Antioxidants in Chocolate
Points in this Section:
- The cacao bean possesses a tremendous variety of anti-oxidant compounds.
- Cacao's primary class of anti-oxidant is the flavanol class.
- Flavanols possess anti-inflammatory/anti-oxidant/anti-bacterial/anti-viral properties.
- Flavanols can also act like hormones, normalize blood platelet clotting, relax blood vessels and fight different forms of dementia.
- Anthocyanins, catechins and epicatechins are also powerful compounds capable of fighting free radicals and protecting the body's tissues and cells.
Free radicals and the damage they cause are linked to dozens of diseases, including dementia, diabetes, heart disease, stroke, arthritis, cataracts, autoimmune dysfunction, asthma, and inflammatory digestive disorders.
- Anti-oxidant nutrients work at a cellular level to protect cells from free radical damage.
Antioxidant Connection: The Antioxidant Components of Chocolate
Numerous reports have found that the cocoa bean has a wide range of phytonutrients. Phytonutrients are compounds found in plants (phyto means "plant" in Greek) and have become a very exciting and promising area of scientific research.
Among cocoa's most important phytonutrients are several classes of polyphenols, which are largely recognized as some of the most powerful antioxidant and anti-inflammatory compounds known today. Polyphenols can be found in a variety of fruits and vegetables ranging from onions to apples, green tea, red wine and cocoa. Polyphenols comprise multiple categories, including phenolic acids, simple phenols, phenylpropanoids, quinines, stilbenes, xanthones, and the largest group-flavonoids (also called bioflavonoids). F1avonoids, which make up about two-thirds of the polyphenol family, include 6 subclasses (their principal food sources are listed as well):
- flavones: sweet red peppers, celery, hot peppers
- flavonols: onions, apples, red wine, green tea, tomatoes, berries
- flavanone: citrus fruits
- flavanol (flavan-3-0Is): cocoa, chocolate, green tea, grapes, apples, red wine
- isoflavones: soybeans, legumes
- anthocyanidins: cranberries, raspberries, acai berries, blueberries
The subclass of flavanol is further broken down into catechins and epicatechins, and if several of the catechins and epicatechins are hooked together they are called proanthocyanidins or procyanidins.
Generally speaking, flavonoids are among the compounds that provide plants, vegetables and fruits with their color - with reds, purples, and blues being the most prevalent. In plants, flavonoids help provide protection from disease, ultraviolet rays and other predators. Flavonoids and other compounds in plants affect taste, color, bitterness and other attributes. Substantial evidence exists suggesting that the darker the compounds in plants affect taste, color, bitterness and other attributes. Substantial evidence exists suggesting that the darker the skin of a fruit is, the more antioxidants it contains. The same is true with chocolate – the more bitter the cocoa is, the more anti-oxidant compounds, (like flavonoids) it contains.
Flavonoids are an impressive group, with abundant research demonstrating they possess anti-inflammatory, anti-oxidant, anti-bacterial, anti-cancer, and anti-viral properties. They also have the ability to act like hormones (without the damaging side effects), protect and repair the liver, relax and dilate the blood vessels, modify blood platelet clotting, maintain mental function, lower the risk of different forms of dementia, fight cancer, prevent tooth cavities and other forms of oral disease, and relieve allergy symptoms, among other benefits.
Anthocyanins are another group of flavonoids that provide powerful nutritional benefits. They act as antioxidant and anti-inflammatory agents, and possess hypoglycemic properties that help the body utilize sugars efficiently, thereby normalizing blood sugar levels. This translates into a lower risk of type 2 diabetes and possibly a reversal of a diabetic state. Because of their ability to lower sugar loads and fight free radicals, anthocyanins can halt free-radical damage of the eyes and extremities where diabetes tends to attack most. What's unique about these compounds is that they not only prevent small blood vessel damage, but also repair damage once it has occurred. In addition, anthocyanins are competent histamine blockers helping to prevent the inflammation associated with allergies, cardiovascular disease, arthritis, and stomach ulcers.
Catechins and epicatechins are another component of chocolate's disease fighting arsenal. These compounds, which are becoming well-known because of their abundance in green tea, are generating much excitement because of their ability to fight cancer.
They do this in 3 different ways. First, they can prevent the formation of carcinogens; second, they turn up the body's natural detoxification defenses; and finally, they suppress cancer promotion.
Animal studies have shown that catechins have other promising qualities as well: acting as antibacterial and antiviral agents, regulating cholesterol and blood pressure, and reducing blood clotting tendencies that may cause heart attacks or strokes.
Epidemiological studies focusing on green tea consumption (and thereby catechin consumption) aren't yet conclusive, but the results that are in, suggest those populations that drink more green tea live longer than those that don't.
Of course, there are many other classes of polyphenols and phytonutrients, some of which are contained in chocolate. While there is still much research to be done, that which is already completed is painting a very positive and promising picture of the health benefits of these amazing compounds.
Antioxidants: A Brief Explanation
Antioxidants are chemicals that fight oxidative damage resulting from free radicals. They add an electron to the unstable free radical molecules, thereby neutralizing them before they can damage a healthy cell. Antioxidants protect other chemicals of the body from free radicals and other reactive oxygen species in the body.
Antioxidants work in 4 different ways: chain-breaking reactions, reduction of reactive oxygen species, scavenging and trapping free radicals, and chelating certain damaging metals.
There are various types of antioxidants, ranging from enzymes like superoxide dismutase (SOD) and glutathione peroxide; vitamins like alpha tocopherol (vitamin E), beta-carotene (vitamin A), and vitamin C,or phytonutrients like the polyphenols (flavanols and catechins) found in cocoa.
Why Are Free Radicals So Dangerous?
No matter how healthy we are or what kind of environment we live in, our body is exposed daily to a cellular process called oxidation. The same oxygen we breathe to live also puts our cells at continual risk because of oxidation, the same process that causes iron to rust, fats to go rancid, and a piece of banana to turn brown.
When it comes to the human body, oxidation causes damage to healthy human tissues on a cellular level. Over time, this damage results in what we generally call aging and can put our health at risk.
When referring to oxidative damage, we typically refer to something called "free radicals." Free radicals, or oxidants, are a natural by-product of cellular metabolism, a beneficial bodily process needed to, among other things, fight infections, convert glucose into energy and even build muscle mass.
These natural by-products, or free radicals, are unstable and highly reactive in the body. Stated basically, free radicals are unstable molecules because they lack an electron and are constantly scavenging other healthy cells for a replacement electron. Experts estimate that every cell experiences 10,000 free radical attacks each hour of every day. If that sounds serious, it is. Unless these scavengers are neutralized, they may succeed in stealing electrons from healthy human cells, leaving those cells damaged and unstable --- creating a chain reaction of dangerous cell mutations. DNA damaged by free radicals can cause cells to replicate incorrectly (or not at all), interfering with proper cell function and often resulting in cell death. Over time, these mutations cause aging and may lead to cancer and other forms of chronic disease. It has been estimated that more than 200 diseases are associated with free-radical damage and oxidative stress.
To make things worse, many of us today are exposed more than ever to above average levels of free radicals due to environmental toxins.
Sources of free radicals include cigarettes, alcohol, environmental chemicals and pesticides, contaminants in our air and water, antibiotics in dietary meat and dairy products, radiation, high-fat diets, sunlight exposure and even exercise. While it is normal to experience some free radical production in the body, the effects of this particular brand of free-radical damage, or oxidative stress, can be devastating. Our ability to fight free-radical damage also decreases with age and can be affected by our stress levels, overall mental and physical health, sleeping habits, diet and other lifestyle factors.
Protection from the dangerous oxidative and carcinogenic effects of free radicals is available in the form of antioxidants -compounds found in various natural food sources, typically plants. Antioxidants work on a cellular level to deactivate free radicals in the body, neutralizing their effects and preventing cell damage, thereby reducing your risk for disease and slowing the aging process.
Science Spotlight: Cocoa's Antioxidant Power
Various studies demonstrate the ability of cocoa to neutralize free radicals and minimize their damage, which is strongly linked to a variety of diseases.
In a 2007 study published in JAMA, German researchers found that 44 volunteers with high blood pressure experienced a significant drop in blood pressure after including small amounts of dark chocolate in their diet for 18 weeks. The researchers also noted that the production and availability of nitric oxide, a key cardio-friendly compound, was also increased in the participants.
Another study from scientists at University of California, Davis, demonstrated that cocoa polyphenols (epicatechins, catechins, and procyanidins) were able to protect blood cells from oxidative stress caused by free radicals.
What Antioxidants Do for Us
The importance of the protection anti-oxidants offer may be immeasurable. Statistics demonstrate that even modest anti-oxidant intake can substantially reduce the risk of numerous health conditions and lower unnecessary health care costs. In spite of this, however, most of us don't consume enough dietary antioxidants, found in certain fruits, vegetables and nuts, to get even minimum protection.
Nevertheless, antioxidants are arguably one of the best ways to prevent disease, slow the aging process and promote overall wellness. If we are not getting the antioxidants we need from our normal diet, supplementation offers a great option to replenishing the free radical protection required.
The antioxidant potential of chocolate is such that it may offer one of the highest potencies among the antioxidant-rich foods discovered to date.
Types of Free Radicals in The Body
The most important free radicals in the body are derivatives of oxygen, better known as reactive oxygen species (ROS). They include:
- O2.- superoxide radical
- ROO. peroxyl radical
- 102 singlet oxygen
- ONOO- peroxynitrite
- OH hydroxyl radical
- H2O2 hydrogen peroxide
- NO. nitric oxide
- HOCL hypochlorous acid
Chocolate: An Antioxidant Powerhouse
Obviously, we've already discussed the importance of antioxidants and how chocolate is an excellent food source of antioxidant nutrients. But it doesn't hurt to repeat it again-chocolate is an anti-oxidant powerhouse.
A recent article highlighted the research completed by Dr. Chang Y. Lee, Chairman of the Department of Food Sciences and Technology at Cornell University. In their work, Dr. Lee and his team discovered that a cup of cocoa contains nearly twice the anti-oxidants of a glass of red wine and up to three times those found in a cup of green tea, both of which have received copious amounts of praise from the scientific arena, as well as the media.
Regarding the findings, Dr. Lee states, "I was surprised to find that cocoa has more than twice the phenolic compounds as red wine and three times the amount in green tea. Before the study began, I expected that cocoa would have levels in the same range as green tea." The results obtained from Dr. Lee and his Cornell University team are typical of what researchers around the world have found in their work.
One of the best and most reliable ways to determine the potency of anti-oxidant-rich foods is through a relatively new testing system commonly known as the ORAC test, which stands for "oxygen radical absorbance capacity". Research using the ORAC testing model (and related models) has uncovered broad-spectrum anti-oxidant capability in cocoa. In fact, the results of these tests have been so impressive that they have grabbed the attention of many researchers worldwide.
For instance. the USDA and Journal of the American Chemical Society recently published data showing that chocolate's ORAC scores were much higher than other well-known anti-oxidant-rich foods such as blueberries, grapes, raisins and prunes. In fact, dark chocolate received a score of 13,120, which is about five times higher than the ORAC value for blueberries and 10 times that of raspberries.
And as shown earlier, cocoa has been found 10 contain various types of anti-oxidant compounds, ranging from anthocyanins to catechins to vitamins E and C. Many experts feel that having a broad spectrum of anti-oxidant constituents allows the body to fight more health conditions and to provide an overall array of defense against free radicals.
There are numerous studies supporting the idea that chocolate is one of the most anti-oxidant-rich foods discovered to date. For instance, the aforementioned study by Dr. Chang Lee and a team of researchers from Cornell University found that dark chocolate contains more than twice the phenolic compounds of red wine and 3 times the amount in green tea, both of which are well known for their free-radical fighting abilities. Another study, which was published in Free Radical Biology and Medicine, discovered that a cocoa beverage was able to lower the blood levels of isoprostanes, a substance that commonly indicates there is stress-induced oxidation occurring in the body. The researchers point to the cocoa’s flavanols as the anti-oxidant factor responsible for fighting the harmful effects of stress.
Findings from researchers in Switzerland found that eating dark chocolate on a regular basis can protect smokers from free radical damage in the arteries caused by smoking. Typically, the cells lining the blood vessels, as well as the blood platelets themselves, are irritated by toxins from cigarette smoke, which eventually makes the blood vessels harden and become narrower. The risk of blood clots is raised dramatically in smokers. The research, which was published in the journal Heart (Corti, 2005), revealed that regular consumption of dark chocolate “improved both endothelial [cell] and platelet function.” The researchers stated that the benefits were measurable in the subjects within a mere few hours after the initial consumption and went on to explain that the “beneficial effect of chocolate is probably explained by its potent anti-oxidant properties.”
Because chocolate’s anti-oxidant activity is key to its ability to fight so many conditions, the following sections will also highlight more research confirming its ability to fight free radicals.
Procyanidins: Well-Absorbed and Well-Used
With various studies linking flavonoid-rich cocoa consumption to a reduced risk of cardiovascular disease and other conditions, the question is raised as to whether the procyanidin content of cocoa plays a pivotal role in its health benefits. In 2002, researchers from the University of California Davis, as well as Emory University and the University of Buenos Aires, investigated whether or not the procyanidins could be detected in human blood after consumption of flavanol-rich cocoa. The results were much in line with other studies, showing that "procyanidins can be detected in human plasma as early as 30 minutes after the consumption of flavanol-rich foods."
Cell Signaling: Another Weapon in Cocoa's Arsenal?
Emerging research is suggesting that the disease-fighting capabilities of flavonoids stems not so much from an antioxidant action, but rather from their ability to act as signal molecules to positively affect other cells. One review, authored by researchers from King's College in London, determined that dietary flavonoids, like the ones contained in cocoa, found that the cell-signaling action of flavonoids was just as likely a source of their health benefits as their antioxidant action.
Most functions of the human body take place through pathways or signaling cascades (signal transduction), like a docking station or a key-lock mechanism. A specific and special molecule (protein or lipid) travels throughout the body and finds a recepror on or in a cell. Hooking itself to that receptor like a key in a lock, it can then turn off or turn on the next function. These multiple complex steps (cascade or pathway) affect the cell function and control most of what makes our bodies work. These molecules are called protein kinases or lipid kinases (over five hundred types). These pathways deal with cancer, inflammation, neuro-degenerative diseases, and proliferative disease. Cocoa flavonoids have the potential to be like protein kinases, binding themselves to the receptors, either activating a pathway or inhibiting a pathway. Oxidative stress definitely impacts these pathways, causing cell proliferation or cell dysfunction. Scientists believe the cell protection actions of cocoa flavonoids are based on their interaction with the signaling pathways.
It has been shown that epicatechin has strong cell protection benefits against oxidative stress in neurons (nerve cells) and fibroblasts (cells that make muscles and connective tissue). Not only do the flavonoids provide anti-oxidant protection, they also protect those cells through these pathways.
This process of cell signaling is becoming a major area of research because of the impact these pathways have on most every disease. Flavonoids are just starting to be examined in terms of protein kinases and will be found to be a major contributor to the many benefits of cocoa.
The Nitric Oxide Link
One of cocoa's most important effects on the body is that it appears to stimulate and enhance the production of nitric oxide (NO). Nitric oxide is essentially a signaling molecule that helps control a range of processes in the body. Research papers continue to accumulate, providing an increasingly promising picture of NO's biological activity and potential clinical uses as a compound that controls a seemingly limitless range of functions in the body. The research shows that NO is involved in the processes and functions governing the activities of the brain, heart, blood vessels, lungs, liver, kidneys, gastro-intestinal tract, reproductive system and other organs.
One of the most intriguing of NO's benefits centers around its apparent involvement in dilation of blood vessels This is important for the health of the vascular system, the heart, the brain and the male genital organs. In fact, Nobel Prize-winning research has centered on NO's effect on the vascular system, and the hugely popular drugs that treat erectile dysfunction operate on the mechanism behind NO's benefits.
The immune system also uses nitric oxide in fighting viral, bacterial and parasitic infections, as well as tumors. It is a mediator of inflammatory conditions (another emerging area of interest for scientists and health professionals) and is necessary for the processes involved in learning, memory, sleep and pain.
- As mentioned earlier, chocolate's wide-ranging benefits are due to a variery of nutrients and compounds.
- Its anti-oxidant power is a big factor in chocolate's health-promoting abilities. In fact,chocolate can contain several times more antioxidants than other traditional antioxidant-rich foods such as red wine, blueberries and green tea.
- Several studies suggest cocoa may be the most antioxidant-rich food discovered to date.
- Studies show that the procyanidins and other antioxidants in cocoa are well-absorbed and available for use in the body after they are consumed.
- Cocoa uses cell-signaling to bring about its disease-preventing and health building benefits. Cell-signaling is a complex yet powerful mechanism that affects nearly all the processes occurring in our bodies.
- Chocolate stimulates the production of nitric oxide (NO), a signaling molecule that controls a range of processes in the body, including that of relaxing blood vessels.