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Wine and the brain

Want to be brainy and avoid dementia? Become a wine expert as Sommeliers brains are larger, including parts of the brain responsible for memory

A year ago or so I was watching a fascinating documentary on the BBC by David Eagleman, "The Brain", and subsequently read his excellent books. It amazing that we take our brain for granted but experience from those experiencing a starvation of input and sensory information e.g. "the Hole" dark punishment cells in prisons such as Alcatraz and lack of developmental input e.g. kids in Romanian orphanages shows what can happen.

When we are born we have roughly the same number of brain cells as in later life but it is the way these cells are wired together is the key. The importance of nurturing the brain during childhood and teenage years helps the brain sort out what is important and what isn't.

Mental gymnastics, a rewarding job and rich social life all seem to delay or prevent dementia. Importantly we can  adapt our brains because of something called "plasticity" through what we do and for example specialists like a London Taxi driver, a concert piannist or even a wine expert all have important structural changes in their brains because of what they do, learn and practice.

Eagleman uses the analogy of the toolbox when overcoming deterioration in the brain and discusses a phenomenon to prevent dementia/Alzheimers called "celebral reserve". He says even if the wrench is broken, we can use a different spanner in the box to do the same task. So elderly sisters in a convent in the United States had physical signs of Alzheimer's disease in the brain when they died e.g. protein anomalies but exhibited no obvious symptoms since they led an active mental life and their brains were able to adapt and "use a different spanner".

Eagleman discusses the basis of reality and the fact that we see, feel, hear, smell is the brain's perception of reality called the "internal model". This brain simulation is like the movie the Matrix as it evokes its perception of the outside world.

The big lesson is that the more you put into your brain, just like training your muscles in a gym, the better the condition and resilience of your brain.

More on brain or "cerebral reserve"

cross word puzzle

The concept of brain or cebrealreserve refers to the ability to tolerate the age-related changes and the disease related changes in the brain without developing clear clinical symptoms or signs of dementia. A considerable amount of biological research has documented that a number of factors including education, work complexity, social network, and leisure activities may contribute to this reserve allowing cognitive brain function to be maintained in old age.  Epidemiological studies have suggest that intellectual challenges experienced across the whole life span may increase the brain reserve and be crucial for preventing the occurrence of dementia symptoms in late life.

The factors that can help boost your brain or cerebral reserve are high education, adult-life occupational work complexity, as well as a mentally and socially integrated lifestyle in late life. All these factors could postpone the onset of clinical dementia and Alzheimers Disease.

The relevance of physical activity itself remains in debate, as most physical activities include also social and mental stimulation. Leisure activities with all three components--physical, mental and social--seem to have the most beneficial effect. 

The Sommelier and brain study in detail

Several studies have assessed the development of new skills in adulthood and associated changes in brain structure. Areas of expertise such as taxi driving and hippocampal volume , juggling and visual and motor regions of the cortex, musicians and the auditory cortex and more recently expertise in perfume has been associated with olfactory regions of the frontal lobe

Similarly, there have been studies looking at distinct functional activation patterns in experts. For example, musicians show a distinct pattern of prefrontal activity compared with non-musicians when listening to different rhythms and sommeliers, or wine experts, showed enhanced regions of the memory network when tasting wines.

Sommeliers’ brains are of particular interest since their expertise is focused on the smell (olfaction ) and taste (gustation), and associated with multiple other functions including memory, judgement, and the amalgamation of this with other senses.

The olfactory regions of the brain are relevant to diseases such as Alzheimer’s and Parkinson’s, where initial degeneration of the brain cells called neurones are isolated to regions important in smell. Furthermore, given that sommeliers are experts not just in a single domain but combine these in an integrating sensory information system.

MRI scanner

In 2016, researchers from the University of Las Vegas in Nevada conducted MRI scans on Masters of Wine to access structural changes in their brain.

This was published in Front. Hum. Neurosci., 22 August 2016

Structural and Functional MRI Differences in Master Sommeliers: A Pilot Study on Expertise in the Brain

Sarah J. Banks*, Karthik R. Sreenivasan, David M. Weintraub, Deanna Baldock, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA

What does the Sommelier brain study show?

This study identified enhanced structural and functional patterns in the smell or olfactory network of sommeliers. These findings are consistent with the learning they undergo in achieving the status of Master Sommelier. Furthermore, the volume of a region of the brain involved in olfactory memory was associated with experience, suggesting that the continued training results in morphological changes of the brain. These results speak to the plasticity of the adult brain in response to sensory expertise. Future research into therapeutic sensory-cognitive training in individuals at risk from neurodegenerative diseases, such as Alzheimer’s or Parkinson’s, which impact the same regions of the limbic system and entorhinal cortex, might provide an important clinical application of these results.

Changes to the brain in sommeliers

Enhanced Volume of the Right Insula

The dorsal subregion of the insula was found to be larger in volume in sommeliers. This is thought to be due to the importance of this region in combining multisensory and higher order cognitive processes, activities that sommeliers practice throughout their training and work. 

Enhanced Activation in Sommeliers Compared with Controls

Multiple regions showed an interaction between group and task, that appeared to be driven by more activity in sommeliers than controls, specifically during the olfactory judgment task.

We assume that the enhanced, more widespread, activation in sommeliers implies more complex processing of the same information. Overall, there was somewhat more activation in the right hemisphere of sommeliers compared with controls. This is consistent with earlier studies that suggest right hemispheric dominance for olfaction and olfactory memory (Jones-Gotman and Zatorre, 1993). 

The visual region enhancements both in the main effect of group (sommeliers more than controls) and in the interaction are interesting, this could be due to training of master sommeliers to use multiple senses while learning about wine, and to use imagery (e.g., of the fruit and vegetable section of a grocery store) when blind tasting5. This might explain the apparently enhanced activation of these regions in sommeliers during the olfactory task.

There was no relationship between enhanced functional activation and years of experience. The regions that were different were more specifically related to olfactory memory and cross modal integration, and it might be that these are the particular strengths that are enhanced in sommeliers.

More about the Sommelier brain study for those interested

Design

After Institutional Review Board (IRB) approval from the University of Nevada Las Vegas (UNLV), a preliminary selection of possible stimuli was conducted with UNLV students. Twelve male participants between the ages of 21–33 were recruited to participate. Following informed consent, participants were given the wine knowledge test. For this pilot study, only participants scoring below 70% were included. Eight non-wine blends were made by mixing varying amounts of vodka, cognac, Fusion brand versus (a non-alcoholic grape juice made from the same grapes as many wines), fruit essences and in some cases water-soaked oak chips. Participants were blindfolded using a cloth sleep mask. The researcher held a glass jar containing either wine or a non-wine underneath the participant’s nose and instructed the participant to inhale through their nostrils. During the first task, participants were asked to tell the researcher if they smelled a wine or a non-wine.

During the second task, participants were asked to tell the researcher if they smelled a white or a red wine. Four white wines and four red wines were included. All jars during both tasks were chosen at random. Immediately following the olfaction tasks, participants were led to a computer and asked to rapidly categorise variably pixilated pictures of zebra patterns or fingerprints to allow the researchers to match this visual task with the olfactory tasks on difficulty of identification.

Participant Selection and Recruitment

Master Sommeliers were recruited with the assistance of JJ, Master Sommelier and extensively involved in both training of sommeliers and in the local community. After being approached informally by him and allowing their contact details to be shared, they were contacted by DB or SB to ascertain interest. All Master Sommeliers were considered eligible. The Court of Master Sommeliers provides a diploma to those who pass their four-stage examination process2. There are only 219 Master Sommeliers worldwide, all of whom have passed this process that takes several years. By including only individuals with this distinction, we could be assured that we were assessing true experts. However, this restriction did limit the number of sommeliers who we could include, and hence posed a limit to the potential sample size.

Results - Non scanner

Scores on the wine knowledge quiz ranged from 20 to 70% with a mean of 45%. Participants were able to distinguish between wines and non-wines with accuracy, ranging from 58 to 100%. Accuracy in distinguishing white wines from red wines varied from 25 to 91%. Accuracy at distinguishing between zebra patterns and fingerprints varied from 93 to 100%. Stimuli were selected based on participant accuracy. 

 Interesting that for the UPSIT control and Sommelier scores were similar

Interesting that for the UPSIT control and Sommelier scores were similar

General olfactory ability was evaluated using the University of Pennsylvania Smell Identification Test (UPSIT; Doty et al., 1984). The test consists of a booklet containing a series of standardized microencapsulated odorants. Scratching the paper releases each odor, which must then be identified by the participant (i.e., “scratch and sniff”). Results of this test indicate the degree to which individuals can identify smells in a forced-choice scenario.

Wine knowledge was assessed using the wine quiz. The wine quiz is a 10-item questionnaire developed for this project by MEP. The quiz contains questions about varietals, terroir, origin and tasting techniques.

Results - MRI

Enhanced Volume of the Entorhinal Cortex

Given the importance of the region to olfactory memory, this finding was expected. Sommeliers spend years learning about the olfactory qualities and other aspects of wine, and no doubt draw on that memory whenever they make a judgment about wine. We further found a relationship between years of experience and cortical thickness of the right entorhinal cortex. In many ways, this finding echoes that of Maguire et al. (2000) in taxi drivers who show enlargement of hippocampal regions with driving experience. It is also similar to the earlier finding of Delon-Martin et al. (2013) in perfumers, who showed increased size of the piriform cortex, a region of olfactory cortex directly adjacent to the entorhinal cortex. Furthermore, although we larger volume of this region bilaterally, compared with controls, the volume of the right hemisphere was larger than the left, consistent with early research on hemispheric lateralization of olfactory memory (Jones-Gotman and Zatorre, 1993). The entorhinal cortex may additionally be involved in more primary odor perception or identification tasks in addition (Wilson et al., 2014), which would also be highly relevant to a sommelier’s experience and skills. Given this region’s sensitivity to aging and neurodegenerative disease, it is especially interesting that we found this result comparing an older group of sommeliers with younger controls.

Enhanced Volume of the Right Insula

The dorsal subregion of the insula was found to be larger in volume in sommeliers. This is thought to be due to the importance of this region in combining multisensory and higher order cognitive processes, activities that sommeliers practice throughout their training and work. The cortical thickness of this region had no relationship with experience, however, which is interesting in comparison to the finding with the entorhinal cortex. It may be that this region changes early in the training process and then plateaus, or that only part of this heterogeneous region responds to cross-modal sensory expertise. Longitudinal studies would be needed to further explore the relative impact of training on different regions. Further study regarding the particular role of subregions of the insula in cross-modal expertise would also be of interest.

Enhanced Activation in Sommeliers Compared with Controls

Multiple regions showed an interaction between group and task, that appeared to be driven by more activity in sommeliers than controls, specifically during the olfactory judgment task. Importantly, task performance was similar between the two groups, making us more confident in the activation differences. We made the tasks similar enough to sommeliers’ work to be meaningful, but also wanted the tasks to require a similar amount of attention in both groups, thus made the tasks entirely novel (i.e., not discriminating types of wine, but rather wine from non-wine). These regions included olfactory, limbic, visual imagery, and multimodal regions. They are similar to those reported in an earlier study with fewer subjects comparing the taste and after-taste of wine and water in sommeliers compared with controls (Delon-Martin et al., 2013; Pazart et al., 2014). We assume that the enhanced, more widespread, activation in sommeliers implies more complex processing of the same information. Overall, there was somewhat more activation in the right hemisphere of sommeliers compared with controls. This is consistent with earlier studies that suggest right hemispheric dominance for olfaction and olfactory memory (Jones-Gotman and Zatorre, 1993). There were some left hemisphere differences in the interaction, always with analogous differences in the right hemisphere, specifically, in the hippocampus, lingual gyrus and precuneus. Previous fMRI studies of taste in sommeliers have also shown mixed lateralization: one study comparing tasting of wine vs. glucose showed more left insula activity compared with controls during the after-taste period (Castriota-Scanderbeg et al., 2005), while the study by Pazart et al. (2014) showed enhanced right but not left anterior insula activation during tasting but not during aftertaste.

The visual region enhancements both in the main effect of group (sommeliers more than controls) and in the interaction are interesting, this could be due to training of master sommeliers to use multiple senses while learning about wine, and to use imagery (e.g., of the fruit and vegetable section of a grocery store) when blind tasting5. This might explain the apparently enhanced activation of these regions in sommeliers during the olfactory task.

We did not demonstrate a difference in activation over the piriform [which we consider to be part of the olfactory cortex (Zatorre et al., 1992) although one cluster extended into the olfactory cortex though only by a few voxels.] in the interaction. Others have noted the inconsistency of imaging studies in olfaction to specifically demonstrate piriform involvement (Zald and Pardo, 2000) although an alternative explanation here might be that this primary olfactory cortex is equally activated by both groups.

From its comparison to activation during a complex visual discrimination task, our results support the specificity of the enhanced activation seen during the olfactory discrimination tasks, and particularly so in sommeliers. While the olfactory network enhancement makes intuitive sense, the result of the current study point to the specificity of this finding. Had we not included this visual control task, one could argue that the Master Sommeliers attended more to perceptual judgment tasks in general, and that this was not specific to tasks involving olfactory stimuli. Our use of a visual judgment task as a comparison provides evidence for the specificity of enhanced cortical activation during processes involving chemical senses in sommeliers.

There was no relationship between enhanced functional activation and years of experience. Future longitudinal studies will be important in learning more about the interrelationship between activation intensity and experience. There may be a causal relationship with those regions that show enhanced activity early in the training process showing enhanced volume or thickness over time. Similarly, we did not find any significant differences in certain parts of the olfactory network including the orbitofrontal cortex. The regions that were different were more specifically related to olfactory memory and cross modal integration, and it might be that these are the particular strengths that are enhanced in sommeliers, however, future research and direct comparison with other olfactory experts such as perfumers might be important to further disentangle the regions that could be specifically enhanced in one expert group over another.