The Healthspan Map · Body system

Immune, Inflammation & Infection

Conditions in this system

Named for a condition in this system

Evidence naming a condition in Immune, Inflammation & Infection — 51 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or leverDirectionStrengthEvidence typeWhat was foundSource
Cardio (moderate + intervals)Do thisStrongRCT / meta-analysisPhysical activity reduces pneumonia risk (meta-analysis, 1,044,492 participants), lowers CRP and improves vaccine response.Physical activity & pneumonia risk (opens in a new tab)
Cardio / VO2maxWatch thisStrongRCT / meta-analysisHigher cardiorespiratory fitness/physical activity lowers pneumonia mortality (dose-response meta) and mitigates immunosenescence and inflammaging.Fitness & infection mortality (opens in a new tab)
EPA/DHA (omega-3)Eat enough ofStrongRCT / meta-analysisEPA/DHA supplementation lowers CRP, IL-6 and TNF-a (umbrella meta-analysis of ~148 trials) via resolvins and NF-kB inhibition.Omega-3 & inflammation (opens in a new tab)
ProteinEat enough ofStrongEstablished clinicalProtein-energy malnutrition is a leading cause of secondary immunodeficiency, impairing cell-mediated immunity, antibodies and phagocytes.Protein-energy malnutrition & immunity (opens in a new tab)
Sleep durationWatch thisStrongRCT / meta-analysisSleeping under 6 h raises cold susceptibility 4.2x, cuts vaccine antibody response ~50%, and drops NK-cell activity ~70%; AASM recommends >=7 h citing immunity.Sleep duration & immunity (opens in a new tab)
Sleep quality (refreshed)Watch thisStrongRCT / meta-analysisPoor sleep efficiency raises cold susceptibility and CRP/IL-6 (Cohen; AASM consensus).Sleep quality & infection (opens in a new tab)
Ultra-processed food — cut backDo thisStrongReview / narrativeHigher ultra-processed food intake is consistently associated with elevated CRP and inflammatory markers.Ultra-processed food & CRP (opens in a new tab)
Vitamin DEat enough ofStrongRCT / meta-analysisVitamin D drives antimicrobial peptides; supplementation reduces acute respiratory infections. One of the three strongest immune micronutrients.Vitamin D & respiratory infection (opens in a new tab)
Added SugarsDon't overdoModerateCohort / observationalHigh added-sugar intake raises CRP/IL-6 via NF-kB and glycation."The association between sugar-sweetened beverages intake, body mass index, and inflammation in US adults", Int J Public Health 2020 (opens in a new tab)
Alcohol — cut backDo thisModerateReview / narrativeExcess alcohol promotes adipose and systemic inflammation (IL-6/TNF-a) and impairs host defence.Alcohol & inflammation (opens in a new tab)
Anchor foodsWatch thisModerateReview / narrativeA whole-food/Mediterranean pattern lowers IL-6 and CRP.Mediterranean pattern & inflammation (opens in a new tab)
Anchor foodsWatch thisModerateRCT / meta-analysisA whole-food/Mediterranean pattern lowers IL-6 and CRP.Mediterranean dietary pattern, inflammation and endothelial function: a systematic review and meta-analysis of intervention trials, Nutr Metab Cardiovasc Dis 2014 (opens in a new tab)
BMIWatch thisModerateReview / narrativeVisceral fat secretes IL-6 and TNF-a, raising CRP and driving chronic low-grade inflammation and impaired immunity.Obesity & inflammation (opens in a new tab)
Body Roundness IndexWatch thisModerateReview / narrativeCentral-adiposity measures track systemic inflammation (IL-6/CRP) and immune dysfunction.Central adiposity & CRP (opens in a new tab)
Colours a dayWatch thisModerateRCT / meta-analysisColourful plant polyphenols and antioxidants blunt oxidative stress and inflammation.Effect of Polyphenol-Rich Interventions on Gut Microbiota and Inflammatory or Oxidative Stress Markers, Nutrients 2025 (opens in a new tab)
Cook real foodDo thisModerateReview / narrativeCooking from whole ingredients cuts ultra-processed additives linked to inflammation.Home cooking avoids additives (opens in a new tab)
CopperEat enough ofModerateReview / narrativeCopper supports superoxide dismutase and innate immune killing; deficiency causes neutropenia and impaired immunity.Copper & innate immunity (opens in a new tab)
Daily movement baselineDo thisModerateRCT / trialRegular moderate activity lowers CRP and inflammatory adipokines over 6-12 months.Moderate exercise & CRP (opens in a new tab)
Falling & staying asleepWatch thisModerateReview / narrativeInsomnia and fragmented sleep predict lower influenza-vaccine antibody titres and higher inflammation.The Sleep-Immune Crosstalk in Health and Disease, Physiol Rev 2019 (opens in a new tab)
Folate (B9)Eat enough ofModerateReview / narrativeFolate is required for immune-cell proliferation and the Th1 response.Folate & lymphocytes (opens in a new tab)
Food & hand hygieneDo thisModerateSystematic reviewHandwashing with soap reduces respiratory infections (~24% pooled), lowering infection burden.Handwashing & infection (opens in a new tab)
IronEat enough ofModerateReview / narrativeIron is required for lymphocyte proliferation and macrophage pathogen-killing; deficiency impairs immunity.Iron & immune cells (opens in a new tab)
Loneliness — reduceWatch thisModerateReview / narrativeLoneliness upregulates inflammatory gene expression (CTRA) and downregulates antiviral defence, raising IL-6/CRP.Social isolation & CTRA (opens in a new tab)
Movement (breaking up sitting)Do thisModerateReview / narrativeMeeting activity guidelines (vs sedentary) improves immune function and lowers low-grade inflammation and immunosenescence.Sedentary time & inflammation (opens in a new tab)
Saturated fatDon't overdoModerateReview / narrativeHigh saturated-fat intake activates TLR4 signalling and pro-inflammatory pathways.Saturated fat & inflammation (opens in a new tab)
SeleniumEat enough ofModerateReview / narrativeSelenium supports antioxidant defence and T-cell/IFN-y responses; deficiency impairs immunity.Selenium & immunity (opens in a new tab)
Sleep regularityWatch thisModerateCohort / observationalIrregular/short sleep and circadian disruption raise CRP and impair antibody responses.Circadian rhythm & immunity (opens in a new tab)
Strength (resistance)Do thisModerateRCT / meta-analysisResistance training reduces CRP and IL-6 (meta-analysis, 18 RCTs) and counters the sarcopenia-inflammation loop.Resistance training & CRP (opens in a new tab)
Sugary drinks & snacks — cut backDo thisModerateReview / narrativeHigh sugar intake raises CRP/IL-6 via NF-kB activation and advanced glycation.Added sugar & inflammation (opens in a new tab)
Tobacco / vaping — quitDo thisModerateReview / narrativeCigarette smoke impairs innate and adaptive immunity and raises inflammatory markers, increasing infection susceptibility.Smoking & immunity (opens in a new tab)
Total FiberEat enough ofModerateReview / narrativeDietary fibre feeds SCFA-producing microbes (butyrate) that lower CRP and regulate mucosal immunity.Fibre, SCFAs & inflammation (opens in a new tab)
Trans fatDon't overdoModerateReview / narrativeIndustrial trans fats raise CRP/IL-6 and endothelial inflammation.Trans fat & CRP (opens in a new tab)
Vitamin A (RAE)Eat enough ofModerateReview / narrativeVitamin A maintains mucosal/epithelial barriers and NK/T-cell function.Vitamin A & mucosal immunity (opens in a new tab)
Vitamin B12Eat enough ofModerateReview / narrativeVitamin B12 supports lymphocyte numbers and NK-cell activity.B12 & immune cells (opens in a new tab)
Vitamin B6Eat enough ofModerateReview / narrativeVitamin B6 supports lymphocyte proliferation and Th1 cytokine responses.Vitamin B6 & immunity (opens in a new tab)
Vitamin CEat enough ofModerateReview / narrativeVitamin C supports barrier integrity and phagocyte/lymphocyte function; among the strongest-evidence immune micronutrients (shortens common cold).Vitamin C & immune function (opens in a new tab)
Vitamin EEat enough ofModerateReview / narrativeVitamin E is a key antioxidant that supports T-cell-mediated immunity, especially with age.Vitamin E & T-cells (opens in a new tab)
Waist-to-height ratioWatch thisModerateReview / narrativeWaist-based adiposity predicts CRP/IL-6 elevation largely independent of BMI.Central adiposity & CRP (opens in a new tab)
Waist-to-hip ratioWatch thisModerateReview / narrativeHigher waist-to-hip ratio marks visceral fat that fuels pro-inflammatory adipokines.Central adiposity & CRP (opens in a new tab)
ZincEat enough ofModerateReview / narrativeZinc is essential for immune-cell development and barrier integrity; deficiency impairs immunity and zinc shortens the common cold.Zinc & immunity (opens in a new tab)
Breath/mind (slow breathing)Do thisEmergingRCT / meta-analysisMeditation and slow-breathing practices reduce CRP and IL-6.Mind-body breathing & inflammation (opens in a new tab)
Flexibility (stretching)Do thisEmergingRCT / meta-analysisYoga/stretching practice tends to lower IL-6, TNF-a and CRP.Yoga & inflammatory markers (opens in a new tab)
IronDon't overdoEmergingReview / narrativeExcess iron promotes bacterial growth and oxidative stress ("nutritional immunity"), a risk when over-supplemented.Iron overload & infection (opens in a new tab)
MagnesiumEat enough ofEmergingReview / narrativeMagnesium participates in immune activation and inflammation regulation.Magnesium & inflammation (opens in a new tab)
Oral & skin careDo thisEmergingRCT / trialPeriodontal/gingival inflammation raises systemic inflammation (CRP); good oral hygiene lowers the immune burden.Periodontal disease & CRP (opens in a new tab)
SodiumDon't overdoEmergingReview / narrativeHigh salt intake drives pathogenic Th17 differentiation and chronic inflammation.Salt & Th17 inflammation (opens in a new tab)
Supplement disciplineDo thisEmergingReview / narrativeCorrecting genuine micronutrient gaps restores immune function; indiscriminate megadosing does not boost a healthy system.Micronutrient repletion (opens in a new tab)
Total SugarsDon't overdoEmergingReview / narrativeHigh total-sugar/refined-carb loads promote post-prandial inflammation.High glycaemic load & inflammation (opens in a new tab)
Total SugarsDon't overdoEmergingSystematic reviewHigh total-sugar/refined-carb loads promote post-prandial inflammation.Association between carbohydrate quality and inflammatory markers: systematic review of observational and interventional studies, Am J Clin Nutr 2014 (opens in a new tab)
Toxic relationships — reduceWatch thisEmergingReview / narrativeChronic conflict and hostile relationships elevate inflammatory signalling.Chronic social stress & IL-6 (opens in a new tab)
ZincDon't overdoEmergingEstablished clinicalChronically high zinc impairs immune function and induces copper deficiency.Excess zinc & immunity (opens in a new tab)

Held for the whole system

Evidence held for Immune, Inflammation & Infection as a whole — 7 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or leverDirectionStrengthEvidence typeWhat was foundSource
Sleep durationWatch thisModerateEstablished clinicalShort sleep raises systemic inflammation and lowers infection resistance.Sleep-restriction and immune literature (opens in a new tab)
Carotenoids (provitamin A)Eat enough ofEmergingEstablished clinicalAs a provitamin A source, adequate carotenoid intake supports vitamin A status and immune function.NIH ODS – Vitamin A & Carotenoids (opens in a new tab)
Inner circle (close ties)Watch thisEmergingMechanisticStrong relationships are linked to better immune function and faster recovery from illness.Social-connection and immune literature (opens in a new tab)
Inner circle (close ties)Watch thisEmergingCohort / observationalStrong relationships are linked to better immune function and faster recovery from illness.Social relationships and physiological determinants of longevity across the human life span, PNAS 2016 (opens in a new tab)
Loneliness — reduceWatch thisEmergingMechanisticChronic loneliness is linked to higher inflammation and weaker immune function.Social-connection and immune literature (Harvard Study synthesis) (opens in a new tab)
Loneliness — reduceWatch thisEmergingCohort / observationalChronic loneliness is linked to higher inflammation and weaker immune function.Social relationships and physiological determinants of longevity across the human life span, PNAS 2016 (opens in a new tab)
Tobacco / vaping — quitDo thisEmergingEstablished clinicalSmoking impairs immune defenses and raises risk of pneumonia, tuberculosis and other infections.US Surgeon General report (opens in a new tab)