Ancient Nutra Wellness Team · 8 September 2026 · 7 min read
6 Monsoon Habits That Lower Your Odds of Getting Sick
By the Ancient Nutra Editorial Team
- September sits at the end of Sri Lanka's southwest monsoon, which runs May to September. The second inter-monsoon, the one people call the second rains, does not begin until October.
- The habit with the strongest experimental evidence behind it is sleep. In a rhinovirus challenge study, adults sleeping under six hours were roughly four times more likely to fall ill than those sleeping over seven.
- Hand hygiene has the best everyday track record, at about an 11 percent relative reduction in respiratory illness, though Cochrane rates that evidence low certainty.
- Zinc may shorten a cold you already have by about 2.37 days. It does not appear to stop you catching one.
- No herb on this list has human trial evidence for preventing infection. Ginger, beli and iramusu belong here as warmth, digestion and heritage, not as armour.
The rain changes the shape of a day before it changes anything about your body. Windows stay shut. Buses fill. Wet clothes stay on longer than they should. Sleep gets shorter because the roads are slower at both ends of the day. Most of what raises the odds of catching something in a wet month is ordinary and behavioural, which is inconvenient, because ordinary things are harder to sell than a bottle.
This list was built by checking each item against a Tier 1 source and keeping only what survived. Two of the six survive as things to do. Two survive with real limits attached. One survives only as heritage. One did not survive at all, and it is on the list precisely because it is the thing most people are currently buying.
What the rain in September actually is
Sri Lanka has four rainfall seasons: the first inter-monsoon in March and April, the southwest monsoon from May to September, the second inter-monsoon in October and November, and the northeast monsoon from December to February (Perera et al., International Journal of Environmental Science and Technology, 2022). Early September is the tail of the southwest monsoon, not the start of the second rains.
That distinction matters for more than pedantry. Southwest monsoon rain concentrates on the wet zone, so Colombo, Gampaha, Kalutara, Ratnapura and Galle carry most of it, while the second inter-monsoon in October and November is the season that spreads rain far more evenly across the island. A household in Jaffna and a household in Galle are not having the same September.
1. Sleep seven hours before you buy anything
This is the one item on the list with a genuinely experimental design behind it. Researchers measured 164 healthy adults with wrist actigraphy for a week, then deliberately exposed them to a cold virus and quarantined them. Adults sleeping under five hours a night were about four and a half times more likely to develop a cold than those sleeping more than seven, and the five to six hour group was almost identical, with the effect holding after adjusting for age, body weight, season, stress and existing antibodies (Prather et al., Sleep, 2015).
Honesty about the size of it: the study is small and the confidence intervals are very wide, so treat four times as a direction rather than a precise multiplier. It is still a stronger piece of evidence than anything else in this article, and it costs nothing. If the rain is pushing your commute later at both ends, protecting the sleep is worth more than anything you can add to a cupboard.
2. Wash your hands more often than feels necessary
Cochrane's 2023 review of physical measures against respiratory viruses pooled 19 trials covering 71,210 people and found hand hygiene associated with roughly an 11 percent relative reduction in respiratory illness (Jefferson et al., Cochrane Database of Systematic Reviews, 2023). The reviewers graded that finding low certainty, and when they narrowed the outcome to laboratory confirmed influenza the effect was no longer statistically significant.
So the accurate sentence is not "handwashing stops infections." It is closer to "handwashing modestly reduces how much respiratory illness goes around, on evidence that is weaker than the public messaging suggests." That is still the best return available for the effort involved, and a wet month with more shared indoor space is exactly when it earns its keep.
3. Keep zinc for the cold you already have
Zinc is widely sold for prevention and the evidence does not support that use. Cochrane's 2024 review found zinc may reduce the average duration of a cold by about 2.37 days, on low certainty evidence, while showing little or no effect on preventing colds in the first place. The same review found zinc probably increases non serious side effects, and rated that harm signal at moderate certainty, which is higher confidence than it gave the benefit (Nault et al., Cochrane Database of Systematic Reviews, 2024).
Read that ordering carefully, because it is unusual and it is the point. The evidence that zinc will give you a mild side effect is better established than the evidence that it will help. The reviewers concluded the current evidence is insufficient to recommend zinc either way. Treat it as something you might reach for once symptoms have started, not something you take through a wet season.
4. Reach for ginger because it is warm, not because it is armour
Ginger is the rhizome of Zingiber officinale, grown across South and Southeast Asia and cultivated in Sri Lanka. On safety it is about as clean as a herb gets: NIH LiverTox assigns it likelihood score E, the lowest category, meaning it is an unlikely cause of clinically apparent liver injury (NIH LiverTox, Ginger).
On effectiveness for infection, the honest answer is that there is nothing to report. The human trial evidence LiverTox recognises for ginger covers nausea in pregnancy, inflammation and digestive function, not immunity, and a randomised placebo controlled trial of ginger extract in 84 respiratory infection outpatients found no significant difference from placebo on viral clearance or symptoms. A warm ginger drink on a wet evening is a good thing that does not need a health claim attached. See Ancient Nutra's Ginger capsules if you prefer it in a fixed daily amount rather than a mug.
Look for
A label that tells you the plant part and the amount per serving, not just a herb name. For a ready to drink shot, check the volume and the serving guidance, and check whether the brand tells you when to stop as well as when to start.
5. Treat beli and iramusu as heritage, not as evidence
Beli is the fruit of Aegle marmelos, long used across Sri Lankan households as a drink, and iramusu is the root of Hemidesmus indicus, the Sinhala name for Indian sarsaparilla. Both are genuinely part of the domestic repertoire here, and that is a real thing worth keeping.
What neither has is a human trial for immunity. A search of the published literature turns up phytochemistry, laboratory work and animal models for both, and no clinical trial in people for either. Neither has an NIH LiverTox monograph, and that absence should be read as not yet evaluated rather than as proven safe. They belong in this article as culture and as a drink you like, which is an honest reason to keep something. See Ancient Nutra's Beli capsules and Ancient Nutra's Iramusu capsules on that basis, not on a promise about infection.
6. Skip the vitamin D top-up unless a test says otherwise
This one changed, and it changed recently. A 2021 pooled analysis of 37 trials found vitamin D supplementation reduced the odds of acute respiratory infection by about 8 percent, a small but statistically significant effect. The updated analysis published in 2025 pooled 46 trials and 64,086 participants and found an odds ratio of 0.94 with a confidence interval of 0.88 to 1.00, which crosses 1.00 and is therefore no longer statistically significant. No subgroup by age, dose or baseline vitamin D status showed a significant benefit (Jolliffe et al., The Lancet Diabetes and Endocrinology, 2025).
That is what it looks like when evidence gets weaker as the trials get bigger. Correcting a diagnosed deficiency is a separate clinical matter and remains between a person and their doctor. Taking vitamin D through a wet season specifically to avoid colds is not supported by the current pooled result.
How should you actually use this list?
Do not start all six at once, and do not treat the six as equivalent, because they are not. Items one and two cost nothing and carry the strongest support, so they come first and they come without a purchase. Item three is a response to symptoms rather than a routine. Items four and five are things to enjoy, with no claim attached. Item six is on the list to be removed from a shopping basket.
If you already keep a warm drink ritual through the wet months, the useful question is not what to add but what to bound. Anything taken daily should have a point at which you stop and see how you feel without it, which is a more informative test than continuing indefinitely and assuming it is working.
Shield Shot box, 30 pack
A ready to drink 30 ml turmeric and ginger shot, 3.3 kcal per serving, one shot a day.
Shop Shield ShotOn turmeric, which is the other ingredient in that shot, Ancient Nutra publishes the caution on the product page rather than burying it: NIH's LiverTox database rates turmeric a category A likelihood for causing clinically apparent liver injury, almost always from concentrated capsule extracts rather than a 30 ml culinary shot. Stop and see a doctor if you notice yellowing of the eyes or skin, dark urine, persistent nausea, or unusual tiredness (NIH LiverTox, Turmeric). The product page also sets the pacing: best as an eight to twelve week course, then a short break, rather than continuous daily use.
Is September part of Sri Lanka's second inter-monsoon?
No. September is the final month of the southwest monsoon, which runs May to September. The second inter-monsoon, often called the second rains, covers October and November.
Do herbal supplements prevent colds during the rains?
Not on the current evidence. Ginger, beli and iramusu have no human trials showing prevention of respiratory infection. They are reasonable as warmth, digestion and tradition, and unreasonable as protection.
Does zinc stop you catching a cold?
No. Cochrane's 2024 review found little or no effect on prevention, and a possible reduction in duration of about 2.37 days once a cold has started, on low certainty evidence.
Is vitamin D worth taking through the wet season?
Not for the purpose of avoiding respiratory infection. The 2025 pooled analysis of 46 trials found an odds ratio of 0.94 with a confidence interval crossing 1.00. A diagnosed deficiency is a different question for a doctor.
How long should a turmeric based daily shot be taken?
Ancient Nutra's product page sets it as an eight to twelve week course followed by a short break, rather than continuous daily use.
The bottom line
Two habits carry this list, and neither is a product. Sleeping over seven hours has the strongest experimental support of anything here, and washing hands more often than feels necessary has the best everyday track record even after Cochrane's own caution about certainty. Zinc has a narrow, real, low certainty use once a cold has already started.
The herbs stay on the list for what they honestly are. A warm turmeric and ginger shot is a pleasant fixed point in a wet week, taken as a bounded course rather than forever, and beli and iramusu are heritage worth keeping without a claim stapled to them. If you want the ritual side of this in more detail, the daily Shield Shot ritual covers the how, and this article covers what the evidence will and will not carry.
Sources and further reading
- Prather AA, Janicki-Deverts D, Hall MH, Cohen S. Behaviorally Assessed Sleep and Susceptibility to the Common Cold. Sleep, 2015. PubMed.
- Jefferson T, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews, 2023. Cochrane Library.
- Nault D, et al. Zinc for prevention and treatment of the common cold. Cochrane Database of Systematic Reviews, 2024. Cochrane Library.
- Jolliffe DA, et al. Vitamin D supplementation to prevent acute respiratory infections. The Lancet Diabetes and Endocrinology, 2025. PMC.
- NIH LiverTox. Ginger. NCBI Bookshelf.
- NIH LiverTox. Turmeric. NCBI Bookshelf.
- Perera et al. Impact of environmental factors on the spread of dengue fever in Sri Lanka. International Journal of Environmental Science and Technology, 2022. PMC.
Written by the Ancient Nutra Wellness Team. The team researches, sources, and tests every ingredient before it earns a place in an Ancient Nutra blend. Questions? Email info@ancientnutra.com or message Ancient Nutra on Instagram.
Medical disclaimer: This article is for educational purposes only and is not medical advice. Statements have not been evaluated by the FDA. Ancient Nutra products are not intended to diagnose, treat, cure, or prevent any disease. Speak with a qualified healthcare provider before starting any new supplement, especially if you take prescription medication or have a medical condition.
