Citrus pectin may reduce anxiety and inflammation: Pilot study

Four weeks of supplementation with a low-methoxy (LM) pectin by CP Kelco led to significant effects on a “vast range of cytokines” at a dose of 20 g per day, according to findings published in Nutrients​.

The study is reported to be the first to present the potential anxiety-modulating and anti-inflammatory effects of LM pectin supplementation in humans.

“The effect of pectin on anxiety scores in humans opens a number of potential clinical applications,” wrote researchers from the University of Nottingham and University College Dublin. “Given the strong safety profile of pectin, nutritional supplementation with this natural polysaccharide represents a safe and cost-effective non-pharmacological approach for enhancing the long-term mental well-being of individuals grappling with anxiety.

“However, given that LM pectin’s effects were tested in healthy volunteers, these findings cannot be extrapolated to clinical populations, and future studies are needed to assess the role of pectin supplementation to assess whether the anxiety-reducing and anti-inflammatory effects are also observed in patient groups.”

Pectin​

The chemical structure of pectin is based on a chain of repeating galacturonic acid units. In very basic terms, galacturonic acid has a ring structure with a carboxyl (CO2-) group jutting out. In nature, a large portion of these carboxyl groups have methanol (CH3OH) bonded via a reaction called esterification.

A high degree of esterification, or many bonded methanol groups, produces a high methoxyl (HM) pectin, while a low degree of esterification gives a low methoxyl (LM) pectin.

The ratio of esterified to non-esterified galacturonic acid units plays a central role in determining the properties and behavior of the pectin, and determines which food applications it can be used in.

The new study, which was co-funded by pectin player CP Kelco, used a LM pectin with a degree of methyl-esterification below 10%.

Study details​

Twenty-nine healthy people were recruited to take part in the first pilot study, where they consumed 20 g/day of the LM citrus pectin or 10 g/day of a maltodextrin control for four weeks.

A separate cohort of 15 people were recruited for another study and they received increasing doses of the pectin. For the first two weeks, the dose was 5 g/day, then 10 g/day for weeks three and four, and then 15 g/day for a final two weeks.

Data from the first study showed that 20 g/day of the LM pectin led to decreases in the pro-inflammatory markers such as TNF-alpha, IL-1 beta, IL-6 and INF-gamma. At the same time, increases in the anti-inflammatory marker IL-10 were also reported. No such improvements were recorded in the control group.

Additionally, the researchers recorded a significant drop in anxiety scores for the high-dose pectin group, compared to the control group.

“These [anti-anxiety] effects were clearly dose-dependent and were significant with doses as low as 10 g,” wrote the researchers. “Importantly, none of these effects were seen in the control group. Although a number of studies have hinted at possible effects of pectin on anxiety in animal models, to the best of our knowledge this is the first study showing significant drops in anxiety scores in humans.

“Interestingly, the drops in anxiety and depression are observed for the 10 g dose, whereas significant drops in inflammation are only found with doses of 15 g or higher. It is thus possible that additional mechanisms not directly linked to pectin’s anti-inflammatory effects, e.g., effects on the gut microbiome unaccounted for by SCFAs, may be responsible for the observed anxiety-reducing properties of pectin supplementation.”

The results of the pilot study were described as highlighting this pectin’s “promising potential” for mood modulation and anti-inflammatory activity, more research is needed to elucidate the specific mechanism(s) of action and the optimal dose and duration for the potential benefits.

Source: Nutrients​
2024, 16​(19), 3326; doi: 10.3390/nu16193326​
“Supplementation with Citrus Low-Methoxy Pectin Reduces Levels of Inflammation and Anxiety in Healthy Volunteers: A Pilot Controlled Dietary Intervention Study”
Authors: A. Vijay et al.