Sweet Smell of Success: Luteolin Supplement for Long-Covid

A recent scientific article has suggested that Luteolin might be a treatment for the ‘brain fog’ linked to Long-Covid.

Luteolin- New Treatment for Long-Covid Loss of Smell

Loss of Smell is a really common symptom of COVID infection, and for some people it does not return for months.

The current treatment is smell rehab, basically retraining your sense of smell with a specific smelling program. Which works for some people.

Woman smelling tulips

A new scientific study has shown that adding a Luteolin supplement to the rehab treatment significantly improved the return of sense of smell to patients who had Long-COVID Loss of smell.

I am going to go through the theory and the studies involved, click here if you just want to skip ahead to where I talk about how this supplement restores the sense of smell.

Is Long-Covid Due to Inflammation in the Brain?

The paper lists symptoms of long-covid and observes that they are very similar to the symptoms of myalgic encephalomyelitis/chronic fatigues syndrome, mast cell activation syndrome or systemic mastocytosis. Basically the author suggests that immune cells and mast cells are stimulated by stress, in this case exposure to COVID.

Image with words 'Long Covid' with DNA and virus particles

Evidence is that IL-6 is elevated in COVID patients, much like ME/CFS patients, and IL-6 promotes and increase in the number of mast cells.

Other evidence is that many of the symptoms experienced by people with Long-COVID are also experienced by people who has had chemotherapy for cancer.

In fact ‘chemobrain’ is a known issue, and it seems to be linked with neuroinflammation with cytokine dysregulation.

woman with headache holding her temples and wincing

Long-COVID symptoms

Symptoms present in long‐COVID syndrome:

  • Angioedema
  • Brain fog
  • Confusion
  • Difficulty multitasking
  • Dizziness
  • Dysautonomia
  • Fatigue
  • Gastrointestinal complaints
  • Headache
  • Hypotension
  • Insomnia
  • Irritability
  • Lightheadedness (syncope)
  • Inability to find the right words
  • Memory loss
  • Myalgias
  • Palpitations
  • Shortness of breath
  • Weakness
woman with headache pressing hands to temples

What is Luteolin?

Luteolin is a bio-flavonoid found in different plants such as vegetables, medicinal herbs, and fruits.

Luteolin is a potent anti-inflammatoryluteolin can suppress cytokines which are linked to inflammation and chronic diseases like rheumatoid arthritis, asthma, atherosclerosis, Alzheimer’s disease and cancer.

Foods that contain luteolin

Luteolin exists in many foods, particularly celery, spinach, artichoke, rooiboos tea, fenegreek seed and peppermint. I have a huge list of luteolin rich foods with how much luteolin they have in this post.

However Luteolin does not get absorbed through the gut very well. So taking Luteolin in a mixture with a fat seems to be important for absorption.

Luteolin as a Treatment for Long-COVID?

This article suggests that Luteolin could be a treatment for Long-COVID through inhibition of mast cell-associated neuroinflammation.

Mast cells could be inhibited with the structurally related natural flavonoids luteolin and quercetin. Both are easily available in supplement form and are generally considered safef. Luteolin and Quercetin inhibit entry of the COVID virus into cells, inhibit neuroinflammation, and reduce cognitive decline. 

Artistic rendition of Brain inflammation

The article states that luteolin is better at penetrating into the brain that quercitin and inhibits both microglia and mast cells, and has been reported to reduce neuroinflammation.

Sounds pretty interesting right?

I am interested, but there is a catch.

The author, Dr. Theoharides, does a lot of research on Luteolin, and…. he the Scientific Director and shareholder in Algonot, the company that makes NeuroProtek® and BrainGain®.

That is not to say that these products might not help with long-COVID, but he is clearly biased.

I am interested in some good studies.

Luteolin and Post-COVID Loss of Smell

Fortunately, there are some interesting recent studies with good design on using Luteolin as a treatment for the loss of smell post-COVID.

This loss of smell (called olfactory impairment or olfactory dysfunction) is a common symptom of COVID. And it really isn’t a small thing, about 10-20% of people who had covid have persistant loss of smell.

People showing this Post-COVID loss of smell are seen to have neuroinflammation, with microglial activation along olfactory pathways and they also had necrosis of the olfactory bulb. So basically inflammation and cell death in the part of the brain that processes smell.

woman smelling purple flowers

Now I think it makes sense that you probably don’t just get inflammation in just one specific part of the brain. But it is quite easy to notice when you lose your sense of smell vs whether you are having brain fog that makes it more difficult to solve problems or understand social interactions. Not quite as cut and dry as not being able to smell something.

And, it also makes it much easier to study scientifically whether a treatment works, because you can fairly easily study a person’s sense of smell, with something called ‘Sniffin’ Sticks’.

So, it might be that loss of smell due to COVID may be a nice way to study treatments that could help with other neurological symptoms of COVID.

Anyhow, the researchers hypothesized that ‘Reducing neuroinflammation may
therefore alleviate anosmia’ so they conducted a randomized trial of the anti-inflammatory agents Palmitoylethanolamide (PEA) and Luteolin in a group of patients affected by persistent olfactory dysfunction after COVID-19.

PEA-Lut treats COVID Loss of Smell

Their first trial was one super small study from 2021 that showed possible improvement, but really it was not that convincing. Unfortunately the randomization of patients in the study (which is what you are supposed to do) ended up with the treatment group and the control group being very different. Hey that can happen, because of you know… randomization.

So they tried again with a multicenter double-blinded randomized-clinical trial with 185 patients and the results were more impressive. They treated people with PEA-Lut and olfactory training (the usual treatment for loss of smell), the control group got a placebo and the olfactory training.

So it was a good study design. The outcome was the abilty to detect the odour on the ‘Sniffin’ Sticks’, which is actually a validated research tool, even if it sound ridiculous.

cinnamon sticks

In this case the groups were more similar prior to treatment (higher numbers do help with that) and they saw that the smelling score improved in 92% of people getting the PEA-Lut, but only in 42% of the people getting the placebo.

More than half (56%) of the people getting PEA-Lut recovered to a normal smelling score, but only 10% of those getting the placebo did.

So, this looks pretty good to me!

And the researchers point out that if smell can improve, then the loss of smell is likely due to neuroinflammation and not cell death. More good news.

This study used PEA-Lut (brand name GLIALIA) – a form of Luteolin micronized with Palmitoylethanolamide (PEA). (Read my post on Luteolin to see why this form may work better due to improved gut absorption).

oil and water mixing

And more good news, these researchers had no conflict of interest, so they do not work for GLIALIA.

Could it get even better? The study went for 90 days, and they wonder if more improvement could occur with more time, or with an increased dose of the PEA-Lut for those that did not fully recover their sense of smell.

Can Luteolin Treat Other Long-COVID Symptoms?

You do have to wonder don’t you?

Now the researchers in the loss of smell study pointed out that they did not assess for baseline or post-treatment neuroinflammation with biomarkers or neuroimaging, or analyse the pharmacokinetics of the PEA-Lut (which might be important as absorption of Luteolin is a known issue). So they cannot say for sure what PEA-LUT is doing in the Long-COVID brain of the people who got their sense of smell back.

artist rendition of cognitive effort

But I think this study is super exciting, because as they point out ‘The observation of olfactory recovery in patients with olfactory loss in excess of 12 months suggests that some SARS-CoV-2 related injury is reversible long after acute illness has subsided.’

So basically, even if a long time has passed, there is hope for treating brain symptoms from COVID. And for anyone who is dealing with Long-COVID symptoms, that is exactly what you are hoping for.

I’ll be very interested to see more studies with Luteolin and long-COVID.

Luteolin Supplement Options

Interested in trying Luteolin? (Of course always get advice from your own health professional, this blog is not medical advice!)

Here are some options of where you can purchase.

Luteolin on Amazon

Palmitoylethanolamide on Amazon

I wrote about how micronized PEA Lut options should be absorbed a lot better than Luteolin alone, so likely worth the extra cost over just buying luteolin.

If you want a good micronized version of luteolin, Mirica is a reputable brand that has many micronised PEA Lut options that have much higher absorption:

Mirica® Palmitoylethanolamide (PEA) and Luteolin

Mirica® Advanced Palmitoylethanolamide (PEA) and Luteolin

Mirica® Luteolin


Long‐COVID syndrome‐associated brain fog and chemofog: Luteolin to the rescue

Randomized clinical trial “olfactory dysfunction after COVID-19: olfactory rehabilitation therapy vs. intervention treatment with Palmitoylethanolamide and Luteolin”: preliminary results

Ultramicronized Palmitoylethanolamide and Luteolin Supplement Combined with Olfactory Training to Treat Post-COVID-19 Olfactory Impairment: A Multi-Center Double-Blinded Randomized Placebo-Controlled Clinical Trial

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