How I got here
My name is Harriet Carroll, and my PhD was in Nutrition and Metabolism. Whilst my PhD was a bit of a mishmash of things, the thing I’m academically most well-known for is my work in hydration and metabolism.
I initially got interested in COVID-19 because SARS-CoV-2 binds to ACE2 so it can enter cells, and ACE2 is important for hydration regulation.
During the first lockdown, I wrote a paper about thirst. Within that paper, I made some links between hydration and the cholinergic system and said this link might be important outwith a solely hydration context, such as understanding interactions with SARS-CoV-2. This relationship seems to have held out.
During this time, I was increasingly interested in COVID-19 and long COVID and did a lot of science communication about it. This included a lot of myth-busting about the vaccines. I will admit now, I was a bit overconfident about some things.
MY COVID EXPERIENCE
In January 2021, I started employment in the NHS as a Clinical Researcher helping run a site of the internationally renowned SIREN study. In March 2021, because I was in the NHS and deemed as working in a high-risk clinical environment (we had unmasked participants in our clinic), I was fast-tracked for my COVID-19 vaccine. Little did I know, there were some unrecognised side effects and I was about to experience a whole bunch of them.
I was initially near bedbound for about 2-3 weeks after my vaccine with a range of symptoms that gradually improved. Despite a high D-dimer (clot breakdown factor), my head CT was clear, so my doctor determined that waiting-and-seeing was the best thing. Sadly, I think waiting and seeing contributed to my ongoing ill-health, and as such, I strongly promote early intervention (too late for many, I know).
I remember frantically trying to find answers and getting constantly dismissed by doctors who hadn't read a single paper about my condition. Looking back, I wish I had some guidance from someone. This guidance is what Long Covid Scientific Consultancy aims to provide.
Over one year later (and with a super engaged new doctor on board), I had some diagnoses: multiple pulmonary emboli, mast cell activation syndrome (MCAS), postural orthostatic tachycardia syndrome (POTS), endocrine dysfunction, and significantly worse myalgic encephalomyelitis (ME) (originally diagnosed at age 17).
My condition was essentially long COVID, but from the vaccine rather than the virus. Cue my (rather intense) interest in vaccine injuries and long COVID. I got involved with advocacy groups (e.g., REACT19), support groups (e.g., UKCV Family) and researchers across the world (e.g. #TeamClots).
Since I was on a COVID-19 NHS contract, and since the NHS does not usually hire non-healthcare registered scientists, my redeployment was unsuccessful and my contract terminated end of April 2023. During my employment, I often spent time helping patients. I would chat to them online and basically offer the service I am offering now. As my health declined and work required longer and longer to recover from, supporting patients in this way became less and less feasible and my inbox/DMs were often abandoned. There seems to be a need for such a service though so I thought I would give this a punt. I don’t feel particularly good taking money from patients, but I have bills to pay and the alternative is to find other employment and remain permanently stressed about the amount of patients that I’m not able to get back to, and therefore end up largely unhelpful to those in need of support and guidance. This feels like a fair compromise and patients I have asked seem supportive.
nutrition & metabolism research
Before COVID, my research was focused on blood sugar control and appetite (including thirst), which all seem to get impacted in long COVID.
Hydration
- My main area of expertise (pre-COVID) is how hydration affects blood sugar, particularly in relation to interactions with the HPA axis (e.g. cortisol)
- From this, I became interested in the party drug ecstasy (MDMA) which offers a cool model to explore the relationship between hydration and blood sugar and I presented this work to MAPS (a US group who are working with the FDA to approve MDMA as a therapy for PTSD)
- I have researched how hydration affects various aspects of appetite
- Although only preliminary evidence, my research provided the first in vivo human evidence for the two different pathways of AVP secretion using an inadvertent stress and hydration model, as well as finding FGF21 is not impacted by hydration status, despite seemingly being implicated in thirst
- I wrote the most extensive review since the 1970s on the mechanisms underlying thirst, incorporating things that seem relevant to long COVID, such as cholinergic dysregulation
- Because I like self-experiments and myth-busting, I consumed basically no fluid for 3 days to demonstrate a few days with no fluid doesn't tend to kill (I was right!)
Sugar and breakfast
- I have conducted research investigating how sugar at breakfast impacts appetite and health markers, and whether having a sweet tooth might impact this
- We also used some fancy statistical modelling to see if we could replicate a crossover trial study design using observational methods, which proved a potentially fruitful model
Other metabolism and appetite research
I have helped conduct other research as well, including studies investigating the metabolic and/or appetite effects of:
- Fibre and the microbiome (unpublished)
- Intermittent fasting
- Neuromuscular electrical stimulation
- Milk minerals
- Standing (versus sitting)
- Dietary patterns
In additional, I have helped with a study characterising the cardiovascular disease risk and metabolic requirements of those with skeletal dysplasia
