Background
Plant stanols are known to lower low-density lipoprotein cholesterol, but other health effects have also been suggested. For example, in asthma patients plant stanols were found to shift the immune response away from the dominant T helper (Th) 2 response by activating regulatory T cells and Th1 cells. It is currently unknown if this effect translates into reduction of clinical symptoms in asthma patients.

Objective
The primary objective is to demonstrate clinical benefits of long-term consumption of plant stanol esters in asthma patients. The secondary objectives are to evaluate the mechanisms via which plant stanol esters modulate the immune system and to evaluate their effects on cardiovascular (CVD) risk parameters.

Methods
A double-blind, randomized, placebo-controlled trial will be carried out with an intervention period of 12 months. We aim to recruit 160 allergic asthma patients, aged 18-70 years old, with a body mass index between 20-35 kg/m². The intervention group will receive soft chews with 3g plant stanols per day. The control group will receive placebo soft chews. The main study endpoint is the change in asthma control questionnaire score from baseline to the end of the study. Secondary endpoints include lung function parameters, markers for immune function, medication use, CVD risk parameters, and vaccination response to tetanus, rabies, and pneumococcal bacteria as a measure for immune function.

Valorization
This study will help to understand the effects of plant stanols on human health, more specifically on the immune system of asthma patients.

Funding
This study is funded by PPP Allowance made available by Health~Holland, Top Sector Life Sciences and Health, to stimulate public–private partnerships (project number LSHM18008), and by Raisio Ltd. This company provides the study products, but is not involved in the design, execution, or data analysis of the study.