The Healthspan Map · Respiratory
Respiratory infections & airway health
Named for Respiratory infections & airway health
| Nutrient or lever | Direction | Strength | Evidence type | What was found | Source |
|---|---|---|---|---|---|
| Food & hand hygiene | Do this | Strong | Systematic review | Hand hygiene produced an ~11% relative reduction in respiratory illness (RR 0.89), a top low-cost prevention behaviour. | Physical interventions to interrupt respiratory-virus spread (Cochrane 2020) (opens in a new tab) |
| Sleep duration | Watch this | Strong | RCT / trial | Actigraphy-measured short sleep sharply raised cold risk after rhinovirus challenge: <5 h → OR 4.50 and 5-6 h → OR 4.24 vs >7 h. | Behaviourally-assessed sleep & the common cold (Prather, Sleep 2015) (opens in a new tab) |
| Sleep quality (refreshed) | Watch this | Strong | RCT / trial | Sleep efficiency below 92% predicted 5.5× higher odds of developing a cold after viral exposure, in graded fashion. | Sleep habits & susceptibility to the common cold (Cohen, Arch Intern Med 2009) (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Strong | RCT / meta-analysis | Causal genetic evidence: smoking raised bacterial pneumonia (OR 2.14), chronic lower-respiratory disease (OR 2.29) and asthma-related pneumonia/sepsis (OR 3.64); it paralyses airway cilia and suppresses immune cells. | Smoking & respiratory infection Mendelian randomisation (Commun Biol 2021) (opens in a new tab) |
| Vitamin A (RAE) | Eat enough of | Strong | Established clinical | Vitamin A deficiency impairs mucosal/epithelial immunity and raises respiratory-infection risk and severity; deficient children benefit clearly from correction. | Vitamin A & pneumonia in children (WHO ELENA) (opens in a new tab) |
| Vitamin D | Eat enough of | Strong | RCT / meta-analysis | Vitamin D supplementation reduced acute respiratory infections, with greatest benefit in the very deficient and with daily/weekly (not bolus) dosing. | Vitamin D & acute respiratory infection IPD meta-analysis (Martineau, BMJ 2017) (opens in a new tab) |
| Alcohol — cut back | Do this | Moderate | Cohort / observational | Alcohol misuse suppresses macrophage function and the gag reflex, raising aspiration and severe bacterial pneumonia risk. | Inflammation & pneumonia susceptibility review (PMC6221464) (opens in a new tab) |
| Anchor foods | Watch this | Moderate | Review / narrative | A nutrient-dense diet supplying vitamins A, C, D, zinc and selenium underpins mucosal and cellular immune defence. | Nutrition & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| BMI | Watch this | Moderate | Cohort / observational | Obesity worsens influenza/COVID/pneumonia outcomes, while underweight/malnutrition also raises infection risk — a U-shaped relationship. | Inflammation & pneumonia review (PMC6221464) (opens in a new tab) |
| Belonging (groups / third place) | Watch this | Moderate | Cohort / observational | Greater social integration/network diversity was associated with increased host resistance to experimental rhinovirus, independent of stress. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Cardio (moderate + intervals) | Do this | Moderate | Cohort / observational | Moderate physical activity was protective against URTI (J-shaped: very intense/overtraining transiently raises risk). | Physical activity, sleep & respiratory infections (PLOS One 2018) (opens in a new tab) |
| Carotenoids (provitamin A) | Don't overdo | Moderate | Systematic review | High-dose beta-carotene supplements increased lung cancer and mortality in smokers/asbestos-exposed adults (CARET) — an excess harm concentrated in smokers. | Vitamin A / beta-carotene for respiratory infection (Cochrane, incl. CARET) (opens in a new tab) |
| Colours a day | Watch this | Moderate | Review / narrative | Colourful produce delivers carotenoids/provitamin A and vitamin C that maintain airway epithelial integrity and antioxidant defence. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Daily movement baseline | Do this | Moderate | Cohort / observational | Higher habitual activity/energy turnover was associated with fewer upper-respiratory infections. | Physical activity & respiratory infections (PLOS One 2018) (opens in a new tab) |
| Falling & staying asleep | Watch this | Moderate | Cohort / observational | Poorer sleep continuity/efficiency in the weeks before exposure lowered resistance to rhinovirus. | Sleep habits & the common cold (Cohen 2009) (opens in a new tab) |
| Grip strength | Watch this | Moderate | Cohort / observational | Frailty and low muscle strength (grip as a sarcopenia proxy) raise pneumonia susceptibility, especially in older adults. | Inflammation & pneumonia review (PMC6221464) (opens in a new tab) |
| Indoor air quality | Do this | Moderate | Cohort / observational | Indoor air pollution/biomass smoke compromises lung defences and low absolute humidity drives seasonal influenza; ventilation lowers transmission. | Inflammation & pneumonia review (PMC6221464); absolute humidity & influenza (Am J Med 2021) (opens in a new tab) |
| Iron | Eat enough of | Moderate | Review / narrative | Iron deficiency impairs respiratory burst, bacterial killing, NK activity and T-cell responses needed for airway defence. | Nutritional supplements & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| Iron | Don't overdo | Moderate | Review / narrative | Iron overload/indiscriminate supplementation increases susceptibility to infection, since pathogens exploit available iron ("nutritional immunity"). | Nutritional supplements & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| Loneliness — reduce | Watch this | Moderate | Cohort / observational | Socially integrated people resisted colds better; isolation/low participation tracked with higher susceptibility. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Oral & skin care | Do this | Moderate | RCT / meta-analysis | Mechanical oral care reduced pneumonia incidence/mortality in institutionalised elders (professional care up to ~40%; ~1 in 10 pneumonia deaths preventable). | Oral hygiene & aspiration pneumonia in frail elders (PMC4541086) (opens in a new tab) |
| Protein | Eat enough of | Moderate | Review / narrative | Protein-energy undernutrition impairs antibody and cell-mediated immunity, raising respiratory-infection risk and severity. | Nutrition & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| Selenium | Eat enough of | Moderate | Review / narrative | Selenium deficiency impairs antiviral immunity, permits viral mutation to greater virulence, and tracks with worse viral-respiratory outcomes. | Nutrition & viral respiratory tract infections (Frontiers Immunol 2022) (opens in a new tab) |
| Supplement discipline | Do this | Moderate | Systematic review | Correcting vitamin D and zinc reduces respiratory-infection risk/duration — but sensible dosing matters, since megadosing vitamin A/E/beta-carotene/iron can backfire. | Micronutrient supplements & respiratory infection meta-analysis (BMJ Glob Health 2021) (opens in a new tab) |
| Ultra-processed food — cut back | Do this | Moderate | Review / narrative | Diet quality (whole foods over ultra-processed) supports micronutrient adequacy and immune competence. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Vitamin A (RAE) | Don't overdo | Moderate | Systematic review | In non-deficient people, high-dose vitamin A supplementation increased acute respiratory-infection incidence (RR 1.08) via temporary immune-regulation malfunction. | Excessive vitamin A supplementation & ARTI meta-analysis (Nutrients 2021) (opens in a new tab) |
| Vitamin C | Eat enough of | Moderate | Systematic review | Low vitamin C status raises pneumonia risk; regular intake shortens cold duration ~8% and halves cold risk (RR 0.48) under heavy physical stress. | Vitamin C for the common cold (Cochrane, Hemilä 2013) (opens in a new tab) |
| Vitamin E | Don't overdo | Moderate | RCT / trial | Even low-dose (50 mg/day) vitamin E raised pneumonia risk in certain male smokers (RR 1.61 at <60 kg; 2.34 at >100 kg) — a clear dose/context harm. | Vitamin E supplementation & pneumonia in smokers (ATBC, PMC2603040) (opens in a new tab) |
| Zinc | Eat enough of | Moderate | RCT / meta-analysis | Low zinc status raises respiratory-infection/pneumonia risk; zinc lozenges shortened cold duration by ~2.25 days. | Zinc supplementation & common-cold duration (PMC7356429) (opens in a new tab) |
| Added Sugars | Don't overdo | Emerging | Review / narrative | High added-sugar intake is associated with transient impairment of neutrophil/immune function and pro-inflammatory load. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Calm rest space | Do this | Emerging | Review / narrative | Psychological stress raised cold risk in dose-response fashion via proinflammatory-cytokine dysregulation; stress reduction is protective. | Pittsburgh common-cold studies: psychosocial predictors (Cohen 2005) (opens in a new tab) |
| Cardio / VO2max | Watch this | Emerging | Cohort / observational | Better fitness supports immune defence, though the effect is smaller than for moderate-activity habits. | Physical activity & respiratory infections (PLOS One 2018) (opens in a new tab) |
| Carotenoids (provitamin A) | Eat enough of | Emerging | Review / narrative | Dietary provitamin-A carotenoids support epithelial/mucosal integrity and antioxidant defence in the airway. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Cook real food | Do this | Emerging | Review / narrative | Home-cooked whole-food meals underpin the micronutrient adequacy that supports airway immune defence. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Copper | Eat enough of | Emerging | Review / narrative | Copper deficiency impairs neutrophil number/function and innate immunity relevant to infection defence. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| EPA/DHA (omega-3) | Eat enough of | Emerging | Review / narrative | Omega-3-derived pro-resolving mediators aid inflammation resolution in the airway, though respiratory-infection benefit is still emerging. | Nutritional supplements & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| Inner circle (close ties) | Watch this | Emerging | Cohort / observational | Diverse close ties contributed to the social-integration protection against respiratory illness. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Morning daylight | Do this | Emerging | RCT / meta-analysis | Daylight-driven vitamin D synthesis supports the anti-infective pathway; correcting deficiency reduces respiratory infections. | Vitamin D & acute respiratory infection IPD meta-analysis (Martineau, BMJ 2017) (opens in a new tab) |
| Movement (breaking up sitting) | Do this | Emerging | Cohort / observational | More physical activity (less sedentary time) was protective against upper-respiratory infection. | Physical activity, sleep & respiratory infections (PLOS One 2018) (opens in a new tab) |
| Selenium | Don't overdo | Emerging | Review / narrative | Selenium supplementation showed both beneficial and detrimental effects on influenza-vaccine immunity depending on dose/form; excess (selenosis) is immunotoxic. | Nutrition & viral respiratory tract infections (Frontiers Immunol 2022) (opens in a new tab) |
| Sleep regularity | Watch this | Emerging | Cohort / observational | Disturbed/irregular sleep contributes to the impaired immune response linked to upper-respiratory infection. | Physical activity, sleep & respiratory infections (Swedish cohort, PLOS One 2018) (opens in a new tab) |
| Staying in touch (social reps) | Do this | Emerging | Cohort / observational | Ongoing social participation formed part of the network diversity linked to host resistance. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Strength (resistance) | Do this | Emerging | Cohort / observational | General activity and muscle maintenance support immune reserve against respiratory infection. | Physical activity & respiratory infections (PLOS One 2018) (opens in a new tab) |
| Sugary drinks & snacks — cut back | Do this | Emerging | Review / narrative | High added-sugar intake promotes transient immune impairment and the weight gain that worsens respiratory outcomes. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Total Fiber | Eat enough of | Emerging | Review / narrative | Fibre/prebiotics feed a gut microbiome whose short-chain fatty acids modulate lung immunity via the gut-lung axis (emerging). | Nutritional supplements & viral respiratory infections (ScienceDirect 2024) (opens in a new tab) |
| Toxic relationships — reduce | Watch this | Emerging | Cohort / observational | Interpersonal/social stress promotes glucocorticoid resistance in macrophages, increasing susceptibility. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Vitamin B6 | Eat enough of | Emerging | Review / narrative | Vitamin B6 deficiency impairs lymphocyte proliferation and antibody production, weakening defence against infection. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Vitamin E | Eat enough of | Emerging | Review / narrative | Vitamin E deficiency impairs immune function; adequacy supports antioxidant protection of immune cells, particularly in older adults. | Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab) |
| Warmth & quality of ties | Watch this | Emerging | Cohort / observational | Social support buffered the pathogenic influence of stress on cold susceptibility. | Pittsburgh common-cold studies (Cohen 2005) (opens in a new tab) |
| Zinc | Don't overdo | Emerging | RCT / meta-analysis | Excess zinc can impair immune function and induce copper deficiency, offsetting benefits — more is not better. | Zinc supplementation & common cold (PMC7356429) (opens in a new tab) |
Held for the whole Respiratory system
These rows name no single condition. The Map records them against the whole body system, so they are shown separately rather than folded in.
| Nutrient or lever | Direction | Strength | Evidence type | What was found | Source |
|---|---|---|---|---|---|
| Blood oxygen (SpO2) | Watch this | Strong | Established clinical | Low SpO2 (hypoxemia) signals impaired gas exchange - respiratory failure, pneumonia, COPD; SpO2 is a core vital sign. | Pulse-oximetry / hypoxemia literature (opens in a new tab) |
| Blood oxygen (SpO2) | Watch this | Strong | Established clinical | SpO2 can fall dangerously (silent hypoxemia) before breathlessness is felt, marking serious respiratory compromise. | Silent-hypoxemia case literature (opens in a new tab) |
| Breathing rate | Watch this | Strong | Established clinical | Respiratory rate is the sentinel, most sensitive vital sign - its values deviate before other vitals in nearly all clinical decline. | Respiratory Rate: The Forgotten Vital Sign (Joint Commission Journal 2018) (opens in a new tab) |
| Breathing rate | Watch this | Strong | Established clinical | Abnormal respiratory rate predicts clinical deterioration and mortality; very high rates (>35/min) predict imminent life-threatening events. | Aglen et al., Acta Anaesthesiol Scand 2025 (scoping review) (opens in a new tab) |
| Carotenoids (provitamin A) | Don't overdo | Strong | RCT / meta-analysis | High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.) | ATBC / CARET trials (NEJM); NIH ODS (opens in a new tab) |
| Carotenoids (provitamin A) | Don't overdo | Strong | RCT / trial | High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.) | The Beta-Carotene and Retinol Efficacy Trial (CARET): incidence of lung cancer and cardiovascular disease mortality during 6-year follow-up after stopping beta-carotene and retinol supplements, J Natl Cancer Inst 2004 (opens in a new tab) |
| Carotenoids (provitamin A) | Don't overdo | Strong | Established clinical | High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.) | NIH Office of Dietary Supplements — Vitamin A and Carotenoids (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Strong | Established clinical | Smoking is the leading cause of lung cancer and of COPD (chronic bronchitis and emphysema), harming nearly every organ. | US Surgeon General report / CDC (2014 onward) (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Strong | Cohort / observational | Lung-cancer mortality rises nearly linearly with smoking, reaching relative risks above 40 in long-term heavy smokers. | Thun et al., "50-year trends in smoking-related mortality in the United States" (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Strong | Established clinical | Lung-cancer mortality rises nearly linearly with smoking, reaching relative risks above 40 in long-term heavy smokers. | US Surgeon General — The Health Consequences of Smoking (opens in a new tab) |
| BMI | Watch this | Moderate | Established clinical | Obesity causes obstructive sleep apnea and obesity-hypoventilation, raising respiratory morbidity. | Obesity clinical review (opens in a new tab) |
| Breath (how you breathe) | Watch this | Moderate | RCT / meta-analysis | Dysfunctional breathing (rapid, shallow, mouth breathing) impairs respiratory efficiency and autonomic function; guided breathing retraining improves both. | Breathing-interventions RCT, 2025 (opens in a new tab) |
| Daytime alertness | Watch this | Emerging | Cohort / observational | Persistent daytime sleepiness can signal underlying sleep-disordered breathing. | Sleepiness and obstructive-sleep-apnea literature (opens in a new tab) |