Welcome to the August 2020 edition of Research Extracts. “The Extracts” is designed to keep busy practitioners and savvy consumers up-to-date on the latest research on diet, nutrients, botanicals, the microbiome, the environment, and lifestyle approaches to good health. Our medical team, which includes NDs, MDs, PhDs, RDs, an MS, and an LAc, has summarized the essence of several of the most interesting studies.

The first three articles focus on the microbiome and/or dietary factors influencing obesity, metabolic syndrome, diabetes, and associated conditions: (1) the microbiome of an infant’s first stool can predict obesity, (2) the Mediterranean Diet can prevent diabetes and insulin resistance via the microbiome, (3) whole-fat dairy can decrease risk of metabolic syndrome, and (4) red light exposure can improve vision. You will also find a link to Hemp Evolution, a podcast channel featuring interviews with hemp experts.


Can the microbiome of a baby’s first stool predict childhood obesity?

The number of overweight and obese children is steadily increasing throughout the world, and for these children, the lifetime risk of obesity, hypertension, dyslipidemia, and type 2 diabetes is higher than for children of normal weight. In previous studies, the intestinal microbiome during the first two years of life has been associated with overweight/obesity status later in childhood. In addition, maternal use of antimicrobials during pregnancy, maternal BMI and weight gain before and during pregnancy, and the maternal microbiome are associated with the infant’s microbiome.

In this study, the research team wanted to determine whether meconium, the first stool passed by a newborn, could predict overweight/obesity later in childhood. First-pass meconium was collected from 212 infants, along with a follow-up stool sample at age one, and annual growth measures (height and weight) through age three.

The meconium microbiome for overweight included increased Bacteroidetes phylum (p=0.013) and decreased Proteobacteria (p=0.04) and Actinobacteria (p=0.02) phyla compared to normal weight children. In addition, Bacteroides genus was higher (p=0.01) and Enterococcus genus was lower (p=0.008) in the meconium of children who were overweight at age three, while Lactobacillus (p=0.04) was lower in overweight babies at their one-year stool follow-up. Meconium microbiome composition predicted the risk of being overweight at age three (p<0.001). 

Contributed by Jennifer L. Greer, ND, MEd

Reference

  • Korpela K, Renko M, Vänni P, et al. Microbiome of the first stool and overweight at age 3 years: A prospective cohort study. Pediatr Obes 2020 Juy 7:e12680. doi:10.1111/ijpo.12680

Are Mediterranean Diet benefits due to changes in SCFA’s in the gut microbiome?

Studies show that adhering to a Mediterranean dietary pattern is associated with lower risks of type 2 diabetes, cardiovascular disease, and all-cause mortality. Benefits seem to be mediated by the diet’s influence on body weight, blood pressure, and fasting lipid and glucose metabolism. While some studies have investigated single nutrient effects provided by the Mediterranean Diet, such as those associated with dietary fiber and monounsaturated fats, the effects of the whole dietary pattern on postprandial metabolism have not been explored.

In this study, 29 obese or overweight men and women, ages 20-60, were randomly assigned to two different dietary interventions: Mediterranean Diet or control for eight weeks. The control dietary intervention had typical features of a Western diet. Adherence to the dietary interventions was assessed by 7-day food records. Subjects were asked to maintain levels of physical activity throughout the study. The protocol was designed to maintain biometric measures throughout the study.

Biometric measurements of body weight, waist and hip circumferences, and blood pressure were measured at baseline, four, and eight weeks. Fasting blood samples and fecal samples for microbial composition were collected at baseline and every four weeks. Participants also underwent blood testing for postprandial blood glucose and lipid measurements over four hours after a test meal at baseline and study conclusion.

Biometric measurements were unchanged at the end of the study in both groups. Glucose and insulin responses at baseline were significantly reduced in the Mediterranean Diet test meal compared to the control meal – an effect that was magnified after eight weeks on the Mediterranean Diet. At the study’s conclusion, oral glucose insulin sensitivity was improved and postprandial plasma butyric acid was increased in the Mediterranean Diet group. In addition, significant changes were noted in gut microbiota in the Mediterranean Diet group compared to the control group. 

The study indicates that butyric acid and possibly other short-chain fatty acids impacted the effect of the Mediterranean Diet on postprandial glucose metabolism, insulin sensitivity, and improved gut microbiota measures.

Contributed by Amanda Frick, ND, LAc

Reference

  • Vitale M, Giacco R, Laiola M, et al. Acute and chronic improvement in postprandial glucose metabolism by a diet resembling the traditional Mediterranean dietary pattern: Can SCFAs play a role? Clin Nutr Published online June 3, 2020. doi:10.1016/j.clnu.2020.05.025

Looking for more information on metabolic syndrome and the Mediterranean Diet – including meal planning and recipes? Check out Thorne’s Metabolic Syndrome Patient Guide.


Counterintuitive association of whole-fat dairy with metabolic syndrome, hypertension, and diabetes

Data from the multi-national Prospective Urban Rural Epidemiology (PURE) study was used to investigate associations between dairy intake and incidence of metabolic syndrome (MetS), its common correlates hypertension and diabetes, and several markers of cardiovascular risk. Data was collected from 147,812 participants in 21 countries and spanned an average of nine years with follow-ups every three years.

After adjusting for covariates, at least two servings per day of dairy (high intake), compared to no dairy intake, was associated with lower mean blood pressure (systolic and diastolic), waist circumference, body mass index, triglyceride-to-HDL cholesterol ratio, and blood glucose. High dairy intake was also associated with lower incidence of metabolic syndrome, hypertension, and diabetes. These effects were greater with more whole-fat dairy compared to mixed whole/low-fat intake; there was no significant association for low-fat dairy alone. Dairy intake was not significantly associated with other tested markers, including HDL cholesterol alone. The type of dairy (milk, cheese, yogurt, butter) did not change the directionality of the associations. These effects were more noticeable in geographic regions with less typical dairy intake.

The authors concluded: “Higher intake of whole-fat (but not low-fat) dairy was associated with a lower prevalence of MetS and most of its component factors, and with a lower incidence of hypertension and diabetes.”

Contributed by Sheena Smith, MS MA

Reference

  • Bhavadharini B, Dehghan M, Mente A, et al. Association of dairy consumption with metabolic syndrome, hypertension and diabetes in 147,812 individuals from 21 countries. BMJ Open Diab Res Care 2020;8(1):e000826. doi:10.1136/bmjdrc-2019-000826
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Looking for nutritional support for metabolic syndrome or weight management?


Exposure to red light could improve vision in people over 40

As we age, mitochondrial density and function decrease in our cells. The rods and cones in the eye are particularly susceptible to aging because they are densely populated with mitochondria, which produce ATP for proper functioning. Color contrast (function of cones) diminishes, and a task like reading a menu in dim light (function of rods) becomes more difficult. Wavelengths of 650-1,000 nanometers (nm) have been shown to improve mitochondrial activity and ATP production in the retina. 

In this study, researchers examined retinal function in healthy adults (ages 28-72) before and after exposure to red light. After vision function tests, the participants were sent home with an apparatus that emitted a 670-nm wavelength light (deep red) and were instructed to gaze into the light three minutes daily for two weeks. 

Evaluation at the study’s beginning found retinal function was diminished in all participants older than 40. After two weeks, retinal function was re-examined. Although the red light had no effect on younger participants, those older than 40 had significant improvement in both cone function (color sensitivity) and rod function (ability to see in dim light) – with a 20-percent improvement in cone function.

Contributed by Kathi Head, ND 

Reference

Looking to support eye health? Consider Memoractiv®, which, in addition to nutrients and botanicals to promote mental focus and cognitive function, contains lutein and zeaxanthin (LuteMax® 2020) to protect the macula from the effects of blue-screen exposure. 


Hemp Evolution: podcasts with the experts

Do you want to hear about hemp from a true expert? The Hemp Evolution podcast features a series of interviews between nutritionist Carl Germano, CNS, CDN, Chris Kilham (also known as The Medicine Hunter), legal expert Marc Ullman, and renowned cannabinoid scientist, Ethan Russo, MD. The 15-minute conversations cover a range of topics from the history of Cannabis to current regulatory, quality, and health issues. 

Contributed by Jacqueline Jacques, ND

Link to access all episodes here.