Now is the time of year people in North America are beginning to plant their gardens. For those of us in Northern Virginia, the last frost date is May 9 (you can check your own here). Gardening has been shown in a meta-analysis to be beneficial to health on its own [1]. The meta-analysis showed gardening to be associated with reductions in depression and anxiety symptoms, stress, mood disturbance, and BMI. It was also associated with increased levels of self-reported quality of life, physical activity levels, and cognitive function.
In the current reality of pandemic and quarantine, we could all use these benefits. So whether you're already planning a garden or just thinking about it, I have outlined some considerations for which herbs you could include below. Each of the herbs listed has been scientifically studied, although the level of evidence supporting each is varied.
So, choose your favorites, and get gardening!
A Quick Note: For centuries, Eastern and folk medicine have relied on the use of culinary herbs in the treatment of diseases, both infectious and chronic. Only recently have we begun to study the relationship of specific herbs on several health outcomes, and so much of the evidence presented below is preliminary. Nonetheless, it is an exciting emerging field that deserves consideration and further research.
Holy Basil
Don't confuse holy basil with Thai basil. Holy basil has more rounded, delicate leaves than it's Thai cousin. Holy basil has been shown in lab studies to inhibit the growth of certain bacteria, yeasts, and molds[2,3]. One preliminary study also showed that four weeks of ingestion of holy basil was associated with significantly increased levels of interferon-γ, interleukin-4, natural killer cells, and percentage of T-helper cells in volunteers[4]. This study lays the groundwork for further investigation of holy basil on improving immune function. However, more research is needed to be conclusive.
Sage
Current evidence suggests that sage is associated with improved brain function and memory. There are well-studied beneficial relationships of sage in people with Alzheimer's disease and other forms of dementia[5]. However, more recent research has explored the role of sage in memory and attention improvement in healthy individuals[6,7]. In one of these studies, a dose of sage extract was linked with immediate memory recall in young, healthy volunteers[7].
Peppermint
Chances are you have heard the health benefits of peppermint touted by those who use aromatherapy. This is because peppermint has a long history of use in folk medicine, and, in fact, peer-reviewed research has supported the use of natural peppermint oil in IBS pain relief and nausea[8,9,10], either through ingestion or aromatherapy.
Rosemary
My personal favorite herb, rosemary, has been linked to effects on suppression of allergy response and nasal congestion[11], perfect for this time of year. Rosemary is also an excellent source of antioxidants because of its high amount of phenolic compounds[12]. There is other preliminary work that studies the relationship between rosemary and cancer, but this work has not been able to draw any conclusions.
Lavender
If you've ever gotten a massage, you probably are familiar with the relaxing effects of lavender oil. Turns out, spas are onto something about lavender's health benefits. Research has shown that lavender may be beneficial to your nervous system[13]. Preliminary research has also shown that lavender tea may reduce perceived fatigue in new mothers[14], although it also showed that the positive effects may be limited to the immediate-term. A meta-analysis reviewing all current research on lavender's health benefits concluded they were inconclusive, but promising[15].
All in all, planting your own garden can be a three-prong beneficial investment to your health via its numerous highlighted associations to improving many health areas to being therapeutic and a much more affordable way of consuming your herbs.
References:
1. Soga M, Gaston KJ, Yamaura Y. Gardening is beneficial for health: A meta-analysis. Prev Med Rep. 2016;5:92-99. doi:10.1016/j.pmedr.2016.11.007
2. Opalchenova G, Obreshkova D. Comparative studies on the activity of basil--an essential oil from Ocimum basilicum L.--against multidrug resistant clinical isolates of the genera Staphylococcus, Enterococcus and Pseudomonas by using different test methods. J Microbiol Methods. 2003;54(1):105-110. doi:10.1016/s0167-7012(03)00012-5
3. Wan J, Wilcock A, Coventry MJ. The effect of essential oils of basil on the growth of Aeromonas hydrophila and Pseudomonas fluorescens. J Appl Microbiol. 1998;84(2):152-158. doi:10.1046/j.1365-2672.1998.00338.x
4. Mondal S, Varma S, Bamola VD, et al. Double-blinded randomized controlled trial for immunomodulatory effects of Tulsi (Ocimum sanctum Linn.) leaf extract on healthy volunteers. J Ethnopharmacol. 2011;136(3):452-456. doi:10.1016/j.jep.2011.05.012
5. Perry NSL, Bollen C, Perry EK, Ballard C. Salvia for dementia therapy: review of pharmacological activity and pilot tolerability clinical trial. Pharmacol Biochem Behav. 2003;75(3):651-659. doi:10.1016/s0091-3057(03)00108-4
6. Scholey AB, Tildesley NTJ, Ballard CG, et al. An extract of Salvia (sage) with anticholinesterase properties improves memory and attention in healthy older volunteers. Psychopharmacology (Berl). 2008;198(1):127-139. doi:10.1007/s00213-008-1101-3
7. Tildesley NTJ, Kennedy DO, Perry EK, et al. Salvia lavandulaefolia (Spanish sage) enhances memory in healthy young volunteers. Pharmacol Biochem Behav. 2003;75(3):669-674. doi:10.1016/s0091-3057(03)00122-9
8. Ford AC, Talley NJ, Spiegel BMR, et al. Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis. BMJ. 2008;337. doi:10.1136/bmj.a2313
9. Alam MS, Roy PK, Miah AR, et al. Efficacy of Peppermint oil in diarrhea predominant IBS - a double blind randomized placebo - controlled study. Mymensingh Med J MMJ. 2013;22(1):27-30.
10. Burns EE, Blamey C, Ersser SJ, Barnetson L, Lloyd AJ. An investigation into the use of aromatherapy in intrapartum midwifery practice. J Altern Complement Med N Y N. 2000;6(2):141-147. doi:10.1089/acm.2000.6.141
11. Takano H, Osakabe N, Sanbongi C, et al. Extract of Perilla frutescens enriched for rosmarinic acid, a polyphenolic phytochemical, inhibits seasonal allergic rhinoconjunctivitis in humans. Exp Biol Med Maywood NJ. 2004;229(3):247-254. doi:10.1177/153537020422900305
12. Jiang TA. Health Benefits of Culinary Herbs and Spices. J AOAC Int. 2019;102(2):395-411. doi:10.5740/jaoacint.18-0418
13. Qneibi M, Jaradat N, Hawash M, et al. The Neuroprotective Role of Origanum syriacum L. and Lavandula dentata L. Essential Oils through Their Effects on AMPA Receptors. BioMed Res Int. 2019;2019:5640173. doi:10.1155/2019/5640173
14. Chen S-L, Chen C-H. Effects of Lavender Tea on Fatigue, Depression, and Maternal-Infant Attachment in Sleep-Disturbed Postnatal Women. Worldviews Evid Based Nurs. 2015;12(6):370-379. doi:10.1111/wvn.12122
15. Koulivand PH, Khaleghi Ghadiri M, Gorji A. Lavender and the Nervous System. Evid-Based Complement Altern Med ECAM. 2013;2013. doi:10.1155/2013/681304