Beverages and Health
2002
10 Key Facts
1. It is estimated that more than one billion people in the world do not have access to
good quality water. This can cause infections, not only via drinking but through the use of
contaminated water in food preparation, and especially due to lack of water to maintain
adequate food hygiene. Lack of instant access to good quality water often results in people
having to travel substantial distances to acquire water and/or spending a significant
proportion of their income (typically 20%) buying water from street vendors. As a result
less time and money are available for food and food preparation. This in turn can adversely
affect nutritional status.
2. Until the 17th century few non-alcoholic drinks were available and people mostly
consumed alcoholic drinks such as ale, cider and wine. Herbal teas or infusions were
consumed as medicines. In the 18th century, tea became the most popular drink in the UK
and, despite the initial high cost, it soon replaced ale as the main drink of the labouring
classes. Carbonated mineral waters were first produced towards the end of the 18th
century. Flavoured versions, which eventually became soft drinks, were introduced during
the 19th century. This is when phosphoric acid was added and colas were created.
Thereafter, the industrial production of fruit juices began, along with the bottling of milk. A
milestone in the development and production of soft drinks was the introduction of
refrigeration thus further increasing the wide variety of beverages available today.
3. Since 1995 there has been a decline in the consumption of milk, milk drinks and hot
drinks like tea and coffee, although this category still represents 40% of total beverage
consumption. Total alcoholic beverage consumption is also decreasing. The most striking
data refer to soft drinks consumption, which is increasing rapidly. The projections for 2005
include a further decline in milk and hot drinks (by 1% and 2% respectively) and a 3%
increase in soft drinks to 30% of the market share. Alcohol is likely to remain stable at
17%. Recently, the UK market has seen an emergence of innovative energy and functional
drinks marketed in a highly sophisticated manner, targeting specific groups of consumers.
4. The last five years have seen a 17% increase in the consumption of bottled mineral
water, and a further 70 % increase is forecast for the next five years. The success of
bottled water is shaping the dynamics of the drinks market and is due to three main
factors: convenience, maintenance of fluid balance and fashion and culture. In this
respect, the UK may be following the trends in other European countries, such as Italy,
France and Germany (the highest consumers in Europe) and may be attributed to the socalled phenomenon of ‘continentalisation’ already observed in eating habits.
5. Data from the National Food Surveys (NFS) have shown a rise in fruit juice intake since
the 1970s and a decline in whole milk intake, which has not been fully offset by the
increase in the intake of low fat milks. One of the major nutrients affected by the decrease
in milk intake is calcium, average intake of which has dropped from 1050 to 850
mg/person/day over the last 40 years. NFS data have also identified a shift in the types of
alcoholic drinks being consumed; wine intake at home has increased significantly. Data
from the National Diet and Nutrition Surveys (NDNS) have shown that for girls, aged 7 to
10 years the most popular drinks were squash and diet squash whilst girls aged 15 to 18
years preferred tea and coffee followed by carbonated drinks. The consumption of fruit
juices and soft drinks contribute to the intake of vitamin C, potassium and folate. Notably,
soft drinks with added calcium are not substitutes for milk since they do not provide the
same range of nutrients. In the older population, aged 65 and over, tea is the most
consumed beverage and intake of milk is twice as high as that of fruit juices. As different
drinks provide different ranges of nutrients, it is important to consume a large variety of
drinks.
6. Milk has been recognised as an important source of nourishment since ancient times; it
has evolved specifically with the function of nourishing mammals and has an important
place in the human diet. NDNS data have shown that the diets of some children are
deficient in some of the nutrients found in milk, e.g. vitamin A and calcium. A serving of
semi-skimmed milk would be sufficient to provide 98% of the Reference Nutrient Intake
(RNI) for vitamin B12, 8% of the RNI for vitamin A and 25-30% of the RNI for calcium in
adolescents. Milk is a nutrient dense food, and low fat milk can make an important
contribution to nutrient intake in a society with an increasing prevalence of obesity.
7. Caffeine and alcohol exert a diuretic effect to varying degrees. Olympic athletes are
advised to avoid these substances because of risk of dehydration. The same advice is
given to passengers on long-haul flights: they should avoid excess tea, coffee, cola and
alcohol because cabin pressure causes water losses higher than normal. However, the
dehydrating effects of these drinks under normal circumstances are much less than
commonly perceived. Various studies on caffeine have concluded that doses of more than
about 250-300mg (equivalent to 3-5 cups of coffee, 5-8 cups of tea, 5-6 cans of
caffeinated soft drinks) have a mild diuretic effect, whilst doses of less than 250 mg do not
show any effect. In coffee drinkers, habituation can be developed, lifting the minimum
effective dose for dehydration.
8. Alcohol has a more potent diuretic effect and 1g is sufficient to increase urine output by
approximately 10ml. However, a significant effect on hydration status has only been noted
with strong alcoholic drinks such as spirits. The crucial factor is alcohol concentration i.e.
the higher the concentration, the greater the net fluid loss. So, for example, whisky
produces a greater negative fluid balance compared with beer, and small quantities of beer
may reinstate fluid balance or lead to positive fluid balance in subjects who are already
dehydrated.
9. There is evidence that chronic mild dehydration is associated with adverse health
consequences. It is therefore important to have an adequate fluid intake. At normal
temperature, with little or no exercise, turnover is around 2.5 litres of fluid/day, whereas
in hot conditions and with heavy exercise the output rises substantially. During exercise it
is important to replace water losses as much as possible by drinking at every opportunity.
Heavy exercise also depletes muscle glycogen, so it is necessary to supply glucose which
also helps stimulate water absorption.
10. Although there is no solid evidence on the effects of dehydration in schoolchildren, it
has been suggested that lack of water intake during the day may cause some adverse
health effects and impairment of cognitive function. Provisions should be made for water
and milk to be included with school lunches and for drinks to be available during physical
activity.
Anna Maria Bedford (Member of the Friends of BNF Group)
Notes: This is a summary of the findings from a British Nutrition Foundation conference
held on 4th December 2001. Speakers were Professor Sandy Cairncross (London School of
Hygiene and Tropical Medicine), Mr Mike Saltmarsh (Inglehurst Foods), Mr Gary
Roethenbaugh (Zenith International), Dr Judy Buttriss (British Nutrition Foundation),
Professor Ron Maughan (University of Aberdeen), Dr Anita Wells (The Dairy Council), Dr
Susan Shirreffs (University of Aberdeen). Dr Gail Goldberg (Senior Nutrition Scientist at
the BNF) and Dr Judy Buttriss (Science Director at the BNF) chaired the meeting.
© British Nutrition Foundation 2002