Improved metabolic function and cognitive performance in middle-aged adults following a single dose of wild blueberry.

PURPOSE: Research has demonstrated cognitive benefits following acute polyphenol-rich berry consumption in children and young adults. Berry intake also has been associated with metabolic benefits. No study has yet examined cognitive performance in middle-aged adults. We investigated the relationships among cognitive and metabolic outcomes in middle-aged adults following wild blueberry (WBB) consumption. METHODS: Thirty-five individuals aged 40-65 years participated in a randomized, double blind, cross-over study. Participants consumed a breakfast meal and 1-cup equivalent WBB drink or matched placebo beverage on two occasions. Participants completed cognitive tasks and had blood drawn before and at regular intervals for 8 h after each meal/treatment. Changes in episodic memory and executive function (EF) were assessed alongside plasma levels of glucose, insulin, and triglyceride. RESULTS: Analysis of the memory-related Auditory Verbal Learning Task (AVLT) word recognition measure revealed a decrease in performance over the test day after placebo intake, whereas performance after WBB was maintained. For the AVLT word rejection measure, participants identified more foils following WBB in comparison to placebo. Benefits were also observed for EF on the Go/No-Go task with fewer errors following WBB intake on cognitively demanding invalid No-Go trials in comparison to placebo. Furthermore, in comparison to placebo, response times were faster for the Go/No-Go task, specifically at 4 h and 8 h following WBB treatment. We also observed reduced post-meal glucose and insulin, but not triglyceride, concentrations in comparison to placebo over the first 2 h following ingestion. Though the addition of Age, BMI, glucose and insulin as covariates to the analysis reduced the significant effect of beverage for AVLT word rejection, metabolic outcomes did not interact with treatment to predict cognitive performance with the exception of one isolated trend. CONCLUSIONS: This study indicated acute cognitive benefits of WBB intake in cognitively healthy middle-aged individuals, particularly in the context of demanding tasks and cognitive fatigue. WBB improved glucose and insulin responses to a meal. Further research is required to elucidate the underlying mechanism by which WBB improves cognitive function.

Assessing consumers' understanding of the term "Natural" on food labeling.

The objective of this study was to gain a better understanding of how consumers' interpret the term "natural" by assessing food choice based on labels describing attributes of a product associated with the term "natural"; to assess food intake of chosen food, and; to determine factors that influence food choice and intake. A randomized, single-visit pilot study was conducted where participants (n = 105) were presented with seven identical bowls of granola each bearing a different descriptive label. Participants were asked to choose and eat the granola (ad libitum) that coincided with what was closest to their view of "natural." Food choice, intake amount, demographics, self-health perception, label use, dietary restraint, and mindfulness were measured. "Organic" (31%), "Made with real grains" (17%), and "No preservatives" (15%) were the top three chosen labels. These choices related to concerns about environment and processing, personal health, and additives and preservatives, respectively (P = 0.049). Income level and age were significantly associated with choice (P = 0.003). Defining the term "natural" for use on food labels will require follow-up researchacrosseconomically diverse populations and age groups to understand expectations of food products bearing the term "natural."

Ratios of soluble and insoluble dietary fibers on satiety and energy intake in overweight pre- and postmenopausal women.

BACKGROUND: Fibers' properties impact different mechanisms involved in satiety and energy intake regulation and metabolic outcomes. OBJECTIVE: Evaluate the effect of fiber types and menopausal status on satiety and metabolic responses in overweight women. METHODS: In a randomized within-subjects design, 19 overweight/obese women [9 premenopausal and 10 postmenopausal] consumed 3 preloads that varied by fiber content and source: 1) 3:1 ratio of soluble:insoluble fiber (SF), 2) 1:3 ratio of soluble:insoluble fiber (IF), 3) no fiber control (NFC). Subjective satiety, cholecystokinin (CCK), glucose, insulin, and triglyceride (TG) were measured for 3 h post-preload followed by in-lab ad libitum test meal and 32 hour food intake monitoring. RESULTS: Significant preload, time and preload by menopausal status interaction was apparent for hunger and fullness (p < 0.05 for both) with SF preload predominantly more satiating in postmenopausal women. CCK and insulin were significantly lower after SF preload (p < 0.0001 for both). Post-preload glucose responses differed by menopausal status: postmenopausal women distinguished between fiber types unlike premenopausal women (p = 0.02). TG was significantly elevated after the IF preload compared to NFC and SF (p = 0.007 and p = 0.008, respectively). CONCLUSIONS:Customized/personalized dietary recommendations for women during their premenopausal and postmenopausal years can help maximize metabolic and appetite control.

A Randomized, Controlled Trial Evaluating Polydextrose as a Fiber in a Wet and Dry Matrix on Glycemic Control.

Functional fibers can help Americans increase their fiber intake by incorporating extracted or synthesized fibers into food products. The United States Food and Drug Administration has recently proposed that "added" fibers must demonstrate a physiological health benefit, such as glucose control, to be included on the Nutrition Facts label as a dietary fiber. The objective of this study was to assess the effects of polydextrose (PDX), a water-soluble glucose polymer resistant to mammalian digestion, on postprandial glucose concentrations when added to relatively high moisture (beverage) versus low moisture (bar) food products. The study was designed as 2 parts with each being controlled, randomized, singe-blinded, cross-over trials. A total of 34 and 19 healthy subjects were asked to consume PDX in a beverage and bar, respectively. PDX was investigated at 0, 8, 12, and 16 g in the beverage and 0 and 12 g in the bar. Blood samples were collected before beverage/bar consumption and for 3 h thereafter to evaluate changes in plasma glucose and insulin concentrations. The 12 g PDX condition had significant impact on both outcomes as glucose was significantly increased in both matrices (P > 0.05) and insulin was increased in bar form only (P > 0.05). PDX was well tolerated at all dosages and matrices investigated. PDX did not lower postprandial glucose or insulin in either matrix at the doses provided; therefore, data do not support reporting PDX as a dietary fiber on the Nutrition Facts label under the current proposed rule using glycemic control as the endpoint for physiological benefit.

Postprandial lipemia in pre- and postmenopausal women.

BACKGROUND AND OBJECTIVE: The increased risk for coronary artery disease observed in postmenopausal (PoW) women is partly explained by a more atherogenic lipoprotein profile. Moreover, natural menopause has been associated with an altered postprandial lipid profile. This study was designed to test the hypothesis that young premenopausal (PrW) and PoW may be independently associated with postprandial lipemia and indirectly associated with atherosclerosis. PATIENTS AND METHODS: A total of 46 healthy PrW and 44 healthy PoW participated in a 5-h intervention study. Blood samples were taken at the baseline and at 1, 2, 3, and 4 h after eating. Total cholesterol, LDL-cholesterol, HDL-cholesterol, fasting, and postprandial triglycerides (PPTG) were determined sequentially in blood samples. RESULTS: PPTG presented significant higher values in PoW compared to PrW (P < 0.05), but other lipids did not significantly differ between groups. PPTG concentrations in PoW were significantly higher than in PrW (P < 0.05). There was a significant time influence (P < 0.05) in TG in PrW and PoW, while time to peak and peak concentration were significantly higher in PoW than PrW. Other lipids were also decreased more in PrW than PoW, but not significantly so. Cholesterol concentrations showed a significant reduction after 2 h, to reach values similar to the baseline after 4 h in PrW but not in PoW. HDL-cholesterol concentration was decreased more in PoW compared to PrW but it was not significant. CONCLUSIONS: Lipid postprandial response indicates a higher cardiovascular risk pattern in PoW compared to PrW.