao is mixed with milk, sugar and some other ingredients the quantity if GABA in chocolate is less than in cacao, possibly reducing the stress reducing effects in human.
In a recent study, they enriched chocolate with GABA and did a placebo controlled crossover trial to the effect of GABA enriched chocolate on psychological stress. Stress was induced by a arithmetic task and they measured heart rate variability and cortisol concentration in saliva to measure psychological stress.
Chocolate enriched with GABA (GABA chocolate) was composed of 38.5% sugar, 7.8% defatted cacao, 29.8% fat, and 0.28% GABA.
The cortisol, one of our stress hormones didn’t increase after the task in the GABA sessions and those taking the GABA chocolate made a quick recovery in heart rate variability to the normal state from the stressful state. GABA doesn’t permeate the blood-brain barrier, so it’s positive effects on stress in this trial as well as in others has to be explained by it’s effects on the peripheral nervous system.
Nakamura, H., Takishima, T., Kometani, T., & Yokogoshi, H. (2009). Psychological stress-reducing effect of chocolate enriched with γ-aminobutyric acid (GABA) in humans: assessment of stress using heart rate variability and salivary chromogranin A International Journal of Food Sciences and Nutrition, 60 (s5), 106-113 DOI: 10.1080/09637480802558508
As you probably know is Dr Shock completely biased when writing about chocolate especially dark chocolate. He mostly writes about the research with positive results of chocolate on cardiovascular diseases. A recent review included 5 studies of adequate quality for inclusion in a recent meta analysis as well as 8 other peer reviewed studies for the effect of cocoa on blood pressure.
In these 13 reports dark chocolate lowered blood pressure in 6 of the 7 open label studies but diastolic blood pressure only in 1 of 6 double blind studies and as you know double blind studies are the one’s with the most scientific conclusions. The inconclusive results of all these 13 studies is suggested to be caused by methodological factors of these studies.
the published studies on chocolate and blood pressure include a relatively small number of subjects, and results are conflicting. In addition, because of secrecy surrounding the production of chocolate and the unique sociocultural context of this popular food, research on efficacy and effectiveness is complex.
The lowering of blood pressure mainly appeared in the open label studies, suggesting a placebo effect. Even the double blind studies could have suffered from unblinding due to the bitter taste and physiological effects of flavanoids in chocolate. Different ways of blood pressure measuring methods were used. Especially the double blind studies provided limited detail or used devices with suboptimal accuracy.
Treatment for high blood pressure is not very hard to find, but when people decide to ignore, thinking it will go away by itself, that’s when it starts to affect the body, especially your blood vessels. Blood vessels damaged by high blood pressure can narrow, rupture or leak. High blood pressure can also cause blood clots to form in the arteries leading to your brain, blocking blood flow and potentially causing a stroke. Repairing blood vessels is very a difficult process, but that’s why a Laser Varicose Vein Procedure is usually recommended when anything like this happens.
Two brands of chocolate were used which seem to differ in chemical and biological properties. Moreover, variations in cocoa bean processing can dramatically alter chemical composition of the final product. Fermentation, roasting, and alkali treatment, while improving flavor, reduce flavanol content. These two brands also purchase cocoa beans from several countries and they blend beans for their products.
So before we can start using dark chocolate as a lifestyle intervention for hypertension and prehypertension some question have to be resolved first. Is it an effect of brand, is their a dose and time dependent effect, what’s the optimal blood pressure measure method?
Until then, take care with dark chocolate
Egan, B., Laken, M., Donovan, J., & Woolson, R. (2010). Does Dark Chocolate Have a Role in the Prevention and Management of Hypertension?: Commentary on the Evidence Hypertension, 55 (6), 1289-1295 DOI: 10.1161/HYPERTENSIONAHA.110.151522
