A sports drink that tests suggest can increase performance levels by up to two percent will go on the market later this year. The key ingredients of the drink, marketed as DeltaG (pron: Delta Gee), are flavoured compounds called ketones which the drink's developers say, are particularly effective in enhancing performance in endurance athletes.
OXFORD, ENGLAND, UK (REUTERS) - DeltaG (Pron: Delta Gee) uses a flavoured organic compound known as an "ester" containing laboratory produced ketones, as its key ingredient. Ketones are also found in the human body as an acid which remains when the body burns fat.
DeltaG's inventor, University of Oxford Professor Kieran Clarke, has spent 20 years developing ketone-based drinks. She says ketones are an extremely efficient form of 'brain food' absorbed rapidly by most organs in the body and a valuable energy source, providing an effective means of increasing metabolic efficiency.
By including ketones in a sports drink, Clarke - who developed a ketone drink for the US army ten years ago - says ketone levels can be increased in a matter of minutes and so could be used by athletes as a source of energy, in addition to carbohydrates, fat, and protein.
"Over time when you haven't eaten you produce these ketones and it takes about seven days to two weeks, in fact, to bring the ketone levels up and we can get that same level within one drink," said Clarke.
When trying to work out the best way to increase ketone levels without fasting or using a high-fat diet, Clarke approached fellow Oxford scientist Jeremy Robertson to create an edible ester.
"We worked with chemists all around the world and eventually we found a chemist here in Oxford, just over the road - Jeremy Robertson - who actually developed a whole lot of esters for us, and then we tasted them, found the one that tasted the best, and went with that one," she said.
Clarke's PhD student Brianna Stubbs, an international rower who represents Great Britain, helped test the drink on athletes in the gym. Those tested on exercise bikes and rowing machines produced a significant improvement in performance.
The rower, whose work on DeltaG recently saw her awarded a prestigious 1851 Royal Commission Fellowship, said her own experience of using the drink was that it made exercise feel easier.
"One of the things that the drink does is it means you produce a lower level of lactic acid and that's part of the reason you get the burn, so if you're producing around two millimals less...if you're going for an hour and the normal amount of power that you produce you're producing less lactic acid then it feels a bit easier and you feel like you can keep going for longer," she said. "We can tell that when the body has ketone it's not choosing between its normal fuels, like it would normally. So the state of having supplemental ketones in the body is completely different to anything that anyone has seen before, because, as Kieran said, normally when you have ketones you're starving, so there isn't a choice between the other fuels. But with supplemental ketones your body still can choose the fats or carbohydrates if it wanted, so it's how ketones affects that choice."
An Under-23 World Champion in the LW2x (two-person lightweight sculling) category, Stubbs says the tests showed real potential for elite athletes like herself.
"In the study that I did the results were that on ketones people went two percent further, which is actually...it doesn't sound like much but in real world terms it's a really, really big effort and if you're at the top level of sport, then any change of that margin is going to be really significant, so that was quite exciting as well," she said.
Clarke and Stubbs admit that for some sports, such as sprinting, a ketone-based sports drink might not be much use, a view shared by leading British sports dietician Richard Miller.
"For endurance performance, so for marathon running or for triathletes or for anything that's sustained long endurance activity, ketones could be an interesting way of powering that performance because it's potentially a limitless energy supply, if somebody was using their own body fat for fuel, as an example. But for things like intermittent exercise, so our team sports like football or hockey or netball or something like that, or high-threshold activity like sprinting or bodybuilding or any sort of Olympic lifting that rely on glucose to power the exercise I think it's got limited potential," said Miller.
In addition to helping athletes, the product also has potential for helping with weight loss, according to Clarke. Tests on rats showed that when given the ketone compound, they ate less and put on less weight than a control group on the same diet. Subsequent trials on eight people with diabetes found that when they drank three ketone drinks a day in conjunction with their normal diet for a week, they lost two percent of their body weight, and had a drop in glucose, cholesterol and fat levels in the blood.
However, with the drink containing around 200 calories, Miller says that any use in weight-loss would have to be accompanied by a substantial reduction in food intake.
"For this drink it's about 200 calories per beverage. For somebody that's trying to reduce their calorie intake we tend to be able to recommend that people reduce calories from beverages, primarily from things like fizzy drinks or sugar-sweetened beverages we tend to reduce those straight away, because they don't tend to reduce people's appetite. Now the ketone drink apparently may have some appetite suppressing effects, so I think the jury's out really in terms of whether it would affect somebody lose weight or whether it would actually stop them making any progress because of the calorie value," said Miller.
According to official British medical advice website NHS Direct, ketogenic diets are linked to bad breath and constipation through lack of roughage. Increased ketone levels may also lead to kidney failure, osteoporosis, cancer and heart disease, but Clarke says those concerns are based on a misunderstanding. She says that our bodies have a parallel system designed to make use of ketones as an energy source, which is faster and more efficient than the way our bodies use glucose.
Clarke also believes the drink could also help treat childhood epilepsy, for which a high-fat ketogenic diet is used as standard treatment, and even Alzheimer's.
DeltaG ketones come in a thick, clear liquid that tastes very bitter, but this was overcome by adding water and flavourings. Drinks in orange, chocolate, coffee and raspberry/cranberry flavours have been deemed most palatable to volunteers and will go on the market in the US this year.