Effect of Psyllium Fiber Supplementation on C-Reactive Protein: The Trial to Reduce Inflammatory Markers (TRIM)

Dana E. King; Arch G. Mainous; Brent M. Egan; Robert F. Woolson; Mark E. Geesey

doi:10.1370/afm.819

Article Figures & Data

Figures

Tables
Additional Files

Download figure
Open in new tab
Download powerpoint
Figure 1.
Trial profile: disposition of screened, randomized, and analyzed patients.

View popup

Table 1.

Initial Demographic Characteristics of the Randomized Patient Population (n = 162) by Fiber Group.

Characteristic	High Fiber	Low Fiber	Control	P Value
^a χ² Analysis of the distribution.
^b Analysis of variance.
No.	51	54	57
Sex, %				.68^a
Male	25.5	31.5	24.6
Female	74.5	68.5	75.4
Race, %				.43^a
Black	35.3	50.0	49.1
White	62.8	48.2	50.9
Other	2.0	1.8	0
Smoker, %				.88^a
Never	60.8	63.0	64.9
Former	19.6	22.2	22.8
Current	19.6	14.8	12.3
Diabetic, %	15.7	18.5	15.8	.91^a
Hypertensive, %	31.4	51.9	36.8	.08^a
Taking statin medication, %	13.7	18.5	15.8	.80^a
Age, years, mean (SD)	51.4 (6.4)	50.6 (6.1)	49.4 (6.1)	.22^b
Body mass index, kg/m², mean (SD)	33.8 (5.9)	32.6 (5.6)	33.7 (6.6)	.55^b
Dietary fiber, g/d, mean (SD)	14.5 (3.9)	13.5 (3.4)	14.1 (4.4)	.42^b
Fibrinogen, mg/dL, mean (SD)	387.9 (75.7)	389.8 (79.5)	380.8 (61.9)	.80^b
White blood cell count, 1,000/μL, mean (SD)	6.38 (2.1)	6.16 (1.9)	6.17 (1.9)	.81^b
C-reactive protein level, mg/L, mean (SD)	7.61 (5.8)	7.62 (6.7)	7.79 (7.5)	.99^b

View popup

Table 2.

Changes in Inflammatory Markers (Intent-to-Treat) From Baseline to 3 Months Among Randomized Participants, by Fiber Group

Inflammatory Marker	High Fiber (n=48)	Low Fiber (n=53)	Control (n=57)
C-reactive protein, mg/L, mean (SD)	0.98 (4.57)	−0.96 (4.45)	0.05 (7.87)
Fibrinogen, mg/dL, mean (SD)	−2.44 (32.69)	−2.29 (35.34)	10.32 (48.92)
White blood cell count, 1,000/μL, mean (SD)	0.01 (1.02)	0.08 (0.87)	−0.09 (1.05)

View popup

Table 3.

Changes in Inflammatory Markers Between Baseline and 3 Months Among Patients Who Were at Least 75% Compliant With Fiber Supplementation and Had No Additions to Medication, by Fiber Group

Inflammatory Marker	High Fiber (n=35)	Low Fiber (n=45)	Control (n=52)
^a Significantly different from control group (t test, P<.05)
C-reactive protein, mg/L, mean (SD)	0.50 (4.67)	−1.12 (4.78)	0.36 (7.94)
Fibrinogen, mg/dL, mean (SD)	−6.30 (34.52)^a	4.20 (35.42)	13.02 (48.62)
White blood cell count, 1,000/μL, mean (SD)	0.08 (0.89)	0.12 (0.92)	−0.01 (1.05)

View popup

Table 4.

Distribution of Interleukin-6 Levels by Fiber Group in the Initial Randomized Patient Population, and After 3 Months, in the Intent-to-Treat Population and Among Protocol Completers

Interleukin-6 Level	High Fiber	Low Fiber	Control	P Value^a
^a Determined by χ² analysis.
Initial population, No.	42	51	54	.043
≤2.5 pg/mL, %	45.2	62.8	38.9
>2.5 pg/mL, %	54.8	37.3	61.1
Intent-to-treat, No.	41	51	56	.217
≤2.5 pg/mL, %	48.8	31.4	42.9
>2.5 pg/mL, %	51.2	68.6	57.1
Protocol completers, No.	34	44	51	.178
≤2.5 pg/mL, %	50.0	29.6	41.2
>2.5 pg/mL, %	50.0	70.5	58.8

Additional Files

Figures
Tables

The Article in Brief

Effect of Psyllium Fiber Supplementation on C-Reactive Protein: The Trial to Reduce Inflammatory Markers (TRIM)

Dana E. King, MD , and colleagues

Background High levels of C-reactive protein (a protein in the blood that indicates inflammation) have been associated with increased risk of cardiovascular disease, whereas diets high in fiber have been shown to lower the risk of cardiovascular disease. This study examines whether supplementing the diet with psyllium, a form of fiber, affects levels of C-reactive protein and other indicators of inflammation in overweight or obese adults.

What This Study Found In overweight or obese adults, taking daily psyllium fiber supplements does not appear to significantly lower the levels of inflammation that play a role in cardiovascular risk. These findings contrast with previous research suggesting that dietary fiber is associated with levels of C-reactive protein.

Implications

A diet naturally high in fiber is important; however, taking a psyllium supplement may not be an effective way to reduce inflammation and risk of cardiovascular disease.
The authors call for further research with other types of fiber or with combinations of nutrients.