Does red or white wine have a greater impact on blood sugar levels in adults with diabetes or at risk of developing diabetes?

Wine and Blood Sugar: Direct Answer

Wine consumed alone has minimal acute effect on blood glucose, but any carbohydrates mixed with wine (as in cocktails or sweet wines) will raise blood sugar—the type of wine (red vs. white) does not matter for glycemic impact. 1

Key Mechanism: Alcohol vs. Carbohydrate Content

The alcohol itself does not raise blood glucose; rather, it's the carbohydrate content that determines the glycemic response. 1

• Moderate alcohol consumption (when ingested alone) has no acute effect on glucose and insulin concentrations in people with diabetes 1
• However, carbohydrate co-ingested with alcohol (as in mixed drinks or sweet wines) may raise blood glucose 1
• One alcoholic beverage is defined as 5 oz wine (red or white), containing approximately 15 g alcohol 1

Red Wine vs. White Wine: No Clinically Significant Difference

Research demonstrates that red and white wine have equivalent effects on blood glucose control, with neither raising blood sugar more than the other when consumed in moderate amounts with meals. 2, 3

• A controlled study of 12 patients with type 2 diabetes found similar glucose, insulin, and triglyceride responses whether patients consumed dry white wine, sweet white wine with added ethanol, or dry white wine with added glucose 2
• Whether wine is dry or sweet has no impact on glycemic control when consumed with meals 2
• The CASCADE trial (2-year randomized controlled trial) found no significant differences in glycemic control between red wine and white wine consumption in 224 patients with type 2 diabetes 3

Critical Safety Considerations

The primary concern with wine consumption in diabetes is delayed hypoglycemia, not hyperglycemia, particularly in patients using insulin or insulin secretagogues. 1, 4, 5

Hypoglycemia Risk Factors:

• Alcohol inhibits both gluconeogenesis and glycogenolysis, creating significant hypoglycemia risk 4, 5
• Evening wine consumption may cause delayed hypoglycemia the following morning, especially in type 1 diabetes 1, 6
• A study of 6 men with type 1 diabetes showed that moderate wine consumption (0.75 g/kg alcohol) at 9 PM led to significantly lower fasting and postprandial blood glucose the next morning, with 5 of 6 subjects requiring hypoglycemia treatment 6
• Alcohol-induced hypoglycemia is not ameliorated by glucagon because it impairs gluconeogenesis rather than causing excessive insulin secretion 5

Mandatory Safety Measures:

• Always consume wine with food containing carbohydrates to minimize nocturnal hypoglycemia risk 1, 4
• Monitor blood glucose frequently after any alcohol consumption, with particular vigilance for delayed effects 1, 4
• Patients using insulin or insulin secretagogues face the highest risk and require intensified monitoring 1, 4

Recommended Limits

Adults with diabetes who choose to drink should limit intake to ≤1 drink/day for women and ≤2 drinks/day for men. 1, 5

• Excessive alcohol (≥3 drinks/day) consumed consistently contributes to hyperglycemia 1, 5
• Chronic heavy alcohol ingestion (≥45 g/day or ≥3 drinks/day) causes deterioration in glucose metabolism 5

Absolute Contraindications

Complete abstinence from alcohol is mandatory for patients with: 1, 4

• History of alcohol abuse or dependence
• Pancreatitis
• Advanced neuropathy
• Severe hypertriglyceridemia
• Liver disease
• Pregnancy

Common Pitfalls to Avoid

• Do not assume wine raises blood sugar acutely—the immediate concern is hypoglycemia, not hyperglycemia 1
• Do not recommend dry wine over sweet wine for glycemic control—research shows no difference when consumed with meals 2
• Do not overlook delayed morning hypoglycemia—this can occur 12+ hours after evening wine consumption 6
• Do not forget that alcohol can blunt hypoglycemia awareness in type 1 diabetes, increasing risk of severe episodes 5