Swapping out tasty but nutrient-poor foods for healthier options can have significant benefits for brain health.
The study, led by Jianfeng Feng, a professor at the University of Warwick, highlighted the importance of establishing a healthy diet from a young age.
“Developing a healthy balanced diet from an early age is crucial for healthy growth,” Feng stated in a press release. “To foster the development of a healthy balanced diet, both families and schools should offer a diverse range of nutritious meals and cultivate an environment that supports their physical and mental health.”
Impact of Diet on Brain Health
Prior research has shown that specific dietary patterns can affect mental and cognitive functions, but there are still gaps and inconsistencies in the data. To address these gaps, the NMH study examined data from 181,990 individuals in the UK Biobank to understand how dietary patterns influence brain structure, blood markers, genetic changes, mental health, and cognitive function.
- Subtype 1—high preference for vegetables, fruits, and proteins, low preference for starches
- Subtype 2—resembles a vegetarian diet with high preference for vegetables and fruits, low preference for proteins
- Subtype 3—unhealthy diet low in fiber, high in proteins and snacks, low preference for vegetables and fruits
- Subtype 4—healthy diet with balanced preferences across all food groups
The study found that food preferences can impact the brain’s adaptability, leading to structural changes that influence mental and cognitive health. Additionally, there is a bidirectional link between mental health and cognition.
Additional Insights
Vegetarian Diet and Mental Health
Subtype 2, the vegetarian diet, was associated with higher rates of mental health symptoms such as anxiety, depression, self-harm, and psychosis. Individuals in this group also exhibited more gene variants related to mental health, suggesting a genetic predisposition to these conditions.
Unhealthy Diet and Inflammation
Subtype 3, the unhealthy diet high in protein but low in fiber, had lower well-being scores and increased likelihood of anxiety, depression, and stroke compared to those following the balanced subtype 4 diet. These results align with previous research linking dietary quality to overall well-being.
Diet and Brain Structure
The study found significant differences in gray matter volume (GMV) in individuals following the unhealthy subtype 3 diet compared to those on the balanced subtype 4 diet. This aligns with previous research linking diets rich in antioxidants, vitamins, and omega-3 fatty acids to higher GMV, while diets high in protein, trans-fat, and saturated fat are associated with lower GMV.
Diet and Cholesterol/Fat Biomarkers
Biomarker analysis revealed that the balanced subtype 4 diet had higher levels of HDL cholesterol, known as “good” cholesterol, compared to the unhealthy subtype 3 diet. Additionally, the vegetarian subtype 2 and subtype 3 diets had lower levels of essential healthful fatty acids like omega-3s, likely due to a lack of fish consumption.
Genetic Influence on Brain Health
The study identified several genes with increased expression in multiple brain regions, many of which also showed changes in GMV. This suggests that genes play a significant role in brain structure and may influence how dietary patterns impact brain health.
Brain-Friendly Foods
The authors of the NMH study recommended a diet rich in vegetables, fruits, grains, nuts, seeds, moderate dairy, eggs, fish, and legumes, similar to the Mediterranean diet. Research indicates that the Mediterranean diet offers multiple health benefits, not just for brain health.
Fruits and Vegetables
A 2020 review highlighted the benefits of high fruit and vegetable intake, particularly citrus, berries, and green leafy vegetables. These foods can improve self-efficacy, optimism, reduce psychological distress, and protect against depression. Experts recommend consuming five servings per day.
Kimberly Pierpont, a registered dietitian nutritionist at The Ohio State University Wexner Medical Center, emphasized the importance of antioxidants found in fruits and vegetables for brain health.
Whole Grains
A 2023 review linked whole grains to improved mood, lower anxiety and depression rates, and higher GMV. Examples of whole grains include brown rice and products labeled “100 percent whole grain” or “100 percent whole wheat.” Refined grains like white rice and bread lack fiber and essential nutrients found in whole grains.
Bran, the outer layer of whole grains, contains folate, which is crucial for cognitive function and DNA repair, as neurons in the brain are not easily replaceable.
Nuts
Another 2020 review found cognitive benefits from nut consumption, especially in individuals at higher risk of cognitive decline. Walnuts, in particular, showed positive results, attributed to their polyphenol content that acts as antioxidants and improves blood flow to the brain.
Extra Virgin Olive Oil
Studies have suggested that extra virgin olive oil may help prevent dementia and delay cognitive decline due to its healthy fat content and phenolic compounds.
Fatty Fish
A 2021 review found that increased fatty fish consumption lowered the risk of Alzheimer’s disease. Omega-3 fatty acids found in fish like salmon, herring, and sardines are essential for brain function and normal brain development.
Spices
A 2020 study associated spicy food intake with improved cognition and biomarker reversal for Alzheimer’s disease. Capsaicin, found in cayenne pepper, may have the potential to impact brain health positively.
Eggs
Research suggests that consuming eggs, particularly one per week, can slow memory decline in later life. Eggs contain nutrients like choline, tryptophan, and lutein, which support cognitive function and memory, especially in older adults.
Moderate Dairy
Regular intake of fermented dairy products like yogurt may help protect against dementia and cognitive decline. Compounds in fermented cheeses like Camembert may also offer neuroprotective benefits.
Legumes
Legumes such as beans, peas, and lentils are rich in vitamins necessary for neurotransmitter synthesis, which can influence mental health and mood.
Brain-Unfriendly Foods
Processed Meat
Studies suggest a link between processed meat consumption and increased risk of depression, dementia, and Alzheimer’s disease.
Sugar
Excessive sugar consumption can have long-lasting negative effects on mood, memory, and cognitive function, contributing to cognitive decline and dementia.
Saturated Fat
Prior research has linked saturated fat to impaired learning and memory, as well as reduced gray matter volume in the brain.
Improving Diet at Any Age
The NMH study emphasizes the importance of adopting a healthy diet early in life. While starting early may yield more benefits, it is never too late to make positive changes to your diet, even in later stages of life.
