Having dealt with hazards in food during a lifetime, it is always nice to be able to look at the benefit side. We all need good news stories. However, even good news stories can be deceptive. There is much fuss made over what is called superfoods, while the overall diet is more important. And scientists test individual food components in isolation reporting highly beneficial effects in unrealistic animal experiments that have no relevance to real life. Resveratrol that can be found in red wine is supposed to be heart protective, but will require daily consumption of many bottles of wine to reach an effective dose.
But dark chocolate seems to be the real thing with normal consumption amounts sufficient to be beneficial to health.
Not all chocolates are the same
Chocolate is made from cocoa solids (cacao), mixed with fat (cocoa butter) and finely powdered sugar to produce a solid confectionery. There are several types of chocolate, dark, milk and white, classified according to the proportion of cocoa solids used in a particular formulation.
Dark chocolate, also known as “bittersweet” or “semisweet” chocolate, contains little or no added sugar, but plenty of antioxidant flavonoids that contribute to the dark colour. More flavonoids means darker chocolate.
Dark chocolate has already been hailed for its positive effects on cardiovascular health and can help lower blood pressure.
Milk chocolate is not a good antioxidant source as milk binds to antioxidants in chocolate making them unavailable.
White chocolate contains no cocoa solids at all and therefore is not a good source of antioxidants.
Let’s look at the details
It is widely known that dietary nitrate leads to the substantial elevation of circulating nitrite, which is subsequently converted into bioactive nitric oxide. Bioactive nitric oxide relaxes blood vessels, increases glucose uptake and regulate muscular contraction. Dietary supplementation with nitrate rich beetroot juice has become increasingly popular in athletes and has consistently been shown to reduce oxygen demands during submaximal exercise allowing athletes to go further for longer.
Dark chocolate works a little differently. Cocoa beans contain a substance called epicatechin, a flavanol that releases vasoactive components from the endothelial cells in blood vessels increasing the bioavailability of nitric oxide. The increased bioavailability and activity of nitric oxide dilate blood vessels and increases blood flow, resulting in a reduction of blood pressure. Previous research have shown that as little as 6g per day can reduce mild hypertension, while around 40g per day can increase blood flow also in healthy patients.
Providing an edge
The previous findings have now been confirmed in a study undertaken at London’s Kingston University The scientists found that the tasty treat could help give sports enthusiasts an extra edge in their fitness training. They used a group of nine amateur cyclists. After undergoing initial fitness tests to establish a baseline for comparison, the participants were split into two groups. The first group was asked to replace one of its normal daily snacks with 40g of a dark chocolate for a fortnight, while the other participants substituted 40g of white chocolate for one of their daily snacks as a control.
The effects of the athletes’ daily chocolate consumption were then measured in a series of cycling exercise tests. The cyclists’ heart rates and oxygen consumption levels were measured during moderate exercise and in time trials. After a seven-day interval, the groups then switched chocolate types and the two-week trial and subsequent exercise tests were repeated.
After eating dark chocolate, the riders used less oxygen when cycling at a moderate pace and also covered more distance in a two-minute flat-out time trial.
All good news.
Benefits confirmed by EFSA
And the beneficial effects have been confirmed by the European Food Safety Authority.
The Belgian chocolate manufacturer, Barry Callebaut, has exclusive use of an existing authorised claim stating that cocoa flavanols “help maintain the elasticity of blood vessels, which contributes to normal blood flow”. The authorised conditions of use require the product label to state that 200mg of cocoa flavanols are needed for the beneficial effect. The current claim can only be used for cocoa beverages with cocoa powder or for dark chocolate which provides at least a daily intake of 200mg of cocoa flavanols.
There has been concern that authorising claims on products such as chocolate could encourage over-consumption. However, the EFSA Opinion states that the amount required for the effect can be eaten within the context of a balanced diet.
So as long as you keep within your normal calorie intake level, feel no guilt when indulging in some dark chocolate.