Full Report - Food, Nutrition, and the Prevention of Cancer

Figure 4.7.4 Maté and oesophageal cancer;
case-control studies
hot tea). 174 Both these studies adjusted for smoking.
Seven case-control studies investigated food temperature162
178-183 189-191 177 182 184-186
; seven investigated hot drinks
188 192 193 ; and four investigated high-temperature hot drinks
and soups combined. 191 194-196 For high-temperature food, six
studies showed increased risk, 162 178-183 187 189 191 which was
statistically significant in three162 179 180 187 189 ; one study
showed non-significant decreased risk. 190 For hot drinks, five
studies showed increased risk, 177 182 185 186 188 which was statistically
significant in four177 185 186 ; two studies showed no
significant association192 193 ; one study showed non-significant
decreased risk. 184 For hot drinks and soups combined,
all four studies showed increased risk, 191 194-196 which was
statistically significant in two. 194 195 Several studies did not
177 180 182 186 194 195
adjust for smoking or alcohol.
High-temperature foods and/or drinks produce heat damage
in the mouth, pharynx, larynx, and oesophagus.
156
Victora 1987 1.47 (0.67–3.25)
Sewram 2003 1.62 (1.01–2.61)
Castelletto 1994 1.70 (1.00–2.89)
De Stefani 2003 3.50 (1.39–8.82)
De Stefani 1990 12.21 (3.78–39.42)
Dietz 1998 5.48 (0.96–31.44)
Rolon 1995 0.90 (0.44–1.86)
Vassallo 1985 Men 4.80 (1.90–12.11)
Vassallo 1985 Women 34.60 (4.88–245.40)
0.2 0.5 1 2 5 10
35
Figure 4.7.5 Maté and oesophageal cancer;
case-control studies
Relative risk (95% CI)
Vassallo 1995 Men 1.26 (1.18–1.35)
Vassallo 1995 Women 1.43 (1.20–1.69)
De Stefani 1990 1.17 (1.12–1.22)
Rolon 1995 1.04 (0.95–1.13)
Sewram 2003 1.17 (1.09–1.25)
De Stefani 2003 1.04 (1.00–1.08)
Summary estimate 1.16 (1.07–1.25)
0.95 1 1.4 1.75
Relative risk, per cup/day
Relative risk (95% CI)
Relative risk, highest vs lowest exposure category
P ART 2 • EVIDENCE AND JUDGEMENTS
Repeated damage of this nature can lead to cancer (also see
chapter 2.4.1.3).
The evidence is inconsistent. There is limited evidence
suggesting that high-temperature drinks are a cause of
oesophageal cancer.
4.7.6 Comparison with previous report
Water was not reviewed in the previous report, which had
little to say about contaminants in water and did not review
arsenic contamination. The previous report did not review
soft drinks as such.
The previous report judged that green tea possibly protects
against stomach cancer, but this was not supported by the
current review. The previous report judged that black tea
probably has no relationship with cancers of the stomach,
pancreas, and kidney. This time the evidence was judged too
limited to draw a clear conclusion. The judgements of the
previous report on coffee were practically the same as in this
Report, except that the previous report judged that drinking
more than five cups per day was a possible cause of bladder
cancer. The evidence now indicates that coffee is unlikely to
have a substantial effect on risk of this cancer. The previous
report judged it possible that maté and other very hot drinks
increase the risk of oesophageal cancer. Since the mid-1990s,
a greater body of consistent data has been published on
maté.
Skin cancer was not reviewed in the previous report.
4.7.7 Conclusions
The Panel concludes:
The evidence that inorganic arsenic in drinking water is a
cause of lung cancer is convincing. Water contaminated in
this way is probably a cause of skin cancer. There is limited
evidence suggesting that water contaminated in this way is
a cause of cancers of the kidney and bladder.
Maté is probably a cause of oesophageal cancer when
drunk scalding hot through a metal straw, as traditional in
parts of South America. The temperature is judged to be
responsible for any increased risk of cancer. There is limited
evidence suggesting that maté as drunk traditionally is a
cause of cancers of the mouth, pharynx, and larynx. There
is limited evidence suggesting that high-temperature drinks
are a cause of oesophageal cancer.
It is unlikely that coffee has a substantial effect on the risk
of cancer either of the pancreas or of the kidney.