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The potential health benefits of legumes as a good source of dietary fibre
Trinidad P. Trinidad*, Aida C. Mallillin, Anacleta S. Loyola, Rosario S. Sagum and Rosario R. Encabo
Department of Science and Technology, Food and Nutrition Research Institute, Gen Santos Avenue, Bicutan, Taguig City,
Metro Manila 1631, Philippines
(Received 22 May 2009 – Revised 24 August 2009 – Accepted 26 August 2009 – First published online 14 October 2009)
Dietary fibre has been shown to have important health implications in the prevention of risks of chronic diseases. The objective of the present study
was to determine the potential health benefits of legumes as a good source of dietary fibre. Six to ten local legumes were studied as follows:
cowpeas, mung beans, pole sitao, chickpeas, green peas, groundnuts, pigeon peas, kidney beans, lima beans and soyabeans. The following studies
were conducted: (a) mineral availability, in vitro; (b) glycaemic index (GI) in non-diabetic and diabetic human subjects; (c) the cholesterol-
lowering effect in human subjects with moderately raised serum cholesterol levels. The highest Fe availability among legumes was for lima
beans (9·5 (SEM 0·1)) while for Zn and Ca, the highest availability was for kidney beans (49·3 (SEM 4·5)) and pigeon peas (75·1 (SEM 7·1)), respec-
tively. Groundnuts have the lowest Fe (1·3 (SEM 1·1)), Zn (7·9 (SEM 1·3)) and Ca (14·6 (SEM 2·8)) availability. Legumes are low-GI foods (,55),
ranging from 6 (chickpeas) to 13 (mung beans). Kidney beans showed significant reductions for both total (6 %) and LDL-cholesterol (9 %), and
groundnuts for total cholesterol (7 %; P,0·05). We conclude that mineral availability from legumes differs and may be attributed to their mineral
content, mineral–mineral interaction and from their phytic and tannic acid content; legumes are considered low-GI foods and have shown potential
hypocholesterolaemic effects. The above studies can be a scientific basis for considering legumes as functional foods.
Legumes: Functional foods: Dietary fibre
Dietary fibre has been shown to have important health impli-
cations in the prevention of risks of chronic diseases such as
cancer, CVD and diabetes mellitus. It comes from the
family of carbohydrates, an NSP, not digested in the small
intestine but may be fermented in the colon into SCFA
such as acetate, propionate and butyrate. SCFA contribute
6·3– 8·4 kJ/g (1·5– 2·0 kcal/g) dietary fibre
(1)
. They enhance
water absorption in the colon, and thus prevent constipation.
Propionate has been shown to inhibit the activity of the
enzyme hydroxy-3-methylglutaryl-CoA reductase, the limiting
enzyme for cholesterol synthesis. Dietary fibre has the ability
to bind with bile acids and prevents their reabsorption in the
liver, and thus inhibit cholesterol synthesis
(2)
. Butyrate
enhances cell differentiation, thus preventing tumour
formation in the colon
(3)
. Dietary fibre’s viscous and fibrous
structure can control the release of glucose with time in the
blood, thus helping in the proper control and management of
diabetes mellitus and obesity
(4,5)
. The glycaemic index (GI),
a classification of food based on the blood glucose response
relative to a starchy food, for example, white bread, or a
standard glucose solution, has been proposed as a therapeutic
principle for diabetes mellitus by slowing carbohydrate
absorption
(4,5)
. Low-GI foods, for example, high-dietary fibre
foods, have been shown to reduce postprandial blood glucose
and insulin responses and improve the overall blood glucose
and lipid concentrations in normal subjects and patients with
diabetes mellitus
(6 – 9)
. A previous study on dietary fibre and
fermentability of legumes showed that legumes are good
sources of dietary fibre (21 –47 g/100 g sample), fermentable
in the colon, and produce SCFA such as acetate, propionate
and butyrate
(10)
.
The general objective of the present study is to determine
the potential health benefits of legumes as good sources of die-
tary fibre. The specific objectives are as follows: (a) to determine
mineral availability in vitro from legumes; (b) to determine
the GI of legumes from non-diabetic and diabetic human
subjects; (c) to determine the cholesterol-lowering effect of
legumes in human subjects with moderately raised serum
cholesterol level. The utilisation of legumes as functional
foods will not only solve the problem of micronutrient
deficiencies and chronic diseases now prevailing in almost
all countries but also encourage the industry and farmers to
produce value-added or healthy products from legumes.
Materials and methods
Test foods
In the present study ten legumes were used as test foods: cow-
peas (Vigna unguiculata (L.) Walp.), mung beans (V. radiata
(L.) R. Wilczek), pole sitao (V. unguiculata subsp. sesquipe-
dalis (L.) Verde), chickpeas (Cicer arietinum), green peas
(Pisum sativum L.), groundnuts (Arachis hypogaea L.),
pigeon peas (Cajanus cajan), kidney beans (Phaseolus
*Corresponding author: Dr Trinidad P. Trinidad, fax þ63 2 8391836, email tpt@fnri.dost.gov.ph
Abbreviation: GI, glycaemic index.
British Journal of Nutrition (2010), 103, 569–574 doi:10.1017/S0007114509992157
qThe Authors 2009
British Journal of Nutrition
vulgaris L.), lima beans (Phaseolus lunatus) and soyabeans
(Glycine soja). Food samples were bought in local markets.
Legumes were soaked in water overnight, and boiled to
cook the next day. Legumes were freeze-dried before
analyses.
Analytical methods
The proximate analysis, and analysis of dietary fibre and
SCFA content of legumes were performed previously
(10 – 11)
.
Total Fe, Zn and Ca were analysed by the wet digestion
method. A 0·1 g sample of freeze-dried test food was weighed
and dissolved in 1 ml of 36 N-sulfuric acid (Analytical
Reagent; Ajax Chemical, Auburn, NSW, Australia) and 3 ml
of 30 % H
2
O
2
(Analytical Reagent; Ajax Chemical), and
made up to 50 ml volume with double deionised water. For
Ca, the digested sample was made up to 50 ml volume with
10 mM-lanthanum chloride (Analytical Reagent, Asia Pacific
Specialty Chemical Limited, Seven Hills, NSW, Australia).
The resulting solution was read in an atomic absorption spec-
trophotometer (Buck Scientific, East Norwalk, CT, USA).
Phytic acid using the Association of Official Analytical
Chemists (AOAC) method and tanmic acids were also
analysed from the test food
(12 – 13)
.
Study 1: Determination of mineral availability, in vitro
Fe, Zn and Ca availability was determined following the
method of Trinidad et al.
(14)
. This method simulated the
amount of mineral released that can be potentially absorbed
in the small intestine and colon.
Study 2: Glycaemic index of legumes
In the study eight legumes were used as test foods: cowpeas,
mung beans, pole sitao, chickpeas, green peas, groundnuts,
pigeon peas and kidney beans. The test foods were prepared
at the Nutrient Availability Section, Food and Nutrition
Research Institute, Department of Science and Technology.
Legumes were soaked in water overnight, boiled the next
day (time of cooking ranged from 20 to 45 min), cooled over-
night and fed to subjects after warming them in a microwave
oven. The control (standard) food was white bread prepared in
a bread maker (Regal Kitchen Pro Collection, KCTNO4584,
made in China, serviced in USA) following the formulation
of Wolever et al.
(9)
as follows: 334 g flour (Wooden Spoon
All Purpose Flour; Pillmico Mauri Food Corporation,
Kwalan Cove, Iligan City, Philippines), 4 g salt, 5 g yeast,
7 g sucrose and 330 ml water per 250 g carbohydrate loaf.
Crust ends were not used for the test meals.
Study participants. Non-diabetic (n7) and diabetic (n6)
human subjects (type 2, non-insulin-dependent diabetes melli-
tus) were physically examined by a medical doctor and eval-
uated by an endocrinologist on the basis of the following
criteria: non-diabetics: BMI 20– 30 kg/m
2
(WHO criteria),
fasting blood glucose 4 –7 mmol/l, aged 35 –60 years,
no physical defect and non-smokers; diabetics: BMI
20 –30 kg/m
2
, fasting blood glucose 7·5 –11·0 mol/l, aged
35– 60 years, no intake of drugs, no complications and non-
smokers. Each subject was interviewed for physical activity
and was asked to fill up a 3 d food intake recall form. Subjects
with common food intake (pattern) and physical activity were
included in the study. The participants’ inclusion in the study
was also based on fasting serum uric acid not greater than
405 mmol/l. The diabetic participants were managed through
dietary consultations and advice.
Protocol of the study. Using a randomised cross-over
design, the control and test foods were fed in random order
on separate occasions after an overnight fast. The control
and test foods contained 50 g available carbohydrates. The
participants were told to fast overnight (10–12 h) before the
start of the study. Feeding of white bread and test foods
were repeated twice.
Blood samples approximately of 0·3– 0·4 ml were collected
by finger prick before and after feeding in a 4 mm diameter
and 10 cm long capillary tubing (PYREX
w
; Corning, Inc.,
Corning, NY, USA) and sealed (Jockel Seal Sticks Cement,
catalogue no. 2454 W15; AH Thomas, Philadelphia, PA,
USA). For non-diabetic participants, samples were collected
at 0 h and every 15 min after feeding for 1 h and every
30 min for the next 1 h while for diabetics, samples were col-
lected at 0 h and at 30 min interval after feeding for a period of
3 h. The serum was separated from the blood using a refriger-
ated centrifuge after all the blood was collected (Expender
Centrifuge; Eppendorf, Hamburg, Germany), and analysed
for glucose levels on the same day using a clinical chemistry
analyser (ARTAX Menarini Diagnostics, Firenze, Italy) after
calibration with the glucose standard (Glucofix Reagent 1;
Menarini Diagnostics, Firenze, Italy). The area under the glu-
cose response curve for each food, ignoring area below the
fasting level, was calculated geometrically
(15)
. The GI of
each food was expressed as the percentage of the mean
glucose response of the test food divided by the standard
food taken by the same subject and was determined by the
following formula:
GI ¼ðIAUC of the test food £100Þ=ðIAUC of the
standard foodÞ;
where IAUC is the incremental area under the glucose
response curve.
Study 3: Cholesterol-lowering effect in human subjects with
moderately raised serum cholesterol levels
In the study six legumes were used, as follows: mung beans,
chickpeas, green peas, groundnuts, pigeon peas and kidney
beans. The test foods were prepared as described above.
Study participants. The study participants were selected
based on the following criteria: moderately raised serum
cholesterol level (200– 239 mg cholesterol per 100 g serum
based on WHO criteria); aged 30– 60 years, no drug intake
for cholesterol-lowering and no complications. They were
interviewed to obtain data on their usual 3 d food intake,
physical activity and smoking habits. The total number of
study participants in the study was twenty (eighteen females
and two males).
Protocol of the study. The study was conducted in a
22-week period (5·5 months), consisting of six 2-week exper-
imental periods, each experimental period separated by a
2-week washout period for a total of five washout periods.
The test foods contained 50 g available carbohydrates.
T. P. Trinidad et al.570
British Journal of Nutrition
Study participants served as their own control. The study par-
ticipants were made to fast overnight (10 –12 h fasting) before
the study. They were weighed, their blood pressure measured
and a sample of blood from their forearm vein was taken. The
study participants were given the test foods to consume every
day to ensure compliance of the participants, except on Fri-
days when three test foods were given to include Saturday
and Sunday intakes. They recorded their respective food
intakes for the duration of the experimental study. On day
15, blood was drawn from the participants after an overnight
fast. Blood samples were taken into plain glass tubes from
the forearm vein, left to clot at room temperature, centrifuged,
and the serum separated. Total cholesterol, HDL-cholesterol
and TAG were measured in a clinical chemistry analyser
(ARTAX; Menarini Diagnostic, Florence, Italy) against stan-
dards (cholesterol, cholesterol standard, 2000 mg/l; HDL-
cholesterol, cholesterol standard, 500 mg/l; TAG, glycerol
standard, 2000 mg/l; all Sentinel CH, Milan, Italy). The
amount of LDL was estimated from the formula used by
Wolever et al.
(16)
as follows:
LDL ¼ððtotal cholesterol 2HDLÞ2TAG=2·2Þ:
The study was conducted according to the guidelines laid
down in the Declaration of Helsinki and all procedures invol-
ving human subjects were approved by the National Human
Ethics Committee, Philippine Council for Health Research
and Development, Department of Science and Technology,
Metro Manila, Philippines. Voluntary written consent forms
were obtained from the study participants.
Statistical analysis
The sample size was chosen to achieve 80 % power at the 5 %
level of significance. Differences between test foods and bio-
markers were determined by two-way repeated-measures
ANOVA and Duncan’s multiple-range test, and correlation
coefficients were determined to relate GI and the different
nutrients present in the test foods using SAS (SAS Institute,
Inc., Gary, NC, USA).
Results
Study 1: Determination of mineral availability, in vitro
Table 1 shows the total mineral, phytic acid and tannic acid
content of legumes. Among the legumes, soyabeans, pole
sitao, cowpeas and mung beans are the best sources of Fe
while pole sitao, groundnuts and cowpeas are the best sources
of Zn. Soyabeans, kidney beans, chickpeas and pigeon peas
are the best sources of Ca. A previous study showed that the
best source of dietary fibre among legumes was soyabeans
(46·9 g per 100 g sample) followed by pole sitao (35 g per
100 g sample) and cowpeas (34 g per 100 g sample)
(10)
. Soya-
beans have the highest phytic acid content followed by
cowpeas, mung beans and groundnuts. Tannic acid is highest
in pigeon peas followed by pole sitao and cowpeas. Dialysable
mineral as a percentage of total mineral content of legumes is
used as a measure of mineral availability. Fe availability is
significantly greater from lima beans (Table 2; P,0·05),
while for Zn availability, kidney beans and lima beans
(P,0·05). Ca availability is significantly greater from
pigeon peas, green peas and pole sitao (P,0·05).
Study 2: Glycaemic index of legumes
The BMI of the non-diabetic subjects was found to be 25·0
(SD 0·6) kg/m
2
; for the diabetics, BMI was 26·8 (SD 1·2)
kg/m
2
. There were no significant differences between the
non-diabetic and diabetic subjects for age and BMI. There
were significant differences observed between subjects
for the fasting blood glucose; that of diabetic subjects
(7·5– 8·5 mmol/l glucose) was significantly greater than that
of the normal subjects (4 – 6 mmol/l glucose; P,0·05).
The initial blood glucose obtained from the non-diabetic
participants for all test foods did not exceed 6·0 mmol/l. All
participants were able to consume all test foods (white bread
twice, test foods twice). Table 3 shows the GI of the test
foods. The GI of the test foods were adjusted to 0·7 to
obtain GI value for the same food on the glucose scale.
Local legumes are considered low-GI foods (GI ,55)
(Table 3). Significant differences in GI were observed in
non-diabetic and diabetic participants for the following
Table 1. Mineral, phytic acid and tannic acid content of legumes (mg per 100 g sample)*
(Mean values with their standard errors)
Fe Zn Ca Phytic acid Tannic acid
Mean SEM Mean SEM Mean SEM Mean SEM Mean SEM
Cowpeas (Vigna unguiculata (L.) Walp.) 10·6
c,y
0·1 6·5
a,b,z
0·6 20·9
e,x
0·2 542·4
b
10·4 368·8
c
6·6
Mung beans (V. radiata (L.) R. Wilczek) 10·7
c,y
0·2 4·8
c,d,z
0·4 27·3
d,x
0·9 488·6
c
0·8 269·8
f
1·6
Pole sitao (V. unguiculata subsp. sesquipedalis (L.) Verde) 11·3
b,y
0·2 7·4
a,z
0·3 20·0
f,x
0·1 433·7
d
4·7 522·6
b
4·3
Chickpeas (Cicer arietinum)7·7
f,y
0·2 4·7
d,z
0·1 51·7
b,x
0·4 278·7
g
0·2 72·1
i
0·8
Green peas (Pisum sativum L.) 7·3
f,y
0·3 5·4
c,z
0·5 33·1
c,x
3·8 308·5
f
3·3 82·1
h
2·2
Groundnuts (Arachis hypogaea L.) 4·2
h,z
0·3 7·3
a,b,y
1·2 10·6
g,x
0·3 470·9
c
9·4 312·6
d
2·9
Pigeon peas (Cajanus cajan)5·4
g,z
0·1 6·1
b,y
0·1 51·4
b,x
4·7 347·2
e
2·0 604·6
a
1·1
Kidney beans (Phaseolus vulgaris L.) 9·8
d,y
0·5 4·2
d,z
0·3 56·2
b,x
2·3 342·4
e
5·6 92·1
h
1·0
Lima beans (Phaseolus lunatus)8·6
e,y
0·5 5·1
b,c,z
1·3 31·7
c,x
2·2 341·2
e
4·4 303·9
e
3·1
Soyabeans (Glycine soja)16·1
a,y
0·2 6·6
b,z
0·3 150·2
a,x
1·2 755·5 3·7
a
219·9
g
1·2
a–h
Mean values within a column with unlike superscript letters were significantly different (P,0 ·05).
x,y,z
Mean values for minerals within a row with unlike superscript letters were significantly different (P,0·05).
* The mineral, phytic acid and tannic acid contents of legumes were analysed as part of the mineral availability, in vitro study.
Benefits of legumes as a source of fibre 571
British Journal of Nutrition
legumes: cowpeas, mung beans, pole sitao and kidney beans
(Table 3; P,0·05).
Study 3: Cholesterol-lowering effect in human subjects with
moderately raised serum cholesterol levels
There was a decreasing trend in both total and LDL-choles-
terol levels among study participants fed with legumes for
14 d (Table 4). However, only kidney beans gave significant
decreases for both total (6 %) and LDL-cholesterol (9 %)
and groundnuts for total cholesterol (7 %). No significant
increase in HDL-cholesterol was observed. Similar results
were observed for TAG (Table 4).
Discussion
Mineral availability from legumes differed and may be attrib-
uted to the mineral content, mineral– mineral interaction, and
the presence of phytic and tannic acids
(17 – 21)
. Fe availability
from legumes was reduced by higher tannic acid content.
The phytic and tannic acid content of legumes did not affect
Zn availability except for groundnuts in terms of phytic acid
content. In general, it was observed that when Ca and Zn
availability was high, Fe availability was low from all of the
legumes studied (Table 2).
Results of the study showed that equal carbohydrates por-
tions (50 g available carbohydrates) of the different test
foods do not have the same glycaemic effect in non-diabetic
and diabetic participants (Table 3). The amount of dietary
fibre present in the test foods may have caused significant
differences in the GI of legumes. Dietary fibre may cause a
delay in the glycaemic responses of legumes similar to pre-
vious studies on dietary fibre and GI of foods
(4,5,15)
. The
increasing levels of dietary fibre, viscosity, cooking, particle
size, form of food and starch structure may all be attributed
to slower nutrient absorption and delayed transit time
(22 – 24)
.
Considering the dietary fibre present in whole foods, insoluble
fibre was related more strongly to the GI than soluble fibre
content
(23)
. The insoluble fibre content of legumes was signifi-
cantly greater than that of soluble fibre in the present study
(10)
.
On the other hand, most of the legumes studied contain protein
in the range of 20– 28 g per 100 g
(10)
. According to several
Table 2. Mineral availability in vitro from legumes*
(Mean values with their standard errors)
Percentage of total mineral content (mg/mg)
Fe Zn Ca
Mean SEM Mean SEM Mean SEM
Cowpeas (Vigna unguiculata (L.) Walp.) 1·9
d,z
0·3 46·9
a,b,y
4·3 64·2
b,x
3·2
Mung beans (V. radiata (L.) R. Wilczek) 7·3
b,z
0·6 40·4
b,c,y
3·4 60·0
b,x
3·7
Pole sitao (V. unguiculata subsp. sesquipedalis (L.) Verde) 2·6
c,d,z
0·9 38·8
c,y
0·8 65·2
a,x
5·5
Chickpeas (Cicer arietinum)3·8
c,z
0·8 16·7
f,y
0·7 41·9
c,x
0·1
Green peas (Pisum sativum L.) 4·1
c,z
2·3 30·6
d,y
2·3 68·5
a,x
2·1
Groundnuts (Arachis hypogaea L.) 1·3
d,z
1·1 7·9
g,y
1·3 14·6
e,x
2·8
Pigeon peas (Cajanus cajan)2·7
c,d,z
2·0 31·9
d,y
4·7 75·1
a,x
7·1
Kidney beans (Phaseolus vulgaris L.) 5·7
b,c,z
2·0 49·3
a,x
4·5 30·0
d,y
0·8
Lima beans (Phaseolus lunatus)9·5
a,z
0·1 47·4
a,y
0·7 56·6
b,x
4·4
Soyabeans (Glycine soja)8·2
b,z
0·6 21·8
e,x
1·8 16·7
e,y
0·4
a–g
Mean values within a column with unlike superscript letters were significantly different (P,0·05).
x,y,z
Mean values within a row with unlike superscript letters were significantly different (P,0·05).
* Mineral availability in vitro estimates the mineral released from food for potential absorption in the small intestine and colon.
Table 3. Glycaemic index (GI) of local legumes in non-diabetic and diabetic participants*
(Mean values with their standard errors)
Non-diabetic (n7) Diabetic (n6)
Mean SEM Mean SEM
Cowpeas (Vigna unguiculata (L.) Walp.) 11
b,x
17
b,y
1
Mung beans (V. radiata (L.) R. Wilczek) 15
a,x
111
a,y
2
Pole sitao (V. unguiculata subsp. sesquipedalis (L.) Verde) 9
c,x
16
b,c,y
1
Chickpeas (Cicer arietinum)6
e,x
15
c,x
1
Green peas (Pisum sativum L.) 9
b,c,x
29
a,x
2
Groundnuts (Arachis hypogaea L.) 7
d,x
15
c,x
1
Pigeon peas (Cajanus cajan)9
c,x
17
a,b,c,x
1
Kidney beans (Phaseolus vulgaris L.) 13
a,x
19
a,b,y
1
a–e
Mean values within a column with unlike superscript letters were significantly different (P,0·05).
x,y
Mean values within a row with unlike superscript letters were significantly different (P,0·05).
* The GI of the different legumes were calculated from the glucose response of the food ingested in diabetic and non-diabetic
participants by dividing the incremental area under the curve (IAUC) of the legume by the IAUC of standard glucose
multiplied by 100.
T. P. Trinidad et al.572
British Journal of Nutrition
investigators, 20 –30 g dietary protein increased insulin
responses sufficiently and reduced glycaemic responses
especially in individuals with non-insulin-dependent diabetes
mellitus
(25,26)
. The protein content of the test foods may
have played a significant role in the low GI of some legumes
tested. The fat content of legumes ranged from 0·2 to 5·8 g per
100 g and may not affect the glycaemic responses of the study
participants from the foods ingested
(10)
. A sufficient amount of
fat in food (23 g fat/kg) can cause an early (0– 90 min)
decrease in glucose response but does not affect the overall
glucose response to food
(25)
. The differences in glucose
responses between the two groups (non-diabetics and dia-
betics) may be due to rates of digestion and absorption in
relation to the food ingested.
Legumes have been shown to be hypercholesterolaemic
foods, for example, kidney beans and groundnuts. Studies on
mixed legumes suggested that their consumption lowers
LDL-cholesterol by partially interrupting the enterohepatic
circulation of bile acids and increases cholesterol saturation
of bile by increasing the secretion of cholesterol
(27)
. Consump-
tion of pinto beans showed decreases in both LDL- and HDL-
cholesterol without affecting serum TAG, VLDL-cholesterol,
or glucose
(28)
. Epidemiological studies revealed significant
inverse relationships between legume intake and the risk of
CVD and CHD. The hypocholesterolaemic property of dietary
fibre in legumes is associated with the water-soluble fraction
of fibre which is fermentable in the colon, for example, galac-
tomannans, uronic acid, glucomannans and galacturonic acids.
However, various water-soluble fibres may differ in their abil-
ity to reduce serum cholesterol
(29,30)
. The Lipid Research
Clinics Coronary Primary Prevention Trial predicted that for
every 1 % decrease in serum cholesterol concentration, there
is a decreased risk of CHD of 2 %
(31)
. There was no significant
increase or decrease in HDL-cholesterol levels of all study
participants. The concentration of serum HDL-cholesterol is
affected by alcohol intake and BMI
(32)
. However, all study
participants were not alcohol drinkers and BMI was not sig-
nificantly different between participants during the duration
of the experimental period. The study on cholesterol-lowering
effects was a short-term (acute) study. A longer-term nutrition
intervention study may give a more conclusive result.
Conclusion
In conclusion: (a) mineral availability from legumes studied dif-
fered and may be attributed to the mineral content, mineral–
mineral interaction, and the presence of phytic and tannic
acids; (b) legumes are considered to be low-GI foods
(GI ,55); (c) some legumes have shown hypocholesterolae-
mic effects. The study may have a significant role in the
proper control and management of chronic diseases, for
example, obesity, diabetes mellitus, cancer and CVD, and
may also contribute in decreasing the prevalence of Fe, Zn
and Ca deficiency. The study can be a scientific basis for
considering legumes as functional foods or functional food
ingredients to supplement rice, bread and other food products.
The utilisation of legumes as functional foods will also encou-
rage the industry and farmers to produce value-added or healthy
products from legumes as well as increase their production.
Table 4. Serum total, HDL- and LDL-cholesterol, and TAG of study participants (eighteen females and two males) fed with legumes†
(Mean values with their standard errors)
Total cholesterol HDL LDL TAG
Before After Before After Before After Before After
Mean SEM Mean SEM Mean SEM Mean SEM Mean SEM Mean SEM Mean SEM Mean SEM
Kidney beans (Phaseolus vulgaris L.) 246 7 231* 7 35 3 36 2 181 7 165* 6 155 12 154 12
Groundnuts (Arachis hypogaea L.) 241 8 225* 7 48 4 43 4 167 9 157 9 133 8 130 9
Mung beans (V. radiata (L.) R. Wilczek) 230 8 223 8 35 3 38 3 164 8 158 6 151 12 135 11
Green peas (Pisum sativum L.) 219 9 212 8 35 2 32 3 155 7 150 6 152 15 153 12
Chickpeas (Cicer arietinum) 241 7 240 10 37 2 34 3 171 5 170 2 173 12 180 20
Pigeon peas (Cajanus cajan) 239 8 237 7 35 3 37 3 170 7 165 5 170 19 178 14
* Mean value was significantly lower than that before ingestion of the test food (P,0·05).
† The changes in serum total, LDL- and HDL-cholesterol as well as TAG were determined before and after ingestion of the test food for 2 weeks with a 2-week washout period in between the test foods.
Benefits of legumes as a source of fibre 573
British Journal of Nutrition
Acknowledgements
The project was supported by the Food and Nutrition Research
Institute, Department of Science and Technology (FNRI,
DOST), Philippines.
The authors wish to thank Mr Zoilo B. Villanueva, Ms
Elaine S. Perez, Ms Josefina A. Desnacido and Ms Paz
S. Lara, Nutritional Biochemistry Section, FNRI, DOST for
their technical assistance.
T. P. T. was the project leader of the study and supervised
the implementation of the project, analysed the data and
results, and wrote the paper for publication. A. C. M. and
A. S. L. determined the mineral availability from food
samples. R. S. S. was in charge of feeding the participants
with test samples and analysis of lipid profiles, while R. R.
E. prepared the food samples and analysed the glucose
responses of study participants. All authors read and approved
the findings of the study.
There is no conflict of interest in the publication of this
paper.
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