“Chocolate is the first luxury. It has so many things wrapped up in it: deliciousness in the moment, childhood memories, and that grin-inducing feeling of getting a reward for being good.” Mariska Hargitay
It all began about 3,000 years ago in prehistoric tropics of South America where the ancient Incas, Mayans, and Aztecs discovered a tree Theobroma Cacao and named it the "food of the gods.” They didn't quite know whether cocoa bean was food or medicine, so they used it for their rituals as a source of power and as currency.
That was until the Spanish conquered the Aztecs. When Cortez noticed that those who drank cocoa had more energy and focus, he decided to make it the foundation of his soldiers' diet. Cocoa beans were soon recognised as another treasure among the many stolen from the conquered Aztecs, and it would regularly make its way across the Atlantic - first to Spain, and then to the rest of Europe. By the end of 17th century, the new, delicious, chocolate beverage became more widely available in luxurious coffee and chocolate houses in London, Paris and Amsterdam.
In recent years, both large randomised placebo-controlled clinical trials and observational studies were looking at how dark chocolate may contribute to health outcomes.
An intriguing study comes from the researchers at Louisiana State University who simulated the human digestive system in glass vessels. One vessel represented the stomach and the small intestine, with their digestive enzymes, and the second one served as a large intestine-like environment, with gut microbes from human volunteers. The scientists then added cocoa powder to the stomach vessel.
It turned out that the artificial stomach and small intestine managed to break down and absorb some of the cocoa beans. Although many of the flavonols were digested this way, there was still plenty of undigested cocoa left. At this point gut bacteria in the artificial colon broke that down further into small molecules that were absorbed into the bloodstream. It turns out that in a real body, this process of flavonols absorption is associated with reduced cardiac inflammation.
Interestingly, when the last undigested cocoa matter, now mostly fibre, began to ferment, it also began releasing substances that lower cholesterol levels. Moreover, the gut microbes that digested the cocoa happened to be valuable probiotics like lactobacillus.
Their number increased after the introduction of the cocoa while the number of less useful microbes like staphylococcus dramatically declined. The study has proven that flavonols are associated with reduced risk of heart disease and cardiac inflammation.
A team of scientists from Australia did a curious experiment using a mathematical model to predict the long-term health effects of a daily dark chocolate consumption in people at high risk of heart disease. The researchers enrolled more than 2,000 participants with high blood pressure and diagnosed metabolic syndrome, but with no evidence of heart disease or diabetes.
The researchers have shown that in the best case scenario (100% compliance), eating up to 60 grams of dark chocolate a day could potentially avert seventy non-fatal, and fifteen fatal cardiovascular events per 10,000 people treated over ten years.
The number of non-fatal and fatal events potentially averted was fifty-five and ten per 10,000 people respectively even when compliance level went down to 80%, and could still be considered an effective intervention strategy.
A recently published study in the journal Heart was looking at how dark chocolate consumption may be linked to the frequency of cardiovascular events like heart attack and stroke. The data was coming from the EPIC-Norfolk study, tracking the impact of diet on the long-term health outcome of more than 25,000 people in Norfolk, England, using food and lifestyle questionnaires.
Nearly 21,000 adults were monitored for an average of almost twelve years. During this time, more than 3,000 people experienced either an episode of fatal or non-fatal heart attack or stroke. The researchers also reviewed available international published evidence on the links between chocolate and cardiovascular disease, involving almost 158,000 people. More than 80% participants said they ate about 7 grams of dark chocolate, with some eating up to 100 grams a day.
Higher levels of a daily intake were associated with a lower body mass index, waist-hip ratio, systolic blood pressure, inflammation marker (C-reactive protein) levels, lower risk of diabetes and more regular physical activity.
The results showed that a daily consumption of dark chocolate was linked to 11% lower risk of cardiovascular disease, 9% lower risk of hospital admissions, and 25% lower risk of cardiovascular death compared with those who didn't eat dark chocolate at all.
In the systematic review within the frame of the same research, five out of nine relevant studies assessing coronary heart disease and stroke outcome have shown that regular chocolate consumption was associated with significantly lower risk of both conditions.
Although it wasn't a randomised controlled trial and no definitive conclusions about cause and effect can be drawn, there was a strong association between eating up to 100 grams of dark chocolate a day and a lower risk of heart disease and stroke.
A well-controlled, randomised trial led by the neuroscientists at Columbia University Medical Center enrolled 37 healthy adults between the age of 50 - 69 and divided them into two arms. One group was asked to drink high - flavanols cocoa (a mixture high in antioxidants), another group was given a low-flavanols cocoa.
After three months, high-flavanols drinkers performed about 25% better on a memory test than those who drank a low-flavanols cocoa. On average, the performance of high-flavanols drinkers was similar to people two to three decades younger on the study’s memory task. Memory test is a useful pattern recognition tool that helps specify our basic memory skills like remembering where we left the keys or recalling someone’s name.
Researchers also noticed an increased function in an area of the brain’s hippocampus called the dentate gyrus, which has been linked to age-related memory change. However, there was no increased activity in another hippocampal region, the entorhinal cortex, which weakens early in Alzheimer’s disease.
This research has proven that antioxidants in dark chocolate improve some memory skills that people lose with age.
Many studies have linked flavanols, especially epicatechin consumption, to good health outcomes. Some scientists say that these antioxidants improve brain blood flow, others claim that they help so-called dendrites grow (dendrites are message-receiving branches of neurons in the brain).
All well-designed studies on dark chocolate refer specifically to cocoa, a natural compound of dark chocolate low in calories. Research doesn’t say that eating a chocolate bar a day improves our health. In fact, milk chocolate or candy bars are really bad for us. They don’t contain a lot of cocoa at all. Instead, they are high in sugar and rich in added highly processed ingredients that actually reduces the number of flavonols and possibly changes the responses of gut bacteria to the cocoa.
Cocoa’s biochemical effects on our body are extremely complex, and a cocoa-based pill is unlikely to appear on the market anytime soon. In the meantime, we can indulge in a piece of good quality dark chocolate or a few spoons of unsweetened cocoa powder to appreciate life even more.