The Nugget
- 🫐 75g of blueberries consumed with a high-carb, low-fat breakfast significantly increased serum antioxidant capacity and lipoprotein oxidation protection versus a sugar/ascorbate control.
Make it stick
- 🍽️ Protecting against oxidation after meals may prevent cardiovascular disease development
- 🥄 Even a modest 1/2 cup serving of blueberries was enough for significant postprandial oxidative protection
- 🫐 The antioxidant effects are likely due to blueberry phenolic compounds, not just the fructose or vitamin C content
Protocol
- 14 healthy participants consumed meals with a control (fructose/ascorbic acid), 35g, or 75g freeze-dried blueberries in a crossover design
- Serum collected at fasting baseline and 1, 2, 3 hours postprandially
- Measured serum antioxidant capacity (ORAC), lipoprotein oxidation, urate, ascorbate, and glucose
- Randomized controlled trial with crossover design; 75g dose reached statistical significance vs control for serum ORAC
Terminology
- ORAC: Oxygen radical absorbance capacity; a measure of total antioxidant capacity
- Phenolic compounds: Bioactive compounds in blueberries like anthocyanins, quercetin, chlorogenic acid
- Postprandial: The period after consuming a meal
- Lipoprotein oxidation: Oxidative damage to lipoproteins that can lead to atherosclerosis
Key insights
Postprandial oxidation and CVD
- Blood sugar and insulin increase after meals, leading to more free radical production
- This postprandial oxidation can damage arteries and lipoproteins over time, contributing to cardiovascular disease development
- Protecting against this oxidative stress after meals with antioxidant-rich foods like blueberries may help prevent CVD
Blueberry dose and antioxidant effects
- The 75g blueberry dose significantly increased serum antioxidant capacity (ORAC) vs control for the first 2 hours
- Even the 35g dose showed a positive lipoprotein oxidation lag time trend over 3 hours
- This suggests a practical 1/2 cup serving of blueberries can provide meaningful postprandial antioxidant protection
Phenolics vs sugars/vitamin C
- The antioxidant effects were likely from blueberry phenolic compounds, not fructose or ascorbic acid
- The sugar and vitamin C levels in blueberries were too low to account for the increased serum antioxidant capacity
- This is the first study to demonstrate blueberries' postprandial benefits are independent of sugars or vitamin C content
Key quotes
- "A practically consumable quantity of blueberries (75 g) can provide statistically significant oxidative protection in vivo after a high-carbohydrate, low-fat breakfast."
- "Serum lipoprotein oxidation demonstrated a positive trend among both blueberry groups."
- "To our knowledge, this is the first report that has demonstrated that increased serum antioxidant capacity is not attributable to the fructose or ascorbate content of blueberries."
- "It is likely that the effects are due to phenolic compounds, either directly or indirectly, as they are a major family of compounds in blueberries with potential bioactive activity."
This summary contains AI-generated information and may have important inaccuracies or omissions.