How do herbs affect the body? When people say an herbal tea is “good for you”, what do they mean? How do herbs get into the organs, parts, and structures they’re purportedly “good for?”

And in the words of my teacher, the legendary herbal elder Michael R.S. Moore, we might ask, “How do herbs strengthen weaknesses, redirect excessive tendencies, move fluids, and excite stagnating tissue?”

Although herbs can affect body structure (anatomy), they primarily affect function (physiology): absorption, metabolism, fluid transport, and excretion. Our bodies turn food into energy and structure through a multi-faceted approach, involving chemistry, physics, metabolism, and cellular respiration. Glucose and oxygen are converted into carbon dioxide and water, and the energy released by this chemical reaction is transferred to Adenosine triphosphate (ATP), which powers the cells in your body. Specific proteins control these reactions, and the gut constantly mixes with the fluids we eat and drink. Overall, the process is similar to photosynthesis, albeit sans direct sunlight.

Then the chemistry of herbs is fascinating and complex, involving many phytocompounds. We divide herbs into five major categories: Aromatic (volatile oils), Astringents (tannins), Bitter (phenol compounds, alkaloids, saponins), Mucilagenuos (mucopolysaccharides) and Nutritive (foodstuffs).

Actions, properties, tastes, flavors, energetics… all have an affinity for a particular body system.

One example you should know

Carminative herbs (such as cumin, ginger, or coriander) are typically rich in volatile oils, with fragrant smells that brighten our kitchens. Inside the body, these herbs affect peristalsis of the digestive system, and relax the smooth muscles of the stomach. This supports digestion and the accumulation of gas in the digestive tract. Peppermint is another classic carminative, often used in tea to treat gas and indigestion—along with having a pleasant flavor.

Herbs work best to affect the body in combination with others; we rarely use them one-at-a-time. Herbs can fit into more than one category, and some are slightly neutral.

Herb classifications:

Aromatic—rosemary, lavender, basil, thyme, oregano, sage, coriander, fennel, tarragon, peppermint. Highly concentrated, hydrophobic, and rich with essential oils and volatile resins (i.e. they smell good!). Their actions primarily provoke the gastrointestinal tract, but also affect the reproductive system, and help maintain a clear respiratory tract and lungs. The mechanical action of the oils causes the tissues to expand.

Astringent—blackberry root, green and black tea, oak, yarrow, rose, witch hazel, goldenseal (cultivated only!). Full of tannins, which dry swollen tissue, shrink and create a tighter barrier. Astringents can dry up mucus, and with regular use can strengthen and tone mucous membranes.

Demulcent—marshmallow root, violet, plantain, chia seed, slippery elm (cultivated only!). Contain a slimy “goo” of mucopolysaccharide chains that soothes, protects, and coats the lining of the GI tract and other mucous membrane tissues. They function best in powdered form, or decocted into cold water. Mucous membranes trap abrasive foreign material, and require lubrication with a protective, antibody-rich slime layer propelled by cilia to prevent pathogen invasion in the lungs and subsequent infection.

Bitter —artichoke, dandelion, gentian, hops, orange peel, agrimony, wormwood. Primarily affect the liver and gallbladder, encouraging salivary and bile secretions that help enhance the effectiveness of digestion. Ingesting bitters on the tongue before meals greatly facilitates the breakdown of fats by stimulating peristalsis and bile production.

Alterative—burdock, cleavers, red clover, dandelion, echinacea. Usually taken in higher quantities to stimulate the body’s immune system and fight off an acute infection. Although these herbs are understudied and not well understood, we know they open elimination channels, encouraging the body’s natural detox process. Plains tribes drank huge quantities of echinacea for rattlesnake bite, hence its common name “snakeroot”.

(More on Echinacea)

Americans seized upon echinacea as a cure-all, and in the early 90s, echinacea and goldenseal were the two most popular herbs in the burgeoning homeopathic market. Companies in Germany imported metric tons of echinacea, including it in soaps and shampoos—a nosustainable use of such a potent herb. Semi-flatbeds of Echinacea angustifolia left the eastern-central plains. Thankfully, almost all echinacea on the market today is cultivated Echinacea pallida, (always be sure to check!) The prairies are gradually recovering from overharvesting, but widespread habitat loss continues at an alarming pace. Daily echinacea use is not recommended: you risk running your immune system to the point of exhaustion. Better to support the body with adaptogens, healthy lifestyle, good food, adequate hydration, and exercise.

Herb classifications Part II

Adaptogenic—ginseng family (eleutherococcus, panax ginsengs, aralia) cordyceps, ashwagandha, rhodiola, schizandra. Restoratively affect the limbic system, helping us adapt to excess physical and mental stress. They have a wide range of actions, from helping stimulate mental focus, to enhancing immune system function. These herbs show strong evidence for strengthening weaknesses, and can play a critical role in recovering from a long-standing illness. However, some adaptogens can contribute to adrenal burnout by causing the adrenals to work harder.

Nervine-Sedative—wild oats, skullcap hypericum, chamomile, hops, passionflower. Nourish and support the body’s central nervous system, coating and soothing overstimulated and frayed nerve endings. Calming the nervous system can be great for teething babies and anxious adults lacking sleep. These herbs won’t knock you out, but rather calm and support the body’s natural craving for adequate sleep.

Carminative—angelica, cardamom, anise, caraway, ginger, peppermint. Rich in volatile oils and stimulate the gut to release more contractions. Carminatives aid in the discharge of excessive gas and effectively stimulate peristalsis, relieve sluggish digestion, pacify stomach cramps, and promote smooth digestion. A pinch of cardamom will help counterbalance and neutralize the gut-lining effect of strongly astringent herbs, like black tea or coffee.

Diuretic—dandelion, parsley, nettle, cleavers, green tea. Stimulate the kidneys, relax the bladder and help us urinate. They can cause rapid movement of fluids if applied correctly and in concert as in a tea blend. Overuse can irritate the kidneys—as anyone who has drunk uva-ursi tea can attest to.

Herb classifications Part III

Diaphoretic—elderflower, garlic, ginger, yarrow, boneset, cayenne. Help raise the body temperature and induce involuntary perspiration, send heat out to the periphery, stimulate circulation, open skin pores, and excite sweat glands. They can greatly speed the elimination of toxins from the system. If the river eddies are backed up with flotsam, the water can’t flow, and a clean flowing lymph system is our “river of life”, crucial for our immunity. Some diaphoretics can relax tense, tight tissues, while others can stimulate and open up capillary beds, bringing heat stuck in the core to the outside periphery.

Emollient—plantain, violet, calendula, aloe vera, licorice, slippery elm, borage. Similar to demulcents, but help soothe and soften irritated skin. They’re typically used in skin creams and salves.

Expectorant—elecampagne, horehound, yerba santa, linden. Contain volatile compounds that enter through our blood into our lungs to be exhaled and help clear our airway by breaking up impacted mucus. Some are very energetic and warming, and can quickly cause highly productive coughing. Some are more mucilaginous and soothing.

Summary

Under stress or illness, our bodies naturally tend toward healing and homeostasis. But stresses can slow the process, including inherited and acquired weaknesses, environmental stress, and the exogenous chemicals in our food and water. Drinking herbal teas can positively affect the body, counterbalancing those obstacles, and speeding the body back towards healthy balance.

Hopefully I’ve illustrated how an herb can affect a particular organ or tissue through the body’s digestive and absorptive actions. Processed like food, alongside what we eat, our hunting-and-foraging bodies have ingested herbs as food for ages. Through generations of trial and error and passing down that information, we have discovered and identified particular plants that are good for healing upset tummies, reducing inflammation, or soothing a headache.

All the hormonal signaling that goes on when we drink a simple cup of tea can be mind-boggling to dwell on. Perhaps the most important nugget is that herbs affect the body by helping calm the elevated or chronic stress responses that degrade us.

May your next cup of tea take your mind into some new territory, thinking about all these functions and messages inside the body!

And of course all of this information comes with a standard health disclaimer: if you intend to treat yourself, I encourage you to visit your local trained and professional herbalist for a complete health evaluation, with subsequent suggestions and recommendations.

Written by Greta de la Montagne, LMTC Herbalist Consultant

References:

 “Herbal Energetics in Clinical Practice” Acrobat file in SWSBM.com

Link to Herb Energetics Chart: https://www.swsbm.com/ManualsMM/HRBENRGT.pdf

Eleutherococcus study in Russia: https://pubmed.ncbi.nlm.nih.gov/34087398/

The interaction between respiratory pathogens and mucus: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4752725/

United Plant Savers Species-At-Risk List: https://unitedplantsavers.org/species-at-risk-list/

UpS list of Herbs and Analogs: https://unitedplantsavers.org/wp-content/uploads/2022/05/22279-UpS-Herb-Analog-List-by-Jane-Bothwell_rev2006.pdf