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					Science in the News: Cola bone warning!

Title: Cola bone warning!

This activity contains an article about research that has found a link between consumption of cola
drinks and osteoporosis in women. The article is followed by questions to encourage students to
assess the strength of the evidence from the study, and to suggest possible further research.

Links to the curriculum:
This looks at the methods that scientists use to find answers to problems, linking to:
Sc1        Scientific enquiry – Evaluating
           2q     Consider whether the evidence collected is sufficient to support any conclusions or
                  interpretations made
           2s     Suggest further investigations
Science in the News: Cola bone warning!

                                          Cola bone warning!

                                          Researchers from the United States say that women who regularly
                                          drink cola soft drinks could be increasing their risk of suffering from
                                          osteoporosis. Osteoporosis is a disease where bones become
                                          lighter, less dense and less strong, and so break more easily.
                                          Currently over 1 million women in the UK have been diagnosed with
                                          the disease, though doctors think many more women may have it.
                                          The researchers’ study involved 2500 people, both men and women
                                          of a variety of different ages. They used dietary questionnaires to
                                          find out how much cola, other carbonated drinks and milk the people
                                          drank, as well as their total calcium intake from other sources, such
                                          as dark, leafy greens or beans. They measured bone mineral density
                                          at the spine and at three different sites from the hips.
                                 The study found that, for women of all ages, drinking cola was linked
                                 with low bone density at all three hip sites, whatever their overall
                                 level of calcium intake, though the bone density in the spine was not
affected. They found no link between men’s consumption of cola drinks and bone density, and no
link between women’s consumption of other carbonated drinks and bone density. Previous studies
have suggested that drinking cola damages bones, because the cola replaces milk in the diet, but
this study showed that women who drank more cola didn’t drink less milk, but they did have less
calcium overall in their diet than other women.
The researchers have suggested that phosphoric acid in cola drinks makes the blood more acidic.
They believe that the body uses calcium from the bones to reduce the blood’s acidity, but not all
scientists agree with this and more studies are needed. A spokesman for the British Soft Drinks
Association reminded young women of the need to protect their bones by eating plenty of calcium-
rich foods, taking weight-bearing exercise, not smoking and reducing alcohol consumption.


1    Discuss the advantages and disadvantages of using dietary questionnaires to find out what
     people eat.

2    Previous studies have suggested that it is drinking less milk, not more cola, which damages
     women’s bones. Does this research support that idea?

3    What evidence is there to suggest it might not be the cola that is doing the damage? What
     could be damaging the bones instead?

Some scientists suggest more studies are needed. Discuss what sort of studies you think might be
helpful in finding out more about the possible link between osteoporosis and cola.
Science in the News: Cola bone warning!



1   Advantages: dietary questionnaires are an easy way to find out what people have been eating,
    without taking up scientists’ time observing and recording and without disrupting people’s lives
    Disadvantages: the results are dependent on people recording accurately, this may not happen
    as people may not remember, or measure, accurately and people may use different base units
    (for example, a ‘portion’ may mean very different amounts to different people)

2   This research does not support the previous studies, as it shows that women drinking more
    cola did not drink less milk, but there was still an effect on their bones

3   The women drinking more cola also had lower overall calcium intakes. Without further study it
    is not possible to tell if it is the extra cola or the reduced calcium that is affecting the bone

A variety of extra studies might be helpful, aimed at finding the answers to questions such as:
        What chemical or biological differences are there between bones in the spine and the hip
         that mean that hip bones appear to be affected by cola, but spine bones are not?
        Does cola still affect women’s bone density if their overall calcium intake remains high?
        Are there differences in lifestyle between men and women that account for the different
         ways cola drinks appear to affect their bones?
        What are the chemical or biological differences between men and women that could
         account for the different ways cola drinks appear to affect their bones?
        Are the differences in the way cola drinks appear to affect men and women related to
         differences in average body size?
        Are there any lifestyle changes that women could make that would offset the apparent
         damage done by cola drinks?
        Do other dietary habits that cause the blood to become acidic affect the bones in the same
         way as cola drinks?

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