Let’s get physical? Health claims guidance reveals sector fragility

30-Jul-2012 - Last updated on 01-Aug-2012 at 08:54 GMT

Beach running in a suit? No approved claims to date

Recently published European Food Safety Authority (EFSA) guidance on physical performance health claims does not provide enough clarity on trial design to enable the beleaguered sector to actually win any claims, a consultant has said.

The 9-page guidance was produced after a consultation period in which only seven stakeholders submitted comments. Other segments like gut health and immunity and cognitive health have drawn a much bigger response from industry and academia.

The document is intended to summarise the Parma-based agency’s position on the sector that seen many more claims rejected than accepted by EFSA’s health claims panel under the 2006 nutrition and health claims regulation (NHCR).

The guidance outlined EFSA thinking on:

Physical performance
Endurance capacity
Muscle function
Physiological effects and their relation to physical performance or endurance

Christiane Alexander, PhD, senior consultant at analyze&realize in Germany said the guidance could be, “of some help” but fell well short of true usefulness.

“There are not enough details for the food industry to be sure how to conduct clinical trials in a satisfactory way to convince the NDA panel (Panel on Dietetic Products, Nutrition and Allergies),” Alexander said.

See said the agency’s guidance was weak because it failed to engage with nutrition and sports scientists.

“This rather brief document clearly indicates that physical performance is an area of nutrition science that needs more expert input from academia and the requirement of interaction between academia and industry to develop more adequate and helpful instructions when it comes to health claim substantiation,” she said.

In the guidance the NDA said studies performed on target groups like athletes could be admissible but noted such a deviation from the ‘healthy subjects only’ mantra of previous years was, “the subject of ongoing discussions with the Commission and Member States with regard to their admissibility.”

Examples of potential admissible physical measures included:

Physical performance during short-term, high intensity exercise vs longer-term, endurance performance
Single exercise bout vs repeated bouts
Weight bearing vs non-weight bearing activities
Time spent to run a certain distance
Distance cycled during a time-trial
Throwing distance in javelin or shot put
Jumping height, walking speed and number of chair-stands in a certain time

“Some of the outcomes proposed (e.g. changes in VO2max, muscle glycogen stores, and substrate oxidation) are not direct measures of endurance capacity but could be used in support of a mechanism by which the food/constituent could exert the claimed effect,” the NDA wrote.

The sports nutrition sector was attacked this month by Oxford University researchers who published a series of damning articles about the sector's efficaciousness in the British Medical Journal.

Drug giant GlaxoSmithKline, the manufacturer of Lucozade and owner of MaxiNutrition, hit back saying more than 80 pieces of research conducted over 40 years backed the effectiveness of its products to assist sports performance and enhance health.

1 comment

The sporting chance for physical performance health claims

Posted by Dr Robert Child, 04 September 2012 - 15:54 GMT

It's a little worrying when a high profile consultancy such as Analyze and Realize claim, “EFSA guidance on physical performance and health claims does not provide enough clarity on trial design to actually win any claims.” The fact is specialist knowledge is required to conduct well-controlled trials that substantiate article 13.5 performance claims. Concepts such as food or supplement loading periods, washout periods, placebo effects, order effects, training effects and many other factors must all be controlled for. Understanding how to achieve this requires rigorous training in scientific research. Although knowledge of human nutrition provides a starting point, detailed understanding of exercise physiology is also required. Having conducted UK government funded food research in a medical department with an ‘international excellence’ research rating; it is naive to think the NDA panel can or should provide an education in research training.
Dr Alexander suggested “the agency’s advice was weak because it failed to engage with nutrition and sports scientists.” However, such engagement is of limited value as sports scientists often have very different research objectives to those of industry, or the EFSA panel. For example a sports scientist might only be interested in determining if a nutrition intervention improved performance for one activity e.g. cycling. However this does not mean similar effects will be seen with other activities e.g. running and it could be misleading to consumers to use a study on cycling to make claims to runners.
In other circumstances a sports scientist may wish to focus on elucidating a particular metabolic pathway, requiring time consuming (and costly) biochemical measurements in blood and muscle. Despite the value of such measures in academic settings the EFSA panel only wish to establish ‘plausible mechanisms of action’. As a consequence, some companies have invested tens of thousands of pounds in unnecessary biomarker measurements. Other biomarkers such as changes in VO2 max, muscle glycogen and substrate oxidation only reflect performance for specific activities. Therefore the NDA are quite right to consider biomarker changes as only providing supportive evidence for mechanisms of performance improvement. In more than 20 years work with elite athletes it is clear that changes in VO2 max, muscle glycogen stores and substrate oxidation do not consistently correlate with performance. This phenomenon is particularly apparent in homogeneous subject groups.

In a quest to provide a simple message to athletes and consumers, dieticians and sports scientists have frequently oversimplified human exercise physiology. This has resulted in important misunderstandings about which physiological factors actually limit performance. For example VO2 max is often measured in laboratory tests, as this is considered a good performance measure. However since the 1970s physiologists have known it is the sustainable percentage of VO2 max that actually determines endurance performance. Despite this, VO2 max is still the most popular aerobic performance measure, simply because it is easier and cheaper to perform than measuring sustainable percentage of VO2 max. Other misunderstandings arise from company marketing literature and the advice of dieticians, who often recommend ‘topping up energy stores’ with carbohydrates before exercise. Increasing body carbohydrate stores will only benefit performance when this is limited by carbohydrate availability and for many activities this is not the case. The weight gain from ‘topping up’ glycogen stores before exercise is detrimental to performance in jumping and sprinting events and may even compromise performance in middle distance running.

Planning a research trial to support an article 13.5 sports performance claim is a significant undertaking for any company. As a basic starting point it is important to select i) an exercise model that allows performance to be assessed, ii) an exercise model that has relevance to the target consumer and iii) an exercise model where the cause of fatigue (i.e. limitation to performance) is same under experimental conditions as occurs in the field. Factors such as the training status of subjects, study design and control measures will all have a bearing on the number of subjects and laboratory visits (hence costs) required to detect significant treatment effects. By taking these basic factors into consideration before undertaking a research trial, food and raw ingredient manufacturers can save a considerable amount of money and maximize their research investment.

About the author: Dr Robert Child is CEO of Alimentarius Ltd. the UK based nutrition, health claims and food law consultancy. Alimentarius submitted an article 13.1 dossier for creatine monohydrate and this ingredient ultimately received a positive EFSA opinion in relation to performance. In addition to work on food law Dr Child is also involved in research trials on raw ingredients and article 13.5 submissions. As a doctor specializing in nutritional biochemistry he has unsurpassed record of success in road cycling. His clients include Olympic and World Champions, as well as Tour De France riders.

www.alimentarius.eu