Effects of Coffee Roasting on Blood Sugar Levels in Healthy Humans

North Carolina State University

Status: Completed

Conditions: Hyperglycemia

Treatments: Dietary Supplement: Medium Roasted Coffee; Dietary Supplement: Dark Roasted Coffee; Dietary Supplement: Light Roasted Coffee; Dietary Supplement: Placebo Comparator

Study type: Interventional

Funder types: Other

Identifiers

NCT05119153

16857

Details and patient eligibility

About

The present study determined the effects light, medium, and dark roasted, brewed coffees on blood glucose responses in normal (n = 19) subjects.

Full description

This is a single-blinded, randomized partial block design conducted over 6 weeks in two parts.

In part 1 (3 weeks), participants were randomly assigned to consume four beverages: a placebo containing water and caramel color, light, medium, or dark roast coffee before, during, or after consumption of a beverage containing 50 g of glucose.

In part 2 (3 weeks), participants were randomly assigned to consume four beverages: a placebo containing water and caramel color, light, medium, or dark roast coffee before, during, or after consumption of a standardized breakfast (corn flakes cereal + skim milk) containing 50 g of glucose.

In each part, fasting and postprandial glucose profiles were determined.

Enrollment: 19 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age 18-64 years old with BMI less than 29 and fasting blood glucose less than 125 mg/dl.

Exclusion criteria

• Age 18-64 years old with BMI less than 29 and fasting blood glucose less than 125 mg/dl.

• Weight less than 110 pounds (55 kg)

• Pre-existing health conditions, such as:

  • High cholesterol
  • Hypertension
  • Cardiovascular disease
  • Gastrointestinal motility disorders
  • Hypo- or hyperthyroidism
  • Anemia
  • Renal disease
  • Liver disease, including hepatitis B or C, cholestasis, cirrhotic liver disease, or non-alcoholic fatty liver disease
  • Chronic or acute pancreatitis
  • Diabetes type 1 or 2
  • Insulin resistance
  • Polycystic ovary syndrome

• Food allergies or intolerances to coffee/caffeine/dairy/corn-based cereals.

• Currently taking prescription medication

• Current smoker

• Consumes more than 3 alcoholic beverages per day

• Pregnant or breastfeeding

• Not willing to take their own blood samples with finger sticks

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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19 participants in 4 patient groups, including a placebo group

Placebo Comparator

Placebo Comparator group

Description:

Placebo composed of water and caramel color.

Treatment:

Dietary Supplement: Placebo Comparator

Light Roasted Coffee

Experimental group

Description:

12 oz light roast coffee beverage prepared at 55 g ground coffee/L water

Treatment:

Dietary Supplement: Light Roasted Coffee

Medium Roasted Coffee

Experimental group

Description:

12 oz medium roast coffee beverage prepared at 55 g ground coffee/L water

Treatment:

Dietary Supplement: Medium Roasted Coffee

Dark Roasted Coffee

Experimental group

Description:

12 oz dark roast coffee beverage prepared at 55 g ground coffee/L water

Treatment:

Dietary Supplement: Dark Roasted Coffee