The Mediterranean Diet and Cognition


Growing evidence suggests that following this eating pattern may improve memory and prevent neurodegenerative disease.

 

Memory loss often is indicative of the normal aging process, but it also may be a sign of neurodegenerative disease development, namely Alzheimer’s disease, a form of dementia that causes problems with memory, behavior, and thinking, and gradually worsens over time. While there’s no known cure for Alzheimer’s, research suggests that a healthful lifestyle that includes following a Mediterranean pattern of eating and regular physical activity may delay or slow the disease’s progression.

 

A Healthful Connection
An estimated 5.2 million Americans of all ages have Alzheimer’s, including 5 million people aged 65 and older as well as approximately 200,000 who have younger-onset Alzheimer’s. Experts believe that number will increase to 7.1 million by 2025 and nearly triple by 2050.

Alzheimer’s is caused by the accumulation of two chemicals in the brain: amyloid and tau. Why they accumulate in abundance is not known, but they negatively affect brain cells that eventually die. Due to the loss of brain cells, the patients with this disease experience cognitive decline. The decline starts from memory because the brain cells responsible for memory are affected first but involves gradually, over the course of about a decade, the decline of all higher cognitive functions.  Alzheimer’s is the most frequent type of dementia. In addition to memory, it impairs the ability to perform activities of daily living and is characterized by a progressive chronic impairment.   Although the reasons aren’t fully understood, there does seem to be a link between a healthful lifestyle and a decrease in cognitive impairment. Recent research has focused more specifically on the positive benefits of the Mediterranean diet and the reduced risk of Alzheimer’s as well as other cognitive functions.

A Mediterranean diet essentially is a plant-based diet that’s characterized by consuming a variety of fresh fruits and vegetables, grains, and plenty of fish. Modest amounts of olive oil are used instead of butter, and you basically use food to flavor food, such as basil, garlic, and onions. It focuses on using seasonal foods, so it’s a fresh and tasty diet. Meat and sweets are consumed in very small portions, and it’s about making fruits and vegetables the main focus of the plate.

Past research has indicated that this diet, high in fruits, vegetables, and unsaturated fatty acids, has been associated with slowing and even preventing the metabolic syndrome, protecting the kidneys, and reducing the risk of other chronic diseases such as heart disease and diabetes and, more specifically, neurodegenerative disease. For example, a meta-analysis published in the October 2013 issue of Annals of Neurology showed that high adherence to a healthful dietary pattern, such as the Mediterranean diet, may be beneficial in the prevention of various conditions linked to the aging brain, including cognitive decline, depression, and stroke. The research team behind the meta-analysis found that a Mediterranean diet was protective for both of the study’s subgroups, participants who had mild cognitive decline and those who had advanced cognitive decline, and showed positive effects when looking specifically at Alzheimer’s.

Another meta-analysis, published in the July 2013 issue of Epidemiology, found that greater adherence to a Mediterranean diet was associated with slower cognitive decline and a lower risk of developing Alzheimer’s. The researchers of this meta-analysis suggested that further studies are warranted to clarify a possible association between diet and mild cognitive impairment or vascular dementia, along with long-term randomized controlled trials looking more closely at the possibility of preventing or delaying the onset of Alzheimer’s.

Researchers and dietitians agree that consuming a diet that is plant based, focused on real and whole foods, and devoid of processed foods and red meat has much to do with its positive effects on cognitive health.

 

Weighing in on the Research
Proponents of the Mediterranean diet tend to single out the health benefits of olive oil and focus on the omega-3 fatty acids. However, some believe the cognitive benefits may result more from a synergistic combination of all the healthful foods that make up the diet. It might be the omegas, the antioxidants, the flavonols, and the large number of vitamins all working together to have the positive benefit of reducing cognitive impairment. Or it may just be the fact that those who consume a Mediterranean diet tend to be healthier individuals in the first place.

While focus often is placed on the foods eaten in any given diet, with the Mediterranean diet, it may be as much about what’s not eaten that makes this diet so beneficial. In a traditional Mediterranean diet, you’re avoiding high amounts of meat, refined carbs, and highly processed foods, and in their place you’re filling up with all the good stuff: minimally processed grains, lots of seasonal and local fruits and vegetables, legumes, olive oil, nuts, and seeds. You’re limiting saturated fats, high-glycemic carbs, sodium, and cholesterol because you’re not eating a lot of meat and highly processed food. The Mediterranean diet originated from one that was locally available in poor countries. They ate things that surrounded them, and there was no room for industrial, imported foods. It was the ‘poor man’s diet’ in which people made something of nothing—foraging foods, fishing the oceans, and growing their own produce.

In addition, research on the brain has indicated that chronic inflammation is a factor in Alzheimer’s development, and therefore the anti-inflammatory effects of the Mediterranean diet are surmised to be a possible reason behind improved cognitive function. Some components present in fruits, vegetables, nuts, red wine, and virgin olive oil are able to exert potent anti-inflammatory effects.

 

Incorporating the Mediterranean Diet
The first step is education about the Mediterranean diet. The keys are that it is plant based, it involves whole foods, and it involves real food.  At its core, the diet focuses on whole, locally available, seasonal plant foods; healthful fats; and fish as the primary non-plant protein. So you can take that concept and apply it to a diet in the Midwest, Northwest, or South by asking: what are the locally available whole plant foods in this region? And what fish are available? Adherence to the diet also means applying it to particular culinary traditions within a person’s lifestyle: for example, if you have Scandinavian heritage, you can apply the Mediterranean diet strategy to your own favorite food traditions by eating whole grain rye bread, enjoying traditional fish dishes, and enjoying favorite vegetable dishes such as those based on beets, cabbage, and carrots.

While the Mediterranean diet is focused on fish as a main protein source, those who have trouble giving up red meat may be pleased to know that grass-fed lean beef, though often much more expensive than non–grass-fed beef, is high in omega-3 fatty acids and low in fat. Contradictory to what people have heard for so long about the Mediterranean diet, this is a way that you’re able to make a compromise and get that beef, which can be hard for some to give up. It’s more costly, so it might be once a week or a special treat.

Produce also can be expensive, but for those who are concerned about cost, buying what’s in season will be most cost-effective and most tasty, too. Roasting vegetables is wonderful, and it’s easy. All you need is a little bit of olive oil and some herbs and spices. You can try any combination: shallots and onions with savory chunks of squash, broccoli and garlic, or whatever it is you prefer. The next day the vegetables are delicious cold or tossed in with a salad.

The bottom line is that one reason the Mediterranean diet has such health potential is that it’s delicious and easy, and it sets people up for success. The diet has evolved over thousands of years. You can have a good percentage of healthful fat—olive oil, avocados, and nuts—which makes everything taste great. And the foods have lots of flavor; they’re fresh and local. Plus it even includes moderate wine consumption. It’s about a lifestyle, not a diet. If you go to the Mediterranean, you’ll observe that people don’t think of their eating style as a diet, it’s just the way they live—and they love it.

 

Lindsey Getz