EU Science Hub

Water

Table of Contents

 

1. Defining water

Water is the main constituent of the human body and is essential for life. It comprises about 60% of body weight in adult males, 50 to 55% in females, and up to 75% in a new-born infant (EFSA 2010). Water, as defined by EFSA, is 'the liquid part of the human body (total body water distributed over the extracellular and intracellular compartment), of the diet (tap and bottled water, beverages, solid food moisture), and of the body excretory and evaporative losses (urine, sweat, faeces, evaporation via respiration and the skin), and the water produced in the body through oxidation of substrates' (EFSA 2010). Additionally, total water intake refers to 'water intake from beverages and foods', while total available water intake is ' the sum of total water intake and oxidation water' (EFSA 2010).

The EU Directive 98/83/EC defines 'water intended for human consumption' as 'all water either in its original state or after treatment, intended for drinking, cooking, food preparation or other domestic purposes, regardless of its origin and whether it is supplied from a distribution network, from a tanker, or in bottles or containers', and  'all water used in any food-production undertaking for the manufacture, processing, preservation or marketing of products or substances intended for human consumption unless the competent national authorities are satisfied that the quality of the water cannot affect the wholesomeness of the foodstuff in its finished form' (EU Council 1998).

Most drinking water contains some minerals, particularly calcium, magnesium and fluoride (naturally or artificially fluoridated). The concentrations of the minerals vary hugely by geography and water treatment process. For example, in Northern Europe, calcium in natural groundwater ranges from 1 to 100 mg/l. The variation depends on the original well water and the composition of the bedrock. Bottled water mineral concentrations also vary widely in Europe, ranging from 0 to 546 mg/l for calcium and from 1 to 126 mg/l for magnesium. Drinking waters that are mineral-rich may provide substantial contributions to total intakes of these minerals in some populations or population subgroups (WHO 2009).

 

 

2. Dietary sources of water

In an average diet, water is predominantly obtained through consumption of drinking water and beverages (80% of daily intake) plus water contained in food (20% of daily intake). Water content is usually between 85% and 100% in non-alcoholic beverages such as brewed tea, brewed coffee, soft drinks and juices (EuroFIR). Table 1 shows the water content in a selection of food items, derived from databases available in EuroFIR (EuroFIR).

 

 

 

 

3. Labelling of drinking water in the EU

EU Directive 2009/54/EC (EU 2009) lays down rules on the exploitation and marketing of natural mineral waters, which are defined as 'microbiologically wholesome water originating in an underground water table or deposit and emerging from a spring tapped at one or more natural or bore exits'. The Directive also includes certain labelling requirements in addition to the general labelling rules for foodstuffs of Regulation (EU) 1169/2011 (EU 2011), such as the analytical composition, the name and place of the spring of origin, and information on any of the permitted treatments.

The term spring water should be used for water that 'is intended for human consumption in its natural state and bottled at source' and which fulfils the various criteria and conditions described in Dir. 2009/54/EC. Effervescent mineral waters instead can be divided on naturally carbonated mineral water, natural mineral water fortified from gas from the spring, or carbonated mineral water in which the added carbon dioxide is of a different origin from the water source.

Any message or design that suggests a characteristic which the water does not possess is strictly prohibited, and so is any indication attributing properties related to preventing and treating disease. EU Member States however can authorise the indications 'stimulates digestion' and 'may facilitate hepato-biliary functions', or indications related to the suitability of a natural mineral water for infant feeding.

Regulation (EU) 1924/2006 (EC 2006) for health and nutrition claims made on foods has certain nutrient claim provisions related to waters:

  • Low sodium/salt claims for waters, 'other than natural mineral waters falling within the scope of Directive 80/777/EEC (EU Council 1980), this value should not exceed 2 mg of sodium per 100 ml'.
  • Very Low sodium/salt claims 'shall not be used for natural mineral waters and other waters'.

The European Commission has aslo authorised health claims in relation to water intake (EU Register on nutrition and health claims), referring to maintenance of normal physical and cognitve functions as well as body temperature. In order to bear the claims, information shall also be given to the consumer that at least 2 litres of water, from all sources, should be consumed per day.

 

 

4. Water intake: effects on health

Water is needed to maintain normal physical and cognitive functions and performance, and regulating body temperature, while water intake is key to prevent dehydration. Table 2 showcases a number of statements issued by public health authorities on the health effects of water intake.

 

 

5. Recommended intakes of water

Table 2 below lists the current recommendations for water consumption by international public health organisations. Almost all national dietary guidelines among EU Member States include recommendations on adequate intake of water and fluids; most specify 1.5 to 2 l of water per day (JRC exp. 2018) . The recommendations reflect different water needs through the lifecycle and between men and women.

 

 

6. Water intake across European Countries

Table 4 presents data on intake of drinking water and non-alcoholic beverages in EU countries, based on recent national surveys. The data is not comparable between countries due to different dietary assessment methods and definitions used to describe non-alcoholic beverages. For instance, some surveys may define all beverages (including drinking water) that do not contain alcohol as non-alcoholic beverages, while some surveys exclude milk and/or fruit juices from their calculations of total non-alcoholic beverage intake. Nonetheless, EFSA notes that water intake in European countries is lower than the recommended or guidance values (EFSA 2010). Several populations, including France, Ireland, Italy and Sweden, consume less than 1500 ml of fluid (non-alcoholic beverages) per day. In terms of drinking water intake, most countries consume less than 1000 ml/d, with the exception of Austria, Germany, Norway and U.K. Restrictions in the work environment, physical disabilities, cognitive or mental problems, lack of social support particularly in vulnerable population groups may affect good hydration.

In adolescents, one dietary survey across 9 EU countries (BE, DE, EL, ES, FR, IT, HU, AU, SE) in 2012 found beverage consumption was 1611 ml/d in boys and 1316 ml/d in girls (Duffey et al 2012). The most consumed fluid per person was water (721.5ml/d), followed by sugar sweetened beverages (SSBs) (227.7 ml/d), and fruit juice (132.6 ml/d). A higher percentage of girls drank water than boys while more boys than girls consumed SSBs.

 

 

 

7. Policy recommendations and implemented policies addressing water intake

 

Several public health organisations have issued policy recommendations to promote water intake (often within the context of reducing sugar-sweetened beverages consumption), especially among children, in order to address overweight and obesity. The European Commission has also compiled series of effective school-based interventions to increase water intake in children (JRC 2016). Table 5 below highlights those policy actions that refer more specifically to promotion of water intake. Educational efforts that increase awareness on the benefits of hydration (and on the risks of dehydration) and on the availability of a variety of hydration sources could lift barriers hydration at the individual level. Similarly, policies that promote water intake in public spaces, work environments, health care institutions and schools can also encourage proper hydration.

Several European countries have implemented policies to increase water intake in children that closely mirror the recommendations above (Table 6). For example, France, Sweden, Lithuania and Romania have mandatory guidelines in schools to make drinking water available and accessible to children. In France, bottled water must be available in vending machines while other drinks and snacks are prohibited. Hungary has introduced a national programme – Hungarian Aqua Promoting Programme in the Young (HAPPY), to promote water consumption by educating students on adequate fluid consumption, and to make water freely available on school premises. Austria has a voluntary programme for school cafeterias; school cafeteria shall provide water and 80% of drinks available shall not contain more than 7.4 g sugar per 100 ml or sweeteners.

 

 

 

References