Can Chocolate be Good for You? The Dark and Light Side of the Force

By Jesica Levingston Mac leod, PhD

It is this time of the year again: San Valentin (aka Valentine’s Day) –  the best excuse to give and more importantly to EAT a lot of chocolate. But, maybe a better gift that receiving chocolate,  is to know that eating chocolate might be good for your health.

In the beginning chocolate was “created” as a medicine –  a healthy beverage –  around 1900 BC by Mesoamerican people. The Aztecs and Mayas gave it the name of “xocolatl”, it means bitter water, as the early preparations of the cacao seeds had an intense bitter taste. Almost one year ago, a longitudinal study, done in the US East Coast, connected eating chocolate with better cognitive function. Yay! Great news, right? The scientists gathered information over a period of 30 years (starting in 1976) from 968 subjects (aged 23-98 years) in the Syracuse-Maine area. The results showed that more frequent chocolate consumption was meaningfully associated with better performance on the global composite score, visual-spatial memory and organization, working memory, scanning and tracking, abstract reasoning, and the mini-mental state examination. Importantly, they pointed out that with the exception of working memory, these relations were not attenuated with statistical control for cardiovascular, lifestyle and dietary factors across the participants.

More good news arrived last summer: an Italian research team announced that flavanol-rich chocolate improves arterial function and working memory performance counteracting the effects of sleep deprivation. The researchers investigated the effect of flavanol-rich chocolate consumption on cognitive skills and cardiovascular parameters after sleep deprivation in 32 healthy participants, who underwent two baseline sessions after one night of undisturbed sleep and two experimental sessions after one night of total sleep deprivation. Two hours before each testing session, participants were assigned to consume high or poor flavanol chocolate bars. During the tests the participants were evaluated by the psychomotor vigilance task and a working memory task, systolic blood pressure (SBP) and diastolic blood pressure (DBP), flow-mediated dilation and pulse-wave velocity. As you might know, sleep deprivation increased SBP/DBP. The result was that SBP/DBP and pulse pressure were lower after flavanol-rich treatment respect to flavanol-poor treatment sleep deprivation impaired flow-mediated dilation, flavanol-rich, but not flavanol-poor chocolate counteracted this alteration. Flavanol-rich chocolate mitigated the pulse-wave velocity increase. Also, flavanol-rich chocolate preserved working memory accuracy in women after sleep deprivation. Flow-mediated dilation correlated with working memory performance accuracy in the sleep condition.

The European Food Safety Authority accepted the following statement for cocoa products containing 200 mg of flavanols: “cocoa flavanols help maintain the elasticity of blood vessels, which contributes to normal blood flow”. This statement means that flavanol-rich chocolate counteracted vascular impairment after sleep deprivation and restored working memory performance. In another study led by Columbia University Medical Center scientists,  dietary cocoa flavanols—naturally occurring bioactives found in cocoa—reversed age-related memory decline in healthy older adults. One possibility is that the improvement in cognitive performance could be due to the effects of cocoa flavonoids on blood pressure and peripheral and central blood flow. Following on this other chocolate attribute, it was shown than weekly chocolate intake may be beneficial to arterial stiffness.

But, there are some bad news!  A review of 13 scientific articles on this topic, provided evidence that dark chocolate did not reduce blood pressure. However, the reviewers claimed that there was an association with increased flow-mediated vasodilatation (FMD) and moderate for an improvement in blood glucose and lipid metabolism. Specifically, their analysis showed that chocolates containing around 100 mg epicatechin can reliably increase FMD, and that cocoa flavanol doses of around 900 mg or above may decrease blood pressure if consumed over longer periods: “Out of 32 cocoa product samples analyzed, the two food supplements delivered 900 mg of total flavanols and 100 mg epicatechin in doses of 7 g and 20 g and 3 and 8 g, respectively. To achieve these doses with chocolate, you will need to consume  100 to 500 g (for 900 mg flavanols) and 50 to 200 g (for 100 mg epicatechin). Chocolate products marketed for their purported health benefits should therefore declare the amounts of total flavanols and epicatechin”.  The method of manufacturing dark chocolate retains epicatechin, whereas milk chocolate does not contain substantial amounts of epicatechin.

The first epidemiological “indication” for beneficial health effects of chocolate were found in Kuna natives in Panama with low prevalence of atherosclerosis, type 2 diabetes, and hypertension. This fact correlated with their daily intake of a homemade cocoa. These traits disappear after migration to urban and changes in diet.

 

There are many  claims about the potential health benefits of chocolate, including anti-oxidative effect by polyphenols, anti-depressant effect by high serotonin levels, inhibition of platelet aggregation and prevention of obesity-dependent insulin resistance. Chocolate contains quercetin, a powerful antioxidant that protects cells against damage from free-radicals. Chocolate also contains theobromine and caffeine, which are central nervous system stimulants, diuretics and smooth muscle relaxants, and valeric acid, which is a stress reducer. However, chocolate also contains sugar and other additives in some chocolate products that might not be so good for your health.

 

Oh well, maybe the love of chocolate is like any other romantic affair: blind and passionate. Apparently, the beneficial dosage is 10 g of dark chocolate per day (>70% cocoa), so enjoy it as long as the serotonin boost for rewarding yourself with a new treat last.

 

Happy Valentine’s Day!

 

 

Sexy Science: How Aphrodisiacs Work

 

By Chris Spencer

This Valentine’s Day, you may find a stunningly beautiful person staring at you with the piercing gaze that only comes from a feeling of pure, unadulterated lust. You then may notice that person’s look of longing slowly morph into a visage of confusion and dismay. The reason they look so dejected is that you clearly aren’t mentally undressing them. You’re lost in thought, trying to work out exactly what it is about oysters that seems to get everyone going. If I were you, I’d satiate my scientific curiosity now, and focus on a different form of satisfaction on Valentine’s Day.

Nutmeg

Using studies in rats, nutmeg has been proven to enhance sexual desire. In fact, reading the study lead me to one of my favourite scientific phrases; “feeding nutmeg increased mountings onto females.” It is as clear cut as that ladies and gents. The probable mechanism nutmeg more than likely stems from its nerve stimulating properties, so grate some onto your risotto on the big night.

Spanish Fly (Lytta vesicatoria)

If like me, you’re a fan of the 1987 Beastie Boys classic “Brass Monkey,” then you’ll be aware of the aphrodisiac potency of the Spanish fly. The beetle secretes cantharidin when threatened – a toxin which is toxic to humans in high enough doses. Despite this, people have been grinding Spanish fly up and putting it in peoples’ drinks for at least 2000 years. The toxin inhibits phosphodiesterase and protein phosphatase activity and stimulates a mild urethral irritation that can lead to priapism (a sustained erection of the penis or clitoris). This one seems to be a difficult one to administer safely, so maybe give it a wide berth. I certainly don’t condone spiking anybody’s drink with it.

Red Wine

That leads me neatly onto alcoholic beverages, specifically red wine. Red wine is a double whammy in terms of getting you in the mood. The high concentration of phenolic compounds such as resveratrol and tannins are present in numerous traditional aphrodisiacs, and they have been shown to increase blood flow to your danger zone. This is another compound which has been shown to make rats mount other rats under experimental conditions. The other side of the coin with red wine is alcohol. Of course alcohol relaxes you, and if you’re with someone new (or trying something a bit new) – that feeling of relaxation may well be vital. Don’t get carried away though, or you gentlemen might find that priapism won’t feature on your list of problems.

Chilli Peppers

The erotic component of hot chillies is capsaicin, a molecule which fools our thermoreceptors into thinking it’s hot. Capsaicin works in two ways: not only does it release endorphins to stimulate a mild euphoria, but it increases circulation and speeds up metabolism, which are similar responses to those experienced during sex.

This one comes with a caveat. If you’re preparing any spicy dishes yourself, take it from me, you’ll probably want to wear gloves while you’re chopping the chillies. There are a couple of rather intimate mucosa that you probably don’t want to get capsaicin anywhere near. “Burning loins” are just a figure of speech, you should endeavour to keep it that way.

Chocolate

That is right, chocolate has done it again. The pharmacologically active substances in chocolate are phenylethylamine, which reportedly enhances pleasurable sensations in the brain and affects serotonin and endorphin levels, and N-acylethanolamines, which may activate cannabinoid receptors to increase tactile sensitivity. Pass the dessert.

Symbolic Aphrodisiacs

A fair number of reported aphrodisiacs don’t actually have a proven mechanism of action. Examples such as the avocado (avocado comes from the Aztec word for testicle tree) and the banana are pretty much just phallic symbols. Oysters are used primarily because of their association with the Aphrodite herself.

That’s not to say that these foods won’t get you going of course. If you and your partner sit down to a candlelit dinner of oysters, then I’d imagine you’ll both know it’s on.