Study: Carrot-derived extract improves immune response

By Nicola Gordon-Seymour

- Last updated on GMT

getty | laylabird
getty | laylabird

Related tags quality of life Immune system

Carrot-derived rhamnogalacturonan-I (cRG-I) increases natural killer (NK) cell function and immune responses that mitigate the symptoms of a common cold and improve quality of life, according to research funded and supported by BeniCaros producer, NutriLeads.

Scientists studying the effect of daily BeniCaros (cRG-I) on 146 healthy subjects for ten weeks observed significant reductions in symptom severity (20-33%) and duration (28-43%) 13 days post infection.

Furthermore, symptomatic relief improved individual self-assessed quality of life scores, including the ability to think clearly, exercise and accomplish daily activities.

“The strength and the enormous consistency of the immune health benefits of BeniCaros was not expected​,” NutriLeads Founder and Chief Scientific Officer, Ruud Albers, Ph.D, told

“BeniCaros clearly accelerated immune responses which resulted in a reduction in both the severity and duration of common cold symptoms. There was also great consistency across subjects who felt better and reported significantly better quality of life scores than the control group.”

Results support previous findings on the protective prophylactic effects of cRG-1, found to enhance innate immune and anti-viral responses to rhinoviral infections.

Training immune responses

BeniCaros has a unique dual mode of action, according to Albers. Taken orally, the dietary supplement passes through the gastrointestinal (GI) tract and “trains”​ innate immune cells to respond faster to viral infections.

The immune system is like “a fire brigade whose job it is to protect”​ and needs to be well-nourished to do its job, he explains.

“Training is critical if the brigade is to perform optimally. BeniCaros provides the training to accelerate responsiveness and thus increase efficiency and protection​,” he comments.

“Trained immune cells circulate throughout the body, including the respiratory tract, to strengthen and optimize natural defences.”

Microbial fermentation stimulates the propagation of beneficial micro-organisms and corresponding metabolites (short chain fatty acids) that offer additional immune support, he continues.

Moreover, cRG-I may be effective in limiting the negative impact of other respiratory viral infections, “since early innate immune and anti-viral responses to respiratory infections depend on the initial local interferon (IFN) responsiveness​”.

Unlike other immune ingredients, BeniCaros does not lead to broad, non-specific activation of the innate immune system. This is important, especially for products designed to be taken daily and long term,” ​he says.

Study design

The double-blind placebo-controlled study comprised four stages including enrolment, eight-week supplementation, response to exposure to rhinovirus-16 (RV16) infection with continued supplementation for two weeks, and a three-week follow-up without cRG-I intake.

Subjects were aged 18 to 65 years with a BMI between 18.5 and 20kg/m2​ and were divided into one of two intervention groups (either 300mg or 1.5g dosage) or the placebo. Health and medication status were assessed and those with a history of allergic, respiratory, cardiovascular or auto-immune conditions, or recent cold symptoms were excluded.

Eligible subjects completed the Wisconsin Upper Respiratory Symptom Score-21 (WURSS-21) questionnaire online the day before infection and every morning for 13 days thereafter. Jackson questionnaires were completed every evening to compile symptom scores.

NutriLeads (Wageningen, The Netherlands) natural cRG-I carrot extract was supplied in powder format and administered once a day with breakfast.

Nasal brush and lavage samples were used to determine RV16 viral load and blood samples to establish immune profiles and measure phagocytic and NK activity. Dose-dependent effects were established with statistical analyses.

Key improvements

Subjects in the intervention group reported fewer cold symptoms, including runny nose, sore throat, cough and feeling tired, and indicated improvements in their ability to think clearly, walk, climb stairs, exercise, undertake work and daily activities, compared with the placebo.

BeniCaros supports a cascade of protective immune responses in the presence of a health challenge. Importantly systemic response was unchanged in the absence of an immune challenge,” ​says Albers.

Symptomatic severity and duration scores in the 300mg group fell by 30% for a runny nose and 20-30% for a scratchy throat, while coughing symptoms were down 20-30%. While duration of head congestion fell between 10 and 20%, subjects reported increased severity, which also applied to chest congestion.

The impact on individual symptom scores was lower for subjects taking 1.5g, however both groups indicated a 10-20% reduction in duration of feeling tired.

Dose-dependent results

cRG-I accelerated local and systemic immune response biomarkers, including critical anti-viral interferon gene expression, and mobilised innate immune cells to infection sites. Ex-vivo stimulation of whole blood samples demonstrated enhanced function of NK cells that play an important role in early innate immune responses.

Reported biological responses to RV16 were dose dependent. BeniCaros at 300mg accelerated IFN gene expression much faster than the higher dose and reflected in corresponding beneficial effects on symptoms. However, nasal immune cell response was faster and higher in the 1.5g group.

Results suggest cRG-I ameliorates the negative effects of this common cold infection and improves individual wellbeing.

The authors conclude: “Carrot is a safe, sustainable, and economically viable solution that could easily be integrated into food products and dietary supplements that aim to support immune fitness and wellbeing.”

BeniCaros supports a cascade of protective immune responses in the presence of a health challenge. Importantly systemic response was unchanged in the absence of an immune challenge,” ​says Albers.

Source: Nutrients

Published online, October 12, 2022:

‘Effects of Dietary Supplementation with Carrot-Derived Rhamnogalacturonan-I (cRG-I) on Accelerated Protective Immune Responses and Quality of Life in Healthy Volunteers Challenged with Rhinovirus in a Randomized Trial’

Authors: Sue McKay, Annemarie Teitsma-Jansen, Esther Floris, Tamara Dekker, Barbara Smids, Ridha Khurshid, Wim Calame, Alwine Kardinaal, René Lutter and Ruud Albers

Related topics Research Immune support

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