“All disease begins in the gut” — Hippocrates
Cold weather brings good things — heavy jumpers, warm boots, tea that actually warms you — and, inevitably, some less welcome ones.
Before you are exposed
The useful work happens in advance. Build immunity before you meet anything, and the meeting goes differently.
Sugar and starch suppress immunity, and the mechanism is not vague. The immune system depends on white blood cells to deal with infection, and those cells are markedly affected by sugar. Somewhere around 75 grams is enough to blunt the response, and the effect lasts for several hours afterwards. Which means you can exercise carefully, take everything you are supposed to take, and undo a good deal of it with one fizzy drink. Starch behaves the same way — glycolysis turns it into sugar, and the effect follows.
What to do instead is the same answer as always: a good chicken stock, which heals and seals the gut wall and keeps the microbiome strong, and plenty of fermented food to keep the population of beneficial bacteria high. Sauerkraut, kefir, sour cream, kimchi, barrel-fermented pickles.
Once you are exposed
The first instinct is a prescription or a trip to the pharmacy. It is worth knowing what is in some of what you would buy. Cough syrups carry a great deal of sugar, with the effect described above.
A great deal of modern medicine began as a plant that was then chemically processed and combined with other substances. Taking the herb whole, in its natural state, is often the way to get the benefit without the rest.
Black walnut
At this time of year you may notice large green nuts the size of tennis balls scattered under the trees. Those are black walnuts. To make a tincture you separate the husk from the interior and use the husk, which contains juglone. Juglone has antifungal and antimicrobial properties, and has been used traditionally against intestinal parasites.
Goldenrod
Goldenrod is often mistaken for ragweed and blamed for seasonal allergies, but it does not release its pollen — the pollen is heavy and sticky, and the plant flowers at the start of autumn. It can in fact be used to calm ragweed allergies.
It is antiseptic and antimicrobial, which makes goldenrod tea useful for a sore throat and for shifting mucus. It is also rich in rutin, a flavonoid that supports circulation and capillary strength.
Honey and garlic
Both have been used medicinally for thousands of years, traceable to Egyptian records and Stone Age paintings. Garlic carries a powerful antioxidant and considerable anti-inflammatory activity. Raw honey contains flavonoids and phenolic acids with antioxidant, anti-inflammatory and antimicrobial effects. Fermenting the two together concentrates all of it.
Elderberry
Elderberry is among the best-known traditional remedies for colds. The dark purple comes from anthocyanin, which is also the source of its anti-inflammatory and antioxidant activity, and which reduces oxidative damage as free radicals are metabolised.
Building a strong immune system with real food, and knowing what the traditional remedies do, is a better position to be in than reaching for something at the point you already feel unwell.