Changes in blood glucose concentrations following consumption of four different beers (carbohydrate content 1.4-12.1g per half pint; alcohol concentration 3.3-5.5% v/v) were examined in seven insulin-dependent men (age 21-41 years; duration of diabetes 5-27 years), who were studied on four evenings, on each occasion drinking a different beer but eating an identical meal. Blood samples were taken before drinking began, at half to one hour intervals during the evening and before breakfast the next morning. The peak increment in blood glucose concentration was linearly related to the carbohydrate content of the beer (r = 0.95,p<0.01), though there were no statistically significant differences between individual beers. Pre-breakfast blood glucose concentrations of <3.5 mmol/l occurred on six out of 14 occasions after the two low carbohydrate beers but on only two out of 14 occasions after the two higher carbohydrate beers (p=0.09). If patients follow the advice given by the BDA on alcohol consumption we suggest that they choose beers and lagers with a carbohydrate content of 3-7g per half pint (275 ml) and an alcohol concentration equal to or less than five per cent.

1. OriginalArticles
The effect of different beers on blood glucose
concentrations in insulin-dependentdiabetes
B HendersonMBMRCP Registrar in General Medicine c E Atkin PhDCChemMRscSenior Biochemist
E HendersonSRD District Dietitian D R W RawsonF~MLSChief MLSO
H Connor MD FRCPConsultant Physician
County Hospital, Hereford H'R1 2ER
Correspondence: Dr H Connor,County Hospital, Hereford H R 1 2ER
Abstract
Changesin blood glucoseconcentrations followingconsumption of four
different beers (carbohydrate content 1.4-12.lg per half pint; alcohol
concentration 3.3-5.5% v/v) were examined in seveninsulin-dependentmen
(age 21-41years; duration of diabetes 5-27years), who were studied on four
evenings, on each occasiondrinking a different beer but eating an identical
meal. Blood sampleswere taken before drinking began, at half to one hour
intervals during the eveningand before breakfast the next morning. The
peak incrementin blood glucoseconcentration was linearly related to the
carbohydrate content of the beer (r=0.95,pC0.01), though there were no
statisticallysignificantdifferencesbetween individual beers. Pre-breakfast
blood glucoseconcentratio& of <3.5 mmoyl occurred on six out of 14
occasionsafter the two lowcarbohydrate beers but on only two out of 14
occasionsafter the two higher carbohydrate beers (p=O.O9). Ifpatients
followthe advicegivenby the BDA on alcoholconsumptionwe suggestthat
they choosebeers and lagers with a carbohydrate content of 3-7g per half
pint (275ml) and analcohol concentrationequal toor lessthan fiveper cent.
Introduction
Diabetic patients are often given con-
fused or conflicting advice about the use
of alcoholic drinks (RefI). The British
DiabeticAssociation (BDA) has recently
advisedpatients that they should not take
morethan three alcoholic drinks daily, in
which case the carbohydrate content of
thedrinkcan beignored(Ref2). TheBDA
also advises patients to avoid beers and
lagers with an alcohol content of more
than five per cent.
The purpose of this study was to
examine the effect on blood glucose con-
centrations of four different beers when
consumed in a normal social context and
in accordance with BDA guidelines.
Patientsand methods
Patients
Sevenmen with Type1diabetes (Table
I) gave informed consent to the study
Table 1
Patient details
which was approved by the Hospital
Ethics Committee. None of the patients
was taking any medication other than
insulin. Teetotallers were not recruited.
Each patient kept a food diary for one
week, and this information was used to
calculate his average consumption of
carbohydrate. Alcohol diaries were kept
for one month and used to calculate
average weekly consumption of alcohol.
One unit of alcohol was defined as275m1
of beer or lager, onesinglemeasure(24cc)
of spirit or one smallglass of sherryor of
wine. All patients continued with their
usual daily activities during thestudy.
Protocol
Each patient attended on four even-
ings, from 1800-2245 hours, during a
four-week period. An identical main
evening meal and late night snack was
eaten on each occasion, the carbohydrate
content being matched to each patient's
average carbohydrate consumption at
these times. Each patient was randomly
allocated to drink one of four different
beers on each eveningand was not aware
of the type of beer he was drinking. One
half-pint was drunk before the meal,
another during and a third after the meal.
Finger prick blood samples were taken
every 30 or 60minutes for measurement
of blood glucose concentration, and
Average daily
Age Duration of % of ideal Insulin dose carbohydrate Averageweekly
Patient (Y) diabetes Cy) body weight u/kgBWh4h Complications (@ alcohol (units)
1 22 11 95 0.8 1 none 270 25
2 41 5 114 0.58 a h 190 8
3 21 17 103 0.96 b,c 180 15
4 34 10 110 0.48 C 220 9.5
5 23 8 113 0.52 b 160 14
6 38 20 100 0.77 C 190 5
7 32 27 126 0.95 C 215 5.5
mean 30 14 709 0.72
S.€M 3 3 4 0.08
204 12
13 2
a=loss of vibrationsense in toes b=traceof proteinuria c- microaneurysmsbut no other retinopathy
Practical DiabetesNovember/December 1987 MI4 No 6 283

2. venous blood samples were taken at the
first and last visits for measurement of
mean cell volume, liver function tests,
serumcreatinineandglycosylatedhaemo-
globin.
OriginalArticles
Effectof differentbeers
Figure 1
Changein blood glucoseconcentrations (mean fSEM)with different beers
mbeerA Obeer6 ObeerC ObeerD
rn-meal s-snack b-beer (275rnll
Methods
Blood glucose concentrations were
measured with a YSI glucose analyser
(Model 23AM), samples having been
collected into capillary fluoride/EDTA
tubes. Most of the blood glucose con-
centrations were measured immedi-
ately, but the before-bed and before-
hreakfast samples were collected from
the patients’homes and analysedon the
morning after the study. Glycosylated
haemoglobin was measured by affinity
chromatography (Pierce Glyco Test
kits).The carbohydrateand alcoholcon-
tents of the beers were measured by high
performance liquid chromatography
using a BioRad HPX87columnand elu-
tion with water at 85°C.
The presence of retinopathy and of
neuropathy were detected by clinical
examinationand of proteinuriaby testing
with ‘Albustix’.
Results are expressed as the mean f
SEM.Statisticalsignificancewasassessed
by using Wilcoxon’s sign rank test and
Fisher’s exact test. The ‘initial’ blood
glucose concentration was calculated as
the average of two samples taken 10
minutes before and immediatelyprior to
consumingthe first drink each evening.
Results
The manufacturers’ f i r e s (quoted in
Ref 3)for carbohydrateand alcoholcon-
tent and our own analyses on samples
from the batches used in this study
showedadiscrepancyinthecarbohydrate
content of beer B but were otherwisein
closeagreement(Table2). We haveused
the results of our own analyses in all
subsequentdata.
The initial blood glucose concentra-
tionscovereda wide range (Table3), and
results were therefore calculated as the
change in blood glucose concentration
abovethe initialvalueand plottedagainst
time (Fig I). Beer A produced a greater
increase in blood glucose concentration
+%
A + 4
:
E
E- + 2
-
0
0
0
0
0
a 0
m
-
0
0
0
-
c
0
I
0 -21
2 4 0120 1800 8 0
Time (mins)
T
- AIc I
1sB
a0
0
‘ 7 7B o t o r o B e f o r e
bod b r o a k f a ~ t
than did the other three beers but the
changeswere not statisticallysignificant.
There was a close linear relationship
between the carbohydrate content of the
beer and the maximum change in blood
glucose concentration (Fig2 next page).
Pre-breakfast blood glucose concentra-
tions of lessthan 3.5 mmoM occurredon
six of the 14 occasions after the two low
carbohydrate beers (C+D) but only two
of the 14 occasions after the higher car-
bohydrate beers (A+B)(p=O.m). Two
patients had blood glucose concentra-
tions before bed of less than 3 mmoM
after the low carbohydrate beers, but
Table2
Alcohol and carbohydrate contents of beers
Alcohol
fa) (6)
A 3.8 3.8
6 3.5 3.3
C 5.6 5.5
D 4.0 4.1
Beer %v/v
(a)manufacturer’s figure
% of carbohydrate
Carbohydrate asmonosaccharides
gper 275ml and disaccharides
fa) (6) (6)
13 12.1 36.1
5.5 8.7 9.4
2.5 2.9 22.9
1.5 1.4 undetectable
(b)analysis of batches used in thisstudy
none was hypoglycaemic at this time
after the high carbohydratebeers.
Daily insulin doses remained identical
duringthestudyandtherewerenostatisti-
cally significant changes in glycosylated
haemoglobin, mean red cell volume or
serum GT activity (Table 4 next page).
Serum creatinineconcentrations (range
76-105 pmoM) and liver function tests
were normal in all patients.
Discussion
This studyhas examinedthe effects of
different beers on short term glycaemic
controlwhen thebeerisdrunkinanormal
socialcontextandaccordingtotheadvice
given by the BDA.
A prebreakfast blood glucose con-
Table3
Initial blood glucose concentrations
Beer Initial blood glucose (mmolAl)
range meanfSEM
A 3.0-21.3 10.4f2.5
6 5.8- 19.I 13.4f1.7
C 5.0-24.5 10.2f2.8
D 3.9- 19.3 10.5f2.0
284 PracticalDiabetesNovember/December 1987 W4 No 6

3. OriginalArticles
Effect of differentbeers
Table4
Clycosylated haemoglobin, MCV and yCT results -~
(mean f SEW
Week 1 Week 4
Clycosylated Hb 70.0f0.8 9.6f7.7
(% of total Hb)
MCV (fl) 88 f I 90 f 7
yCT (id/) 75 f 2 76 f 2
Figure2
Relationship between carbohydratecontent and maximumincrease in blood
glucoseconcentrationy = 0.29~+2.01;r = 0.95,p c 0.01
'1
2 4 6 8 10 1 2
Carbohydrate g/ 1 / 2 pint
centration of less than 3.5 mmoVl
occurred on sixout of 14 occasions after
the two low carbohydrate beers, com-
pared with only two out of 14 occasions
after the higher carbohydratebeers. This
difference did not achieve statistical
significance (p=O.W), and to have an
80%chanceof showingadifferenceatthe
5% levelwould have requiredasampleof
35patientswhich wasnot a practicalpru-
position. Nevertheless we consider that
the results in this study are sufficientto
advise patients against the use of low
carbohydrate beers and lagers, which
havethe theoreticalpotential for causing
hypoglycaemia as a result of both their
high alcohol and their low carbohydrate
content(RefI).
The increase in blood glucose concen-
tration was proportional to the
carbohydrate content of the beer, and
beer A, which contained 12 grams of
carbohydrateper half-pint,causeda con-
siderable increase in blood glucose con-
centration which was still present on the
followingmorning.Not onlydidthisbeer
have the highest total carbohydratecon-
tent of those studied, but it may also be
relevant that the percentage of carbo-
hydrate present as mono- and di-
saccharideswasalsohigherthaninanyof
the other beers.
Based on the results from this studywe
suggestthat patientsshouldbeadvisedto
choosebeers with acarbohydratecontent
of at least 3 grams and not more than 7
gramsper half-pint. Fifty-threeof the106
beers and lagers listed in 'Countdown'
(Ref3)meet thesecriteria. Moreinforma-
tion is needed about the carbohydrate
composition of different beers. The
carbohydratecontentof one of the beers
used inthisstudywas58% higherthanthe
manufacturer's f i r e quoted in Ref 3,
and informationabout the percentage of
carbohydrate which is present as simple
sugarsis not readilyavailable.
Acknowledgements
We are grateful to HP Bulmer Limited
for chemicalanalysisof the beers used in
this study.
References
I. ConnorHandWrksV. Alcoholonddiabctes.
Diabetic Medicine, 1985; 2: 413-6.
2. Day JL. The Diabetes Handbook (insulin
dependent diabetcsJ. Thorsons. Wellingborough,
1986;pp 54 and 222.
3. Countdown.British DiabeticAssociation. 2nd
edition. 1985; pp23745.
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