During his postdoctoral fellowship in the mid-2000s, Dr. Buck discovered that a common food additive called carrageenan can block the transmission of human papillomaviruses (which cause genital warts and cervical cancer). The idea of using food to fight viruses has sparked his imagination ever since. In January 2021, when a team of Taiwanese scientists led by Dr. Chi-Huey Wong showed that feeding hamsters mint tea helped them fight off Covid infections, Dr. Buck sat up and took notice. A subsequent publication from Dr. Mirko Trilling’s lab at the University of Duisburg-Essen found that a compound called caffeic acid, which is abundant in mint-family herbs, stimulates innate cellular defense pathways that suppress the replication of SARS-CoV-2, the virus behind Covid-19. More recently, several small clinical trials have found that people given extracts of mint family herbs show significantly milder Covid symptoms or even resist the infection entirely. After seeing these exciting results, Dr. Buck decided it was time to write an article for the peer-reviewed journal Medical Hypotheses, and to start a Substack blog to help get the word out.

The global spread of Covid in early 2020 required scientists to rapidly gather and share evidence to assist in preventing transmission and treating symptoms. Early rounds of official guidance were based upon preliminary lab experiments and small observational trials. Predictably, some of these early “best-guess” guidelines, such as hydroxychloroquine, ended in spectacular failure. Dr. Buck’s concern is that the idea of using mint tea to fight Covid might have been a precious baby that inadvertently got thrown out with the dirty hydroxychloroquine bathwater.

Although it may seem risky to try unproven medical interventions, it is far riskier to idly wait for conclusive evidence while a pandemic ravages the world. In a blog post, Dr. Buck refers to it as the “sit tight and assess” fallacy, after a scene in the satirical disaster movie Don’t Look Up. Our current regulatory infrastructure sometimes fails to appropriately weigh the risk of inaction in the face of an unfolding calamity.

It’s a well-known fact that eating certain types of foods can be beneficial to health. With this thought in mind, Dr. Buck proposes that routinely eating common culinary herbs of the mint family – for example, Simon and Garfunkel’s classic trio of sage, rosemary, and thyme – might decrease the severity of Covid symptoms or even help people resist becoming infected altogether. Since these herbs are widely available, easy to grow, and have been safely used by humans for millennia, it’s an experiment people can easily try in their own kitchens while waiting for larger randomized controlled trials to more conclusively address the hypothesis.

Dr. Buck’s review article recounts the story of another neglected herbal medicine known as wormwood. Teas made from various species of wormwood have been used to treat fevers for centuries. In 2015, Dr. Youyou Tu was awarded a Nobel prize for her discovery of the powerful antimalarial drug artemisinin in wormwood leaf extracts. Alongside artemisinin, the plant also produces a variety of additional anti-parasitic compounds. This is important because it’s a well-established fact that multi-drug cocktails can help fight the emergence of drug-resistant pathogens. These findings inspired a scientist named Pam Weathers to lead a series of clinical trials investigating whether pills made from compressed wormwood leaves could serve as an inexpensive alternative to pharmaceutical-grade artemisinin. Unfortunately, Dr. Weathers’ trial encountered technical obstacles and eventually became mired in controversy.

Dr. Buck proposes a simplified trial design in which people could be sent either active wormwood leaf preparations or a placebo herb preparation via regular mail service. Volunteers would then report back symptoms via a cellphone app. This decentralized approach might circumvent some of the challenges Dr. Weathers’ team encountered. In the simplest possible trial design, people could be sent wormwood seeds (or seeds for inactive control plants) that they could grow themselves and use as tea that might prevent or treat malaria.

Dr. Buck envisions similar trials to test the mint versus Covid hypothesis. In particular, he notes that different varieties of basil (another mint family herb) produce wildly different amounts of the proposed antiviral compound, caffeic acid. A decentralized design could theoretically enable a large trial at very low cost.

In related thoughts, Dr. Buck sings the praises of consuming mint and other herbal concoctions in daily life, whether drinking complex herb teas or indulging in delicious pesto pasta dishes. With a habit of upping his intake when necessary and encouraging his loved ones to adopt the same approach, he proudly proclaims that all those who have heeded his sage advice remain so-called “novids,” having never contracted the virus despite virtually guaranteed exposure. Indeed, as part of this vital research, Dr. Buck has rather gallantly tested several herb-based cocktails, resulting in a series of entertaining tasting sessions. This has prompted an impassioned plea for quality herbal cocktail ingredients. Purely for the purposes of robust scientific research, of course.