Welcome to the last 2021 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 interesting recent studies.

In this issue you will find new studies on: (1) chocolate for improving mood, (2) coffee for cognitive support, (3) socioeconomic effects on metabolic syndrome, and (4) the effect of drinking water on your gut microbiome.

If you’re tired of hearing people tell you that some of your favorite foods and beverages aren’t good for you, then you’ll no doubt appreciate the first two studies. In addition, the first and the last studies showcase the importance of the gut microbiome’s wide-ranging effects on health.

Thorne Mental Health Moment: Chocolate, Mood, and the Microbiome

It’s possible you have had an experience of chocolate making you feel better – maybe chocolate is something you reach for when you’re feeling blue or having a bad day. Researchers are taking an interest in this phenomenon – they’re trying to understand if the connection is something that could have value in promoting mental well-being. Studies show that individuals with low or depressed mood are motivated to consume chocolate,1 while other studies show significantly improved mood following chocolate consumption.2

Researchers are honing in on cocoa polyphenols – the antioxidant component most concentrated in dark chocolate – as the likely active ingredient that supports mood.3 One question remains however – how does this work? Some research suggests that cocoa polyphenols improve mood by promoting a healthy inflammatory response in the brain. Cocoa constituents have also been shown to be neuroprotective and improve blood flow to the brain.4

This new study suggests the microbiome might play an important role in the connection between chocolate consumption and improved mood.5 Researchers are taking an increasing interest in how gut bacteria can transform components of food into bioactive compounds that impact various areas of health. In this Korean study, three groups of healthy young adults ate chocolate with 70-percent polyphenols, or chocolate with 85-percent polyphenols, or no chocolate (control group). Two standardized questionnaires (The Positive and Negative Affect Schedule [PANAS] and Beck Depression Inventory) were used to assess mood, and subjects had tests conducted to evaluate their microbiome via genomic sequencing. Body composition was also assessed because it can impact the microbiome; subjects kept a diet diary so total intake of calories, protein, fat, and carbohydrate could be assessed.

Overall, there were no significant differences between the 70-percent polyphenol group and the control group. But the 85-percent group showed significantly reduced negative emotional states as measured by PANAS. This same group also demonstrated more microbiome diversity, with higher levels of Blautia obeum and lower levels of Faecalibacterium prausnitzii. Based on these findings, the researchers suggest that high-polyphenol dark chocolate might be influencing mood via the microbiome. Polyphenols such as those in chocolate are known to have prebiotic effects6 – meaning they can influence the type and amount of bacteria and other organisms that make up the microbiome. In this case, it appears the shift resulting from high-polyphenol dark chocolate resulted in microbiome changes that could contribute to the production of mood-supportive compounds. Although more research is needed to further examine this connection, it adds to the body of evidence for both dark chocolate and the microbiome playing a role in a healthy emotional state.

How healthy is your microbiome. Get some insights with Thorne’s at-home Gut Health Test.

Contributed by Jacqueline Jacques, ND


  1. Willner P, Benton D, Brown E, et al. “Depression” increases “craving” for sweet rewards in animal and human models of depression and craving. Psychopharmacology (Berl). 1998;136(3):272-283. doi:10.1007/s002130050566
  2. Macht M, Mueller J. Immediate effects of chocolate on experimentally induced mood states. Appetite. 2007;49(3):667-674. doi:10.1016/j.appet.2007.05.004
  3. Smith DF. Benefits of flavanol-rich cocoa-derived products for mental well-being: A review. J Funct Foods. 2013;5(1):10-15. doi:10.1016/j.jff.2012.09.002
  4. Sokolov AN, Pavlova MA, Klosterhalfen S, Enck P. Chocolate and the brain: Neurobiological impact of cocoa flavanols on cognition and behavior. Neurosci Biobehav Rev. 2013;37(10, Part 2):2445-2453. doi:10.1016/j.neubiorev.2013.06.013
  5. Shin JH, Kim CS, Cha L, et al. Consumption of 85% cocoa dark chocolate improves mood in association with gut microbial changes in healthy adults: a randomized controlled trial. J Nutr Biochem. 2022 Jan;99:108854. doi: 10.1016/j.jnutbio.2021.108854.
  6. Sorrenti V, Ali S, Mancin L, et al. Cocoa polyphenols and gut microbiota interplay: bioavailability, prebiotic effect, and impact on human health. Nutrients. 2020;12(7):1908. doi:10.3390/nu12071908

Coffee Can Slow Cognitive Decline

Gone are the days of dissing coffee. Although coffee got a bad rap for years, recent studies have found several health benefits associated with moderate coffee consumption. We have reported on some of these in past Research Extracts, including coffee consumption and: (1) decreased risk of overall mortality in diabetes, (2) reduced risk of colon cancer, (3) decreased risk for type 2 diabetes – filtered but not unfiltered coffee, and (4) decreased risk for heart failure – caffeinated but not decaffeinated coffee.

This study looked at coffee’s effect on brain function in 227 Australian adults ages 60 or older with normal cognitive function. At baseline, they filled out a food frequency questionnaire, which included coffee consumption. They were then followed for 26 months (over 10 years) and participated in a battery of cognitive function tests. A subset of 60 participants were also tested periodically with PET scans for assessment of beta-amyloid (proteins that form brain plaque in Alzheimer’s disease) accumulation in the brain and with MRIs to test for grey and white matter and hippocampal volume. These results were compared with coffee consumption measured in grams of brewed coffee per day (the researchers considered one cup to be 240 grams). The lowest third of coffee consumers drank 0-26 grams daily (averaging far less than one cup daily), the middle third drank 36-250 grams daily (less than or equal to one cup daily), and the highest third drank 360-750 grams daily (between a cup and a half and three cups daily).

Higher coffee consumption was associated with significantly slower cognitive decline in executive function, attention, and early signs of Alzheimer’s disease over the follow-up period. In addition, the highest one-third had the least accumulation of beta-amyloid. These results support previous research that found drinking 1-2 cups of coffee daily is associated with decreased risk for a cognitive disorder and drinking 2+ cups daily is associated with decreased beta-amyloid accumulation. There was no effect of coffee consumption on grey or white matter or hippocampal volume. Whether the coffee was caffeinated or not and method of brewing were not considered in the study.

The authors conclude that “increased coffee consumption could contribute to slower cognitive decline potentially by slowing the rate of cerebral beta-amyloid accumulation, and in doing so, ameliorate the associated neurotoxicity from beta-amyloid-mediated oxidative stress and inflammatory processes.”

Although this study did not establish caffeine as a contributing factor, other studies have found caffeine is partially responsible for the brain-supportive effects of coffee. Explore Thorne’s Memoractiv, which combines unique nutrients and botanical ingredients with PURENERGY (a low-dose caffeine/pterostilbene complex) to help maintain mental edge.*

Contributed by Kathi Head, ND


Socioeconomic Differences and Metabolic Syndrome Remission

The rate of metabolic syndrome (MetS) incidence among adults has been shown to have an inverse association with socioeconomic position (SEP) – i.e., those with a higher SEP tend to have lower rates of MetS, while those with a lower SEP tend to have higher rates of MetS. However, socioeconomic differences and MetS remission has not been well studied.

To better understand the relationship between SEP and MetS remission, a subsample from the Lifelines Cohort Study – a study of health and health related behaviors from 167,000 individuals across three generations – was analyzed. SEP variables in the study included years of education, net household income, and occupational prestige. MetS remission occurred when no more than two MetS components were present at follow-up (high waist circumference, elevated blood pressure, elevated triglycerides, low HDL level, fasting glucose ≥ 100 mg/dL). Additional health behaviors included physical activity, smoking status, alcohol intake, and diet quality. Variables were assessed at baseline and follow-up, an average of 3.8 years later.

At follow-up, 42.7 percent of participants had experienced remission from MetS. Although years of education and higher household income were individually associated with MetS remission, occupational prestige was not. The authors note that those with higher levels of education were likely to have experienced MetS remission due to an increase in healthier behaviors; however, for those with higher income, MetS remission occurred regardless of health behaviors. This is an important distinction because interventions focused on health behaviors might not be sufficient to achieve MetS remission for all SEP variables, and future research should focus on other modifiable factors related to SEP.

Want lifestyle guidance regarding metabolic syndrome? Check out Thorne’s Metabolic Syndrome Guide at thorne.com. Thorne also has supportive products, including our new Metabolic Health capsules and metabolic-supportive protein power – MediBolic.*

Contributed by Jennifer L. Greer, ND, MEd


Drinking Water Source and Intake Are Associated with Distinct Gut Microbiota Signatures

Although environmental exposure, dietary intake, and lifestyle factors are the largest influencers on the human microbiome composition, the effect of drinking water on the gut microbiome is poorly understood. The adequate intake for daily water consumption set by the Institute of Medicine is 2.7 liters and 3.7 liters for women and men, respectively, and suggests 70-80 percent should come from plain drinking water and other beverages. Water pH, solute and mineral composition, natural intrinsic microbiome communities, and residual chlorine and disinfection byproducts remain in most tap waters, likely impacting our microbiome composition. 

In this study, participants were selected from the Artifact Genome Project database managed by researchers at the University of California, San Diego. Only samples with complete profiles and food frequency questionnaire data were considered, but were further filtered by age, geographical location, and antibiotic use. Subjects (n=3,413) for the drinking water source (bottled, city filtered, or well) analysis and 3,794 subjects for the drinking water intake (grouped as high and low drinkers) were included, and microbiome samples were analyzed using 16s sequencing. 

The analysis found microbiome alpha-diversity was highest in subjects who drank mostly well water compared to other sources. There were differences in beta-diversity between drinking water sources, and the highest variance between groups was comparing bottled with well water. Bottled and city water drinkers were enriched with Bacteroides, Odoribacter, Streptococcus, Veillonella, and Fusobacterium genera compared with well-water drinkers. Well-water drinkers had higher Dorea genus than city and filtered water drinkers. Bottled water drinkers were enriched with different genera from the Lachnospiraceae family compared to city-water drinkers. And Campylobacter was abundant in the low drinkers. 

The researchers conclude that water source ranks among the key contributing factors explaining gut microbiota variation, with effect sizes comparable to alcohol intake and diet type. Although this study was limited by its inability to account for delivery mode, the presence of chronic diseases, and used 16s rRNA gene data, which limits taxonomy resolution, it was a large sample size and is the first to explore the impact water has on the gut microbiome. 

Interested in how your diet, environment, and lifestyle habits impact your microbiome? Take Thorne’s at-home Gut Health Test to measure your beta-diversity and learn your levels of the bacteria highlighted in this study.

Contributed by Laura Kunces, PhD, RD