I was not able to find any paper on Google Scholar about a study on the effect of a low-histamine diet on obstructive sleep apnea. How many is "many" and where

I was not able to find any paper on Google Scholar about a study on the effect of a low-histamine diet on obstructive sleep apnea. How many is "many" and where is this documented? The few matches for low-histamine diet and apnea come from what I would consider fringe and untrustworth research, often suggesting a low-histamine diet helps a large number of medical issues, but not pointing to study giving numbers, describing the severity of the apnea, and other things I would expect. I was able to find papers which studied the effect of anti-histamine drugs on obstructive sleep apnea, like https://journals.sagepub.com/doi/abs/10.2500/ajra.2013.27.3921 https://journals.sagepub.com/doi/abs/10.2500/ajra.2013.27.39... for when people also have allergic rhinitis. "adding [anti-histimines] to this treatment did not show improved effects compared with placebo treatment". I presume people taking anti-histamines would have a lower amount of histamines in their body, so if there were a correlation it would have been seen. (Alternatively, it says that a low-histamine diet is not effective for CPAP when suffering from allergic rhinitis.) It is apparently quite hard to identify what "low-histamine diet" means. In "Low-histamine diets: is the exclusion of foods justified by their histamine content?" at https://www.mdpi.com/2072-6643/13/5/1395 https://www.mdpi.com/2072-6643/13/5/1395 , which specifically concerns "the symptomatology of histamine intolerance", notes the "great heterogenicity in the type of foods that are advised against for histamine intolerant individuals. Excluded foods were, in most cases, different depending on the considered diet. Only fermented foods were unanimously excluded." > The design of a low-histamine diet is challenging due to different handicaps. One of these is the lack of consensus on the histamine level below which a food is said to be considered low in histamine. Thus, variable histamine levels in food ranging between 5–50 mg/kg have been pointed out as potential thresholds, while other authors are much more demanding and consider foods with low histamine concentrations to be those that contain amounts below 1 mg/kg [ 12 ,26 –28 ]. Moreover, there is no specific regulation for the food industry to declare the occurrence or absence of histamine in food labelling, which could help histamine intolerant individuals to make suitable and informed choices. > Overall, providing dietary recommendations and guidelines in the frame of a low-histamine diet is difficult for healthcare professionals. If it's difficult for healthcare professionals to even determine what is low-histamine - and that's for people who are specifically histamine intolerance - and no studies to back up your suggestion ... why should anyone think your proposal has merit? There is a long history of using the "why the closed mind?" argument to sell snake oil treatments, so I would not advise using argument and instead point to supporting evidence.