Mediterranean Diet and Long Term Cognitive Function

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Mediterranean Diet and Long Term Cognitive Function

Postby Bill Glasheen » Mon May 11, 2015 3:47 pm

The expression "You are what you eat" most definitely applies to athletes. Many in the martial arts business - students and teachers alike - are in search of a greater lifestyle approach (the "do" in karate do) in their quest for health and well being. Back when I started MA I was gifted with a great metabolism which was more in need of more calories than it was better quality food. But as I began to push myself to achieve world class practitioner status (or at least as close as I could get), I began to tweak the small stuff. My journey was a torturous one, but it kept coming back to something fairly similar to The Mediterranean Diet.

Below is part of a WSJ article and an abstract about one of the more complete and carefully run studies on the relationship between diet and long term cognitive abilities. You folks who are in this for the long run might want to take note. And what's good for the brain is often good for healing and general health.

- Bill

WSJ wrote:Mediterranean Diet Boosts Brain Power, Study Finds
The popular diet, supplemented with olive oil or nuts, helped stave off cognitive decline

May 11, 2015 11:05 a.m. ET
The Mediterranean diet, supplemented with a handful of nuts or a few tablespoons of olive oil a day, can counteract the effects of aging on the brain’s ability to function, a new clinical study suggests.

The study, published online Monday in JAMA Internal Medicine, was unusual in that it employed rigorous scientific practices to test the effect of the diet on health. Most previous evidence showing benefits from the Mediterranean diet was gathered through observational studies, a less conclusive research technique.

“This was the first clinical, randomized study using a dietary pattern for good health,” said Emilio Ros, who led the study at Hospital Clinic, part of the University of Barcelona in Spain. Data gathered from previous observational studies suggested that adhering to a Mediterranean-type diet related to better cognitive function and a reduced risk of dementia, but observational studies have limitations, he said. “This clinical trial removes the bias and provides first-level evidence,” said Dr. Ros, director of the lipid clinic at Hospital Clinic’s endocrinology department.

The Mediterranean diet, which has also shown benefits in cardiovascular health, emphasizes vegetables and fruits, unrefined grains and beans. It also includes fish and wine and minimal consumption of meat and full-fat dairy products.

The study involved 447 cognitively healthy participants, 55 to 80 years of age, who were divided into three groups. Two groups followed the Mediterranean diet and added either 30 grams of mixed nuts (walnuts, hazelnuts and almonds) a day, or five tablespoons of extra virgin olive oil a day. The third group, acting as a control, was advised to follow a low-fat diet. The subjects were followed for a median of just over four years.

The results showed that, compared with the control group, memory function remained stronger in the Mediterranean diet plus nuts group, while frontal (attention and executive function) and global cognition benefited in the Mediterranean diet plus olive oil group.

The diminished decline in cognitive function likely stems from the abundance of antioxidants and anti-inflammatory agents found in the supplemental foods, Dr. Ros said. Olive oil and nuts are rich in phenolic compounds that might counteract oxidative processes in the brain, leading to neurodegeneration, the study said. “If you can delay your age-related cognitive decline, you can process tasks with higher speed,” said Dr. Ros.

Jane Cerhan, a clinical neuropsychologist at the Mayo Clinic in Rochester, Minn., who wasn’t involved in the research, said clinical studies of age-related cognitive decline are needed in regard to diet, “which is why this study is an extra good one, because of its size and randomized design.” However, she said: “The changes observed in cognition were very small and didn’t actually show that those diets improved cognition, they just showed less decline.” Based on the research, she said, people shouldn’t rush out to buy lots of olive oil and nut, but she encourages they follow a balanced diet that includes healthy foods such as these.

The research was a substudy of a larger investigation, designed by Dr. Ros, that found the Mediterranean diet, supplemented with additional olive oil or nuts, reduced the incidence of major cardiovascular events among people at high cardiovascular risk. That study, which involved nearly 7,500 participants and known by the acronym Predimed, was published in 2013.

In the latest study, Dr. Ros said participants were given 1 liter of olive oil per week, but that amount was intended for their entire household. He recommends that, to decrease age-related cognitive delay, people should add 5 tablespoons of olive oil as well as a handful of nuts per day into their diet.

“I like walnuts, which are high in omega-3 fatty acids,” he said. In general, he would like to see everyone improve their diets “by eating more fish, less meat, and improving your legume intake.” He also suggested adding the Spanish “sofrito” sauce of slowly simmering tomatoes, onions, and garlic in olive oil and garlic to dress rice and pasta dishes in weekly menus. “We believe this is an antioxidant cocktail.”


The JAMA network is down right now. I'll post the abstract later.
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Re: Mediterranean Diet and Long Term Cognitive Function

Postby Bill Glasheen » Tue May 12, 2015 2:02 pm

To the lay person, this may seem like overkill. To the scientist, not so much.

There's a lot of "Internet advice" being given these days by people who pay attention to what's posted on Facebook pages (often by fraudsters like David Wolfe who steer you to their site to sell you schlock) or what they may hear on Dr. Oz. Occasionally it's at least harmless; sometimes it isn't.

And then there are the "observational studies" published which show you that Group A did better than Group B, where Group A is inherently different by self-selection so we aren't really measuring the effect of the observed treatment or habit. (This is the association vs. causality issue that many people don't quite grasp.) Observational studies aren't always useless. They often give us hints that there may be something interesting going on. But we can't really be sure we've identified something interesting until we run a controlled study and remove all the potential confounding effects.

The gold standard for a definitive study is the following:

1) You have first principles reasons to suspect that something interesting is going on. This is important. If you measure 1000 different things, occasionally something weird will happen in your experiment. It is possible to flip a coin 100 times and have it come up heads 96 times. So basically you don't want to tempt fate and luck with what we call fishing expeditions.

2) You set up an experiment where you randomly assign a large group of people to either the treatment(s) or to no treatment. Sometimes no treatment means a placebo. The placebo is important where there is a possible mind-body effect. Most of what I hear being touted by the health nuts in our midst involve this; if you believe, it can happen. That effect actually can be blocked by the drug naloxone. But if all it takes is belief (a.k.a. the mind-body effect), well you don't need the silly treatment. So your control group - sometimes with placebo - is there to act as a benchmark and to remove said mind-body effect.

3) You run the experiment.

4) Every group's result will fall on a statistical spread of pretty darn good to not so good. We measure the central tendency of that spread with either a mean or a median (50th percentile) value. There will be mean values and spreads for the treatment group(s) and the control groups. If the difference between the group(s) is greater than the differences within the group(s), then you feel confident that something systematic and hopefully interesting is going on. What you measure may be something like body weight or lab results from blood samples or performance on a test or maybe survival. The statistics applied involve accepted ways of looking at the spreads and the differences of means, and trying to state with a given degree of certainty that differences you see are real - or not.

The following study is such a gold standard study. The foundation for it was multiple observational studies where it appeared that people who ate a Mediterranean Diet tended to do better than people who ate other kinds of diets. So they isolated a few components of this diet (e.g. fish servings or nuts or the use of olive oil) and measured the difference with vs. without these components of said diet.

For the record... There are similarities between the typical Okinawan Diet and the Mediterranean Diet. Both involve consumption of fish, which contain beneficial fatty acids. They also involve less use of beef, sugar, and of course the (deservedly) much maligned high fructose corn syrup.


Mediterranean Diet and Age-Related Cognitive Decline
A Randomized Clinical Trial
Cinta Valls-Pedret, MSc1,2; Aleix Sala-Vila, DPharm, PhD1,2; Mercè Serra-Mir, RD1,2; Dolores Corella, DPharm, PhD2,3; Rafael de la Torre, DPharm, PhD2,4; Miguel Ángel Martínez-González, MD, PhD2,5; Elena H. Martínez-Lapiscina, MD, PhD2,5; Montserrat Fitó, MD, PhD2,4; Ana Pérez-Heras, RD1,2; Jordi Salas-Salvadó, MD, PhD2,6; Ramon Estruch, MD, PhD2,7; Emilio Ros, MD, PhD1,2
[+] Author Affiliations

JAMA Intern Med. Published online May 11, 2015. doi:10.1001/jamainternmed.2015.1668


Oxidative stress and vascular impairment are believed to partly mediate age-related cognitive decline, a strong risk factor for development of dementia. Epidemiologic studies suggest that a Mediterranean diet, an antioxidant-rich cardioprotective dietary pattern, delays cognitive decline, but clinical trial evidence is lacking.

To investigate whether a Mediterranean diet supplemented with antioxidant-rich foods influences cognitive function compared with a control diet.

Design, Setting, and Participants
Parallel-group randomized clinical trial of 447 cognitively healthy volunteers from Barcelona, Spain (233 women [52.1%]; mean age, 66.9 years), at high cardiovascular risk were enrolled into the Prevención con Dieta Mediterránea nutrition intervention trial from October 1, 2003, through December 31, 2009. All patients underwent neuropsychological assessment at inclusion and were offered retesting at the end of the study.

Participants were randomly assigned to a Mediterranean diet supplemented with extra-virgin olive oil (1 L/wk), a Mediterranean diet supplemented with mixed nuts (30 g/d), or a control diet (advice to reduce dietary fat).

Main Outcomes and Measures
Rates of cognitive change over time based on a neuropsychological test battery: Mini-Mental State Examination, Rey Auditory Verbal Learning Test (RAVLT), Animals Semantic Fluency, Digit Span subtest from the Wechsler Adult Intelligence Scale, Verbal Paired Associates from the Wechsler Memory Scale, and the Color Trail Test. We used mean z scores of change in each test to construct 3 cognitive composites: memory, frontal (attention and executive function), and global.

Follow-up cognitive tests were available in 334 participants after intervention (median, 4.1 years). In multivariate analyses adjusted for confounders, participants allocated to a Mediterranean diet plus olive oil scored better on the RAVLT (P = .049) and Color Trail Test part 2 (P = .04) compared with controls; no between-group differences were observed for the other cognitive tests. Similarly adjusted cognitive composites (mean z scores with 95% CIs) for changes above baseline of the memory composite were 0.04 (−0.09 to 0.18) for the Mediterranean diet plus olive oil, 0.09 (−0.05 to 0.23; P = .04 vs controls) for the Mediterranean diet plus nuts, and −0.17 (−0.32 to −0.01) for the control diet. Respective changes from baseline of the frontal cognition composite were 0.23 (0.03 to 0.43; P = .003 vs controls), 0.03 (−0.25 to 0.31), and −0.33 (−0.57 to −0.09). Changes from baseline of the global cognition composite were 0.05 (−0.11 to 0.21; P = .005 vs controls) for the Mediterranean diet plus olive oil, −0.05 (−0.27 to 0.18) for the Mediterranean diet plus nuts, and −0.38 (−0.57 to −0.18) for the control diet. All cognitive composites significantly (P < .05) decreased from baseline in controls.

Conclusions and Relevance
In an older population, a Mediterranean diet supplemented with olive oil or nuts is associated with improved cognitive function.

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Re: Mediterranean Diet and Long Term Cognitive Function

Postby gmattson » Wed May 13, 2015 1:03 pm

thanks for posting this very interesting study and information Bill.
"Do or do not. there is no try!"
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