1a.Objectives (from AD-416):
The overall goal of the proposed studies is to determine whether high fat meal-induced postprandial lipemia (a single meal experimental protocol) causes monocyte activation, cerebral inflammation and alteration in patterns of brain activity associated with performing memory tasks, and whether concomitant blueberry intake alleviates such pathophysiological consequences of ingesting a high fat meal in healthy human subjects.
1b.Approach (from AD-416):
Our experimental approaches are: first, to determine whether single high fat meal
induces monocyte activation in healthy subjects, and whether the monocyte activation leads to microglial cell activation and alteration of neural activity as assessed by fMRI of brain, and then whether blueberry supplementation suppresses monocyte and microglial cell activation, and restores the alteration of neural activity.
This is the final report for this project which terminated in September of 2013. The research relates to objective 3 of the inhouse project “Prepare transgenic mice in which Toll-like receptor 4 (TLR4) is over-expressed in adipose tissue. Then, determine whether enhanced inflammation in adipose tissue induced by over-expression of TLR4 promotes the development of insulin resistance, and ehther dietary n-3 PUFAs ameliorate these processes". In objective 3 of the inhouse project, we proposed to study the anti-inflammatory efficacy of phytochemicals in transgenic mice if extramural funds became available. This research, funded by the U.S. Highbush Blueberry Council, studies the anti-inflammatory effects of blueberry powder (a source of phytochemicals) in human subjects instead of mice. Twenty-three healthy subjects have been studied with consumption of placebo, 2 or 4 servings of blueberry powder along with a moderately high-fat single meal to determine whether blueberry powder intake attenuates monocyte activation induced by such a meal. The study found the following:
Four servings of blueberry powder significantly reduced IL-6 levels in postprandial plasma compared to fasting plasma (p=0.043). Postprandial whole blood showed a significant elevation of IL-1b levels compared to fasting whole blood (p<0.0001). Four servings of blueberry powder showed a trend to reduce IL-1b levels in postprandial blood (p=0.08). Intake of blueberry powder did not affect the postprandial plasma levels of TNF-a, IL-6, and IL-8. Overall, these results suggest that blueberry supplementation tends to reduce monocyte activation induced by a moderately high-fat meal, which could have benefits in reducing the risk of diet-induced, chronic inflammatory disease.