Monday, June 4, 2007

For the love of....Chocolate. The health benefits and detriments of chocolate

One food that has derailed more diets than any other is probably chocolate. Whether it's birthday cake or that tempting chocolate bar at the grocery check-out, chocolate is always hard to resist. As a trainers and nutritionist, I often include it as a cheat food. "Only in moderation," I will tell my clients. Lately, there has been a lot of attention on chocolate. Should we believe the media hype surrounding the potential health benefits of this sinful food? Here’s the scoop on everything you ever needed to know about chocolate.

The idea that the sweetness of fruit is going to satisfy a chocolate craving is sometimes hard to believe. When the urge hits, there is very little that can be done to stop it until the only thing left of that Hersey's bar is the package. So why do we need it so bad?

There appear to be many reasons why chocolate seems to be so addictive. For example, the sugar in chocolate can increase the levels of the mood-boosting neurotransmitters: serotonin and endorphins. Chocolate also contains an amphetamine-like compound called phenylethylamine (PEA), which is generated in relatively high amounts in the brain when happy events occur (i.e., falling in love). Chocolate also contains caffeine (although not very much), which provides an energy boost and small amounts of a substance called anandamide that mimics the pleasurable effects of marijuana by binding to the same receptor sites on brain cells as the active ingredient in the plant. Even the aroma of chocolate may affect brain chemistry.

However, the addiction some people claim they have to chocolate is not nearly as strong as the urge for nicotine or other highly addictive substances. The sweetness, aroma and the melt-in-your mouth quality of chocolate makes it very appealing. Despite this, there is a real difference between being addicted to something (e.g. cigarettes, heroin) and just liking something a lot. Liking chocolate has both its positives and negatives.

Cocoa and chocolate products have been delicacies for centuries, but only recently have they been recognized as significant sources of phytochemicals with healthful effects. Chocolate and cocoa powders are derived from beans that contain hefty amounts of phytochemicals called flavonoids that are also found in fruits, vegetables, tea and wine. Flavonoid compounds are found almost exclusively in the plant kingdom, and it’s estimated that there are more than 4,000 of them. Various epidemiological studies have shown that populations consuming a diet rich in flavonoids (including foods such as wine, tea and certain fruits and vegetables) have lower rates of heart disease and stroke.

The specific flavonoids in chocolate receiving the most interest are the procyanidins, which are also present in apples and grapes. Both tea and red wine contain flavonoids called catechins. These catechins can bind together to make larger molecules called procyanidins that are present in the cocoa bean.

Some of the ways that chocolate’s flavonoids can be heart-healthy include:

Antioxidant Protection
Antioxidants fight free radicals, destructive molecules that are implicated in heart disease and other ailments like cancer. Flavonoids present in cocoa and chocolate may protect the heart by inhibiting the oxidation of the “bad cholesterol” called LDL (oxidized LDL is much more likely to result in the formation of plaque on the artery wall). Studies have shown that as the amount of chocolate flavonoids in the blood increases, there is a corresponding decrease in the markers associated with oxidation damage. In addition, the antioxidants in cocoa and chocolate may help spare other antioxidants such as vitamin C and E, which allows them to act longer to fight off foreign invaders.

Reduced Platelet Activity
Some studies indicate that after consuming flavonoids in chocolate, there is a decrease in markers associated with platelet aggregation and adhesion (stickiness of the blood/blood clotting). Both platelet aggregation and adhesion are associated with a higher risk of plaque formation on the artery wall. As plaque formation increases, so does the risk of a heart attack by blocking flow of blood to the heart. Thus, chocolate can almost have an aspirin-like effect.

Relaxation of Blood Vessel Wall
Cocoa and chocolate flavonoids may protect the heart by increasing concentrations of a substance called nitric oxide that relaxes the inner surface of blood vessel walls. This has the effect of increasing dilation of the arteries, which improves blood flow and heart functioning. This function of cocoa and chocolate may help those who have high blood pressure. In fact, a small study found that dark chocolate lowered blood pressure in those with hypertension.

Researchers found that 15 days of dark chocolate intake improved insulin sensitivity (increased glucose uptake). Nitric oxide bioavailability deeply influences insulin-stimulated glucose uptake, and flavonoids present in dark chocolate and cocoa increase nitric oxide bioavailability. This same study saw a reduction in blood pressure among dark chocolate participants.

Reduced Inflammation
Research reported found that procyanidins (flavonoid found in the cocoa bean) can reduce blood levels of leukotrienes, which are a pro-inflammatory substance. This has positive effects on the immune system. In addition, this benefit could help protect the heart as inflammation in the lining of the artery walls is believed to be part of the damaging process that leads to cardiovascular disease.

The well publicized healthy properties of chocolate have lead many to believe they can enjoy chocolate in all its many forms. Not so! While the exact amount of cocoa or chocolate needed daily to exert health benefits is still yet to be determined, some studies have needed up to four ounces of antioxidant rich chocolate per day to elicit positive outcomes. Considering that an ounce of chocolate has roughly 145 calories and eight to ten grams of fat, if most people simply added this much chocolate to their existing diets, it would be detrimental to achieving their fitness goals. Individuals should be encouraged to substitute good-quality chocolate for other less healthy treats such as donuts, muffins and candy.

Also, all the studies showing promising health benefits from chocolate have used dark (“bittersweet”) chocolate and not the overly processed milk chocolates full of sugar that most people are consuming. Many find the taste of dark chocolate to be too overpowering and thus opt for the higher sugar forms with a lot less flavonoids.

To know which forms of chocolate are best as a treat or satisfy those cravings, here is a simple guide you can use:

1. Cocoa
Pure cocoa is the best type of chocolate substance to consume since it’s the richest source of flavonoids and contains none of the added sugar and fat present in processed chocolate. Cocoa is made when chocolate liquor (the ground up center of the cocoa bean) is pressed to remove much of the cocoa butter. It is virtually calorie free. Cocoa powder can be added to smoothies, oatmeal and plain yogurt.

When purchasing a cocoa powder, make sure the only ingredient is cocoa powder (unsweetened cocoa). To preserve the flavonoids, it’s wise to look for a brand that uses non-alkaline processing. Alkalized cocoa is also known as “dutch” cocoa. This process, which increases the pH of the product, has a negative impact on flavonoid levels.

Carob powder comes from the dried pods of the carob tree. Although research has found that carob does contain relatively high amounts of antioxidants, its impact on heart health has yet to be studied to any great length.

2. Dark Chocolate Over Milk Chocolate
Dark chocolate contains up to twice as much antioxidants as milk chocolate. Milk chocolate, which is made when dry milk is added to sweetened chocolate, contains more milk and less chocolate liquor than dark chocolate. In fact, the major problem with milk chocolate is that the first two ingredients are often sugar and milk, leaving less pure chocolate and therefore less flavonoids.

In addition, research has found that the addition of milk to dark chocolate may cause chemical bonds to form between milk proteins and antioxidants in chocolate, thereby inhibiting the absorption of antioxidants into the body. However, this is a finding that has yet to be fully proven.

If cocoa, cocoa solids or chocolate liquor (the ground up center of the cocoa bean) is the first ingredient, then you know you are getting a lot of chocolate and less sugar. Chocolate bars with at least 70 percent cocoa can be considered “dark chocolate” and will have more flavonoids and less sugar. A bar that lists sugar as the first ingredient will contain less than 50 percent cocoa.

So there you have it folks. The skinny (and fat) on chocolate. It has it's pro's and it's con's. Just like pretty much everything in life, "Only in moderation" is still the motto to follow. Don't deny yourself the indulgences of chocolate, but don't over do it either. Otherwise, you'll have a lot of working out to do to make up for it.

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