Mediterranean-Style Diet for a Happier, Bigger Brain

Mediterranean-Style Diet for a Happier, Bigger Brain

While no single food can promise better mood or mental sharpness into old age, specific dietary patterns might just help to shape our cognitive and psychological well-being.

Over the past five years, evidence from animal and human studies has been pointing to the importance of a Mediterranean-style diet for prevention of depression and anxiety.[1] Now we have proof – via MRI scans – that a Mediterranean-style diet helps to prevent brain shrinkage as well.

In October of 2015,Professor D. Felice Jacka, a psychiatric nutritionresearcher and her colleagues published a study showing that older adults (aged 60-64) who consumed a Western-style diet for 4 yearsdeveloped a significantly smaller left hippocampus of the brain.  The hippocampus region – shaped like two sea-horses- is associated with learning, memory and mood-regulation.

Non-Mediterranean (i.e., Western) type diets are usually based convenience and ‘long shelf-life’ foods. People who follow these patterns of eating tend to also consume sugary soft-drinks, refined carbohydrates, industrialized oils and fast foods weekly –  the very things which set the stage for insulin-resistance and inflammation.Western-style diets also tend to be deficient in foods such as fish, greens, [2]and antioxidant-rich vegetables and fruit.

By contrast, Mediterranean-style diets are characterized by minimal sugar, olive oil, an abundance of fresh vegetables and fruits, moderate to low amounts of lean meats, and home-cooking.

Good news: you can grow a bigger brain even if you make those positive dietary changes late in life.

Nourish the mindIn Jacka’s study, the age 60-64 test group who consistently ate  Mediterranean-style diet over 4 years, developed a significantly larger left hippocampal volume, even though fish was eaten only once weekly. These results were independent of other factors occurring at the same time, such as age, gender, labour force status, depressive symptoms and medication, physical activity, smoking, hypertension and diabetes.[3]

Why does hippocampus size matter? A well-functioning hippocampus is critical not only for memory retention, but for the creation of new brain cells (neurogenesis).The hippocampus needs to stay healthy because it is also one of only two areas of the brain where adult neurogenesis takes place. The left side of the hippocampus is especially prone to neurodegeneration.  Indeed, it is here patients with Alzheimer’s Disease will show damage.

While the dietary patterns of Okinawa Japan, and Scandinavia deserve honourable mention for their inclusion of fish and for being low in sugar, right now studies seem to be supporting the dietary patterns of Spain, Greece and Italy in terms of offering the highest benefits around cognitive and mental health. While lifestyle and other factors might play into overall health, what sets the Mediterranean diet apart may have to do with its inclusion of nuts and use of olive oil (verses industrial seed oils[4]), a wider selection of fruits and vegetables, and moderate intake of red wine.

Investigating the olive oil and nut consumption phenomenon further, in 2015, a team of researchers in Spain compared the results of older adults who ate a low-fat Western diet, a Mediterranean diet supplemented with extra-virgin olive oil, and a Mediterranean style diet containing 30 grams a day of mixed nuts (almonds, hazelnuts and walnuts).

Some very interesting results emerged: the group consuming nuts did better when compared to the control group in memory tests, memorizing names or words, while the olive oil group did better on tests requiring speed of thought which relies on the frontal lobe of the brain associated with‘executive function. The study was published in JAMA Internal Medicine.[5]

Jacka and other researchers are still trying to unravel the many co-factors which underpin brain health, such as inflammation[6], insulin-resistance, oxidative stress[7]and the gut microbiome.[8]  For the time being, however, it would not hurt to look into a nutrient-dense, Mediterranean-style diet in preventing depression, anxiety and brain shrinkage.While there is no ‘one’ diet that is best for everyone, there are dietary ‘patterns’ such as home-cooking, which would benefit most people.

The Mediterranean diet contains some foods such as whole grains, eggs, legumes and vegetables belonging to the nightshade family, and these foods may be problematic for people with arthritis, joint pain, autoimmune disease or severe gastro-intestinal issues.In adopting a Mediterranean-style diet – or any other type of diet – the best results will come while working with a registered or certified health professional who can individualize your diet and answer your questions.

 

Ingredients common to the cuisines of Greek, Italian, Spanish (and Middle-Eastern) diets include:

Olive OilHealthy Fats such as Olive oil: Our brains are about 60 percent fat in composition.One of the most common fats in the brain is oleic acid, amono-unsaturated fat which is found in avocados, olive oil, sunflower seeds, and many types of nuts.

Healthy fat intake stabilizes blood sugar, preventing insulin spikes which are damaging to the body’s tissues.

Omega 3-rich seafoods such as sardines, squid and shellfish: The omega-3 fatty acid decosahexaenoicacid (DHA), is strongly associated with increase in the size of the hypothalamus. It is believed that a diet high in shellfish and cold-water fish has driven the evolution of the human brain.

Sea food offers additional nutrients which are also vital to brain health and immunity such as Iron, zinc, copper, selenium.

Medicinal Teas suchas ‘Sideritis’: Sideritis, (also known as Ironwortor Greek Mountain tea), is enjoyed throughout Greece and many parts of Europe. A mice model of research is showing that Sideritis extracts may reverse the accumulation of the protein plaques associated with Alzheimer’s Disease, according to studies at the Otto von Geuricke University in Germany. Professor of Neurology, Jens Pahnke found that the tea lessened brain damage by nearly 80% in mice with Alzheimer’s.  The suggested human dose is 4 cups a day for a period of at least two months, according to Professor Pahnke. The tea, a member of the mint family, is pleasant tasting, caffeine free and carries no side effects even when taken in large quantities.[9]

Herbs such as Rosemary: Popular in culinary dishes, rosemary can improve brain function and enhance memory and concentration. Use as a spice or tea: 1 tsp. of fresh dried leaves to 1 cup hot water. Steep 15 minutes.

Spices: Antioxidant and blood sugar-lowering spices such as cloves, cinnamon and turmeric root.

Legumes:Scientists from the University of Toronto reported in Archives of Internal Medicine, October 2012 issue, that eating more legumes helps improve glycemic control in people with Type II diabetes while also lessening risk of developing coronary heart disease. Examples of legumes include peas, chick peas, lentils, alfalfa and beans.

Moderate amounts of lean meat: Mediterranean and Middle-Eastern cultures often follow religious fasting periods or periods where they abstain from meat altogether.

Red WineModerate amounts of red wine or dark purple/black fruits: resveratrol is a polyphenol found in red grapes and other fruits such as pomegranate. Resveratrol and dark purple/black foods, stimulate the creation of new brain cells while reducing oxidation (rust) and turning down inflammatory processes in the body

Pomegranates: contain very high levels of polyphenols, which are plant-derived molecules with anti-inflammatory and brain cell protective properties.Human studies demonstrate significant improvements in cognition and memory with consumption of 8 ounces of pomegranate juice daily.

Sea Salt versus table salt: Mediterranean-type dietstend to include sea salt – which contains magnesium and other trace minerals – rather than sodium chloride table salt. Minerals such as magnesium relax the blood vessels, whereas sodium chloride would make the blood vessels more rigid, resulting in hypertension.

Naturally Fermented foods: such as yogurt, pickles, and sauerkraut. The L. rhamnosusstrain turns on GABA receptors in our brains helping us to feel calm under stress. L. casei is associated with lowered stress while taking tests.

Based on the production of health-promoting short-chain fatty acids, a vegan, vegetarian or Mediterranean diet is also best for gut health, according to the results of a new study published in the journal Gut.

 

For further reading:

 

Footnotes:

[1] Jacka, N. Felice, Cherbuin, N, Anstey, K.J., Sachdev, P, and Butterworth, P.Western diet is associated with a smaller hippocampus: a longitudinal investigation.BMC Med. 201513:215, 8 September 2015 DOI: 10.1186/s12916-015-0461-x https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-015-0461-x

[2] Low levels of folate are linked with severe gray matter atrophy and atrophy of the hippocampus, a main memory-processing center in the brain. Similarly, people with lower vitamin B12 levels have been shown to have progressive brain atrophy, with rates of brain volume loss 517% greater than those with higher levels.

[3] According to Professor Jacka and colleagues, “A healthy “prudent” dietary pattern (in line with a Mediterranean type diet), was associated with a 45.7 mm3 (standard error 22.9 mm3) larger left hippocampal volume, while higher consumption of an unhealthy “Western” dietary pattern was (independently) associated with a 52.6 mm3 (SE 26.6 mm3) smaller left hippocampal volume.”

[4] Industrial seed oils are processed to stay shelf-stable for many years. They include soybean, corn, safflower, sunflower, cottonseed, and canola (rapeseed) oils.

[5] Cinta Valls-Pedret, MSc, Aleix Sala-Vila, DPharm, PhD, Mercè Serra-Mir, RD, Dolores Corella, DPharm, PhD; Rafael de la Torre, DPharm, PhD, Miguel Ángel Martínez-González, MD, PhD, Elena H. Martínez-Lapiscina, MD, PhD, Montserrat Fitó, MD, PhD, Ana Pérez-Heras, RD, Jordi Salas-Salvadó, MD, PhD, Ramon Estruch, MD, PhD, Emilio Ros, MD, PhD1,2Mediterranean Diet and Age-Related Cognitive Decline:  A Randomized, Clinical Trial, JAMA Intern Med. 2015;175(7):1094-1103. doi:10.1001/jamainternmed.2015.1668. http://archinte.jamanetwork.com/article.aspx?articleid=2293082

[6] Berk M, Williams LJ, Jacka F, O’Neil A, Pasco JA, Moylan S, et al. So depression is an inflammatory disease, but where does the inflammation come from? BMC Med. 2013;11:200.

[7] Moylan S, Berk M, Dean OM, Samuni Y, Williams LJ, O’Neil A, et al. Oxidative &nitrosative stress in depression: Why so much stress? NeurosciBiobehav Rev. 2014;45C:46–62.

[8] Dash S, Clarke G, Berk M, Jacka FN. The gut microbiome and diet in psychiatry: focus on depression. CurrOpin Psychiatry. 2015;28:1–6.

[9] The types of Siferitis used in the study were Sideritiseuboea and Sideritisscardica.Krohn MBracke A2Avchalumov Y3Schumacher T4Hofrichter J4Paarmann K1Fröhlich C4Lange C4Brüning T1von Bohlen Und Halbach O2,Pahnke J5.Brain. 2015 Aug;138(Pt 8):2370-82. doi: 10.1093/brain/awv137. Epub 2015 May 18. Accumulation of murine amyloid-β mimics early Alzheimer’s disease.