Falling sick now as an adult never fails to bring back the smell of onions to my airways. I have never been a fan of the smell of raw onions and I remember having to eat them as a home remedy for persistent coughs as a child. Now, I have come to appreciate that my displeasure for raw onions was in part related to skepticism towards home remedies. As a medical student, I have started reading more on the scientific basis of some home remedies and have found that the new found knowledge has made the smell of raw onions more bearable. In this piece, I share the scientific basis behind 5 common Ghanaian home remedies.
Anecdotally, I have found that my hacking cough stopped within three days of consuming raw red onions. As I sat through basic science lectures in medical school, I came to wonder whether my getting better over three days was due to the consumption of raw onions or just my immune system doing a wonderful job. Turns out it was probably the former. Onions contain high amounts of quercetin, an antioxidant which not only helps to reduce inflammation, but also relaxes smooth muscles in the airways via cyclic Adenosine Monophosphate mediated pathways [1]. Translation: You know how sometimes when you have a cough, you get a fever, your body gets achy, and your airways can feel tight, making it hard to breathe? Well, it seems the quercetin in onions might help with all of those things! It helps the tiny muscles in your breathing tubes loosen up, making it easier to breathe. It does this through a specific process inside your cells, kind of like flipping a switch that tells those muscles to chill out. Quercetin has also been acclaimed as one of the most powerful natural antibiotics accounted for by its large composition of sulphur compounds. A study by Heinz et al. measured the prevalence of upper respiratory tract infections (UTRIs) before and after a quercetin supplementation of 1000mg/day for 3 weeks. The results of the study suggest a reduction in the incidence of UTRIs [2]. Another science direct article suggests that quercetin’s antibacterial properties can be attributed to its inhibition of the supercooling activity of DNA gyrases as tested on E. coli bacteria [3]. Think of DNA gyrase like a special unzipping tool that bacteria like E. coli use to make copies of their DNA and grow. So, quercetin can mess with this unzipping tool – stopping the gyrase from doing its job properly. When the gyrase can’t work, the bacteria can’t copy their DNA, and so they can’t grow, multiply, or make you sick.
Some parents slather garlic paste on their children with high fevers as a first aid intervention. It turns out that the potential anti-fever (i.e., anti-pyrrhic) effects of topical garlic paste application are due to allicin, the compound responsible for garlic’s sharp smell. However, it is unclear that this effect can be had with topical application of ground garlic. However, ingesting garlic can have anti-pyrrhic and anti-inflammatory properties [4]. Importantly, the harshness of garlic has warranted caution against topical garlic application because it can lead to skin blisters and burns [5].
Most Ghanaian children have been confined to a stool with their head covered by a cloth as they face a bucket of boiling hot water, eyes shut to relieve nasal congestion. The menthol drops would lead to almost instantaneous reliefs but the heat and sweat would have you wishing you were somewhere else. We would come out from the setup drenched in water droplets but happy because we could finally have a night blessed with nose breathing. And as someone who grew up with many sinus issues, I cherished those nights. Steam therapy offers these relieving effects because it thins out mucus making it easier to drain [6]. Additionally the water droplets hydrate the dry and irritated airways that typically accompany UTRIs. In my home, Robb original ointment ® was typically added to the water to provide that menthol relief. Interestingly, it appears menthol doesn’t actually relieve the airways directly but rather tricks the brain into believing you’re breathing better, providing psychological rather than nasal relief. Of note, while steam treatment helps to relieve congestion symptoms, it does not combat infections. Therefore, done without supportive antibiotic therapy, steam therapy would be ineffective against URTIs.
Ginger is recognized in different cultures for its efficacy against URTIs. Jung San Chang et al. suggest that fresh ginger has antiviral effects because it inhibits the initial stages of the Human Respiratory Syncytial Virus infection by preventing viral attachment and viral internalization [7]. When you get infected with a virus, it usually starts by sticking to your cells (i.e., attachment) and then getting inside them (i.e., internalization). By doing these two things, it can stop the viral infection from really taking hold. Of note, the antiviral properties of ginger are mostly effective within a short period after exposure to the virus. Unfortunately, when you start to develop symptoms the antiviral effects of ginger are a lot less effective. However, at this point, ginger still has very potent anti-inflammatory properties. For example, it stimulates mucosal cells to release the interferon β which is an essential protein in the immune system’s antiviral response. Imagine your body’s defense system has special cells in your nose or throat. When a virus tries to attack, these cells can send out a powerful alarm signal. The signal wakes up defense cells and tells them to release a crucial protein called interferon and this protein interferes with the virus’ multiplication. The nature of the ginger matters here as dried ginger is ineffective against viral infections. We should equally note that there are significant drawbacks to consuming large quantities of ginger. For example, it can have some blood thinning effects, which is especially dangerous for patients on blood thinners like warfarin [8].
Shea butter is a fat derived from the nut of an African Shea tree. It has proven to be hydrating on the skin and is an ingredient in many hair products. Besides its capillary prowess, shea butter has also been quoted as an important nasal congestion home remedy. In a study conducted by Tella, Shea butter [9] served as a better nasal decongestant than even conventional nasal drops in participants who had moderate to severe nasal congestion [9]. Opubo et al. showed that patients were completely decongested four hours after nose swab application of non-saponifiable shea butter extract and the authors attributed this to the inhibitory effects shea butter has on pro-inflammatory compounds like COX-2 and inducible nitric oxide synthase. In other words, shea butter helps to turn off or slow down inflammation-causing switches like COX-2 and inducible nitric oxide synthase. Therefore, shea butter can help lessen inflammation in the body by reducing COX-2 and inducible nitric oxide synthase activity. Shea butter also hydrates the nasal mucosa making it less susceptible to irritation and further discomfort. Opubo et al. have found that shea butter extracts have better nasal decongestant activity than traditional anti decongestants [10]. The traditional anti decongestants work by causing vasoconstriction to the nasal mucosa but this mechanism can lead to rebound congestion because of ischemia of the nasal mucosa, causing further irritations hours after using the decongestant [11]. In non-doctor English, traditional decongestants try to clear stuffy noses by squeezing tiny blood vessels. This reduces the swelling and opens up your airways temporarily. However, the squeezed blood vessels can lead to rebound congestion because the blood vessels can be squeezed for so long that they don’t get enough blood flow (this is called ischemia). Then, when the decongestant wears off, your nose gets even more stuffed up and irritated than it was before. Notwithstanding, I must note that there is not enough research to make definitive claims about the decongestant properties of shea butter so the dosages and side effects are also not known yet.
In summary, the scientific investigation into African home remedies is gradually illuminating the mechanisms behind their perceived efficacy. While some practices may indeed be attributed to the placebo effect, others, like the use of onions, ginger, and potentially shea butter, offer exciting avenues for therapeutic discovery. However, the consistent theme across these remedies is the critical need for more robust, well-designed research, including controlled clinical trials and standardized protocols, to fully understand their benefits, risks, and optimal applications. Bridging the gap between traditional knowledge and modern scientific validation is crucial for harnessing the full potential of these time-honored remedies within a contemporary healthcare framework.
1. Townsend EA, Emala CW. Quercetin acutely relaxes airway smooth muscle and potentiates β-agonist-induced relaxation via dual phosphodiesterase inhibition of PLCβ and PDE4. American Journal of Physiology-Lung Cellular and Molecular Physiology. 2013 Sep 1;305(5):L396–403.
2. Heinz SA, Henson DA, Austin MD, Jin F, Nieman DC. Quercetin supplementation and upper respiratory tract infection: A randomized community clinical trial. Pharmacological Research. 2010 Sep;62(3):237–42.
3. Plaper A, Golob M, Hafner I, Oblak M, Šolmajer T, Jerala R. Characterization of quercetin binding site on DNA gyrase. Biochemical and Biophysical Research Communications. 2003 Jun;306(2):530–6.
4. Wong C. The Health Benefits of Allicin [Internet]. Verywell Health. 2020. Available from: https://www.verywellhealth.com/the-benefits-of-allicin-88606
5. Wells D. How to Treat Acne and Some Other Skin Conditions with Garlic [Internet]. Healthline. Healthline Media; 2018 [cited 2025 Jun 21]. Available from: https://www.healthline.com/health/garlic-for-acne#precautions
6. Cafasso J. Steam Inhalation: Cold, Sinuses, Procedure, Benefits, Cough, and [Internet]. Healthline. 2018 [cited 2025 Jun 21]. Available from: https://www.healthline.com/health/steam-inhalation
7. Js C, Kc W, Cf Y, De S, Lc C. Fresh Ginger (Zingiber Officinale) Has Anti-Viral Activity Against Human Respiratory Syncytial Virus in Human Respiratory Tract Cell Lines [Internet]. Journal of ethnopharmacology. 2013. Available from: https://pubmed.ncbi.nlm.nih.gov/23123794/
8. Slattery E. Ginger Benefits [Internet]. www.hopkinsmedicine.org. 2023. Available from: https://www.hopkinsmedicine.org/health/wellness-and-prevention/ginger-benefits
9. Tella A. Preliminary studies on nasal decongestant activity from the seed of the shea butter tree, Butyrospermum parkii. British Journal of Clinical Pharmacology. 1979 May;7(5):495–7.
10. Opubo Benedict LT, Iyeopu Miniakiri S, Sokiprim A, Ediriverere Nosa O, Musa S. Nasal Decongestant Effects of Vitellaria Paradoxa (Shea Butter) Extracts: A Hospital Based Study. Journal of Otolaryngology and Rhinology [Internet]. 2023 Dec 31 [cited 2025 Jun 21];9(2). Available from: https://clinmedjournals.org/articles/jor/journal-of-otolaryngology-and-rhinology-jor-9-138.php?jid=jor
11. Wahid NWB, Shermetaro C. Rhinitis Medicamentosa [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538318/
