Category Archives: Mental Health and Cognition

The Mediterranean Diet is Associated with Decreased Cognitive Decline: A Review of Current Literature

The Mediterranean Diet, and other health diets in general, have been shown to be associated with decreased cognitive decline as well as decreased risk of developing dementia.

Photo by Flickr user  Vince Alongi (https://www.flickr.com/photos/vincealongi/233836385)
Photo by Flickr user Vince Alongi (https://www.flickr.com/photos/vincealongi/233836385)

A new review study, published in the journal Advances in Nutrition aimed to collect all the research (in the human model) through May 2014 related to diet, cognitive decline, and dementia, in order to get a better understanding of the relationship between diet and this kind of mental health.

6 cross-sectional, 12 longitudinal, 1 trial, and 3 meta-analysis studies related to diet and cognitive decline or dementia were evaluated for this review.

Important Findings:

  • Stronger adherence to the Mediterranean diet was associated with significantly less cognitive decline and decreased incidence of dementia or Alzheimer’s disease across 14 of studies (out of 22) on the subject through May 2014.
  • Those studies not focused solely on the Mediterranean diet but other healthy diets in general also found significant associations between adherence to healthy eating and declines in cognitive dysfunction including decreased risk of dementia (found in all 6 cross-sectional studies and 6 of 8 longitudinal studies).

While results were not sweeping across the board, most of the studies included in this review agreed and showed that the

Photo by Flickr user  Fechi Fajardo (https://www.flickr.com/photos/37078205@N06/4340759130)
Photo by Flickr user Fechi Fajardo (https://www.flickr.com/photos/37078205@N06/4340759130)

Mediterranean Diet, or otherwise healthy diet, decreased the risk of cognitive decline, dementia, or Alzheimer’s disease.

Despite this majority finding, more research needs to be done to get a better understand of the discrepancies in the other studies that did not find similar results, in case the results are something greater than simple population variability.

Source:

van de Rest, O., Berendsen, A.A.M., Haveman-Nies, A., and de Groot, L.C.P.G.M. 2015. Dietary patterns, cognitive decline, and dementia: A systematic review. Advances in Nutrition 6: 154-168.

Adding To the Inconsistencies in Research: There May Be More to Reducing Risk of Cognitive Dysfunction Than Diet Alone

As we’ve seen before here on The French Paradox, diet can have a significant effect on mental health and cognitive function in adults.

Photo by Flickr user  Pedro Ribeiro Simões (http://www.flickr.com/photos/pedrosimoes7/13910019233)
Photo by Flickr user Pedro Ribeiro Simões (http://www.flickr.com/photos/pedrosimoes7/13910019233)

Despite the many studies that seem to show this effect, the results are not consistent and thus require further study.

A new study published in the Journal of Alzheimer’s Disease aimed to compare a variety of diets and their effects on cognitive dysfunction, including Alzheimer’s Disease, all-type dementia, and all-type cognitive impairment in Swedish elderly men.

1,138 Swedish elderly men aged 70 years old were followed over 12 years. Dietary information was collected using a 7 day diet record book that was filled out by all participants.

Diets examined were: the WHO recommendations/Health Diet Indicator, a Mediterranean-style diet, and a low carbohydrate/high protein diet.

Dietary information was then compared with and correlated with incidence of Alzheimer’s Disease, all-type dementia, and all-type cognitive impairment.

Important Findings:

  • At the end of the 12 year follow-up:
    • 4% of men developed Alzheimer’s Disease.
    • 6% of men developed all-type dementia.
    • 4% of men developed all-type cognitive impairment.
  • There were no strong associations between diet and any of the cognitive dysfunction examined in this study.
  • There was a possible beneficial relationship between a Mediterranean-style diet and all-cognitive impairment.

The results of this study did not find any significant associations between diet and cognitive dysfunction in Swedish elderly men, adding to the already inconsistent results found between studies. The did see a trend toward a possible beneficial relationship between a Mediterranean-style diet and all-cognitive impairment, however, these results were not statistically significant.

Photo by Flickr user  Pedro Ribeiro Simões (http://www.flickr.com/photos/pedrosimoes7/262478037)
Photo by Flickr user Pedro Ribeiro Simões (http://www.flickr.com/photos/pedrosimoes7/262478037)

It is possible that perhaps the sample size was too small to see any effect, or there are other factors involved that have a stronger influence on cognitive dysfunction than diet alone.

The three diets in this study are somewhat similar, in that they are all considered to be relatively “healthy” diets compared to a Western-style diet. Inclusion of this diet would have been important for this study, as this type of diet is consumed by a significant number of people throughout the world.

It is possible that there weren’t enough participants in this study to be sensitive enough to pick up any real differences in terms of associations with cognitive dysfunction. It’s also possible (and likely) that there is single type of diet for every individual, and there are other factors involved that contribute to the development (or lack thereof) of cognitive dysfunction.

Source:

Olsson, E., Karlström, B., Kilander, L., Byberg, L., Cederholm, T., and Sjögren, P. 2015. Dietary Patterns and Cognitive Dysfunction in a 12-Year Follow-Up Study of 70 Year Old Men. Journal of Alzheimer’s Disease 43: 109-119.

Low-Level Alcohol Consumption Affects Brain Function in Young Adults: MRI Study Results

Heavy alcohol consumption in young adolescents whose brains are

Photo by Flickr user Mike Burns (http://www.flickr.com/photos/mike-burns/7459858)
Photo by Flickr user Mike Burns (http://www.flickr.com/photos/mike-burns/7459858)

still developing has been shown to have negative effects on cognitive function, showing damage to be permanent, particularly in the areas of the brain responsible for “executive functioning” or working memory, reasoning, task management, and other cognitive functions.

While most studies tend to focus on heavy or binge drinking, few have focused primarily on low to moderate amounts of alcohol and effects on the younger adult brain.

A new study published in the journal Alcohol aimed to determine the effect of low-level alcohol consumption in young adults on cognitive counting-stroop-test-french-paradoxprocessing, using novel fMRI methods.

This study used data from 29 young adults enrolled in a 20 year from birth through young adulthood cohort. Participants did not do drugs and they did not suffer from any cognitive development issues. The number of alcoholic drinks consumed per week was determined for each participant using questionnaires.

To be sure participants were not under the influence of drugs or alcohol before

Photo courtesy nature.com
Counting Stroop Test:   Photo courtesy nature.com

the MRI procedure, urine tests were performed.

During the MRI procedure, the Counting Stroop cognitive test was performed.

Important Findings:

Continue reading Low-Level Alcohol Consumption Affects Brain Function in Young Adults: MRI Study Results

Mediterranean Diet is Good for Brain Health: Or Is It? Inconsistencies Among Studies Make Generalizing Difficult

Nutrition, lifestyle, and diet choices have been implicated as influencing cognitive health of various populations. Specifically,

Photo by Flickr user  Ian MacKenzie (https://www.flickr.com/photos/bravenewtraveler/2275900255/)
Photo by Flickr user Ian MacKenzie (https://www.flickr.com/photos/bravenewtraveler/2275900255/)

research has shown that adherence to the Mediterranean diet is associated with improved cognitive health and brain aging in the elderly population.

A new review in the journal Current Opinion in Clinical Nutrition and Metabolic Care focused on the longitudinal studied published between 2013 and mid-2014 on the effect of diet on cognitive health and brain aging. A total of 6 longitudinal studies and 2 large-scale meta-analyses were performed during this time.

Important Findings:

  • The two meta-analyses indicate that there appears to be an effect of adherence to the Mediterranean diet on cognitive health in the elderly.
    • Adherence to the Mediterranean diet reduces risk of Alzheimer’s.
    • Adherence to the Mediterranean diet reduces risk of cognitive impairment.
  • The six longitudinal studies from the US and Europe show mixed results in the effect of Mediterranean diet adherence and cognitive health benefits.
  • At present, there is a lack of evidence supporting the idea that the Mediterranean diet is an “optimal dietary strategy” for reducing the risk of age-related cognitive health problems.

The results of this review suggest that there are a lot of inconsistencies in results of several recent studies related to adherence to the Mediterranean diet and cognitive health in the elderly. In general, there does seem to be evidence to support the idea that the Mediterranean diet may be beneficial for long-term mental health in some populations,

Photo courtesy of Wikimedia.com. Public domain.
Photo courtesy of Wikimedia.com. Public domain.

however, the inconsistencies make it difficult to generalize across all populations (for example, all elderly).

While some studies may show benefit, differences in experimental design as well as sample size make it very difficult to draw any conclusions on a general population level. Much more research is needed to clear up these discrepancies, and researchers should be more careful when planning experimental design such that reviews of current literature may (or may not!) reveal more interpretable results.

Source:

Feart, C., Samieri, C., and Barberger-Gateau, P. 2015. Mediterranean diet and cognitive health: an update on available knowledge. Current Opinion in Clinical Nutrition and Metabolic Care 18(1): 51-62.

Adherence to the Mediterranean Diet is Associated with Greater Academic Performance in Primary Schoolchildren

A study published last year in the Journal of Nutrition Education and Behavior performed a cross-sectional study to determine any potential associations between adherence to the Mediterranean

Photo courtesy of pixabay.com
Photo courtesy of pixabay.com

diet, body weight, energy, and academic performance in Greek school-aged children.

528 primary schoolchildren between the ages of 10 and 12 years old (split relatively evenly between boys and girls) from 21 different schools in and around Athens, Greece were recruited for this study.

Activity levels, anxiety levels, self-esteem/self-perception levels, body image dissatisfaction, and dietary habits for each child were measured using self-reported questionnaires.

Academic performance was evaluated by the children’s teachers, who then completed questionnaires to be analyzed by the researchers.

Finally, height, weight, BMI, waist circumference, and abdominal obesity were measured for each child.

Important Findings:

Continue reading Adherence to the Mediterranean Diet is Associated with Greater Academic Performance in Primary Schoolchildren