The Healthspan Map · Digestive / Gastrointestinal
Digestive discomfort
Named for Digestive discomfort
| Nutrient or lever | Direction | Strength | Evidence type | What was found | Source |
|---|---|---|---|---|---|
| Food & hand hygiene | Do this | Strong | Established clinical | Refrigerate perishables within 2h (1h above 90F); the 40-140F danger zone and handwashing prevent foodborne GI illness. | Food safety & hand hygiene (CDC) (opens in a new tab) |
| Total Fiber | Eat enough of | Strong | RCT / meta-analysis | Soluble fibre (psyllium) is first-line for constipation, raising stool frequency and easing straining. | Fibre for chronic constipation (opens in a new tab) |
| Ultra-processed food — cut back | Do this | Strong | RCT / trial | Emulsifiers (CMC, P80) in ultra-processed food disrupt the gut barrier and microbiome, promoting GI symptoms and inflammation. | Dietary emulsifiers & gut (opens in a new tab) |
| Ultra-processed food — cut back | Do this | Strong | RCT / trial | Emulsifiers (CMC, P80) in ultra-processed food disrupt the gut barrier and microbiome, promoting GI symptoms and inflammation. | Randomized Controlled-Feeding Study of Dietary Emulsifier Carboxymethylcellulose, Gastroenterology 2022 (opens in a new tab) |
| Added Sugars | Don't overdo | Moderate | RCT / meta-analysis | Excess free sugars/fructose drive osmotic diarrhoea, gas and bloating. | Free sugars & osmotic/fermentation GI (opens in a new tab) |
| Alcohol — cut back | Do this | Moderate | RCT / meta-analysis | Alcohol lowers LES pressure and raises reflux esophagitis and ulcer risk. | Alcohol & upper-GI disease (opens in a new tab) |
| Anchor foods | Watch this | Moderate | RCT / meta-analysis | Whole-food, fibre-rich meals improve IBS and functional GI symptoms. | Diet & gut-brain axis (IBS) (opens in a new tab) |
| Breath/mind (slow breathing) | Do this | Moderate | RCT / meta-analysis | Slow diaphragmatic breathing reduces reflux and functional GI symptoms. | Diaphragmatic breathing & reflux/IBS (opens in a new tab) |
| Cardio (moderate + intervals) | Do this | Moderate | RCT / trial | Moderate aerobic exercise reduces IBS symptom severity and improves motility. | Exercise & IBS (opens in a new tab) |
| Choline | Don't overdo | Moderate | Established clinical | Excess choline causes GI distress - vomiting, diarrhoea, stomach cramps - plus sweating and fishy body odour. | Choline excess & GI (opens in a new tab) |
| Colours a day | Watch this | Moderate | RCT / meta-analysis | Diverse plant intake supports microbiome diversity and bowel regularity. | Plant diversity & microbiome (opens in a new tab) |
| Cook real food | Do this | Moderate | RCT / trial | Cooking from whole ingredients cuts exposure to emulsifiers/additives linked to GI symptoms. | Home cooking avoids additives (opens in a new tab) |
| Copper | Don't overdo | Moderate | Established clinical | Acute copper excess causes gastroenteritis - abdominal pain, nausea, vomiting, diarrhoea - with erosive gastropathy. | Copper toxicity & GI (opens in a new tab) |
| Daily movement baseline | Do this | Moderate | Review / narrative | Regular activity speeds colonic transit and reduces constipation. | Physical activity & bowel function (opens in a new tab) |
| Iron | Don't overdo | Moderate | RCT / trial | Oral iron commonly causes nausea (~22%), constipation (~24%) and heartburn. | Oral iron GI side effects (opens in a new tab) |
| Loneliness — reduce | Watch this | Moderate | RCT / meta-analysis | Chronic stress/loneliness worsens IBS and functional GI symptoms via the gut-brain axis. | Gut-brain axis & stress (opens in a new tab) |
| Magnesium | Eat enough of | Moderate | Review / narrative | Low magnesium associates with constipation; magnesium eases it osmotically. | Magnesium & constipation (opens in a new tab) |
| Magnesium | Don't overdo | Moderate | Established clinical | Excess magnesium pulls water into the bowel, causing diarrhoea (it is used as a laxative). | NIH Office of Dietary Supplements — Magnesium (opens in a new tab) |
| Saturated fat | Don't overdo | Moderate | Review / narrative | High saturated-fat intake slows emptying and aggravates reflux/dyspepsia. | High saturated-fat & GI (opens in a new tab) |
| Selenium | Eat enough of | Moderate | Review / narrative | Selenium deficiency alters gut microbiota, is common in IBD (~31%), and can cause chronic diarrhoea and intestinal inflammation. | Selenium & gut microbiota/IBD (opens in a new tab) |
| Selenium | Don't overdo | Moderate | Established clinical | Excess selenium (selenosis) causes GI upset - nausea, diarrhoea, vomiting - plus metallic taste and garlic breath. | Selenosis & GI (opens in a new tab) |
| Sleep duration | Watch this | Moderate | RCT / meta-analysis | Poor/short sleep worsens IBS and functional GI symptom severity. | Sleep & gut-brain axis (opens in a new tab) |
| Sleep quality (refreshed) | Watch this | Moderate | RCT / meta-analysis | Non-restorative sleep is bidirectionally linked with GI symptom flares. | Sleep quality & IBS (opens in a new tab) |
| Sugary drinks & snacks — cut back | Do this | Moderate | RCT / meta-analysis | High free-sugar/fructose loads drive osmotic diarrhoea, gas and bloating. | Fermentable sugars & GI (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Moderate | Cohort / observational | Smoking weakens the lower esophageal sphincter, raising GERD and ulcer risk. | Smoking & GERD/peptic ulcer (opens in a new tab) |
| Total Fat | Don't overdo | Moderate | Review / narrative | High-fat meals slow gastric emptying and relax the LES, worsening reflux. | High-fat meals & reflux (opens in a new tab) |
| Total Fiber | Don't overdo | Moderate | RCT / meta-analysis | Excess/fermentable fibre added too fast causes bloating, gas and cramping (especially in IBS). | Too much fibre & bloating (opens in a new tab) |
| Vitamin C | Don't overdo | Moderate | Established clinical | Vitamin C above bowel tolerance (~2 g) causes osmotic diarrhoea and cramping. | NIH Office of Dietary Supplements — Vitamin C (opens in a new tab) |
| Water / hydration | Do this | Moderate | Review / narrative | Adequate fluid softens stool and eases constipation. | Hydration & constipation (opens in a new tab) |
| Zinc | Don't overdo | Moderate | Established clinical | High-dose zinc causes nausea, vomiting and GI upset. | NIH Office of Dietary Supplements — Zinc (opens in a new tab) |
| BMI | Watch this | Emerging | RCT / meta-analysis | Higher BMI raises reflux/GERD risk dose-dependently (~+68% per 10 kg/m2; obesity roughly doubles risk). | Obesity & GERD meta (opens in a new tab) |
| Caffeine — mind amount & timing | Do this | Emerging | RCT / meta-analysis | Caffeine can relax the LES and trigger reflux/heartburn in sensitive people. | Caffeine reflux trigger (opens in a new tab) |
| Calcium | Don't overdo | Emerging | Established clinical | Calcium supplements can cause constipation, bloating and gas. | NIH Office of Dietary Supplements — Calcium (opens in a new tab) |
| Choline | Eat enough of | Emerging | Mechanistic | Insufficient choline disrupts the gut barrier and promotes intestinal inflammation and altered microbiota (and fatty-liver disease). | Choline & intestinal barrier (opens in a new tab) |
| Chromium | Don't overdo | Emerging | Established clinical | High-dose or inorganic chromium irritates the GI tract (gastritis, abdominal pain, vomiting, bloody diarrhoea); supplements may cause mild GI upset. | Chromium GI irritation (opens in a new tab) |
| Iodine | Don't overdo | Emerging | Established clinical | Excess iodine irritates the GI tract, causing nausea, vomiting, diarrhoea and abdominal upset. | Iodine toxicity & GI (opens in a new tab) |
| Movement (breaking up sitting) | Do this | Emerging | Review / narrative | Prolonged sitting associates with slower transit and more GI complaints. | Sedentary time & GI (opens in a new tab) |
| Niacin (B3) | Don't overdo | Emerging | Review / narrative | High-dose niacin causes flushing with nausea and loose stools. | Niacin flushing & GI (opens in a new tab) |
| Pantothenic acid (B5) | Don't overdo | Emerging | Established clinical | Large doses of pantothenic acid (~10 g/day) can cause mild diarrhoea and GI distress. | Pantothenic acid high-dose GI (opens in a new tab) |
| Supplement discipline | Do this | Emerging | Established clinical | Excess supplements (magnesium, vitamin C, iron, zinc) commonly cause diarrhoea/nausea; discipline limits this. | NIH Office of Dietary Supplements — Magnesium (opens in a new tab) |
| Total Sugars | Don't overdo | Emerging | RCT / meta-analysis | High total-sugar loads (incl. fructose/lactose) ferment and cause bloating/diarrhoea. | Fermentable sugars & bloating (opens in a new tab) |
| Vitamin D | Don't overdo | Emerging | Established clinical | Vitamin D excess (via hypercalcemia) causes nausea, vomiting and constipation. | NIH Office of Dietary Supplements — Vitamin D (opens in a new tab) |
Held for the whole Digestive / Gastrointestinal 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 |
|---|---|---|---|---|---|
| Added Sugars | Don't overdo | Strong | Established clinical | Added/free sugars are the single most important risk factor for dental caries - the most prevalent noncommunicable disease worldwide (2.5 billion people). (Oral cavity mapped under GI.) | WHO — Guideline: Sugars intake for adults and children (opens in a new tab) |
| Added Sugars | Don't overdo | Strong | Systematic review | Added/free sugars are the single most important risk factor for dental caries - the most prevalent noncommunicable disease worldwide (2.5 billion people). (Oral cavity mapped under GI.) | Effect on caries of restricting sugars intake: systematic review to inform WHO guidelines, J Dent Res 2014 (opens in a new tab) |
| Alcohol — cut back | Do this | Moderate | Established clinical | Alcohol causes pancreatitis and digestive-tract cancers (esophageal, colorectal, liver, oral cavity). | Global Burden of Disease Alcohol Collaborators, Lancet 2018 (opens in a new tab) |
| Fluoride | Eat enough of | Moderate | Established clinical | Fluoride hardens tooth enamel and inhibits/reverses caries; low fluoride raises dental-caries (tooth-decay) risk - community water fluoridation is a landmark public-health measure. Oral/dental health is grouped under the Digestive system (the mouth is the entrance to the GI tract), matching the added-sugars mapping. | NIH ODS / IOM DRI - Fluoride (opens in a new tab) |
| Fluoride | Eat enough of | Moderate | Established clinical | Fluoride hardens tooth enamel and inhibits/reverses caries; low fluoride raises dental-caries (tooth-decay) risk - community water fluoridation is a landmark public-health measure. Oral/dental health is grouped under the Digestive system (the mouth is the entrance to the GI tract), matching the added-sugars mapping. | NIH Office of Dietary Supplements — Fluoride (opens in a new tab) |
| Fluoride | Don't overdo | Moderate | Established clinical | Excess fluoride during tooth development causes dental fluorosis - enamel mottling and pitting. Dental/oral effects are grouped under the Digestive system for consistency with all other tooth-related mappings. | NIH ODS / fluorosis studies (opens in a new tab) |
| Fluoride | Don't overdo | Moderate | Established clinical | Excess fluoride during tooth development causes dental fluorosis - enamel mottling and pitting. Dental/oral effects are grouped under the Digestive system for consistency with all other tooth-related mappings. | NIH Office of Dietary Supplements — Fluoride (opens in a new tab) |
| Sodium | Don't overdo | Moderate | Cohort / observational | High salt intake is linked to increased gastric (stomach) cancer risk. (Cancer folded into system.) | LPI – Sodium (opens in a new tab) |
| Tobacco / vaping — quit | Do this | Moderate | Established clinical | Smoking is a cause of cancers of the oral cavity, esophagus, pancreas and colorectum, and of peptic-ulcer disease. | US Surgeon General report / CDC (opens in a new tab) |