7. THE SUBSTANCES QUESTION
Pillar 6: Harmful Substance Avoidance
Let's talk about the things that complicate surgery and impair healing.
Smoking, excess alcohol, excessive screen time, and environmental toxins—these all affect how your body heals, how anaesthesia works, whether you develop complications post-operatively.
The research is clear: optimising your substance use before surgery improves outcomes significantly. And this is one area where you have total control.
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How Substances Impact Surgery
Substances that impair healing, interact with anaesthesia, or increase inflammation affect:
- Wound healing (slowed, with higher infection risk)
- Anaesthesia interactions (unpredictable responses, complications)
- Bleeding risk
- Immune function
- Recovery timeline
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SMOKING: The Biggest Modifiable Risk Factor
Smoking is one of the most powerful predictors of surgical complications.
Why it matters:
- Nicotine constricts blood vessels. Reduced blood flow to wounds means slower healing and higher infection risk.
- Carbon monoxide reduces oxygen transport. Tissues aren't getting oxygen needed for healing.
- Smoking impairs immune function. Body is less able to fight infection.
- Smoking delays healing. Wounds take significantly longer to close.
Sørensen (2012) conducted a meta-analysis showing that smoking increases post-operative complication rates by 30–50% and dramatically delays wound healing. Even brief cessation (2 weeks) before surgery improves outcomes significantly. Surgeon, 10(2), 76-82.
The Timeline:
- 2 weeks: Better than nothing. Significant improvement in blood oxygen.
- 4 weeks: Dramatic improvement. Oxygen transport normalises. Immune function improves substantially.
- 8 weeks: Optimal. All parameters close to normal.
Myers K, Hajek P, Hinds C, McRobbie H. Stopping smoking shortly before surgery and postoperative complications: a systematic review and meta-analysis. Arch Intern Med. 2011 Jun 13;171(11):983-9. doi: 10.1001/archinternmed.2011.97. Epub 2011 Mar 14. PMID: 21403009.
How to Quit:
- Nicotine replacement therapy (NRT): Patches, gum, lozenges—safe pre-operatively
- NHS Stop Smoking service: Free, very good (0300 123 1044 or your GP)
- Apps: Smoke Free (excellent)
- Support: Counselling, group support, accountability from friends/family
Post-op: This is your motivation window. Stay quit.
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ALCOHOL: The Complicated One
Alcohol doesn't have smoking's dramatic impact, but it still impairs healing.
Why it matters:
- Dehydration. Alcohol is a diuretic. Dehydration impairs healing.
- Liver stress. Your liver metabolises alcohol and anaesthetic drugs. Adding both is extra stress.
- Sleep disruption. Alcohol disrupts sleep architecture—poor quality sleep.
- Bleeding risk. Alcohol can thin the blood.
- Inflammatory effects. Chronic alcohol increases systemic inflammation.
- Nutrient absorption. Alcohol interferes with absorbing nutrients you need.
Tonnesen H, Rosenberg J, Nielsen HJ, Rasmussen V, Hauge C, Pedersen IK, Kehlet H. Effect of preoperative abstinence on poor postoperative outcome in alcohol misusers: randomised controlled trial. BMJ. 1999 May 15;318(7194):1311-6. doi: 10.1136/bmj.318.7194.1311. PMID: 10323814; PMCID: PMC27867.
Guidelines:
- Avoid completely 4 weeks at least before surgery
- Post-op: Avoid until off painkillers (usually 1–2 weeks)
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SCREEN TIME: The Often-Overlooked Factor
Excessive screen time—particularly before bed—disrupts sleep through blue light exposure. Since sleep is critical for surgery recovery, managing screen time matters more than most people realise.
How it impacts you:
- Blue light suppresses melatonin. Your sleep hormone gets disrupted.
- Sleep quality degrades. You sleep more lightly, with less restorative deep sleep.
- Circadian rhythm disruption. Your natural sleep-wake cycle gets confused.
- Anxiety increases. Late-night screen time—especially social media and news—elevates anxiety.
Screen Time Guidelines:
- No screens 1–2 hours before bed. This is critical for sleep quality.
- Avoid: Social media and news just before bed (increases anxiety).
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HARMFUL CHEMICALS: In Home & Environment
Environmental toxins—in household products, air quality, water—can add inflammatory burden to your body when it needs to be optimised for healing.
Common culprits:
- Air pollution. Impairs wound healing and immune function.
- Household cleaners. Volatile organic compounds (VOCs) create indoor air pollution.
- Plastic off-gassing. Chemicals like BPA from plastics can affect hormone balance and immunity.
- Pesticides/herbicides. Inflammatory burden.
- Poor water quality. Contaminants can stress immune and detoxification systems.
Lee (2022) demonstrated that environmental toxin exposure increases systemic inflammation and impairs wound healing. J Wound Manag Res 2022 February;18(1):11-16
Simple Strategies:
- Switch to non-toxic cleaners. Vinegar, baking soda, castile soap work brilliantly.
- Improve air quality. Open windows, use HEPA filters, add plants.
- Filter your water. Simple pitchers or faucet filters reduce contaminants.
- Reduce plastic use. Use glass or stainless steel where possible.
- Minimise pesticide exposure. Choose organic produce when possible, avoid lawn chemicals.
- Declutter & ventilate. Remove off-gassing items, let your home air out.
These don't require dramatic changes—small shifts reduce inflammatory burden on your body.
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Integrated Approach to Harmful Substances
Think of this pillar as harm reduction in service of healing.
You're not avoiding these things to be virtuous. You're making strategic choices to:
- Maximise immune function
- Minimise inflammatory burden
- Optimise sleep quality
- Support your body's healing capacity
The 4–8 weeks before surgery is the perfect time to make these shifts. And many patients find that once they've made them, they don't go back.
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⚠️ MEDICAL DISCLAIMER
Before making changes to medications, stopping substances, or starting cessation programmes, consult your GP, surgical team, or addiction specialist. This is especially important for alcohol (sudden cessation can be unsafe) or if you have substance use disorders.
