Functional Drinks And Sports Nutrition

A European perspective.

By Joerg Gruenwald and Janine Freder

In 2000, the U.S. functional food market remained the largest in the world at $17 billion. But as a trading block, the European Union (EU) is a close match with approximately $16 billion (Table 1). Europe’s larger growth in functional foods compensates for its flatter supplement market.

Performance enhancement is one of the key lifestyle issues related to functional food. Consumers look to their food to provide general good health and wellbeing to maintain consistent mental and physical performance rates. However, there are important occasions when people want to push themselves beyond their usual limits. This is not a new phenomenon; athletes have always chosen meals that contain plenty of protein and carbohydrates and students often work through the night before an important deadline aided by many cups of coffee. However, as new drinks and foods are becoming more and more effective, performance enhancement is—and will continue to be—a hot topic.

There are two types of performance enhancers: those that improve mental performance and those that improve physical performance. There is some overlap, but the majority of products target one or the other. Almost all products are aimed purely at short-term enhancement. Longer term improvements imply a focus on general well being, as healthy maintenance of the body is the only effective way to ensure good performance levels over a longer time frame.

Physical performance enhancers tend to work by delivering large amounts of energy in a format that is quickly digested by the body. The main uses are in sports, although there is also a strong fashion aspect, particularly among younger people. With sports, there are two principal reasons for the use of performance enhancing food or drink: competitive advantage or greater endurance. Products that offer competitive advantage provide extra energy in a quick-to-digest form, allowing more intense performance. Products that offer greater endurance are used by many athletes when they become tired toward the end of a training session. The extra energy allows them to achieve more than they would otherwise be capable of.

Sport nutrition products can roughly be divided into five categories: sports drinks, high-carbohydrate energy drinks, sports bars, sports shakes and energy gels. Sports drinks contain 5-7% multiple carbohydrates by volume with a high glycemic index and about 48-73 mg/100g sodium. High-carbohydrate energy drinks contain more than 13% carbohydrates by volume and often B vitamins like thiamin, niacin and riboflavin (10-40% of RDA).

In sports bars, carbohydrates make up more than 70% of total calories. Fat content, however, is low (1-2 g/bar) or absent. In sports shakes, the carbohydrate content is generally a little lower: > 65% of total calories (> 18 g/100 ml) and fat does not exceed 25% of total calories. Proteins make up 15-20% of total calories and vitamins and minerals are optional at low levels (10-40% of RDA). Energy gels contain more than 50% carbohydrates by volume (> 50 g/100 ml); vitamins and minerals are absent or found in traces.

Sports beverages are recommended for activities lasting more than one hour. They can be beneficial as a source of fuel for working muscles and will speed the absorption of water and glucose from the small intestine; therefore, continued ex­ercise does not deplete muscle glycogen as fast and performance time may be lengthened. Sports drinks are also supposed to help reduce recovery time by rapidly restoring muscle glycogen after ex­ercise and to be beneficial when exercising under humid and/or hot conditions, as the electrolytes help to enhance fluid absorption.

The market for sports and energy drinks shows very strong growth in almost all European countries except France. The Swedish and U.K. markets are seeing particularly high growth, while the German market also shows very strong growth but from a much larger base (Table 2).

In Germany, so-called “wellness drinks” demonstrated growth of 41.3% (1999: 196.9 million. DM; 2000: 278.3 million DM), while sports drinks, although showing an increase in quantity, de­creased by 6.2%. Energy drinks, however, increased by 20.1 % (Table 3).

The Caffeine Conundrum

Consumers often look to functional products to provide mental stimulation when they feel tired or to think more clearly. The novel aspect is that new active ingredients that are more effective stimulants are being sought.

Most products that claim to be mental stimulants are drinks and their only active ingredient is caffeine. Caffeine is probably the most popular and readily available drug in the world. Caffeine occurs naturally in plants and is found in leaves, seeds and fruits such as coffee, cocoa beans, tea leaves and kola nuts. Caffeine acts as a mild stimulant to the nervous system: it increases alertness, attention, insomnia and mental ability. However, caffeine intake also has negative side effects, such as anxiety, gastrointestinal distress, nervousness, irritability, insomnia and inability to concentrate.

The use of caffeine has been controversial in sport performance since the negative side effects can hamper performance. Some studies have shown caffeine intake prior to exercise can enhance performance while other studies have found caffeine to be of no benefit. While the mechanisms responsible for im­proved performance have not been clear­ly established, several theories exist. One possible mechanism is that caf­feine ingestion before exercise triggers the production of plasma epinephrine, which then stimulates the release of fat into the blood, making more fat available as an energy source rather than the limited muscle-glycogen stores, thereby delaying the onset of fatigue.

There is no legal requirement to de­clare the amount of caffeine; however certain groups of consumers may be in­terested in controlling caffeine intake for medical reasons. The Food Advisory Com­mittee (FAC) minutes of a May 6, meeting recommend that ‘mainstream’ soft drinks (which are likely to be consumed by children) should not exceed 125 ml/l and if they do, they should carry a label warning about the levels of caffeine and the un­suitability of such levels for young children. Major brands of high caffeine energy drinks already carry such a warning. The Draft Commission Directive on the labelling of foodstuffs containing quinine and foodstuffs containing caffeine (September 2001) proposes that where caffeine is used as an ingredient in a proportion in excess of 150 mg/l or 150 mg/kg, the words “high caffeine content” must be on the label of the product. The effective caffeine content must also be indicated on the list of ingredients immediately after the word “caffeine.”

Many consumers find performance en­hancing foods exciting, but some are concerned about side effects or habituation. Therefore, thorough research and further clarification of safety aspects are important for the future. However, as the trend towards wellness increases, sport nutrition or functional drinks should show further growth potential.NW