Research Update articles are produced in order to keep practitioners up to date on impactful research that is relevant to the field of integrative medicine. These articles may contain summaries of recent studies, events, or other industry news that advance current knowledge and standards of care.
The following article summarizes the research conducted by González et al. titled “Reduction of small dense LDL and Il-6 after intervention with Plantago psyllium in adolescents with obesity: a parallel, double-blind, randomized clinical trial,” which was published in Springer Nature in 2021. (2)
Background
The prevalence of obesity remains a global concern. With over two billion people considered to be living with overweightness and one-third with obesity, the necessity to address this public health crisis remains. (4) Obesity is associated with many comorbidities, such as nonalcoholic fatty liver disease, type 2 diabetes mellitus, hypercholesterolemia, and insulin resistance, and it often affects children and adolescents before even reaching adulthood. (1)(2) The risk of cardiovascular diseases (CVDs) in children and adolescents also increases with the incidence of obesity. (2)
Psyllium is a fiber derived from husks of the seeds of Plantago ovata. Its botanical actions vary greatly; it may provide benefits as a wound healing aid, a mucilage, and an antidiarrheal and anticonstipation agent. (3) As a hypoglycemic agent, it has been shown to decrease interleukin-6 (IL-6), which when elevated, may induce insulin resistance, increase inflammation, and increase the risk of metabolic syndrome. (2)(3) As a cholesterol-lowering agent, it has also been shown to decrease low-density lipoprotein cholesterol (LDL-C), an important marker for CVD. While many researchers have studied the effects of the intervention of plantago and other fibers on obesity and its comorbidities, this article stands out as the first to study adolescents with obesity.
Methods
The design of this study was a parallel, double-blinded, randomized, placebo-controlled trial. Mexican high-school students aged 15 to 19 who had at least one CVD risk factor and were non-smokers were included. Those who did not follow at least 80% of the diet and fiber study protocol; had familial hypercholesterolemia with a first-degree relative with LDL-C, premature CVD, or positive genetic testing for familial hypercholesterolemia; or for whom metabolic or infectious disease was discovered mid-study were excluded from the trial.
Individuals were randomly assigned to either the psyllium group or the placebo group. Those in the psyllium group underwent a seven-week intervention receiving 10 g of daily psyllium, while those in the placebo group received 10 g of daily rice flour. Both were diluted in 250 mL of water and were consumed in the morning on an empty stomach, followed by an additional 250 mL of water. The dosing was tracked by a checklist in WhatsApp, and an investigator, who was also blinded in the study, visited the participants daily. Participants sent photography as proof of compliance. Any adverse effects were to be reported in an open-ended questionnaire.
Participants were informed to continue their usual dietary habits. ESHA’s Food Processor Nutrition Analysis software analyzed data collected via 24-hour dietary recalls performed throughout the study to determine the averages of the initial and final energy intakes. Nutritional information was recorded as well. Anthropometric measurements of height and weight were conducted using a SECA stadiometer and scale, and waist circumference, blood pressure, and body mass index (BMI) were also recorded. Researchers collected serum samples from venous blood from participants after 12 hours of fasting. Glucose and lipid levels were measured via an autoanalyzer, and Il-6 and insulin were measured via their respective enzyme-linked immunosorbent assay (ELISA) kits. Lipid subclasses of small dense LDL (sdLDL) and high-density lipoprotein (HDL) were measured via gradient electrophoresis.
Results
Of the 113 individuals in the study, six of the 56 in the psyllium and seven of the 57 in the placebo were lost to follow-up, resulting in acquiring data from 50 participants in each group for analysis. No significant differences were observed between the two groups at baseline. However, post-treatment, the psyllium group demonstrated a significant decrease in mean BMI (0.50 kg/m2), waist circumference (0.50 cm), total cholesterol (15.4 mg/dl), non-HDL-C (0.10 mg/dl), and LDL-C (14.3 mg/dl) compared to their baseline counterparts. LDL-C, non-HDL-C, and total cholesterol were also decreased in the placebo group post-treatment (10.5 mg/dl, 7.2 mg/dl, and 8.9 mg/dl, respectively), though no anthropomorphic changes of statistical significance were noted. The psyllium group also showed decreased mean Il-6 levels (1.56 pg/ml), an absent finding in the placebo group, and decreased sdLDL particles (40.38%) compared to the placebo. No adverse events were reported in either group.
Critical analysis
The study design of 50 individuals in two groups allowed for an equally weighted analysis and a sample size large enough to establish an 80% power calculation, adding to the statistical strength and study design of the protocol. Interestingly, LDL-C decreased post-treatment in both groups, despite no significant changes or differences in nutritional intake, which the authors note may have been due to observation bias of participants slightly altering their diet. Lack of full dietary control in the participants is a notable limitation of this study.
The bottom line
Plantago ovata psyllium significantly decreased CVD markers sdLDL and IL-6 in adolescents with obesity. While the mechanism by which this occurs is not fully understood, several aspects have been supported with evidence including changes in microbiota, increased short-chain fatty acid levels which increase insulin sensitivity in the liver, attenuation of carbohydrate breakdown in portal circulation, and reduced lipogenesis. Supplementation of psyllium into the diet at a dose of 10 g per day for seven weeks shows safe and promising results for decreasing the risk of comorbidities and adiposity indices in obese adolescents.
- Brown, C. L., Halvorson, E. E., Cohen, G. M., Lazorick, S., & Skelton, J. A. (2015). Addressing Childhood Obesity: Opportunities for Prevention. Pediatric clinics of North America, 62(5), 1241–1261.
- González, A. P., Flores-Ramírez, A., Gutiérrez-Castro, K. P., Luévano-Contreras, C., Gómez-Ojeda, A., Sosa-Bustamante, G. P., Caccavello, R., Barrera-de León, J. C., Garay-Sevilla, M. E., & Gugliucci, A. (2021). Reduction of small dense LDL and Il-6 after intervention with Plantago psyllium in adolescents with obesity: a parallel, double blind, randomized clinical trial. European journal of pediatrics, 180(8), 2493–2503.
- Sarfraz, R. M., Khan, H., Maheen, S., Afzal, S., Akram, M. R., Mahmood, A., Afzal, K., Abrar, M. A., Akram, M. A., Andaleeb, M., Haider, I., Abbas, K., & Yasmeeni, T. (2017). Plantago ovata: A comprehensive review on cultivation, biochemical, pharmaceutical and pharmacological aspects. Acta poloniae pharmaceutica, 74(3), 739–746.
- Seidell, J. C., & Halberstadt, J. (2015). The global burden of obesity and the challenges of prevention. Annals of nutrition & metabolism, 66 Suppl 2, 7–12.