Category Archives: Science

“Healthy” Chocolate

Not all chocolate is created equal, and the kind that’s cheapest and easiest to get—sweet, highly processed bars—is the least likely to be beneficial.

The best option is plain cacao, either beans or nibs. The concentration of flavonoids, which seem to be generally beneficial, decreases with fermentation and roasting, so the closer you get to raw cacao, the better off you are. Flavonoids, in addition to promoting cardiovascular health, are very bitter, so you can use bitterness as a quick-and-dirty test for healthy cacao beans. It doesn’t work so well on sweetened chocolate, though, unless you know that the varieties you’re comparing have identical amounts of sugar.

If you get your chocolate in bars, you’ll want the maximum cocoa content. According to Chocolate and Health, “From experience, a dark chocolate containing about 2% flavanols [a subcategory of flavonoids] is really on the edge of being too bitter. Currently 70% cocoa chocolates only contain about 0.7% of flavanols because of heavy processing. The same chocolate would still be tasty with the flavanols content at least double.” This means that darker chocolates are often best. You can also look for makers that specify low roasting temperatures.

Because flavonoids are heat sensitive, their concentration changes when you cook or bake chocolate. There are a few tricks to maximize flavonoid content when cooking besides just keeping the temperature low. Cacao flavonoids survive best when cooked with minimal water and plenty of fat in high-density foods. For example, if you make a chocolate cake with cocoa powder it will lose more flavonoids than the same cake made with baking chocolate, which contains more fat. A dense brownie is preferable to a light, fluffy one.

If you’re cooking with cocoa powder, check whether it has been alkalized or “dutched.” This process was developed to help it dissolve better in water instead of clumping, but it can reduce the flavonoid content by over seventy percent. Alkalization may also affect the bioavailability of the flavanols that remain.

On “superfoods”

In recent years, the food industry has latched onto the term “superfood”—applying it to anything deemed nutritious, especially fruits and vegetables that are high in antioxidants. The chocolate industry has leapt onto the bandwagon, which isn’t entirely surprising. Throughout its history the fruit of the cacao tree has been hailed as magical and medicinal. While recent nutritional studies support the notion that chocolate may have beneficial effects as one component of a well-balanced diet, there’s little basis for some of the medical miracles attributed to it.

“Superfood,” like so many food labels (“natural” and “pure” come to mind) is a marketing term and nothing more. It has no regulated meaning or standard definition. Its purpose, as Tom Philpott, writing for Mother Jones Magazine, points out, is not to inform but to sell products. “People can only eat so much, and in industrialized countries where food is plentiful, they don’t tend to consume more of it as their incomes grow. . . . One way the industry responds to this stagnation is to roll out ‘new and improved’ products.” In some cases, those “new and improved” foods are the same old thing in fresh packaging, and that’s generally the case with “superfood” chocolate.

 

Special thanks to Joshua K. Endow, plant biologist, for sanity-checking this chapter!

 

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Chocolate and Laxatives

Apart from claims about the health value of cacao itself, chocolate has long been used as a flavoring for unpalatable medicines and vitamins.

One of those chocolate-flavored medicines is Ex-Lax. The active ingredient is senna, which is quite bitter, but sweetened chocolate helps it taste better. The only problem with chocolate-flavored laxatives is that people occasionally enjoy them a bit too much, and overdose on the potent laxative hidden under the tasty chocolate.

Recent research, however, indicates that chocolate may affect the gastrointestinal system in its own right. Cacao extract inhibits the activity of Escherichia coli and Vibro cholera in the intestine. While the amount of cacao in an Ex-Lax tablet may not have a substantial effect on our gut bacteria, this might corroborate the traditional Mesoamerican use of cacao to treat diarrhea.

Chocolate and Mood

Depending on who you ask, you might hear that “Chocolate appears to promote the neurotransmitter serotonin release as well, thereby producing calming, pleasurable feelings,” (Chocolate as Medicine).

Hernando Cortés, the Spaniard who took control of the Aztec empire, also noticed it’s stimulating effect, saying that “A cup of this precious drink permits a man to walk for a whole day without food.”

The general sense of positivity might come from biogenic amines like phenylethylamine or the cannabinoid anandamide, while theobromine is almost certainly the stimulant. There’s probably also a psychological component. Chocolate is associated with holidays and special events, love and happiness. Those associations inform the feelings we experience when we eat chocolate, in addition to whatever chemical effect it has.

The Bitter Aphrodisiac

illustration of madame de pompadour reading the joy of sex, winking, and licking chocolate off her lips
Madame de Pompadour

When first introduced to Europe, chocolate was hailed as an aphrodisiac—reportedly it was a favorite drink of Casanova. One account claims that Madame de Pompadour, a mistress to Louis XV, used chocolate to “become hot-blooded” when the king claimed she was a “cold fish.” Another report claims that the roles were reversed and Pompadour recommended it to the king, who was otherwise “cold as a dead duck.” Madame du Barry, the last official mistress to Louis XV, also provided chocolate to her numerous lovers.


If you want to improve your mood with chocolate, you should know that the effect probably won’t last. At least one researcher has found that while people enjoy anticipating and eating chocolate, that pleasure doesn’t negate depression and it is often followed by guilt.

Chocolate Headaches

Enough people report chocolate headaches and migraines that several epidemiological studies have been conducted, and cacao usually comes in fairly high on the list, following only stress, inconsistent sleep, menstruation, alcohol, and hunger.

That may sound like pretty clear evidence, but remember that epidemiological studies are usually based on self reporting. All it means is that if you ask people, lots of them will say chocolate causes migraines or headaches. When you get into the lab, the story changes. Double-blind studies, with control groups receiving a placebo instead of chocolate, reached very different conclusions. In those, participants who ate a carob-based placebo were just as likely to get headaches as those who ate real chocolate.

Why the discrepancy? It could have to do with small sample sizes. Even the largest double-blind headache study had only 67 participants. They may, through sheer bad luck, have gotten a disproportionately low percentage of people whose migraines are triggered by cacao. That theory is supported by some older, even smaller studies which only involved people who had already identified chocolate as a potential migraine trigger—they found a strong positive correlation between chocolate and headaches. So it’s possible that the large studies weren’t really big enough to accurately represent the population at large. It could also be that a few people get headaches from chocolate, and others just think they do.

If there are people who mistakenly believe that chocolate causes their headaches, they may have good reason for it. Stress and hunger are both common, well-known migraine triggers. People who are stressed or hungry are also likely to crave chocolate. The scenario would go: you’re stressed, so you’re craving chocolate, so you eat chocolate. Later on, you end up with a migraine because of the stress. It seems like chocolate was the cause, but if anything it was actually a warning of the impending headache.

There’s one more possibility. For some people, chocolate might be only part of the headache trigger. On it’s own, it may be fine. When combined with other factors like stress or sleeplessness, it could be the straw that breaks the camel’s back. This seems plausible, given the effects of the chemicals in chocolate. Theobromine and biogenic amines affect the nervous system. They also, like flavonoids, have an effect on blood pressure and heart rate. Since migraine headaches result from both neurological and vascular factors, it wouldn’t be surprising if chocolate has an effect on them.

Theobromine and Friends

Theobromine is to chocolate as caffeine is to coffee. Both, plus the theophylline in tea, are notable stimulants from the same chemical family, the methylxanthines. They have many effects on humans, but they’re best known for suppressing drowsiness—as anyone who has had a shot of espresso in the evening will know.

a chemical line drawing representation of a theobromine molecule
A theobromine molecule

Theobromine is a key part of chocolate’s molecular signature, occurring in only a handful of plants (tea, yerba mate, kola nuts, and a few others). Cacao also contains caffeine, so archaeologists look for the two together when identifying ancient Mesoamerican pottery that may have contained chocolate. Theophylline (the characteristic methylxanthine in tea) is present in cacao as well, though its concentration depends on the variety.

All methylxanthines are stimulants, but they may have slightly different effects. Caffeine, especially in large doses, tends to leave you wired and jittery. Theobromine has a weaker effect on the nervous system. It lowers blood pressure, which may be why chocolate is known for inducing general happiness. Theobromine’s stimulant effects may also be partially responsible for chocolate’s reputation as an aphrodisiac. Theophylline—present in cacao, but more often associated with tea—tends to increase blood pressure, and eases breathing. While the amount of theophylline in a cup of tea is too small to have a noticeable effect, in higher concentrations it is used to treat asthma and other respiratory diseases.

In addition to its role as a stimulant, theobromine has an effect on the respiratory system similar to that of theophylline. It has recently been tested as a cough suppressant, though theobromine-based cough medication isn’t yet available in most of the world. An initial trial suggested theobromine may actually be better than codeine as a cough suppressant, but there were only ten test subjects. The dose tested was around 1000mg, which you can get from as little as fifty grams (two ounces) of dark chocolate, depending on how it is processed and prepared. Full-scale clinical trials have been completed in both South Korea and the UK, but the results are not yet available. In early 2016 we checked with the lead researcher, Professor Alyn Morice, who said they are waiting to publish until the medication is ready to go before regulatory bodies.

Theobromine has one other notable effect: given a high enough dose, it is poisonous. While it’s usually very difficult to get a lethal dose from eating chocolate, people with certain genetic conditions may be far more susceptible. Other animals are much more suceptible to the effects of theobromine. It’s been used to poison coyotes and dope racehorses. It definitely affects dogs, cats, birds, pigs, and cows. Plenty of people have a dog who has gorged themselves on Hershey’s Kisses, but it doesn’t mean the dog is immune. It’s actually a reflection of the low cacao content in commercial milk chocolates. That same dog could be in serious trouble if they get their paws on a bar of 70% dark. Initial symptoms of theobromine poisoning include nausea and vomiting, as well as diarrhea, but severe cases can lead to seizures and heart attacks.

Dose that would kill 50% of dogs (LD50) Lowest dose known to have a toxic effect on humans (TDL0) Daily dose that is known to have a substantial negative effect on humans
Pure Theobromine 0.005 oz/lb 0.0004 oz/lb 0.016 oz/lb
Raw Cacao 0.16–0.32 oz/lb .01-.02 oz/lb 0.5–1 oz/lb
Dark Chocolate 1 oz/lb .09 oz/lb 3.5 oz/lb
Milk Chocolate 3 oz/lb 0.27 oz/lb 10 oz/lb

Table 1: Theobromine Poisoning Dosages

Based on the dosages in Table 1, some simple math tells us how much chocolate you (or your dog) would have to eat to be affected. Dosages are described by the quantity of poison per pound of body weight. Given, for example, the dose of dark chocolate needed to have a substantial effect on most people (3.5 ounces per pound) we can multiply by the weight of the average human (137 pounds) to determine that they would have to eat 477 ounces of dark chocolate, on a daily basis, to meet that level. Someone with a low tolerance for theobromine, however, could experience some effects after consuming only 12 ounces of dark chocolate—several large bars. It takes even less raw cacao to have the same effect. Milk chocolate’s theobromine content is about one third that of dark chocolate, so it takes far more to have a comparable effect.

Biogenic Amines

Literally, these are “amines produced by living organisms or biological processes,” and they show up all over the place in biological systems. In the human body, various biogenic amines serve as neurotransmitters regulating everything from sleep and appetite to motivation and addiction.
Some of the biogenic amines present in chocolate affect the vascular system, causing symptoms like blushing and blood pressure variations. It’s possible for their effects to be more severe, though, ranging from headaches to potentially-fatal cardiovascular shock. Fortunately, the quantity of biogenic amines in chocolate is small, though it may increase slightly with extra roasting.
Perhaps the best-documented single biogenic amine in chocolate is phenylethylamine, which triggers the release of dopamine and noradrenaline in humans. Some people think it is responsible for chocolate’s aphrodisiac effect, because dopamine is associated with infatuation and love. Others claim it may delay fatigue and increase stamina—something people have believed about chocolate since the early colonial era, if not before.
Some chocolate experts, however, argue that the amount of phenylethylamine in cacao is so minuscule that it’s effect on neurochemistry is negligible. So far, there doesn’t seem to be enough evidence to definitively sway the argument in either direction, and it’s complicated by the differences between individuals and the brain’s ability to acclimate to stimuli.
Another biogenic amine that could be responsible for the joy people derive from chocolate is anandamide. That’s because it is a cannabanoid compound; it activates the same receptors in the human nervous system as the THC in cannabis. It’s unlikely you’ll get high off chocolate, though—like phenylethylamine, anandamide shows up in chocolate in very low concentrations. If you try to reach an altered state of consciousness by eating cacao, you’ll probably only be conscious of a full stomach.

Nutrients and Antinutrients

Cacao is full of trace minerals and other nutrients. The exact mix varies depending on growing conditions, fermentation, and even grinding machinery. Unfortunately, cacao also contains numerous antinutrients: compounds that reduce our bodies’ ability to absorb things like iron and calcium from food.

On the one hand, chocolate contains copper, iron, magnesium, calcium, potassium, and zinc—all crucial, in small quantities, for our body. Some of those minerals come from the soil, but others may be deposited in chocolate by grinding machinery.

On the other hand, chocolate is high in antinutrients like flavonoids (yes, the very same beneficial chemicals from the previous section) and organic acids, which actually reduce nutrient absorption. As a result, it’s hard to tell what nutrients you’re really getting from chocolate.

Iron is a good example of this complexity. The iron in chocolate is more concentrated than chicken liver or beef. Unfortunately, chocolate—like all plants—contains mostly non-heme iron, which is less bioavailable than the heme iron in meat. So there’s plenty of iron in chocolate, but not all of it makes its way into your body. In addition, flavonoids and some organic acids can block iron absorption, so you’ll get even less iron from raw cacao or lightly-roasted chocolate. Not all organic acids block iron absorption, though; ascorbic acid actually assists with iron absorption.

Given the variability of cacao sourcing and processing, it’s very difficult to say for sure what nutrients you’ll ultimately get out of a given bean, let alone how your body will handle them.

Flavonoids: Chocolate and the Heart

Throughout history, chocolate has been touted as and aphrodisiac, a “pure food,” and a magical panacea. Today, when people talk about the health benefits of chocolate, they’re most often referring to recent research on flavonoids.

Flavonoids and phenols and catechins, oh my!

For this chapter, I’ll mostly stick to the term “flavonoids.” If you’re reading about chocolate elsewhere, though, the language can get complex.

When we talk about flavonoids in chocolate, we’re usually talking about catechin and epicatechin. (Some authors don’t mention epicatechin, since the two are isomers—they have the same atoms, just arranged differently.) Catechin and epicatechin are flavanols, which is a subcategory of flavonoids. Because flavonoids have multiple phenol groups, they are sometimes called by the even broader term polyphenols.

You may also encounter the word “antioxidant,” which is very general in a different way. All the previous terms describe chemical formulas and structures, but “antioxidant” refers to how a compound behaves in certain chemical reactions. Some antioxidants are flavonoids, but not all flavonoids are antioxidants.

There is some good evidence that flavonoids from chocolate may have beneficial effects on cardiovascular health, but it’s far from certain. The study that started research in that direction has recently been called into question, and the mechanisms by which cacao improves the human circulatory system are poorly understood.

Researchers were inspired to investigate the effect of chocolate on heart health when a study of the Kuna—people indigenous to South America who tend to eat large quantities of chocolate—revealed that they had an extremely low risk of cardiovascular disease. The exception to this rule was those Kuna who went to live in urban areas, and as a result consumed less cacao.

Since the initial Kuna findings, numerous studies have taken different approaches to verifying cacao’s effect on the heart and circulatory system. One found that older people with mild hypertension had lower blood pressure after 18 weeks of eating about 6 grams of dark chocolate per day. Another study evaluated nearly five thousand people in the US and found an “inverse correlation between chocolate consumption and the prevalence of cardiovascular disease.” Other studies in Germany and Sweden have had similar results. It seems fairly clear that eating a little cacao probably reduces high blood pressure and risk of stroke.

The reason for this probably has something to do with flavonoids’ antioxidant effect. Plant-derived antioxidants are often credited with miraculous healing powers, from curing cancer to reversing aging, because they can prevent certain types of cell damage. The flavonoids in cacao, however, don’t make it to most of the body. The only places they reach in any substantial concentration are the bloodstream and the gastrointestinal tract. So it’s unlikely that cacao flavonoids will reach skin, bones, or lungs, but they might actually have an impact on your blood and your heart—and at least one study confirms that within two hours of consuming 45 grams of dark chocolate, your blood cells are more resistant to oxidative damage than than they are after you eat flavonoid-free white chocolate.

Researchers have explored cacao flavonoids’ effect on all sorts of other things: skin health, cognitive function, insulin sensitivity, and cholesterol levels are among the more notable. It’s too soon to draw any conclusions, though, since most of those are exploratory studies. Moreover, some of the studies aren’t even using chocolate. They actually perform the tests with cacao extract, a concentrated flavonoid powder so bitter many people refuse to eat it.

Studies of cocoa flavonoids still refer back to the original Kuna findings as the first evidence that cacao reduces blood pressure. But in 2013, cultural geographer Jeffrey Barnes questioned that research. In visits to Panama, he noticed that the Kuna ate less chocolate than originally reported. Furthermore, they rarely consumed locally-grown cacao, preferring imported Colombian cacao that was lower in flavonoids. Whatever it is that keeps the Kuna in excellent cardiovascular health, there’s a good chance it has nothing to do with their cacao intake.

Chocolate’s Culinary Cousin by Amy Bugbee

What’s in my vanilla?

black and white illustration of vanilla vine climbing the trunk of a cacao tree
VANILLA VINE AND CACAO TREE

Natural Vanilla Flavor,” “natural flavor,” “and other natural flavors”—no doubt you have read these words on many a food label. Perhaps even on the ingredients label of a bottle claiming to be Pure Vanilla Extract. You may have even chosen this bottle of extract over the imitation stuff deeming it better. The truth is, neither Natural Vanilla Flavor or imitation vanilla have anything to do with a vanilla bean!

“Natural Vanilla Flavor” can be any number of naturally occurring substances according to the premier reference guide on the subject, a two thousand and some page book called Fenaroli’s Handbook of Flavor Ingredients, by George A. Burdock. Commonly, “Natural Vanilla Flavor” is made from lignin, a tarry brown byproduct from wood processing, and waste product of paper mills. It is used for a variety of industrial and agricultural applications, including cement making, and in addition to Vanillin, it’s used to make xylitol sugar!

Another substance used to create “Natural Vanilla Flavor” is castoreum, which is literally the castor sacs, or rather, glands from the nether regions of the furry, dam-building beaver, which they use to mark their territory. Of course flavor and scent makers claim proprietary rights, and would never consider putting castoreum on the label, they are protected by the umbrella of “Natural Vanilla Flavor.”

DIY vanilla extract

The real mystery here is why? Sure, the vanilla bean is expensive, growing and curing it is a long and arduous process, but—and this is a big but, a huge but—the vanilla bean can be used over and over and over again! In fact, you can extract vanilla from vanilla beans until the bean disintegrates, and that takes years!

If you decide to make your own extract—to avoid the lignin and the castoreum, and who would blame you?—Vanilla beans when treated properly in a mix of water and liquor can be used over and over again for years! And don’t let that be their first stop, make it their last, after you’ve cooked with it, infused with it, and any other use you can think of, a simple rinse and dry, and your magical vanilla bean is ready to go again!