Food for Thought

Diets and foods to support cognitive function.

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Everyone wants to stay sharp. As individuals get on with age and experience forgetfulness, they often turn to supplements meant to support memory and other cognitive function. While that may be helpful, it’s always more effective to engage in healthy habits before those vulnerable years. Having a healthy diet and lifestyle is the most critical way to achieve longevity and delay cognitive decline as we age. Luckily, there are a variety of foods and specific dietary systems that support cognitive health.

Healthy Diets

The Mediterranean Diet. This diet consists of foods that replicate the eating habits of communities on the Mediterranean Sea, particularly Greece, Southern Italy and Spain. “The birthplace of the Mediterranean diet is Crete, an island off the coast of Greece,” says Michael Ozner, M.D., FACC, FAHA, medical director, Center for Prevention and Wellness, Baptist Health South Florida and author of The Complete Mediterranean Diet. “In Mediterranean regions of the world we see a much lower risk of cardiovascular disease and Alzheimer’s disease.”

Ozner says the prevalence of diseases like cardiovascular disease (heart attack and stroke) in the Western and developed world can be attributed to the overconsumption of processed foods. This contrasts with the Mediterranean diet, which consists of non-processed foods. “You’ve got to put the right fuel in your car for it to function properly and if you pull into the gas station and you put diesel fuel into a gasoline powered car, it would break down,” explains Ozner. “That’s what we’re doing in the U.S. and the developed world, we are consuming highly processed foods and wondering why we are not healthy.”

Foods typical to the Mediterranean diet include whole grains, fruits and vegetables of all different colors that provide a wealth of antioxidants to fight free radicals, raw nuts rich in minerals, antioxidants, beans rich in protein and fiber as well as cold water fish that are an important source of omega-3 fatty acids. “Interestingly, in the United States, we find a lot of people to be deficient in omega-3 fatty acids; they either don’t eat fish or the type of fish they eat aren’t rich in omega-3 fatty acids. Examples of omega-3 rich fish are salmon, mackerel, trout, sardines and herring,” says Ozner. “It’s important to not only consume omega-3 rich fish at least twice a week but also to know your omega-3 blood level to ensure that you are not omega-3 deficient.”

Extra-virgin olive oil is also consumed in a Mediterranean diet and it is an important source of antioxidants that help to maintain optimal cardiovascular health. Besides fish, meat that fits into the Mediterranean diet includes poultry and occasionally, red meat. Ozner explains that the originators of the Mediterranean diet only ate red meat a couple times a month, typically on special occasions. Processed meats like hot dogs, salami and bologna are avoided in the Mediterranean diet. Interestingly, the Mediterranean diet also encourages red wine during a meal. “The red wine brings a lot of antioxidants and polyphenols to the table, but an important point is that it’s not consumed in isolation, it’s consumed with food,” says Ozner. “The reason why that’s important is that besides having antioxidants and polyphenols and resveratrol, it also helps to decrease carbohydrate absorption. It’s also consumed in moderation.”

The Mediterranean diet also has the benefits of scientific research. “One of the studies I often cite when I lecture is by Nikolaos Scarmeas and his colleagues at Columbia Presbyterian,” says Ozner. “It was a four-year trial where they randomized people to a Mediterranean diet and at the end, the more adherent the individuals in this trial were over four years to following a Mediterranean diet, the lower their risk was of developing Alzheimer’s disease. Those who had the highest adherence had a 40% reduction in the risk of developing Alzheimer’s disease.”

Another study conducted by Ramon Estruch and colleagues was called the PREDIMED study, which showed that greater adherence to the Mediterranean diet was associated with a significant reduction in cardiovascular disease.

The Mediterranean diet is ideal for the average person, because the ingredients are familiar and easy-to-find compared to more restrictive diets such as low-carb diets. This is great for individuals and families, even with small children. Even a moderate Mediterranean-style diet may support cognitive health.

For example, one study published in the Journal of the American Geriatrics Society examined information from 5,907 older adults who participated in the Health and Retirement Study (2). The participants filled out questionnaires about their eating habits and then researchers measured the participants’ cognitive abilities, specifically memory and attention skills. Results showed that older individuals who ate a Mediterranean-style diet had a 35% lower risk of scoring poorly on cognitive tests and even those who ate a moderate Mediterranean-style diet had 15% lower risk of scoring poorly.

Paleo Diet. Modeled after the diet of hunter-gatherers, the Paleolithic diet shares some principles with the Mediterranean diet such as no processed foods and encouraging foods high in healthy fat such as omega-3s as well as fruits and vegetables, but because the diet is based on hunter-gatherers and not farmers, the diet restricts foods such as grains, dairy, potatoes and legumes (3). The Paleo diet also encourages red meat consumption more so than the Mediterranean diet as a source of important nutrients such as iron, zinc, B vitamins and fatty acids (4). It is important to note that the Paleo diet differentiates between conventional corn-fed beef and organic grass-fed beef, which is the much healthier option.

The Paleolithic era, a period of about 2.5 million years, is associated with physiological changes in the human body as people adapted to climate change and learned to control fire and how to use stone tools (5). Anthropologists believe that the diet of our Paleolithic ancestors influenced neural expansion, increased brain size, and reduced gastrointestinal tract size. Proponents of the Paleo diet link the brain health benefits to reduced inflammation by removing processed and refined foods such as sugar and consuming nutrient-rich foods (6).

The Paleo diet still needs plenty of research to determine its efficacy for supporting brain health, but early studies show promise. One small study took sedentary individuals with type 2 diabetes and randomized one group to the Paleo diet, another to the Paleo diet plus exercise and there was a third non-intervention group for reference (7). “We found that after weight loss, with associated improved insulin sensitivity and cardiovascular fitness, functional brain responses increased in the right occipital cortex and the right anterior hippocampus compared with a weight-stable reference group,” write the researchers. “Furthermore, gray matter volume in the right hippocampus increased in the intervention groups.”

While there were no changes in memory performance, the increases in brain activity are still great signs. “Our results strongly suggest that lifestyle interventions can improve both hippocampal structure and function in individuals with type 2 diabetes,” they write. “This may counteract the increased risk for Alzheimer’s disease in this patient group.”

The Food

There is a good deal of nutrient-dense food that supports cognitive health. A few of these have been termed “superfoods” and are utilized in finished functional food and beverage products that are marketed for supporting cognitive health. “Consumers are increasingly looking for functional benefits in the foods they are purchasing, particularly their snack foods, as snacking has become ubiquitous,” explains Andrea Spirov, founder and CEO of Houston, TX-based B.O.S.S. Food Co., which makes raw superfood bars. “Going back to 2015, Packaged Facts research showed that 61 percent of nutrition bar users looked for foods with nutrients that target specific health conditions. Superfoods are everywhere, and sometimes I think it can be difficult for people to believe that so many common foods are extremely nutrient dense and can offer functional benefits.”

Chief among them are berries, most recognizably blueberries, which have been studied extensively for their antioxidant capacity. Antioxidants’ ability to reduce oxidative stress can be attributed to the polyphenols, which blueberries are very rich in. “Along with their antioxidant properties against ROS (Reactive Oxygen Species), polyphenols are known to have other health benefits such as anti-inflammatory, anti-cancer, anti-ulcer, and anti-infective properties,” writes Erin Kelly et al. in a review published in Molecule (8). “Polyphenols may also have indirect peripheral effects, such as improving cardiovascular health resulting in increased blood flow to the brain.”

Polyphenols can be classified into five major groups that include diferuloylmethanes, stilbenes, flavonoids, phenolic acids and tannins. Flavonoids are considered the main compounds responsible for the antioxidant activities in berries — in particular, anthocyanins and flavonols. “Anthocyanins have been identified in several brain areas and have been associated with neuroregeneration and protection,” writes Kelly et al. “Berries are one of the best options for polyphenol related neuroprotective studies because they contain several different kinds of these compounds that can work together and have a synergistic effect in the central nervous system.”

Blueberry is the dominant ingredient in B.O.S.S Food Co.’s Think bar, for example. However, as Ozner mentioned previously, a single ingredient in isolation is not enough to provide benefits, it’s the totality of one’s diet, or in this case, the totality of the product. Alongside blueberry, the Think bar also includes walnuts, dates, almonds, bananas, apple and coconut oil. “Walnuts may be even more powerful than blueberries,” explains Spirov. “They contain phytonutrients that protect the brain, along with DHA and choline, which also are crucial to cognitive health. Coconut oil complements this, with one study calling it an ‘anti-stress functional oil.’ Almonds are rich in vitamin E, a potent and recognized antioxidant, which is on the government’s list of ‘Nutrients of Concern’ because most people do not consume enough of the vitamin.”

Another important angle of cognitive health is mood. Nutrient-rich ingredients like cacao, pumpkin seeds, bananas and hemp seeds provide a synergistic recipe for lifted spirits. “Raw cacao is the starring ingredient in our Smile bar, containing polyphenols that have been shown to improve mood along with other significant health benefits,” says Spirov. “It boosts serotonin levels while its phenethylamine stimulates the release of endorphins. Pumpkin seeds contain vitamin B6, which is needed for serotonin synthesis, and magnesium. Bananas contain the mood-boosting chemical dopamine, as well as B6 and magnesium. Hemp seeds have the perfect balance of omega-7 and omega-3 fatty acids, the latter of which are very important for the brain.”

Dan Ehrlich, founder and CEO of IQ Juice, also emphasizes the importance of antioxidants to support cognitive health. IQ Juice is a line of functional beverages that each have different functions, but a base that supports brain health, specifically fresh-pressed apple cider and passion fruit juice. “The most potent of these antioxidants is quercetin, a bioflavonoid well-known for its brain health benefits,” says Ehrlich. “Apples are the best source for quercetin among fruits. The passion fruit in IQ Juices contains many kinds of antioxidants from various polyphenols to Vitamin C.  They all help fight inflammation, which is key in supporting cognitive function throughout our lifetime.”

Quercetin has been shown in animal studies to alleviate Alzheimer’s disease pathology in mice, even improving performance on learning and spatial memory tasks (9). Apples and apple cider, in this case, are an important source of fiber as well. “A non-processed diet like the Mediterranean diet is rich in fiber and processed food is fiberless food, so fiber becomes very important, both soluble and insoluble,” explains Ozner. “Fruits, vegetables, nuts and legumes are rich in fiber. It also interacts with our gut microbiome and helps with satiety.”

“Much of our immunity begins in the gut,” says Ehrlich. “There’s a well-documented gut/brain connection that leads to health, in part by the consumption of soluble fiber. Apple Cider, because it is pressed, not juiced or strained, maintains some of the soluble fiber from the whole fruit. This fiber helps fight toxins in our intestines by the production of butyrate, which protects the brain by reducing inflammation.”

In addition to the apple cider and passion fruit juice, IQ Juice also has a Memory blend that incorporates blueberry, tart cherry, gotu kola and vitamin E. “Tart cherries are rich in melatonin and tryptophan, which help support sleep — vital for cognitive function,” says Ehrlich. “Production of melatonin decreases with age, so adding tart cherry to the diet becomes more important as we get older. Tart cherry is very high in vitamins A and C, important antioxidants to fight inflammation and support a healthy brain.”

One animal study published in Journal of Medicine Food tested how a combination of tart cherry and essential fatty acids from Nordic fish oil would affect mice with Alzheimer’s disease. Subjects were given the combination or placebo daily for two weeks prior to being induced with Alzheimer’s and for an additional 17 days. Results showed that mice given the tart cherry and fish oil combo experienced fewer cognitive deficits when tested for object-recognition, place-recognition, and Morris-water-maze tasks. Researchers found that the combo also protected against inflammation and loss of neurons (10).

Gotu kola is an interesting ingredient that is used both as a culinary vegetable and medicinal herb. “Gotu Kola, an herbaceous plant from Asia, contains triterpenoid compounds, or saponins, that have been shown to have anti-inflammatory properties and improve circulation, which benefits the brain through oxygenation, improving cognition,” says Ehrlich. “The antioxidant properties of Gotu Kola have antioxidant effects, which helps to eliminate plaque and free radicals from the brain.”

An animal study published in Brain and Behavior testing the efficacy of the herb as it relates to age-related cognitive decline found that aged mice given the herb in the drinking water for two weeks prior to behavioral testing, experience improved performance (11). “[This suggests] effects on hippocampal and cortical dependent memory as well as on prefrontal cortex mediated executive function,” writes Nora E. Gray et al. “There was also an increase in synaptic density in the treated animals, which was accompanied by increased expression of the antioxidant response gene NRF2 as well as the mitochondrial marker porin.”

Functional foods and beverages like these are creative approaches to fill in nutritional gaps, but as with any food or supplement, when done in isolation without any overall dietary and fitness intervention, benefits will be non-existent. Consumers also want to get creative and play around with recipes that incorporate the best produce and proteins, not to mention on-the-go solutions for the busy young professionals and/or parents who want to enhance their nutritional intake by making smoothies and bars at home. Brands like Navitas Organics and Nutiva can be great sources of organic ingredients like cacao, hemp seeds, chia, nuts as well as oils like coconut and ethically sourced red palm oil. Share recipes through social media and email campaigns and have demonstrations occasionally to help customers understand how easy making nutritious meals and snacks can be.  WF

References

  1. F. Maron “Mediterranean Eating Habits Prove Good for the Brain.” https://www.scientificamerican.com/article/mediterranean-eating-habits-prove-good-for-the-brain/, Accessed July 22, 2018.
  2. “Mediterranean-style diets linked to better brain function in older adults.” https://www.sciencedaily.com/releases/2017/07/170725154208.htm, Accessed July 21, 2018.
  3. McMillen. “The Paleo Diet.” https://www.webmd.com/diet/a-z/paleo-diet, Accessed July 22, 2018.
  4. Stephenson. “Red Meat and The Paleo Diet: How Often and What Type?” https://thepaleodiet.com/red-meat-paleo-diet-often-type/, Accessed July 22, 2018.
  5. Hima, et al. “Paleolithic Diet.” https://www.ncbi.nlm.nih.gov/books/NBK482457/, Accessed July 23, 2018.
  6. “Your Brain On Paleo.” https://paleoleap.com/brain-on-paleo/, Accessed July 22, 2018.
  7. Stomby, et al. “A Paleolithic Diet with and without Combined Aerobic and Resistance Exercise Increases Functional Brain Responses and Hippocampal Volume in Subjects with Type 2 Diabetes.” Front Aging Neurosci. 9: 391. 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5722796/
  8. Kelly, et al. “Biochemical Properties and Neuroprotective Effects of Compounds in Various Species of Berries.” Molecules. 23(1): 26. 2018. http://www.mdpi.com/1420-3049/23/1/26/htm
  9. M. Sabogal-Guáqueta, et al. “The flavonoid quercetin ameliorates Alzheimer’s disease pathology and protects cognitive and emotional function in aged triple transgenic Alzheimer’s disease model mice.” Neuropharmacology. 93: 134–145. 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387064/
  10. J. Matchynski, et al. “Combinatorial treatment of tart cherry extract and essential fatty acids reduces cognitive impairments and inflammation in the mu-p75 saporin-induced mouse model of Alzheimer’s disease.” J Med Food. 16(4):288-95. 2013. https://www.ncbi.nlm.nih.gov/pubmed/23566055
  11. E. Gray, et al. “Centella asiatica increases hippocampal synaptic density and improves memory and executive function in aged mice.” Brain Behav. 8(7). 2018. https://www.ncbi.nlm.nih.gov/pubmed/29920983

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