What effects does alcohol have on blood health?

Effects of Alcohol on Blood Health

Alcohol has significant effects on blood health, with light to moderate consumption decreasing platelet aggregation and providing antithrombotic benefits, while heavy consumption (≥35 drinks per week) increases risk of hemorrhagic events and hypertension. 1

Effects on Blood Clotting

Antithrombotic Effects (Light to Moderate Consumption)

• Moderate alcohol consumption (up to 60 mL or about 2 standard drinks daily) significantly reduces platelet aggregation through:

  • Inhibition of prostaglandin synthesis (similar mechanism to aspirin) 2
  • Decreased plasma fibrinogen levels 1, 3
  • Potential reduction in cellular tissue factor levels 2

• These effects provide an antithrombotic benefit similar to that of aspirin 2

Negative Effects (Heavy Consumption)

• Heavy drinking (≥35 drinks per week) is associated with:
  • 2.27 times higher risk of hemorrhagic stroke 4
  • 2.04 times higher risk of non-variceal gastrointestinal bleeding 4
  • Increased factor VII (7%) and plasminogen activator inhibitor-1 (21%) 3

Effects on Blood Pressure

• Alcohol consumption has a dose-dependent relationship with blood pressure 5, 6

• Even at levels close to consumption guidelines (20g per day), blood pressure increases 5

• For consumption above 30g daily, each additional 10g of alcohol increases:

  • Systolic blood pressure by 1-2 mmHg
  • Diastolic blood pressure by 1 mmHg 6

• Heavy drinkers (6-8 drinks/day) have significantly higher blood pressure:

  • 9.1 mmHg higher systolic blood pressure
  • 5.6 mmHg higher diastolic blood pressure compared to non-drinkers 2

Other Blood-Related Effects

• Alcohol can cause bone marrow suppression of red blood cell production 7
• In some alcoholic patients, this can lead to sideroblastic anemia 7
• Chronic heavy alcohol use affects the balance between coagulation and fibrinolysis, potentially increasing thrombosis risk 3

Recommendations for Alcohol Consumption

• For cardiovascular protection, consumption limits should be:

  • ≤2 drinks per day for men
  • ≤1 drink per day for non-pregnant women 2, 1

• These limits should not be exceeded as higher consumption increases risk of:

  • Hypertension
  • Hemorrhagic stroke
  • Gastrointestinal bleeding 2, 4

Important Caveats

• The protective effects of alcohol are seen only with light to moderate consumption
• Alcohol should never be recommended specifically as a preventive measure due to risks of:
  • Addiction
  • Hypertension
  • Cardiomyopathy
  • Increased accident risk 2, 1
• Blood pressure effects of alcohol are reversible with reduction in consumption 5
• Individual responses to alcohol may vary based on genetics and other factors 3