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Background: Previous studies reported inconsistent findings regarding the effects of psyllium supplementation on obesity measures. This systematic review and meta-analysis was performed to summarize data from available randomized clinical trials (RCTs) on the effect of psyllium supplementation on body weight, body mass index (BMI), and waist circumference (WC) in adults. Methods: PubMed, SCOPUS, Cochrane Library, and Google Scholar were searched to identify relevant articles up to August 2018. The effect sizes were presented as weighted mean difference (WMD) and 95% confidence intervals (CI) by using random effects model. To detect dose-response relationships, we used fractional polynomial modeling. Results: A total of 22 RCTs were included. Meta-analysis did not find any significant effect of psyllium supplementation on body weight (MD: -0.28 kg, 95% CI: -0.78, 0.21, p = 0.268), BMI (MD: -0.19 kg/m2, 95% CI: -0.55, 0.15, p = 0.27) and WC (MD: -1.2cm, 95% CI: -2.6, 0.2, p = 0.09). Subgroup analysis showed that psyllium dosage, kind of psyllium administration, duration of trial, study design, sample size, and gender were potential sources of heterogeneity. Moreover, there was nonlinear association between duration of psyllium consumption, BMI and WC. Conclusion: Psyllium supplementation does not reduce body weight, BMI, and WC significantly.
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Critical Reviews in Food Science and Nutrition
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The effects of psyllium supplementation on body
weight, body mass index and waist circumference
in adults: A systematic review and dose-response
meta-analysis of randomized controlled trials
Manije Darooghegi Mofrad, Hadis Mozaffari, Seyed Mohammad Mousavi, Ali
Sheikhi & Alireza Milajerdi
To cite this article: Manije Darooghegi Mofrad, Hadis Mozaffari, Seyed Mohammad Mousavi,
Ali Sheikhi & Alireza Milajerdi (2019): The effects of psyllium supplementation on body weight,
body mass index and waist circumference in adults: A systematic review and dose-response meta-
analysis of randomized controlled trials, Critical Reviews in Food Science and Nutrition, DOI:
10.1080/10408398.2018.1553140
To link to this article: https://doi.org/10.1080/10408398.2018.1553140
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Published online: 18 Mar 2019.
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REVIEW
The effects of psyllium supplementation on body weight, body mass index
and waist circumference in adults: A systematic review and dose-response
meta-analysis of randomized controlled trials
Manije Darooghegi Mofrad
a,b
, Hadis Mozaffari
a
, Seyed Mohammad Mousavi
a
, Ali Sheikhi
a
, and
Alireza Milajerdi
a,b
a
Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS),
Tehran, Iran;
b
StudentsScientific Research Center (SSRC), Tehran University of Medical Sciences (TUMS), Tehran, Iran
ABSTRACT
Background: Previous studies reported inconsistent findings regarding the effects of psyllium
supplementation on obesity measures. This systematic review and meta-analysis was performed to
summarize data from available randomized clinical trials (RCTs) on the effect of psyllium supple-
mentation on body weight, body mass index (BMI), and waist circumference (WC) in adults.
Methods: PubMed, SCOPUS, Cochrane Library, and Google Scholar were searched to identify
relevant articles up to August 2018. The effect sizes were presented as weighted mean difference
(WMD) and 95% confidence intervals (CI) by using random effects model. To detect dose-response
relationships, we used fractional polynomial modeling.
Results: A total of 22 RCTs were included. Meta-analysis did not find any significant effect of
psyllium supplementation on body weight (MD: 0.28 kg, 95% CI: 0.78, 0.21, p¼0.268), BMI
(MD: 0.19 kg/m
2
, 95% CI: 0.55, 0.15, p¼0.27) and WC (MD: 1.2 cm, 95% CI: 2.6, 0.2,
p¼0.09). Subgroup analysis showed that psyllium dosage, kind of psyllium administration, dur-
ation of trial, study design, sample size, and gender were potential sources of heterogeneity.
Moreover, there was nonlinear association between duration of psyllium consumption, BMI
and WC.
Conclusion: Psyllium supplementation does not reduce body weight, BMI, and WC significantly.
KEYWORDS
Psyllium; body weight;
anthropometry;
meta-analysis
Introduction
Overweight and obesity are one of the most important pub-
lic health problems (World Health Organization 2003).
Some studies have shown that approximately 1.5 billion
adults are overweight (World Health Organization 1999)
which over 300 million of them are obese (Wilborn et al.
2005). According to recent surveys throughout the world, the
number of persons who are overweight or obese is increasing
(Collaboration 2016). It is well known that obesity could con-
tribute to some chronic diseases such as type 2 diabetes melli-
tus (Pagotto et al. 2008), cardiovascular diseases (Artham
et al. 2008), dyslipidemia (Fried et al. 2008), fatty liver
(Marovi
c2008). There is no single or simple approach to
decrease growing rate of obesity due to multidimensional
nature of this problem. New interventions are needed to
effectively prevent and treat overweight and obesity.
It is established that modification of diet could be critic-
ally effective to prevent obesity or improve weight manage-
ment (Fock & Khoo 2013). Epidemiological studies have
shown that higher fiber consumption is associated with
lower body weight, BMI, WC (Du et al. 2010; Newby et al.
2007; Thompson et al. 2017), improved blood lipids (Brown
et al. 1999; Lairon et al. 2005; Wu et al. 2003), glycemic and
insulin response (Thompson et al. 2017). However, it is
difficult for people to consume fruits and vegetables so
much that provide the required amount of fiber for the
body (Clemens et al. 2012; Trumbo et al. 2002). Thus,
supplementation with fiber could be an easy, cost-effective
approach to increase fiber intake.
The ground husk of psyllium seed (psyllium plantago or
plantago ovata) consists of a mixture of polysaccharides con-
taining hexoses, pentoses, anduronic acids (Rotblatt 2000).
It is a viscous, soluble, gel-forming non-fermented fiber
supplement. Psyllium supplement is quite popular among
consumers since it is financially practical, and is released with
different flavors and in various forms such as capsules,
wafers, powdered drink mixes. The advantages of taking psyl-
lium over other kinds of soluble fibers are that it is less read-
ily fermented and consequently the prevalence of flatulence
and abdominal bloating is fairly low (Blackwood et al. 2000).
Various human studies examined the effect of psyllium
on glucose and insulin homeostasis, lipids and lipoprotein,
body weight, body composition and appetite (Anderson
et al. 2000; Delargy et al. 1997; Pal et al. 2011; Tai et al.
CONTACT Alireza Milajerdi amkhv@yahoo.com Department of Community Nutrition, School of Nutritional Science and Dietetics, Tehran University of
Medical Sciences, No. 44, Hojjat-dost Alley, Naderi St., Keshavarz Blvd, Tehran, Iran.
Supplemental data for this article can be accessed at https://doi.org/10.1080/10408398.2018.1553140
ß2019 Taylor & Francis Group, LLC
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION
https://doi.org/10.1080/10408398.2018.1553140
1999; Ziai et al. 2005). Psyllium can affect body composition
through several mechanisms including gastric emptying
(Yao and Roberts 2001), satiety (Holt et al. 1992), gut hor-
mones such as cholecystokinin (Burton-Freeman, Davis, and
Schneeman 2002), and change in the glycemic index or
insulin response (Anderson et al. 2004).
However, the studies that were conducted on humans
showed rather controversial results as most of them proved
that there is no significant relationship between psyllium
consumption and improvement of body weight and body
composition (Rodrıguez-Mor
an, Guerrero-Romero, and
Lazcano-Burciaga 1998; Sol
a et al. 2010). However, it was
seen in other clinical trial studies that psyllium supplemen-
tation might lead to weight loss (Abutair, Naser, and Hamed
2016; Noureddin, Mohsen, and Payman 2018).
Some reviews examined the effect of psyllium supplemen-
tation on obesity measures (Jane, McKay, and Pal 2018; Pal
and Radavelli-Bagatini 2012; Wanders et al. 2011). However,
they have investigated a considerable low number of studies
and the findings of them are inconsistent. To the best of
our knowledge, no meta-analysis has been conducted to
examine the effects of psyllium supplementation on obesity
indices in adults. Here, we have performed a systematic
review and meta-analysis of randomized clinical trials to
evaluate the effectiveness of psyllium supplementation on
weight loss in adults.
Methods
Data source and search strategy
A systematic review and meta-analysis of RCTs were con-
ducted based on the Preferred Reporting Items for
Systematic Reviews and Meta-analyses (PRISMA) guidelines
(Moher et al. 2009).
We systematically searched PubMed, SCOPUS, Cochrane
Library, and Google Scholar up to August 2018 through
Medical subject headings (MESH) and following keywords:
(Plantago OR Psyllium OR Metamucil OR Lunelax OR
mucilage OR ispaghula OR psyllium-husk OR psyllium
husk) AND (Obesity OR Obesity/complications OR Intra-
Abdominal Fat OR Abdominal Fat OR body weight OR
body mass index OR Waist Circumference OR Waist-Hip
Ratio OR Waist-Height Ratio OR Abdominal obesity OR
waist OR BMI OR WC OR WHR OR WHtR OR anthro-
pometryOR fatness OR visceral OR central obesity OR vis-
cera OR Lean body mass OR body fat OR fat mass OR
metabolic syndrome OR body compositionOR percentage
fat mass OR FM OR %FM OR visceral adipose tissue OR
overweight OR adiposity). Moreover, the reference lists of
the included studies and related reviews were searched to
find other relevant trials. There was no restriction on publi-
cation dates or languages.
Eligibility criteria
Studies were included if they had the following criteria: (1)
evaluated the effect of psyllium intake on weight, BMI, and
WC; (2) the study design was RCT (either parallel or cross-
over design), (3) recommended psyllium consumption
(whether prescribed through supplements or added to
foods), (4) had control group; (5) reported sufficient infor-
mation about weight, BMI, and WC at baseline and the final
of the intervention or change in psyllium and the control
group, (6) done on adult subjects (>18 years), (7) were pub-
lished in English.
Studies were excluded if they had the following exclusion
criteria: (1) non-RCTs studies, (2) carried out on children,
pregnant women or animals, (3) investigated the effect of
other interventions along with psyllium in cases but not in
control group, (4) studies with no control group, (5) studies
not written in the English language, (6) studies did not
report weight, BMI, and WC at baseline and the end of the
intervention or change in, (7) studies that their full text was
inaccessible. In addition, studies which reported mean
change and standard deviation (SD) in percentage were
also excluded.
Two reviewers (MDM and HM) independently assessed
titles, abstracts and then if necessary the full text of the
articles based on inclusion and exclusion criteria whereas a
chief investigator (AM) was also present to resolve any dif-
ferences or controversies.
Data extraction
Two reviewers (MDM and HM) independently abstracted
the outcomes of interest from the included studies. Eligible
studies were reviewed and the following data were extracted:
(1) the first authors name; (2) year of publication; (3) study
location; (4) study design; (5) health status; (6) number of
participants in the psyllium and control groups; (7) age
(mean, range), gender and number of individuals in each
gender; (8) baseline, final and change values of anthropo-
metric indices; (9) type of psyllium and placebo; (10) how
psyllium supplementations were administered and dose of
psyllium; (11) duration of treatment; (12) type of outcome
(primary/secondary); (13) influences of psyllium intake on
outcomes (yes/no). In studies where effect sizes were
reported multiple times during follow-up, the effect size
after the longest follow-up was used. In studies with the
similar target population, we selected the study that had a
greater number of subjects.
Quality assessment
Cochrane criteria were used for quality assessment in the
included studies (Higgins 2011). Two authors (MDM and
HM) independently assessed the risk of bias in each study
by following criteria: random sequence generation, allocation
sequence concealment, blinding of participants and person-
nel, blinding of outcome assessment, incomplete outcome
data, selective outcome reporting and other potential sources
of bias. Studies were classified as low risk, high risk or
unclear based on each item (Table 1).
2 M. DAROOGHEGI MOFRAD ET AL.
Statistical analysis
To estimate the overall effect size of the intervention, we
used the mean change and SD for weight, BMI, and WC.
The SD of the mean change for studies that not reported
was estimated by the following formula: SD
change
¼square
root [(SD
baseline2
þSD
final2
)(2 RSD
baseline
SD
final
)]
(Borenstein et al. 2011). The correlation coefficient of the
formula was calculated using data from included studies
reporting both baselines, final mean and SD as well as
changes in body weight, BMI and WC (R¼0.9). The effect
sizes were presented as the weighted mean difference
(WMD) and 95% confidence intervals (CI) using the ran-
dom-effects model (DerSimonian and Laird method). To
assess heterogeneity across studies, we used the Q test and
I
2
index (Higgins et al., 2003). Subgroup analysis was con-
ducted based on pre-defined factors, including gender, sam-
ple size, control group type (control, placebo), study
duration (<10 wk, 10 wk), study design (parallel or cross-
over design), kind of psyllium administration (food, supple-
ment), and psyllium dosage (<10 g/d, 10 g/d) to identify
the potential source of heterogeneity. A sensitivity analysis
was conducted to evaluate the effect of each study on overall
effect size. Publication bias was assessed using visual evalu-
ation of funnel plots and Eggers weighted regression tests.
If any publication bias was found, Duval & Tweedie trim
and fillmethod was used to adjust analysis for its effects
(Duval and Tweedie 2000). The nonlinear potential effects
of psyllium dosage (g/day) and duration of treatment (wk)
were investigated using fractional polynomial modeling
(polynomials). All statistical analyses were carried on using
Stata software (version 14). P<0.05 was considered statistic-
ally significant.
Results
At first, we obtained 553 articles by initial search in data-
bases and reference lists. After eliminating 75 articles due to
duplication, we screened the remaining 478 articles by title
and abstract. After that, 64 articles were removed. After exe-
cuting our criteria 42 articles were excluded because of the
following reasons: were done on similar populations (n¼7),
did not report relevant data (n¼11), did not have accessible
full text (n¼6), did not provide complete data (n¼3), were
review articles (n¼2), abstracts (n¼3), as well as studies
that assessed the effect of psyllium along with other inter-
ventions (n¼8), and were not published in English language
(n¼2). In the end, twenty-two studies were included in the
current systematic review and meta-analysis. Flow-chart of
study selection is shown in Fig. 1.
Systematic review
Characteristics of the included studies are indicated in
Table 2. All the trials compared psyllium consumption with
a control groups and were written in English from 1983 to
2018. Totally, 1458 individuals participated in our included
studies (730 in intervention and 728 in control groups).
Table 1. Cochrane risk of bias assessment of randomized controlled trials of the effect of psyllium on anthropometry indices in adults.
Study
Random
sequence generation
Allocation
concealment
Blinding of
participants, personnel
Blinding of
outcome assessment
Incomplete
outcome data
Selective
outcome reporting
Other sources
of bias
Noureddin 2018 L L H H LLL
Ricklefs-Johnson, Johnston, and Sweazea (2017)L U L L LLL
Pal et al. (2016) LLL LLLL
Abutair, Naser, and Hamed (2016) UUU UULL
Akbarian et al. (2016) L L H H LLL
Akbarzade et al. (2015) L L U U L L L
Asghar, Gill, and Shah Murad (2011) U U H H L L L
Sol
a et al. (2010) LLL LLLL
Cicero et al. (2010) LHH HULL
Cicero et al. (2007)LULLULL
Sartore et al. (2009) UHH HULL
Vuksan et al. (2008) UUU ULLL
Sola et al. (2007) L U H H LLL
Cavaliere, Floriano, and Medeiros-Neto (2001)LLL LLLL
Romero (1998) UUU UULL
Rodrıguez-Mor
an, Guerrero-Romero, and
Lazcano-Burciaga (1998)
UUL L ULL
Davidson et al. (1998) L U L L LLL
Summerbell et al. (1994) LLL LULL
Wolever et al. (1994) UUU ULLL
Bell et al. (1990)ULLLULL
Anderson et al. (1988)ULLLULL
Hylander and R
ossner (1983)UULLULL
1
H: high risk of bias; L, low risk of bias; U, unclear risk of bias.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 3
They were aged from 18 to 80 yrs. Most of the trials were
carried out on overweight and obese subjects
(BMI >25 kg/m
2
). Three studies included healthy subjects
(Hylander and R
ossner 1983; Romero et al. 1998; Vuksan
et al. 2008) and other trials were conducted on patients with
hypercholesterolemia (Anderson et al. 1988; Asghar, Gill,
and Shah Murad (2012); Bell et al. 1990; Davidson et al.
1998; Romero et al. 1998; Sol
a et al. 2010; Summerbell et al.
1994; Wolever et al. 1994), diabetes (Abutair, Naser, and
Hamed 2016; Noureddin, Mohsen, and Payman 2018;
Ricklefs-Johnson, Johnston, and Sweazea 2017; Rodrıguez-
Mor
an, Guerrero-Romero, and Lazcano-Burciaga 1998;
Sartore et al. 2009), overweight or obesity (Cavaliere,
Floriano, and Medeiros-Neto 2001; Pal et al. 2016), nonalco-
holic fatty liver (NAFLD) (Akbarian et al. 2016; Akbarzadeh
et al. 2015), metabolic syndrome (Cicero et al. 2010), hyper-
tension (Cicero et al. 2007), and myocardial infarction or
stable angina (Sola et al. 2007). Four studies had cross-over
designs (Cavaliere, Floriano, and Medeiros-Neto 2001; Sola
et al. 2007; Vuksan et al. 2008; Wolever et al. 1994), while,
the rest eighteen studies had parallel designs (Abutair,
Naser, and Hamed 2016; Akbarian et al. 2016; Akbarzadeh
et al. 2015; Anderson et al. 1988; Asghar, Gill, and Shah
Murad (2012); Bell et al. 1990; Cicero et al. 2010; Cicero
et al. 2007; Davidson et al. 1998; Hylander and R
ossner
1983; Noureddin, Mohsen, and Payman 2018; Pal et al.
2016; Ricklefs-Johnson, Johnston, and Sweazea 2017;
Rodrıguez-Mor
an, Guerrero-Romero, and Lazcano-Burciaga
1998; Romero et al. 1998; Sartore et al. 2009; Sol
a et al.
2010; Summerbell et al. 1994). Studies were conducted in
United States (US) (n¼4) (Abutair, Naser, and Hamed
2016; Bell et al. 1990; Davidson et al. 1998; Ricklefs-
Johnson, Johnston, and Sweazea 2017), Iran (n¼3)
(Akbarian et al. 2016; Akbarzadeh et al. 2015; Noureddin,
Mohsen, and Payman 2018), Italy (n¼3) (Cicero et al.
2010; Cicero et al. 2007; Sartore et al. 2009), Canada (n¼2)
(Vuksan et al. 2008; Wolever et al. 1994), Spain (n¼2)
(Sol
a et al. 2010; Sola et al. 2007), Mexico (n¼2)
(Rodrıguez-Mor
an, Guerrero-Romero, and Lazcano-Burciaga
1998; Romero et al. 1998), United Kingdom (UK)
(Summerbell et al. 1994), Sweden (Hylander and R
ossner
1983), Brazil (Cavaliere, Floriano, and Medeiros-Neto 2001),
Lahore (Asghar, Gill, and Shah Murad (2012), Palestine
(Abutair, Naser, and Hamed 2016), Australia (Pal et al.
2016). One study was conducted exclusively on women
(Cavaliere, Floriano, and Medeiros-Neto 2001), while four
studies were done only on men (Anderson et al. 1988; Bell
et al. 1990; Romero et al. 1998; Sola et al. 2007). Psyllium
was administrated in doses varying between 1.7 and 15 g/d,
for an intervention duration of 248 weeks in the studies.
Psyllium was submitted as a food components (Bell et al.
1990; Davidson et al. 1998; Noureddin, Mohsen, and
Payman 2018; Romero et al. 1998; Summerbell et al. 1994;
Vuksan et al. 2008; Wolever et al. 1994) or supplements
(Abutair, Naser, and Hamed 2016; Akbarian et al. 2016;
Akbarzadeh et al. 2015;Andersonetal.1988; Asghar, Gill, and
Records identified through
database searching
(n=548)
ScreeningIncluded Eligibility Identification
Additional records identified
through other sources
(n=5)
Records after duplicates removed
(n =478)
Records screened
(n = 478)
Records excluded
(n =414)
Full-text articles
assessed for eligibility
(n =64)
Studies included in
qualitative synthesis
(n =22)
Studies included in
quantitative synthesis
(meta-analysis)
(n =22)
Full-text articles excluded: (n =42)
-Not English language studies (n=2)
- Had done on similar populations
(n=7)
- Had not full text (n= 6)
- Did not report relevant data (n=11)
-Publications without complete data
(n=3)
- Review articles (n=2)
-Abstracts (n=3)
-Studies that evaluated the effect of
psyllium in combination with other
interventions (n=8)
Figure 1. Flow diagram of study selection.
4 M. DAROOGHEGI MOFRAD ET AL.
Table 2. Demographic characteristics of included studies.
Code/Author (year)
Study
location
Subjects
and gender Age, y1 Design
Intervention type
Duration
(wk) Outcomes
outcome
Notes
about subjects
Outcome(s)
(yes/no)
Outcome
kind
Intervention
(name and
composition)
Control (name
and composition)
Intervention
mean ± SD
Control
mean ± SD
1. Noureddin,
Mohsen, and
Payman (2018)
Iran F: 42
M: 9
MþF: 51
PSY: 24 (20/4)
CON: 27 (22/5)
PSY: 58 ± 7.2
CON: 55.9 ± 8.7
Parallel psyllium pre-mixed
in a maltodextrin
cookies (2.5 g/
cookie) four
cookies twice/d
placebo
(maltodextrin
cookies)
12 -BMI
-weight
BMI (kg/m
2
):
Before: 29.3 ± 5.2
After: 28.5 ± 4.9
Weight (kg):
Before: 78.9 ± 13.8
After: 76.9 ± 12.9
BMI (kg/m
2
):
Before: 28.7 ± 5.9
After: 28.6 ± 5.6
Weight (kg):
Before 73.1 ± 12
After: 73.1 ± 11.3
51 patients with
type 2 diabetes
and chronic
constipation
-BMI (yes)
-weight (yes)
Primary
2. Ricklefs-Johnson,
Johnston, and
Sweazea (2017)
US F: 8
M: 9
MþF: 17
PSY: 8 (4/4)
CON: 9 (4/5)
3075 yrs
gar: 58.5 ± 9.4
Cont: 59.7 ± 7.9
Parallel Ground psyllium
husk
(9 g/package)/d
Placebo
(ground
flaxseed)
8 -BMI
-weight
-WC
BMI (kg/m
2
):
Before: 29 ± 6.7
After: 29 ± 6.6
Weight (kg):
Before: 70.6 ± 13
After: 70.5 ± 13.1
WC (cm):
Before: 100 ± 20.3
After: 98.83 ± 20.3
BMI (kg/m
2
):
Before: 31.7 ± 4.2
After: 31.4 ± 4.1
Weight (kg):
Before 73.3 ± 8.6
After: 73.9 ± 8.2
WC (cm):
Before: 105 ± 12.7
After: 102.2 ± 12
17 adults with
type 2 diabetes
-BMI (no)
-weight (no)
-WC (no)
primary
3. Pal et al. (2016) Australia F: 49
M: 39
MþF: 88
PCY: 43 (28/15)
CON: 45 (21/24)
PSY: 49.9 ± 11.14
CON: 49.8 ± 12.07
Parallel Psyllium
supplement
(5 g/ package)
3 times/d
placebo (rice flour) 36 -BMI
-weight
-WC
BMI (kg/m
2
):
Change: -0.18 ± 1.45
Weight (kg):
Change: -0.47 ± 4.7
WC (cm):
Before: -2.05 ± 3.75
BMI (kg/m
2
):
Before: 0.33 ± 1.19
Weight (kg):
change: 0.87 ± 3.52
WC (cm):
Before: -0.13 ± 3.6
88Individuals with
overweight
and obesity
-BMI (no)
-weight (no)
-WC (yes)
Primary
4. Abutair, Naser,
and
Hamed (2016)
Palestine F: 18
M: 18
MþF: 36
PSY: 18
CON: 18
>35 yrs Parallel psyllium
(3.5 g/supplement)
three supplements
twice/d þ
regular diet
Control (regu-
lar diet)
8 -BMI
-weight
-WC
BMI (kg/m
2
):
Before: 31.8 ± 2.82
After: 30.9 ± 2.94
Weight (kg):
Before: 91.7 ± 14.42
After: 88.8 ± 14.78
WC (cm):
Before: 106.2 ± 7.66
After: 103.5 ± 7.65
BMI (kg/m
2
):
Before: 31.5 ± 2.66
After: 31.8 ± 2.66
Weight (kg):
Before: 87.3 ± 13.45
After: 88.1 ± 13.37
WC (cm):
Before: 107.5 ± 7.07
After: 107.9 ± 6.77
36 adults with
type 2 diabetes
-BMI (yes)
-weight (yes)
-WC (yes)
Primary
5. Akbarian
et al. (2016)
Iran F: 27
M: 8
MþF: 35
garlic: 16
(11/5)
CON: 19 (16/3)
2774 yrs
PSY: 45. 7 ± 12.8
CON: 49.2 ± 10
Parallel Psyllium (5 g/
package)
twice/d
control 12 -BMI
-weight
BMI (kg/m
2
):
Before: 29.9 ± 2.4
After: 29.2 ± 2.4
Weight (kg):
Before: 80.4 ± 9.6
After: 78.5 ± 9.2
BMI (kg/m
2
):
Before: 31.2 ± 4.5
After: 30.6 ± 4.5
Weight (kg):
Before: 75.3 ± 11.7
After: 73.7 ± 12.2
35 Patients with
NAFLD
-BMI (no)
-weight (no)
Primary
F: 25
M: 10
MþF: 35
PSY: 18
(14/4)
CON: 17 (11/6)
2575 yrs
PSY: 53.5 ± 7.6
CON: 55.5 ± 9
Parallel Psyllium (5 g/
package)
twice/d þ10 g
Ocimum
basilicum
Ocimum basilicum 12 -BMI
-weight
BMI (kg/m
2
):
Before: 34.6 ± 7.6
After: 33.6 ± 7.2
Weight (kg):
Before: 84.7 ± 20.78
After: 82.7 ± 19.56
BMI (kg/m
2
):
Before: 30.1 ± 4.5
After: 29.5 ± 4.5
Weight (kg):
Before: 78.9 ± 13.8
After: 76.9 ± 12.9
35 Patients with
NAFLD
-BMI (no)
-weight (no)
Primary
6. Akbarzade
et al. (2015)
Iran F: 40
M: 25
FþM: 65
PSY: 38
(25/13)
CON: 37
(15/22)
18-77 yrs
Gar: 46.1 ± 17.1
Cont: 43.8 ± 11.7
Parallel Psyllium (5 g/
package)
twice/d
Placebo(crashed
wheat)
10 -WC WC (cm):
Before: 102.1 ± 9.1
After: 87.5 ± 9.01
WC (cm):
Before: 105 ± 10.3
After: 103.7 ± 10.5
65 Patients with
NAFLD
-WC (yes) Primary
(continued)
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 5
Table 2. Continued.
Code/Author (year)
Study
location
Subjects
and gender Age, y1 Design
Intervention type
Duration
(wk) Outcomes
outcome
Notes
about subjects
Outcome(s)
(yes/no)
Outcome
kind
Intervention
(name and
composition)
Control (name
and composition)
Intervention
mean ± SD
Control
mean ± SD
7. Asghar, Gill, and
Shah Murad
(2012)
Lahore F þM: 128
PSY: 65
CON: 63
2570 yrs Parallel psyllium husk
(10g/d) three
times/
dþ250 mg
niacin
250 mg niacin 12 -Weight Weight (kg):
Before: 70.1 ± 3.5
After: 68.9 ± 4.7
Weight (kg):
Before: 72.2 ± 3.1
After: 70.9 ± 1.9
128 hyperlipidemic
patients
Weight (no) Primary
8. Sol
a et al.
(2010)
Spain,
France,
Holland
F: 118
M: 91
FþM: 209
PSY: 108
(62/46)
CON: 101
(56/45)
4367 yrs
PSY: 54.2 ± 9.9
CON: 55.5 ± 11.5
Parallel Psyllium (14g/d)
four times/d
placebo 8 -Weight Weight (kg):
Change: 0.83 ± 1.91
Weight (kg):
Before: 0.54 ± 1.84
209 mild-moderate
hypercholester-
olaemic
patients
Weight (no) Secondary
9. Cicero
et al. (2010)
Italy F: 47
M: 46
FþM: 93
PSY: 48
(24/24)
CON: 45
(23/22)
5070 yrs
PSY: 58.4 ± 2.5
CON: 57.2 ± 2.1
Parallel Psyllium (10.5 g/d)
three times/
dþstandard diet
Standard diet 24 -weight
-WC
Weight (kg):
Before: 80.2 ± 4.1
After: 76.9 ± 4.1
WC (cm):
Before: 100.4 ± 10.3
After: 96.3 ± 7.2
Weight (kg):
Before: 80.1 ± 4.3
After: 78.9 ± 4.3
WC (cm):
Before: 102 ± 8.3
After: 99.5 ± 7.3
93 patients with
metabolic
syndrome
-weight (no)
-WC (yes)
Primary
10. Cicero
et al. (2007)
Italy F: 47
M: 46
FþM: 93
PSY: 48
(24/24)
CON: 45
(23/22)
5070 yrs
PSY: 58.4 ± 2.5
CON: 57.2 ± 2.1
Parallel Psyllium (10.5 g/d)
three times/
dþstandard diet
Standard diet 24 -BMI BMI (kg/m
2
):
Before: 26.8 ± 1.5
After: 25.8 ± 1.1
BMI (kg/m
2
):
Before: 26.4 ± 1.4
After: 26.3 ± 1.1
93 hypertensive,
overweight
patients
-BMI (yes) Primary
11. Sartore
et al. (2009)
Italy F: 13
M: 27
FþM: 40
PSY: 20
(6/14)
CON: 20
(7/13)
>18 yrs
Gar: 61 ± 8.7
Cont: 60 ± 8
Parallel Psyllium (3.5 g/
sachet)three
times/
dþcontrolled
diet
controlled diet 8 -BMI
-WC
BMI (kg/m
2
):
Before: 30 ± 3.93
After: 29.35 ± 3.9
WC (cm):
Before: 101.7 ± 11.2
After: 99.8 ± 11.4
BMI (kg/m
2
):
Before: 30.48 ± 2.9
After: 29.5 ± 2.87
WC (cm):
Before: 104.1 ± 8
After: 101.3 ± 7.37
40 adults with
type 2 diabetes
-BMI (no)
-WC(no)
Secondary
12. Vuksan
et al. (2008)
Canada F: 11
M: 12
FþM: 23
PSY: 23
CON: 23
1959 yrs
PSY: 35 ± 12
CON: 35 ± 12
Cross
over
Bran Buds with
Psyllium (9g/d)
control 3 -weight Weight (kg):
Before: 70 ± 15
After: 69.3 ± 15.1
Weight (kg):
Before: 70 ± 15
After: 69.7 ± 15.9
23 healthy
persons
-weight (no) Secondary
13. Sola
et al. (2007)
Spain M: 28
PSY: 28
CON: 28
4870 yrs
PSY: 61.4 ± 8.6
CON: 61.4 ± 8.6
Cross
over
Psyllium (3.5 g/
sachet) three
times/d
Placebo
(hemicellulose
and lignin
klason)
8 -BMI
-weight
-WC
BMI (kg/m
2
):
Before: 28.2 ± 3.18
After: 28.24 ± 3.49
Weight (kg):
Before: 77.3 ± 8.7
After: 77.35 ± 9.46
WC (cm):
Before: 95.3 ± 3
After: 93.6 ± 6.1
BMI (kg/m
2
):
Before: 28.2 ± 3.18
After: 28.1 ± 3.32
Weight (kg):
Before: 77.3 ± 8.7
After: 76.9 ± 9.15
WC (cm):
Before: 95.3 ± 3
After: 93.3 ± 3.2
28 men with CVD
(myocardial
infarction or
stable angina)
-BMI (no)
-weight (no)
-WC (no)
Secondary
14. Cavaliere,
Floriano, and
Medeiros-Neto
(2001)
Brazil F: 60
Both: 60
PSY: 60
CON: 60
27-42 yrs
PSY: 40.9 ± 8.9
CON: 40.9 ± 8.9
Cross
over
psyllium
hydrophillic
mucilloid
(6 g/d)þorlistat
placebo þ
orlistat
8 -BMI
-weight
BMI (kg/m
2
):
Before: 38 ± 5.26
After: 37.24 ± 5.1
Weight (kg):
Before: 96.8 ± 17.8
After: 94.9 ± 17.7
BMI (kg/m
2
):
Before: 38.1 ± 4.8
After: 36.9 ± 7.9
Weight (kg):
Before: 98.7 ± 16.8
After: 96.7 ± 15.8
60 obese
patients
-BMI (no)
-weight (no)
Secondary
(continued)
6 M. DAROOGHEGI MOFRAD ET AL.
Table 2. Continued.
Code/Author (year)
Study
location
Subjects
and gender Age, y1 Design
Intervention type
Duration
(wk) Outcomes
outcome
Notes
about subjects
Outcome(s)
(yes/no)
Outcome
kind
Intervention
(name and
composition)
Control (name
and composition)
Intervention
mean ± SD
Control
mean ± SD
15. Romero
et al. (1998)
Mexico M: 20
PSY: 10
CON: 10
2045 yrs
PSY: 38 ± 6
CON: 36 ± 8
Parallel 100 g cookies mixed
by 1.7 g
psyllium/d
100 g cookies
mixed by 0.6 g
wheat bran/d
8 -BMI
-weight
BMI (kg/m
2
):
Before: 26.5 ± 2.2
After: 26.3 ± 2.3
Weight (kg):
Before: 83.4 ± 10.4
After: 83.5 ± 10.6
BMI (kg/m
2
):
Before: 26.6 ± 3.1
After: 26 ± 3.7
Weight (kg):
Before: 83.1 ± 13.9
After: 82.1 ± 14.2
20 hypercholester-
olemic subjects
-BMI (no)
-weight (no)
Secondary
M: 24
PSY: 10
CON: 14
2045 yrs
PSY: 35 ± 5
CON: 29 ± 9
Parallel 100 g cookies mixed
by 1.7 g
psyllium/d
100 g cookies
mixed by 0.6 g
wheat bran/d
8 -BMI
-weight
BMI (kg/m
2
):
Before: 38 ± 5.26
After: 37.24 ± 5.1
Weight (kg):
Before: 84 ± 11.5
After: 83.2 ± 10.2
BMI (kg/m
2
):
Before: 38 ± 5.26
After: 37.24 ± 5.1
Weight (kg):
Before: 77 ± 8.5
After: 74.8 ± 7.8
24 normo choles-
terolemic
subjects
-BMI (no)
-weight (no)
Secondary
16. Rodrıguez-
Mor
an,
Guerrero-
Romero, and
Lazcano-
Burciaga (1998)
Mexico F: 69
M: 54
FþM: 123
PSY: 63
(33/30)
CON: 60
(36/24)
3075 yrs
PSY: 57 ± 4.1
CON: 56.5 ± 6.1
Parallel Psyllium(4 g/packet)
three times/d
Placebo( microcrys-
talline cellulose)
6 -weight Weight (kg):
Before: 70.6 ± 13
After: 70.5 ± 13.1
Weight (kg):
Before: 73.3 ± 8.6
After: 73.9 ± 8.2
123 adults with
type 2 diabetes
-weight (no) Secondary
17. Davidson et al.
(1998)
US F: 47
M: 67
FþM: 122
PSY: 56
(25/31)
CON: 58
(22/36)
2180 yrs
PSY: 55.3 ± 1.5
CON: 55.6 ± 1.6
Parallel Psyllium containing
foods(3.4 g
psyllium) once/d
Control foods 24 -weight Weight (kg):
Change: 0.04 ± 1.49
Weight (kg):
Change: -0.63 ± 1.9
122 mild to mod-
erate hyperchol-
esterolemia
patients
-weight (no) Secondary
F: 47
M: 63
FþM: 100
PSY: 42
(15/27)
CON: 58
(22/36)
2180 yrs
PSY: 56.1 ± 1.4
CON: 55.6 ± 1.6
Parallel Psyllium containing
foods (3.4 g
psyllium) thee
times/d
Control foods 24 -weight Weight (kg):
Change: 0.29 ± 0.84
Weight (kg):
Change: -0.63 ± 1.9
100 mild to mod-
erate hyperchol-
esterolemia
patients
-weight (no) Secondary
F: 38
M: 60
FþM: 98
PSY: 40
(16/24)
CON: 58
(22/36)
2180 yrs
PSY: 54.9 ± 1.8
CON: 55.6 ± 1.6
Parallel Psyllium containing
foods (3.4 g
psyllium) twice/d
Control foods 24 -weight Weight (kg):
Change: -0.86 ± 2.46
Weight (kg):
Change: -0.63 ± 1.9
98 mild to moder-
ate hyperchol-
esterolemia
patients
-weight (no) Secondary
18. Summerbell
et al. (1994)
UK F: 15
M: 22
FþM: 37
PSY: 19
(7/12)
CON: 18
(8/10)
3863 yrs
PSY: 47
CON: 48
Parallel 60 g of a
breakfast cereal
containing 9.6 g
psyllium/d
breakfast cereal
containing 2.9 g
soluble fiber/d
9 -BMI BMI (kg/m
2
):
Before: 25.4 ± 3.2
After: 24.7 ± 3
BMI (kg/m
2
):
Before: 27.2 ± 4
After: 26.5 ± 4.2
37 mild-moderate
hypercholester-
olaemic
patients
-BMI (no) Secondary
19. Wolever
et al. (1994)
Canada F: 9
M: 9
FþM: 18
PSY: 18
(9/9)
CON: 18
(9/9)
54.1 ± 2.6 Cross
over
Psyllium
enriched(7.3 g/d)
breakfast cereal
Wheat- bran-based
breakfast cereal
2 -weight Weight (kg):
Before: 70.6 ± 13
After: 70.5 ± 13.1
Weight (kg):
Before: 70.6 ± 13
After: 70.5 ± 13.1
18 modestly hyper-
cholesterolemic
subjects
-weight (no) Secondary
Wheat- bran-based
breakfast cereal-
þpsyllium(3.8 g/
package) twice /d
Wheat- bran-based
breakfast cereal
2 -weight Weight (kg):
Before: 77 ± 8.48
After: 77.2 ± 8.48
Weight (kg):
Before: 76.8 ± 8.08
After: 76.6 ± 7.48
18 modestly hyper-
cholesterolemic
subjects
-weight (no) Secondary
(continued)
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 7
Shah Murad (2012); Cavaliere, Floriano, and Medeiros-Neto
2001; Cicero et al. 2010; Cicero et al. 2007; Hylander and
R
ossner 1983; Pal et al. 2016; Ricklefs-Johnson, Johnston,
and Sweazea 2017; Rodrıguez-Mor
an, Guerrero-Romero,
and Lazcano-Burciaga 1998; Sartore et al. 2009; Sol
a et al.
2010; Sola et al. 2007) in the included studies.
All studies were randomized clinical trials (RCTs).
However, ten trials did not report the method used for ran-
dom allocation (Abutair, Naser, and Hamed 2016; Anderson
et al. 1988; Asghar, Gill, and Shah Murad (2012); Bell et al.
1990; Hylander and R
ossner 1983;Rodrıguez-Mor
an,
Guerrero-Romero, and Lazcano-Burciaga 1998;Romeroetal.
1998; Sartore et al. 2009; Vuksan et al. 2008; Wolever et al.
1994). Nine studies reported allocation blinding process
(Akbarian et al. 2016;Akbarzadehetal.2015; Anderson et al.
1988;Belletal.1990; Cavaliere, Floriano, and Medeiros-Neto
2001; Noureddin, Mohsen, and Payman 2018; Pal et al. 2016;
Sol
aetal.2010;Summerbelletal.1994). In addition, six trials
did not perform double blinding (Akbarian et al. 2016;
Asghar, Gill, and Shah Murad (2012); Cicero et al. 2010;
Noureddin, Mohsen, and Payman 2018; Sartore et al. 2009;
Sola et al. 2007). Risk of bias for included studies was
assessed using the Cochrane collaboration tool (Table 1).
Meta-analysis results
Findings on the effect of psyllium on body weight: Eighteen
studies with twenty-three arms, including a total of 1306 par-
ticipants (case ¼653, and control ¼653) reported body weight
as an outcome measure. Pooled results from the random-
effects model showed a non-significant effect of psyllium con-
sumption on body weight compared to control group (MD:
0.28 kg, 95% CI: 0.78, 0.21, p¼0.268) with significant het-
erogeneity among the studies (I
2
¼82.1%, p<0.001) (Fig. 2).
Subgroup analysis showed that psyllium dosage (<10 g/d:
I
2
¼0%, p¼0.914), kind of psyllium administration (supple-
ment: I
2
¼33.5%, p¼0.15), trial duration (wk) (<10 wk:
I
2
¼34.8%, p¼0.09), study design (cross-over: I
2
¼0%,
p¼0.968), sample size (<40: I
2
¼45.4%, p¼0.057), and
gender (men: I
2
¼0%, p¼0.601) were potential sources
of heterogeneity. Moreover, subgroup analysis showed that the
effect of psyllium supplementation on body weight was signifi-
cant in studies with higher duration, studies used psyllium in
dosage 10 g/d, those conducted on both genders, studies with
higher sample size, studies administered psyllium as supplement
and studies had parallel design (P<0.000 for all) (Table 3).
To examine the effect of each study on the pooled
effect size, we conducted a sensitivity analysis (Supplementary
Fig. 1). In 2 studies (Abutair, Naser, and Hamed 2016; Cicero
et al. 2010) the reduction of body weight was greater in the
intervention group than in the control group. Thus, when
these studies were removed from this meta-analysis, the effect
of psyllium on body weight would be decreased insignificantly
(MD: 0.01 kg, 95% CI: 0.22, 0.24, p¼0.914). Low hetero-
geneity (I
2
¼9.3%, p¼0.337) between studies were seen when
the mentioned studies were withdrawn. Also, no significant
effect of psyllium supplementation on body weight was seen
in subgroups after removing these 2 studies.
Table 2. Continued.
Code/Author (year)
Study
location
Subjects
and gender Age, y1 Design
Intervention type
Duration
(wk) Outcomes
outcome
Notes
about subjects
Outcome(s)
(yes/no)
Outcome
kind
Intervention
(name and
composition)
Control (name
and composition)
Intervention
mean ± SD
Control
mean ± SD
20. Bell et
al. (1990)
US M: 38
PSY: 19
CON: 19
24-69 yrs
PSY: 44 ± 13
CON: 47 ± 14
Parallel 57 g package of
psyllium enriched
cereal (3 g
psyllium)/d
Placebo
(corn flake)
6 -weight Weight (kg):
Before: 79.3 ± 9.1
After: 79 ± 9.1
Weight (kg):
Before: 77.8 ± 8.7
After: 77.6 ± 8.7
38 mild to
moderate
hyperchol-
esterolemia
-weight (no) Secondary
21. Anderson et al.
(1988)
US M: 28
PSY: 14
CON: 14
30-65 yrs
PSY: 47.6
CON: 45.9
Parallel Psyllium (3.4 g/
packet) three
times/d
Placebo (cellulose) 8 -weight Weight (kg):
Before: 76.5 ± 14.5
After: 75 ± 13.8
Weight (kg):
Before: 74.5 ± 10.8
After: 73.7 ± 10.8
28 men with
hyper-
chlosterolemia
-weight (no) Secondary
22. Hylander and
R
ossner (1983)
Sweden F þM: 66
PSY: 43
CON: 23
18-72 yrs
PSY: 42
CON: 42
Parallel Psyllium (6.6 g
/packet) once/d
control 2 -weight Weight (kg):
Before: 80.4 ± 17.3
After: 76.2 ± 16.3
Weight (kg):
Before: 76.9 ± 9.4
After: 72.3 ± 9.5
66 members of a
weight
loss club
-weight (no) Primary
F, female ; M, male ; PSY, psyllium ; CON, control; BMI, body mass index; WC, waist circumference ; NAFLD, nonalcoholic fatty liver disease, CVD, cardiovascular disease, US, united states; UK, united kingdom.
1
Values are overall ranges and means ± SDs in each group.
8 M. DAROOGHEGI MOFRAD ET AL.
Findings on the effect of psyllium on BMI: Eleven
studies with thirteen arms, including a total of 632 partici-
pants (case ¼315, and control ¼317) reported BMI as an
outcome measure. Overall results from the random-effects
model indicated that psyllium consumption resulted in non-
significant reduction in BMI (MD: 0.19 kg/m
2
,95%CI:0.55,
0.15, p¼0.27) compared to control group. There was significant
heterogeneity among studies (I
2
¼81.1%, p<0.000) (Fig. 3).
Subgroup analysis showed that psyllium dosage (<10 g/d:
I
2
¼0%, p¼0.85), kind of psyllium administration (food:
I
2
¼31.4%, p¼0.177), study design (cross-over: I
2
¼0%,
p¼0.341) and gender (men: I
2
¼0%, p¼0.716) were potential
sources of heterogeneity. The effect of psyllium supplementa-
tion on BMI was non-significant in all subgroups, except for
studies with a duration of 10 week, those used psyllium in
higher doses (10 g/d), studies used psyllium supplements,
those studies that were conducted on both genders, and studies
that had parallel design (P<0.000 for all).
We conducted a sensitivity analysis to assess the effect of
each study on the pooled effect size (Supplementary Fig. 2).
Two studies (Abutair, Naser, and Hamed 2016; Cicero et al.
2010) had a major effect on overall WMD. Also, when
removed from the analysis, the estimated effect size of
psyllium supplementation on BMI increased insignificantly
(MD: 0.009 kg/m
2
, 95% CI: 0.20, 0.21, p¼0.935) .Also, by
removing these studies, low heterogeneity (I
2
¼10.2%, p¼0.
347) between the studies were observed. Moreover, in case
of removing the mentioned studies, BMI (p¼0.027) signifi-
cantly decreases if the study duration is 10 weeks or more.
Findings on the effect of psyllium on WC: Among
eligible studies, seven studies including a total of 388
participants (case ¼196, and control ¼192) reported the
effect of psyllium consumption on WC. Psyllium consump-
tion did not influence on WC (MD: 1.2 cm, 95% CI: 2.6,
0.2, p¼0.09) with significant heterogeneity among studies
(I
2
¼88.4%, p<0.001) (Fig. 4). Subgroup analysis could not
identify the sources of heterogeneity (Table 3). In addition,
sensitivity analysis did not provide evidence for the influ-
ence of an individual study on the overall effect size
(Supplementary Fig. 3).
Non-linear dose-responses between the dose of psyllium
intake and outcomes
We failed to show nonlinear dose-response effect of psyl-
lium on body weight (P-nonlinearity ¼0.21) (Supplementary
Fig. 4), BMI (P-nonlinearity ¼0.16) (Supplementary Fig. 5)
as well as WC (P-nonlinearity ¼0.62) (Supplementary Fig.
6). Duration of psyllium consumption was shown to have
Figure 2. Forest plot showing the effects of psyllium supplementation on body weight in adults using the random effects model.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 9
not a significant non-linear relationship with body weight
(P-nonlinearity ¼0.21) (Supplementary Fig. 7). However,
BMI (P-nonlinearity ¼0.044) (Supplementary Fig. 8) and
WC (P-nonlinearity ¼0.015) (Supplementary Fig. 9) change
in non-linear fashion.
Publication bias
No sign of publication bias in the meta-analysis of
psylliumconsumptiononweightandWCwasseenwhen
assessed by visual inspection of the funnel plot
(Supplementary Figs. 10 and 12).Thesameresultwas
obtained with testing with Eggers linear regression
(weight: p ¼0.29, and WC: p¼0.19). Visual inspection
of the funnel plot and Eggers regression test revealed
a significant publication bias among included studies
(P¼0.01) for BMI (Supplementary Fig. 11). Thus,
we performed the trim & fill test to correct it before
meta-analysis. After correction effect size (WMD: 0.
69 kg/m
2
,95%CI:1.05, 0.33), six studies were added.
Figure 3. Forest plot showing the effects of psyllium supplementation on body mass index (BMI) in adults using the random effects model.
Figure 4. Forest plot showing the effects of psyllium supplementation on waist circumference (WC) in adults using the random effects model.
10 M. DAROOGHEGI MOFRAD ET AL.
Discussion
The present systematic review and meta-analyses of RCTs
summarized the effects of psyllium supplementation on
anthropometric measures in over 18 years old subjects. This
study did not show a significant effect of psyllium on body
weight, body mass index, and waist circumference in com-
parison with control group in adults. The effect of duration
of psyllium consumption on BMI and WC was non-linear.
We did not find a significant effect of psyllium on body
weight in this study. A systematic review study in this regard
also did not find a significant effect of dietary supplementation
with psyllium on body weight (Pittler and Ernst 2004). However,
another review at 2012 suggested that dietary supplementation
with psyllium may play a role in controlling body weight in
those with overweight and obesity (Pal and Radavelli-Bagatini
2012). Although the majority of individuals in the included stud-
ieswereoverweightorobesity,wefailedtoshowanysignificant
effect of psyllium on body weight. As our subgroup analyses
showed, supplementation with higher doses of psyllium through
longer durations and in studies with larger sample sizes caused
significant reduction in body weight. In line with these findings,
a recent study showed that supplementation with psyllium
decreased participantshungeranddesiretoeat,whichwas
more considerable in higher doses (Wanders et al. 2011).
Our study did not show significant effect of psyllium on
BMI. Findings from most studies in this area are in line
with our study (Romero et al. 1998; Sartore et al. 2009; Sola
et al. 2007). However, a systematic review study suggested
that consumption of psyllium-based cereals for breakfast can
be related to lower BMI and lower risk of being overweight
or obese (Williams 2014). It should be noted that few studies
have investigated the effect of psyllium supplementation on
BMI. In addition, our subgroup analysis showed that supple-
mentation with higher doses of psyllium in longer periods
may influence this anthropometric measure. Therefore,
further studies are needed to reach a firm conclusion about
the effect of psyllium supplementation in different doses and
durations on BMI.
Oral consumption of psyllium also did not significantly
change WC in our study. Although few studies have been
done in this area, several available studies did not find
a significant effect of psyllium on WC (Ricklefs-Johnson,
Johnston, and Sweazea 2017; Sartore et al. 2009). In contrast
with our finding, a recent meta-analysis enrolling twenty
eight RCTs showed a significant reduction in low density
lipoprotein (LDL) cholesterol and alternate lipid markers
including non-high density lipoprotein (non-HDL) cholesterol
and apolipoprotein B (apoB) following psyllium supplementa-
tion (Jovanovski et al. 2018). In addition, some studies
reported a significant improvement in metabolic syndrome
following supplementation with psyllium (Abutair, Naser, and
Hamed 2018; Jane, McKay, and Pal 2018). It should be kept
at mind that WC is one of the components of metabolic
syndrome. In addition, as mentioned for body weight and
BMI, we found that psyllium supplementation in higher doses
and longer duration as well as among larger sample sizes will
be effective in reduction of WC. However, further studies are
still required to reach a firm conclusion.
Table 3. Pooled estimates of effects of psyllium on anthropometric indices in adults in different subgroups.
Number of trials WMD (95% CI) Pvalue P-heterogeneity I
2
(%)
weight BMI WC weight BMI WC weight BMI WC weight BMI WC weight BMI WC
Total 23 13 7 0.28 (0.78, 0.21) 0.19 (0.55, 0.15) 1.2 (2.6, 0.2) 0.268 0.27 0.09 <0.001 <0.001 <0.001 82.1 81.1 88.4
PSY dose
<10 g/d 11 5 1 0.33 (0.03, 0.7) 0.25 (0.08, 0.59) 1.63 (1.64, 4.90) 0.07 0.138 0.329 0.914 0.85 0.340 0 0
10 g/d 12 8 6 0.77 (0.98, 0.56) 0.65 (0.80, 0.51) 1.80 (2.26, 1.34) <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 88.1 81.6 89.5
PSY kind
food 9 5 0.23 (0.08, 0.56) 0.01 (0.26, 0.22) 0.153 0.89 <0.001 0.177 84.2 31.4
supplement 14 8 0.83 (1.05, 0.61) 0.71 (0.87, 0.56) <0.001 <0.001 0.15 <0.001 33.5 87.1
Duration of treatment
<10 wk 14 8 4 0.15 (0.46, 0.14) 0.10 (0.31, 0.10) 0.96 (1.59, 0.33) 0.308 0.310 0.003 0.09 <0.001 <0.001 34.8 77.5 91.2
10 wk 9 5 3 0.69 (0.92, 0.46) 0.78 (0.94, 0.61) 1.74 (2.19,1.28) <0.001 <0.001 <0.001 <0.001 0.085 0.052 91.6 55.1 66.2
Sample size
<40 10 7 2 0.05 (0.59, 0.49) 0.30 (0.55, 0.06) 2.72 (3.64 ,1.79) 0.85 0.014 <0.001 0.057 <0.001 <0.001 45.4 75.5 86.4
40 13 6 5 0.55 (0.75, 0.36) 0.60 (0.76, 0.45) 1.42 (1.94, 0.90) <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 88.4 85.7 89.7
Study design
parallel 18 6 0.58 (0.77, 0.39) 0.60 (0.74, 0.46) 2.07 (2.55, 1.58) <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 85.2 79.8 87.3
Cross over 5 1 0.28 (0.30, 0.87) 0.17 (0.22, 0.57) 0.30 (0.91, 1.51) 0.338 0.399 0.629 0.968 0.341 00
Gender
men 5 3 0.30 (0.39, 1.00) 0.20 (0.12, 0.52) 0.393 0.230 0.601 0.716 0 0
women 1 1 0.21 (1.19, 1.61) 0.58 (0.35, 1.51) 0.769 0.222 –– –
both 17 9 0.57 (0.76, 0.38) 0.68 (0.83, 0.54) <0.001 <0.001 <0.001 <0.001 85.9 76.1
BMI, body mass index; WC, waist circumference; WMD, weighted mean difference; CI, confidence interval.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 11
Psyllium seed is a source of viscous, water-soluble fibers.
It is one of the most widely used fiber supplements all over
the world. Psyllium is a gel-forming soluble fiber which
indicating several health protecting properties (Blackwood
et al. 2000). Studies have shown that consumption of psyl-
lium lowers intestinal fat absorption and serum concentra-
tion of lipids (Baer et al. 1997). In addition, psyllium has
been shown to improve glucose and insulin responses in
humans (Karhunen et al. 2010; Pal et al. 2011; Sierra et al.
2002; Ziai et al. 2005). Psyllium forms a viscous gel in aque-
ous solutions, therefore, it may reduce contact of glucose to
the small intestines absorptive epithelium (Moreno et al.
2003). Furthermore, consumption of this soluble fiber may
delay gastric emptying and slow down carbohydrate uptake
(Gropper and Acosta 1987). The effect of psyllium on obes-
ity indices is attributed to its influences on appetite and gut
hormones(Burton-Freeman, Davis, and Schneeman 2002;
Holt et al. 1992). Psyllium consumption significantly
increases fullness, which might be due to changes in concen-
trations of intestinal hormones (Burton-Freeman, Davis, and
Schneeman 2002), decreases in intestinal passage rates
(Dikeman, Murphy, and Fahey 2006), and prolonged chew-
ing time(Zijlstra et al. 2009; Zijlstra et al. 2008).
In addition, some adverse events such as flatulence, bloat-
ing, indigestion, nausea, vomiting and retrosternal pain were
reported after the use of psyllium in some studies (Pittler,
Schmidt, and Ernst 2005).
This is the first systematic review and meta-analysis on
the effect of psyllium on various obesity indices. All studies
we included were RCTs. Low evidence for the presence of
publication bias was found for body weight and WC.
However, some limitations of this study might resulted in
non-significant findings. Psyllium was used in different dos-
ages and in different forms in included studies. In addition,
intervention period was varied among those studies.
Furthermore, participants in included studies were in differ-
ent physiological status. Adjustment for probable confound-
ing factors was not done in most cases. Moreover, using
different study designs may be another source of bias. The
majority of participants in these studies were overweight
and obese. So, we could not conduct subgroup analysis
based on starting BMI of individuals. It was difficult to
detect true effect of psyllium on obesity measures alone
because of therapeutic effect of some placeboes which com-
pare with psyllium in some studies and could contribute to
non-significant findings. Although we performed subgroup
analysis by several pre-defined factors, there may be some
other important items that we did not consider them in
our analysis.
In conclusion, we found no significant effect of psyllium
on body weight, body mass index, and waist circumference
in adults. Further large scale studies, using different doses of
psyllium and with longer period of intervention are required
to confirm these findings.
Disclosure statement
No conflict of interest was declared.
Authorscontribution
A.M and M.D.M conceived and designed the study. M.D.M and H.M
conducted systematic search, screened articles, selected eligible articles
and extracted information from eligible studies. S.M.M and A.S per-
formed analysis and interpreted results. All authors contributed to
writing, reviewing or revising the paper. A.M. is the guarantor. All
authors have read and approved the final manuscript. All authors had
full access to all the data and take responsibility for the integrity of the
data and the accuracy of the data analysis.
Abbreviations
BMI Body Mass Index
CI Confidence Intervals
FM Fat Mass
LDL Low Density Lipoprotein
HDL High Density Lipoprotein
ApoB Apolipoprotein B
MESH Medical Subject Headings
NFLD Non-alcoholic Fatty Liver
PRISMA Preferred Reporting Items for Systematic Reviews and
Meta-analyses
RCTs Randomized Clinical Trials
SD Standard Deviation
UK United Kingdom
US United States
WC Waist Circumference
WHR Waist-Hip Ratio
WHtR Waist-Height Ratio
WMD Weighted Mean Difference
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14 M. DAROOGHEGI MOFRAD ET AL.
... [22][23][24][25][26] Meanwhile, 3 studies reported that there were no intergroup or intragroup differences on body weight after dietary supplementations. [27][28][29] The authors also highlighted other associated risk factors of obesity and adverse events reported after CATs approach or supplementation. The identified findings of all the studies are summarized in Tables 1 and 2. ...
... In addition, some adverse events such as bruising, flatulence, flu, vomiting and other gastrointestinal problems were reported after the use of CATs in some studies. 11,16,26,28,29 Some studies did not even provide detailed information regarding the safety aspects especially in regard to long-term usage of CATs. Although these alternative treatments are mostly based on natural products and are generally well-tolerated, their effectiveness and possible serious events must still be thoroughly ascertained. ...
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Despite various strategies, overweight and obesity problems are still increasingly prevalent worldwide with serious health outcomes. Consequently, the continuous demand for more effective, safe and acceptable therapies for reducing body weight is also escalating—including complementary and alternative therapies (CATs). The aim of this review is to provide a summary of the most commonly- and recently-used CATs, with evaluation of their safety and efficacy for weight loss. Electronic scientific databases such as Scopus, PubMed and EBSCO Host were explored for articles that reported CATs for overweight and obesity treatment from 2015 to December 2019. Only systematic reviews, meta-analysis and randomized controlled trials (RCTs) published in English were included. Studies whereby CATs were not utilized for reducing body weight were excluded. Eight systematic reviews and meta-analyses and 11 additional RCTs with 765 participants (50.2% overweight and 49.8% obese) related to hypnotherapy, acupuncture and dietary supplements met the inclusion criteria. Their results suggested that spirulina, chitosan, probiotic, EPA + DHA, vitamin D, fiber, and herbal extract supplementation may all provide small reductions in body weight (ranging from 1-10 kg). Interestingly, hypnotherapy and acupuncture reported significantly greater reduction in body weight compared with placebo (p < 0.001 and p < 0.0001, respectively). Nonetheless, the evidence is still relatively limited and not encouraging to provide a definitive conclusion due to the methodological shortcomings and the presence of adverse events in chitosan and fiber supplementation. Hence, studies of this nature need to be further replicated and improved to corroborate the efficacy and safety of the CATs to combat weight issues.
... The relationship between NDC intake and type 2 diabetes mellitus (T2DM) has been clinically investigated for decades. Many recent meta-analyses and clinical studies have shown that a high intake of NDCs, especially dietary fiber, for >1 month lowered the risk of developing T2DM and might have therapeutic effects in patients with T2DM [88,89], although some studies have shown no significant effects of dietary fiber on T2DM [90]. Randomized studies of 15 studies from 1980 to 2010 suggested that an increasing dietary fiber diet reduced fasting blood glucose and glycosylated hemoglobin (HbA1C) levels in patients with T2DM [91,92]. ...
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Metabolic diseases (MDs), including cardiovascular diseases (CVDs) and diabetes, occur when the body’s normal metabolic processes are disrupted. Behavioral risk factors such as obesity, physical inactivity, and dietary habits are strongly associated with a higher risk of MD. However, scientific evidence strongly suggests that balanced, healthy diets containing non-digestible carbohydrates (NDCs), such as dietary fiber and resistant starch, can reduce the risk of developing MD. In particular, major properties of NDCs, such as water retention, fecal bulking, viscosity, and fermentation in the gut, have been found to be important for reducing the risk of MD by decreasing blood glucose and lipid levels, increasing satiety and insulin sensitivity, and modifying the gut microbiome. Short chain fatty acids produced during the fermentation of NDCs in the gut are mainly responsible for improvement in MD. However, the effects of NDCs are dependent on the type, source, dose, and duration of NDC intake, and some of the mechanisms underlying the efficacy of NDCs on MD remain unclear. In this review, we briefly summarize current studies on the effects of NDCs on MD and discuss potential mechanisms that might contribute to further understanding these effects.
... Another recent metanalysis investigated the effects of psyllium consumption (whether prescribed through supplements or added to foods) on BMI and/or weight, including RCTs, both parallel and crossover, not necessarily placebo-controlled. From the metanalysis of the eleven studies (involving a total of 632 participants) reporting BMI as outcome, a non-significant reduction in BMI was observed, although subgroup analysis showed that psyllium supplementation at higher doses (≥10 g/d) significantly decreased BMI in studies with a duration ≥10 week [91]. ...
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The use of food supplements for weight loss purposes has rapidly gained popularity as the prevalence of obesity increases. Navigating through the vast, often low quality, literature available is challenging, as is providing informed advice to those asking for it. Herein, we provide a comprehensive literature revision focusing on most currently marketed dietary supplements claimed to favor weight loss, classifying them by their purported mechanism of action. We conclude by proposing a combination of supplements most supported by current evidence, that leverages all mechanisms of action possibly leading to a synergistic effect and greater weight loss in the foreseen absence of adverse events. Further studies will be needed to confirm the weight loss and metabolic improvement that may be obtained through the use of the proposed combination.
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Plantago (Plantaginaceae) is an herbal plant, which is used in folk medicine, functional food, and dietary supplement products. Recent pharmacological and phytochemical studies have shown that polysaccharides isolated from Plantago have multiple medicinal and nutritional benefits, including improve intestinal health, hypoglycemic effect, immunomodulatory effect, etc. These health and pharmacological benefits are of great interest to the public, academia, and biotechnology industries. This paper provides an overview of recent advances in the physicochemical, structural features, and biological effects of Plantago polysaccharides and highlights the similarities and differences of the polysaccharides from different species and in different parts, including leaves, seeds, and husks. The scientific support for its use as a prebiotic is also addressed. The purpose of this review is to provide background as well as useful and up-to-date information for future research and applications of these polysaccharides.
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It is known that obesity has reached epidemic proportions and its management is of high clinical importance. In this chapter we will discuss recent data about the role of nutraceuticals and functional foods in obesity and body weight management, including the mechanisms responsible for their favorable effects. In addition, the impact of healthy dietary patterns on weight loss will be addressed. Apart from influencing the imbalance between energy intake and output, nutraceuticals may prevent and/or decrease the development of oxidative stress and inflammation in obesity, as well as favorably influence other cardiovascular disease risk factors, thereby limiting obesity-related complications. A place for nutraceuticals in daily clinical practice is emerging, but the current evidence supporting their use is still limited. Further research will lead to the development of novel nutraceuticals/functional foods/dietary patterns to successfully prevent and/or combat obesity.
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Psyllium gum is a hydrocolloid found in the husk of seeds from Plantago ovata. Psyllium husk has been used in traditional medicine in areas of India and China. Its consumption has been shown to provide nutritional benefits, such as the capacity to reduce the glycaemic index, to minimize the risk of cardiovascular diseases, to decrease cholesterol and constipation problems and others. Thus, interest in the incorporation of psyllium in food products is twofold. First, it can be a natural alternative to the use of other gums and hydrocolloids considered additives. Second, it can be used to improve the nutritional properties of products in which it is incorporated. However, for this purpose, it is necessary to add great quantities of psyllium. This review analyses the potential use of psyllium in distinct food products, considering its advantages and inconveniences as well as possible solutions for undesired effects. Among the analyzed products there are bakery products and, in particular, gluten-free breads where psyllium has been used as a gluten substitute. The incorporation of psyllium into dairy products such as yogurts and those derived from fruits, among others, is also addressed.
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Background: Studies have identified viscous dietary fiber as potentially attenuating cholesterol, including psyllium, which reduces LDL cholesterol and thus may complement cardiovascular disease (CVD) treatment. Objectives: The aims of this study were to update evidence on the effect of psyllium on LDL cholesterol and to provide an assessment of its impact on alternate markers: non-HDL cholesterol and apolipoprotein B (apoB). Design: Medline, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were searched through 3 October 2017. Independent reviewers extracted relevant data and assessed risk of bias. We included randomized controlled trials with a duration of ≥3 wk that assessed the effect of psyllium on blood lipids in individuals with or without hypercholesterolemia. Data were pooled by using the generic inverse variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed by Cochran's Q statistic and quantified by the I2 statistic. Overall quality of the evidence was assessed by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Results: We included 28 trials in our analysis (n = 1924). Supplementation of a median dose of ∼10.2 g psyllium significantly reduced LDL cholesterol (MD = -0.33 mmol/L; 95% CI: -0.38, -0.27 mmol/L; P < 0.00001), non-HDL cholesterol (MD = -0.39 mmol/L; 95% CI: -0.50, -0.27 mmol/L; P < 0.00001), and apoB (MD = -0.05 g/L; 95% CI: -0.08, -0.03 g/L; P < 0.0001). Effect estimates for LDL cholesterol and non-HDL cholesterol were graded as moderate quality on the basis of downgrades for inconsistency and graded as high quality for apoB. Conclusion: Psyllium fiber effectively improves conventional and alternative lipids markers, potentially delaying the process of atherosclerosis-associated CVD risk in those with or without hypercholesterolemia. This trial is registered at www.clinicaltrials.gov as NCT03346733.
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Diets with high fiber content improve most metabolic syndrome (MetS) profile in nondiabetic individuals, but there is scarce information about the role of fiber intake in patients with the MetS and diabetes. The objective of this study is to determine whether soluble fiber supplementation improve MetS profile for 8 weeks of intervention in newly diagnosed type 2 diabetes (T2D) adult patients. After one week of dietary stabilization phase, 36 newly diagnosed T2D patients were stratified to different strata according to sex, age, fasting blood sugar (FBS), and waist circumference (WC). Then they were randomly allocated into 2 groups. The psyllium group (n = 18) received 10.5 g of psyllium daily for 8 weeks. The control group (n = 18) maintained their regular diet for 8 weeks. Soluble fiber supplementation showed significant reduction in the majority of MetS profile; FBS (43.55 mg/dL, p < 0.001), triglyceride (37.89 mg/dL, p < 0.001), total cholesterol (20.32 mg/dL, p < 0.001), systolic blood pressure (7.50 mmHg, p < 0.001), diastolic blood pressure (2.78 mmHg, p = 0.013), and WC (2.54 cm, p < 0.001) in the intervention group compared with the control group after 8 weeks of intervention. The high-density lipoprotein cholesterol was reduced in both groups, but this reduction was insignificant. The improvement in the MetS profile was enhanced by combining psyllium to the normal diet. Consumption of foods containing moderate amounts of these fibers may improve MetS profile in newly diagnosed T2D patients. This study was registered in Current Controlled Trials (PHRC/HC/28/15). Keywords: Metabolic syndrome; Type 2 diabetes; Fibe
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Background: There is strong epidemiologic evidence that dietary fiber intake is protective against overweight and obesity; however, results of intervention studies have been mixed. Soluble fiber beneficially affects metabolism, and fiber supplementation may be a feasible approach to improve body composition and glycemia in adults with overweight and obesity.Objective: We evaluated randomized controlled trials (RCTs) of isolated soluble fiber supplementation in overweight and obese adults on outcomes related to weight management [body mass index (BMI; in kg/m(2)), body weight, percentage of body fat, and waist circumference] and glucose and insulin metabolism (homeostasis model assessment of insulin resistance and fasting insulin) through a systematic review and meta-analysis.Design: We searched PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature and Cochrane Library databases. Eligible studies were RCTs that compared isolated soluble fiber with placebo treatments without energy-restriction protocols. Random-effects models were used to estimate pooled effect sizes and 95% CIs. Meta-regressions were performed to assess outcomes in relation to the intervention duration, fiber dose, and fiber type. Publication bias was assessed via Begg's and Egger's tests and funnel plot inspection.Results: Findings from 12 RCTs (n = 609 participants) from 2 to 17 wk of duration are summarized in this review. Soluble fiber supplementation reduced BMI by 0.84 (95% CI: -1.35, -0.32; P = 0.001), body weight by 2.52 kg (95% CI: -4.25, -0.79 kg; P = 0.004), body fat by 0.41% (95% CI: -0.58%, -0.24%; P < 0.001), fasting glucose by 0.17 mmol/L (95% CI: -0.28, -0.06 mmol/L; P = 0.002), and fasting insulin by 15.88 pmol/L (95% CI: -29.05, -2.71 pmol/L; P = 0.02) compared with the effects of placebo treatments. No publication bias was identified. Considerable between-study heterogeneity was observed for most outcomes.Conclusions: Isolated soluble fiber supplementation improves anthropometric and metabolic outcomes in overweight and obese adults, thereby indicating that supplementation may improve fiber intake and health in these individuals. However, the interpretation of these findings warrants caution because of the considerable between-study heterogeneity. This trial was registered at clinicaltrials.gov as NCT03003897.
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The persistent obesity crisis, with its increased risk for the metabolic syndrome (MetS), type 2 diabetes, and cardiovascular disease (CVD), continues to damage the health of populations globally, including children. Diets rich in the fiber provided by fruit and vegetables support good metabolic health, although few adults and children achieve the recommended daily target. Daily fiber supplementation, particularly with soluble fiber products, such as psyllium, oat bran, or a newer product such as PolyGlycopleX, may provide a convenient solution. Literature searches were conducted to identify original research articles, systematic reviews, and meta-analyses with the search terms psyllium, oat bran, PolyGlycopleX, and PGX, AND adults and children AND overweight, obesity, and metabolic syndrome. Data source was Embase and PubMed from 1980 to 2017. The results show that the addition of a soluble fiber product, most notably psyllium, improves blood lipid profiles, particularly total and low-density lipoprotein cholesterol, as well as glycemic response, and increases satiety, and by thus improving MetS and CVD risk factors, may augment the processes initiated by weight reduction diets. Although less studied than psyllium, the available evidence has shown that β-glucan present in oat bran has a beneficial effect on MetS and CVD risk factors, particularly blood lipids and glycemia. Early research has found PolyGlycopleX to provide similar benefits to other soluble fiber products, and suggest it may also assist with weight loss. This critical review demonstrates that soluble fiber supplements used as an adjunct to dietary and lifestyle modifications may assist with the treatment of CVD and MetS risk factors. More research is needed to further clarify the benefits of PolyGlycopleX in particular, as well as to develop safe and efficacious recommendations for fiber supplementation of all types for children in general.
Article
Objective: To compare the effects of baked psyllium supplementation versus those who received a placebo on constipation symptoms, body weight, glycemic and lipids control in patients with type 2 diabetes (T2D) and chronic constipation. Methods: In a single-blinded, randomized controlled trial, 51 patients with T2D and chronic constipation with body mass index (BMI) 20-47 kg/m2 received either 10 g of psyllium pre-mixed in cookies twice per day or placebo cookies for 12 weeks. Constipation symptoms, body mass index (BMI), fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), and lipid profile were determined at the beginning and end of 4, 8, and 12-week period. Constipation was evaluated with a stool diary (ROME III). Results: The psyllium group showed improvement in constipation symptoms, body weight, glucose and lipid values compared with the baseline and the placebo group. Body weight and FPG decreased from baseline in the psyllium group (P < 0.001 and P = 0.056, respectively). The differences (95% CI) of absolute change of body weight (-2.0 (-3.0, -1.0) kg; P < 0.001), FPG (-13.6 (-24.3, -2.9) mg/dl; P = .040), and HbA1c (-1.7 (-2.9, -0.5)); P = 0.002) between the groups were statistically significant. Cholesterol (-21.5 (-25.6, -14.4); P < 0.001), triglycerides (-20.0 (-32.3, -7.7); P = 0.021) and constipation symptoms (1.5 (0.4, 2.3); P < 0.001) decreased in the psyllium group. The compliance was good and no adverse effects were observed. Conclusion: In patients with T2D and chronic constipation, psyllium supplementation decreased constipation symptoms, body weight, glycemic, cholesterol, and increased HDLC levels.
Article
Background: Underweight and severe and morbid obesity are associated with highly elevated risks of adverse health outcomes. We estimated trends in mean body-mass index (BMI), which characterises its population distribution, and in the prevalences of a complete set of BMI categories for adults in all countries. Methods: We analysed, with use of a consistent protocol, population-based studies that had measured height and weight in adults aged 18 years and older. We applied a Bayesian hierarchical model to these data to estimate trends from 1975 to 2014 in mean BMI and in the prevalences of BMI categories (<18·5 kg/m2 [underweight], 18·5 kg/m2 to <20 kg/m2, 20 kg/m2 to <25 kg/m2, 25 kg/m2 to <30 kg/m2, 30 kg/m2 to <35 kg/m2, 35 kg/m2 to <40 kg/m2, ≥40 kg/m2 [morbid obesity]), by sex in 200 countries and territories, organised in 21 regions. We calculated the posterior probability of meeting the target of halting by 2025 the rise in obesity at its 2010 levels, if post-2000 trends continue. Findings: We used 1698 population-based data sources, with more than 19·2 million adult participants (9·9 million men and 9·3 million women) in 186 of 200 countries for which estimates were made. Global age-standardised mean BMI increased from 21·7 kg/m2 (95% credible interval 21·3–22·1) in 1975 to 24·2 kg/m2 (24·0–24·4) in 2014 in men, and from 22·1 kg/m2 (21·7–22·5) in 1975 to 24·4 kg/m2 (24·2–24·6) in 2014 in women. Regional mean BMIs in 2014 for men ranged from 21·4 kg/m2 in central Africa and south Asia to 29·2 kg/m2 (28·6–29·8) in Polynesia and Micronesia; for women the range was from 21·8 kg/m2 (21·4–22·3) in south Asia to 32·2 kg/m2 (31·5–32·8) in Polynesia and Micronesia. Over these four decades, age-standardised global prevalence of underweight decreased from 13·8% (10·5–17·4) to 8·8% (7·4–10·3) in men and from 14·6% (11·6–17·9) to 9·7% (8·3–11·1) in women. South Asia had the highest prevalence of underweight in 2014, 23·4% (17·8–29·2) in men and 24·0% (18·9–29·3) in women. Age-standardised prevalence of obesity increased from 3·2% (2·4–4·1) in 1975 to 10·8% (9·7–12·0) in 2014 in men, and from 6·4% (5·1–7·8) to 14·9% (13·6–16·1) in women. 2·3% (2·0–2·7) of the world's men and 5·0% (4·4–5·6) of women were severely obese (ie, have BMI ≥35 kg/m2). Globally, prevalence of morbid obesity was 0·64% (0·46–0·86) in men and 1·6% (1·3–1·9) in women. Interpretation: If post-2000 trends continue, the probability of meeting the global obesity target is virtually zero. Rather, if these trends continue, by 2025, global obesity prevalence will reach 18% in men and surpass 21% in women; severe obesity will surpass 6% in men and 9% in women. Nonetheless, underweight remains prevalent in the world's poorest regions, especially in south Asia.
Article
Despite reported benefits of flaxseeds and psyllium, to our knowledge no studies have compared their effectiveness in adults with type 2 diabetes (T2D). While both psyllium and flaxseeds are plant-derived fibers, flaxseeds contain additional compounds associated with cardiovascular health including alpha linolenic acid, phytoestrogen lignans, vitamin E and carotenoids. The objectives were to determine primarily whether flaxseeds were more effective than psyllium at improving weight and cardiovascular health (glucose, lipids and blood pressure) and secondarily inflammation and oxidative stress in subjects with T2D. We hypothesized, when matched for fiber mass content, daily supplementation with ground flaxseeds (28 g/d) would be more effective than ground psyllium fiber (9 g/d) for improving adiposity and glycemic regulation, serum lipids, blood pressure and markers of inflammation and oxidative stress in participants with T2D. In this comparative effectiveness parallel-design study, adults (18-75y) with T2D were randomized to consume either supplement for 8 weeks with anthropometrics and blood samples collected at baseline and week 8. Flaxseed and psyllium reduced waist circumference (−2.8 ± 2.0 and −1.2 ± 2.4 cm, respectively; p = 0.002 within groups) and oxidized lipoproteins (−2.8 ± 4.2 and −0.1 ± 1.5 nM/L, respectively; p = 0.037 within groups) without affecting body mass, lipids, or blood pressure. Flaxseeds alone increased nitric oxide (+2.4 ± 3.3 vs −0.9 ± 2.7 nM/L; p = 0.044 between groups) suggesting flaxseeds may offer additional vasoprotection. Thus, fiber supplementation is an effective means to reduce waist circumference and oxidative stress in individuals with T2D. In addition, this study was the first to show that flaxseeds increase nitric oxide bioavailability in the vasculature of subjects with T2D.