A Healthy Diet Supports Brain Health

They say, "You are what you eat." It turns out this is particularly true for your brain.

A poor diet can contribute to increased risk of neurodegeneration.^1,2 A healthy diet can help maintain peak mental performance and shield against cognitive decline and dementia.

For example, one study found that older adults who closely adhered to a Mediterranean diet had a whopping 72% lower risk of developing dementia than those who did not follow this diet.³

The Link Between Diet and Brain Function

A healthy diet provides a wide array of vital nutrients, including healthy fats like omega-3 fatty acids, minerals like magnesium, plant compounds like polyphenols/carotenoids, and more.⁴

Poor diets, including the standard American diet, are often lacking in these nutrients. They provide excess calories and an overabundance of unhealthy fats, carbohydrates, and processed sugars.⁴

The brain can be critically impacted by diet.

A large population study that followed over 10,000 Brazilian participants for eight years found that consuming even modest amounts of ultra-processed food is associated with a 28% faster rate of cognitive decline as compared to those who don't eat it.⁵

Epidemiological studies and reviews of clinical trials support the theory that certain modifiable lifestyle factors, including diet, are linked to cognitive function and risk of its deterioration in older age.^6-8

Generally, the most protective diets (including Mediterranean, MIND, and DASH) include:

• Ample amounts of fruits, vegetables, nuts, and legumes (beans, peas, and lentils),
• Moderate consumption of fish, and
• Low to moderate intake of dairy and meat products.⁹

Multiple reviews and analyses of human studies suggest that the more people adhere to diets that follow these patterns, the better their cognitive function and the lower their risk of cognitive decline and dementia, including Alzheimer's.^6,7,9

Healthy eating patterns are particularly supportive of cognitive function, lowering the risk of neurodegenerative disease and age-associated cognitive decline.^10,11

For instance, greater legume and nut intake correlates with better performance in cognitive functioning.7

On the other hand, typical Western diets are associated with overall cognitive function decline,¹² dementia, increased risk of Alzheimer's,² and diminished executive function.⁷

The Best Brain Diets

Two of the beneficial dietary patterns are the Mediterranean diet^11,13-16 and the MIND diet.^17,18

Both emphasize eating large amounts of vegetables, fruits, whole grains, olive oil, legumes, nuts, and fish. They limit red meat intake, contain little or no highly processed foods, and include small amounts of wine.

The MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet emphasizes consuming green leafy vegetables like spinach and kale and prioritizes berries over other fruit.⁹

Numerous studies show that following the Mediterranean^14,15 or MIND diet^17,18 correlates with better cognitive function, a significant reduction in risk for cognitive dysfunction, and lower risk of Alzheimer's and other forms of dementia.

In one study, older adults who most closely followed a Mediterranean diet had a massive 72% lower risk of developing dementia compared to those who did not adhere to this diet.³

Key Nutrients Tied to Cognitive Function

Brain-health diets include large amounts of specific nutrients that may be particularly beneficial. They include:

• Polyphenols and carotenoids. These health-promoting plant compounds have potent antioxidant and anti-inflammatory properties. Examples found in many fruits and vegetables include lutein, zeaxanthin, resveratrol, and more.¹⁹
• Olive oil. Olive oil is a rich source of polyphenols such as oleuropein that have been found to be neuroprotective.²⁰ Diets that include olive oil have been tied to better cognitive function and reduced risk of dementia.²¹
• Vitamin C. Various studies have linked vitamin C status to cognitive function.^22,23 Low levels of vitamin C have been tied to reduced mental vitality. Oral intake of 500 mg vitamin C two times a day for four weeks has been shown to improve levels of attention in healthy young adults in a clinical trial.²⁴ Citrus fruits, tomatoes, broccoli, and spinach are important sources of vitamin C.²⁵
• B vitamins. Vitamins B6, B12, thiamine (B1), and folate (B9) all may support short-term memory in aging individuals and are found in various fruits and vegetables.²⁶ Deficiencies of any of these can cause depression, confusion, fatigue, brain fog, and irritability.²⁷
• Magnesium. In observational studies, those with the highest magnesium levels perform better on cognitive tests, have lower risk of developing dementia, and maintain larger brain volumes.^28-30 Seeds and nuts, spinach, beans, some fruits, and soybeans are good sources.³¹

WHAT YOU NEED TO KNOW

Brain-Supporting Diets

• Studies show that largely plant-based diets low in processed foods are associated with better cognitive function and reduced rates of cognitive decline and dementia.
• The Mediterranean and MIND diets, which emphasize vegetables, fruits, whole grains, olive oil, legumes, nuts, and fish, shield against brain aging and risk for cognitive impairment while boosting mental function.

How Diet Supports the Brain

There are numerous ways that diet impacts the brain. Here are just some of the most important:

• Neuroinflammation: Cognitive decline and neurodegenerative diseases such as Alzheimer's and Parkinson's disease are all driven, in part, by inflammation in the brain. A healthy diet can prevent or reduce neuroinflammation.³²
• Oxidative stress: A largely plant-based diet provides antioxidants that help counter oxidative stress, including vitamin C, vitamin E, polyphenols, and carotenoids.³²
• Obesity and metabolic disease: Excess body weight and metabolic abnormalities are associated with impaired cognitive function and accelerated development of cognitive dysfunction. A healthy diet can help prevent or reverse these body changes.¹¹
• Gut dysbiosis: The close link between gut health and brain health is known as the "gut-brain axis."³³ Poor diet is the top cause of dysbiosis, an abnormal mix of gut microorganisms that encourages inflammation and metabolic problems.

  Improving the gut microbiome through better diet can boost brain health.³⁴ Research has suggested that adherence to a Mediterranean diet may reduce the risk of neurodegenerative diseases by maintaining a balanced microbiome.³⁵

• Inhibition of NF-kB: Excess calorie intake increases activity of the protein complex nuclear factor-kappa B (NF-kB), which contributes to chronic inflammation and metabolic disease. A healthy diet can inhibit NF-kB, reducing these contributors to brain deterioration.³²

A mostly plant-based diet can provide these and other benefits to support optimal brain health, as shown in human studies.³⁶

Summary

Consistent findings document that ingesting more unprocessed and plant foods, such as those found in the Mediterranean and MIND diets, is significantly associated with improved brain health and lower rates of dementia.

Some specific foods and nutrients found in these diets, including olive oil, fish-derived omega-3 fatty acids, polyphenols, carotenoids, vitamins and minerals, have been shown to provide cognitive benefits.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

Comprehensive Nutrition and Brain Aging Study

The results of a fascinating new study were published in the medical journal NPJ Aging, associated with the prestigious Nature journal.³⁷ It represents one of the largest and most comprehensive studies that have assessed links between diet and nutrition and brain health.

This study stands out from many others that have evaluated the links between diet and brain health in a number of notable ways. For one, many prior studies used only one marker of brain health or a small set of markers. For example, they may have used a single standardized test to evaluate cognitive function.

The design of the study by Zwilling et al. was much more comprehensive. Not only did the authors assess cognitive function, but they also used brain imaging and other testing to evaluate brain structure and metabolism. As there are structural and metabolic changes that can accompany brain aging and progression of cognitive decline, looking at these results gives a much broader assessment of brain health status and allowed the researchers to estimate each subject's "brain age."

The other way this study differentiates itself is in the way it assessed diet and nutrition. Many other studies assess dietary intake of nutrients based on detailed surveys, questionnaires, or journals completed by the subjects. These methods are, of course, prone to inaccuracy and subjectivity.

The Zwilling study instead used blood-based biomarkers of diet and nutrition to objectively measure the levels of nutrients found in each subject's body. Unlike a survey or questionnaire, a blood test is not something that a subject could "fake" or misremember.

What did the researchers find? They discovered that the subjects generally fell into two major groups defined by their brain aging and dietary/nutrient patterns. The scientists called the first group the "accelerated aging" group because their brain aging markers were significantly more advanced compared to the other group. The second group was called the "delayed aging" group because their brain structure and function were superior to the first group and testing revealed "slower-than-expected" brain aging.

They found that demographics (age, gender) and anthropometrics (body weight, BMI, etc.) could not account for the differences between these two groups. Instead, they found that the delayed aging group was associated with a greater body content of several key nutrients. For one, they had higher levels of some important healthy fats, including some monounsaturated fatty acids and omega-3 polyunsaturated fatty acids.

In addition to healthy fats, they found elevated levels of the carotenoids lutein and zeaxanthin as well as vitamin E and choline. Lutein and zeaxanthin have long been recognized in maintaining eye health, but recent studies show their levels also correlate with healthier brain function and reduced risk of dementia.^38-42 Choline is an essential nutrient that is also important for healthy brain function.⁴³

This compelling study adds to the growing knowledge of dietary patterns and specific nutrients that are most important to optimal brain health and reducing risk of accelerated brain aging and cognitive decline.

New Study Data: Diet, Inflammation, and Brain Health

It is recognized that chronic inflammation is a major contributor to rapid aging and risk for many age-related diseases—including cognitive decline and dementia.^44,45 And diet is a major determinant of body-wide inflammation. While some foods have an anti-inflammatory effect, many foods consumed in modern Western diets are pro-inflammatory, meaning they contribute to and worsen inflammation.⁴⁶

Some diets—such as the Mediterranean diet discussed in this article—are considered anti-inflammatory, including a greater intake of anti-inflammatory foods and nutrients and less pro-inflammatory ones.

A study published this year looked at data from the famous and robust research cohort, the UK Biobank, to evaluate the impact of anti-inflammatory diets on risk for dementia. The subjects included in this analysis had a history of cardiometabolic disease—including type II diabetes and/or a history of heart disease or stroke.⁴⁷

Cardiometabolic disease is an important risk factor for accelerated brain aging for at least two reasons. First, poor diet and inflammation are underlying causes of both cardiometabolic health and brain health. Furthermore, poorly controlled metabolic disease is an additional contributor to risk for cognitive decline and dementia. In other words, this group of UK Biobank subjects with cardiometabolic disease would normally be at high risk of progressing to dementia.

The researchers in this study used a detailed dietary questionnaire to estimate the intake of over 30 key nutrients known to be either anti-inflammatory or pro-inflammatory. Using this information, they were able to calculate dietary inflammatory index scores for each subject.

With over 12 years of follow-up, they were able to determine that people with cardiometabolic disease who followed an anti-inflammatory diet, compared to those who did not, were 31% less likely to develop dementia. While all patients with cardiometabolic disease have some increased risk for cognitive decline, an anti-inflammatory diet can have an important impact and can significantly reduce the risk.

In addition, the study evaluated brain MRIs of subjects. They found that those with more anti-inflammatory diets had larger gray matter brain volumes and less evidence of white matter disease. In other words, an anti-inflammatory diet appears to be protective against the damage and loss of brain volume that is seen in older adults suffering from cognitive deterioration.

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