10 studies from Experimental Biology that caught our eye Part 2: Omega-3s, lutein and mistletoe
First up in part 2 is a fascinating study from scientists from Tufts University, the University of Illinois at Urbana-Champaign, Oregon Health and Science University, and Abbott Nutrition about lutein, DHA and cognition.
As we’ve reported before, lutein is emerging as an important bioactive for brain health, and recent studies have reported that brain lutein and cognition may be dependent on brain levels of the omega-3 DHA (docosahexaenoic acid).
Data presented in San Diego showed that lutein and DHA are distributed differentially in brain regions controlling different domains of cognitive function.
“Co-localization of lutein and DHA in some membranes and regions, but not others, may be indicative of varied, and specific, functions of lutein in different brain regions,” wrote the researchers in The FASEB Journal. “Results from this study provide the first steps toward understanding lutein’s mechanism of action in the brain and its relationship to DHA.”
The study was supported financially by Abbott Nutrition through the Center for Nutrition, Learning, and Memory at the University of Illinois, DSM Nutritional Products, the USDA, and the NIH.
Omega-3s and MetS
The next study to catch our eye was from scientists at the Universidad Anahuac and the Mexican Institute of Social Security, who reported results from a randomized clinical trial with 226 obese adolescents.
At the start of the study, about 31% of participants in both groups met the criteria for metabolic syndrome (MetS), a condition characterized by central obesity, hypertension, and disturbed glucose and insulin metabolism.
After three months of supplementation with 1.2 grams per day of omega-3 long chain polyunsaturated fatty acids (LCPUFA), the frequency was still comparable between the groups. However, for those who did not have MetS at the start of the study, fewer developed it in the omega-3 group, compared with placebo (sunflower oil).
“The results of the study provide evidence that LCPUFA n-3 supplementation to obese adolescents protects against the risk to acquire MetS,” wrote the researchers in The FASEB Journal.
The study was funded by the Mexican Institute of Social Security.
DHA or EPA for cardiometabolic risk?
Scientists from Université Laval in Quebec City examined if DHA or EPA (eicosapentaenoic acid) exerted different effects on blood lipids and inflammatory markers in adults at risk of cardiovascular diseases.
Data from their double-blind, placebo-controlled crossover trial indicated that 3 grams per day of DHA was more effective than 3 grams per day of EPA for reducing diastolic blood pressure, triglyceride levels, HDL cholesterol levels, and levels of the pro-inflammatory interleukin-18 (IL-18). DHA also decreased levels of adiponectin levels more than EPA, said the researchers. Adiponectin is a protein hormone that plays an important role in the regulation of insulin sensitivity and energy.
“DHA is more effective than EPA in modulating blood lipids and inflammatory markers. Further studies are needed to determine the impact of a long term DHA supplementation on cardiovascular risk in men and women,” wrote the researchers in The FASEB Journal.
The study was funded by the Instituts de recherche en santé du Canada.
Mistletoe for age-related muscle loss?
Korean scientists reported that supplements containing Mistletoe (Viscum album L. var. coloratum Ohwi) may strengthen muscles and improve function in elderly subjects.
Data from their 12-week, double-blinded, randomized, parallel-group, placebo-controlled trial indicated that two grams per day of mistletoe resulted in significantly greater measures of muscle strength, compared with placebo.
A one gram per day dose of mistletoe was associated with improved physical performance (gait speed), compared with the 2 gram dose and the placebo group.
“Mistletoe was proven to beneficial role in muscle strength and function in older adults, regardless of its dose,” they concluded in The FASEB Journal. “In further study, the elucidation of molecular pathway which is associated with regulation of muscle biogenesis is needed to perform in biopsy muscle.”
Navy beans and gut health
The final study was presented by scientists from the University of Guelph and Agriculture and Agri-Food Canada, and looked the potential of cooked navy bean flour to impact the gut microbiota and modify the integrity of the gut barrier.
Lab mice were divided into four groups and fed a low or high fat diet with or without navy bean flour (20%) for 12 weeks. In the lean animals (low fat groups), adding navy bean flour to their diet did modify the abundance of specific gut microbial families, including increasing Prevotellaceae and decreasing Peptococcaceae, Streptococcaceae, Clostridiaceae, Rikenellaceae, and Porphyromonadaceae, compared to the low fat diet with no bean flour.
Gut barrier integrity and function was also improved by adding the bean flour to the low fat diet, with increased mucus production, anti-microbial defenses, and tight junction protein expression reported by the researchers.
The high-fat diet-fed animals developed obesity, they said, but adding the navy bean flour to the high fat diet improved the gut microbiota activity and community structure.
“Specifically, fecal abundance of Akkermansia muciniphila, whose abundance is inversely related to the severity of the obese phenotype, was increased in the [high fat diet + navy bean flour] group versus [high fat diet only] by 20-fold,” wrote the researchers. This was associated with reduce expression of various inflammatory mediators.
Gut barrier integrity was also improved in the high fat diet + navy bean flour group versus the high fat diet only group, they said.
“In conclusion, bean supplementation enhanced gut barrier integrity and exerted a beneficial colon-function priming effect that helps mitigate the severity of the obese phenotype,” they wrote in The FASEB Journal.
For more of our coverage of new science presented at Experimental Biology 2016, please follow the links below.
