A study from the UK published in Nature Mental Health (NMH) on April 1, found that a healthy, balanced diet links to superior cognitive function, mental well-being, and brain health. It even increases gray matter, an effect associated with higher intelligence. The findings provide more evidence that the adage, “You are what you eat,” applies to both the mind and the body.
The results were so robust that lead author Jianfeng Feng, a professor at the University of Warwick, emphasized the importance of adopting an optimal diet in childhood.
“Developing a healthy balanced diet from an early age is crucial for healthy growth,” he said 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.”
Diet Links to Striking Effects on Brain Health
While prior research indicates certain dietary patterns are associated with mental and cognitive effects, gaps and inconsistencies are present. To narrow the gaps, the NMH study used data on 181,990 individuals from the UK Biobank to identify dietary patterns and how they link to brain structure, blood biomarkers, genetic changes, mental health, and cognitive function.
Analysis of food preferences and consumption revealed that people fall into one of four main dietary patterns:
- Subtype 1—a higher preference for vegetables, fruits, and proteins and a lower preference for starches
- Subtype 2—resembles a vegetarian diet, with a higher preference for vegetables and fruit and a lower preference for proteins
- Subtype 3—an unhealthy diet low in fiber, with a higher preference for proteins and snacks and a lower preference for vegetables and fruits
- Subtype 4—a healthy diet, consisting of balanced preferences among all food groups
A primary discovery was that food preferences affect the adaptability of the brain, which can lead to structural changes that influence mental and cognitive health. Secondly, a directional link exists between mental and cognitive health—meaning mental health plays a role in cognition.
Further Findings
Vegetarian Diet Links to Increased Mental Conditions
Subtype 2, the vegetarian diet, linked to a higher incidence of mental health symptoms, including anxiety, depression, self-harm, and psychosis. People in this group had more gene variants in mental health, which suggests the possibility that genetic susceptibility may underlie increased mental health conditions.
Unhealthy Diet Links to Inflammation and Mental Disorders
Subtype 3, the unhealthy diet, high in protein but low in fiber, had lower well-being scores than other subtypes. Individuals in this group had a higher likelihood of anxiety, depression, and stroke than those in the healthy, balanced subtype 4 diet. These results are consistent with earlier research that associates dietary quality with well-being.
The authors theorized that this link may stem from the effects of high-fat foods, which increase the release of inflammatory factors and cause gut bacteria to permeate through intestinal walls. Blood and biomarker evidence supported this theory, as subtype 3 had higher levels of substances indicating inflammation than subtype 4. These findings are in line with earlier studies, such as a 2020 review, that associate an unbalanced diet with a higher likelihood of mental disorders.
Diet Affects Brain Structure
One difference in structure involved gray matter volume (GMV). Gray matter is the part of the brain that processes information, versus white matter, the part of the brain that permits communication between gray matter regions.
The unhealthy subtype 3 diet had significantly lower GMV in 11 brain regions, compared with the balanced subtype 4 diet. This concurs with earlier studies, such as a 2017 study, that link a diet plentiful in antioxidants, vitamins, and omega-3 fatty acids to higher GMV. It is also consistent with research associating diets high in protein, trans-fat, and saturated fat to lower GMV.
Diet also affects white matter, with subtype 3 showing poorer integrity in this structure than subtype 4. This was noted in an array of brain regions involved in memory, cognition, motivation, emotions, and sensory and motor symptoms. It also corroborates prior studies, such as a 2016 study, that indicate healthy dietary components are associated with increased white matter integrity.
Diet Affects Cholesterol and Fat Biomarkers
Biomarkers appeared to be sensitive reflectors of diet quality. The balanced subtype 4 diet had higher levels of HDL, “good” cholesterol, than the unhealthy subtype 3 diet. The vegetarian subtype 2 diet and subtype 3 diet had significantly lower levels of important healthful fatty acids, such as omega-3s, which may stem from a lack of fish in the diet.
Genes May Influence Brain Health
The authors identified an array of genes with elevated expression in multiple brain regions. Many of these regions also showed changes in GMV, a finding that supports the theory that genes have a critical influence on brain structure and may affect how dietary patterns impact brain health.
What Foods Are Brain Friends?
The authors of the NMH study suggested that a healthy diet consists of balanced amounts of vegetables, fruits, grains, nuts, seeds, moderate dairy, eggs, fish, and legumes. This diet resembles the Mediterranean diet, which is rich in these foods and low in red meat. It is worth noting that research indicates the Mediterranean diet has multiple health benefits, including those unrelated to brain health.
Below are discoveries from prior research on the mental and cognitive health benefits of each brain friend food group.
Fruits and Vegetables
A 2020 review found that the most robust research findings on this food group indicated high fruit and vegetable intake and certain subgroups—including citrus, berries, and green leafy vegetables—offer several advantages. These foods may foster higher levels of self-efficacy and optimism, as well as decrease psychological distress and protect against depression. Experts recommend getting five servings per day.
In an email to The Epoch Times, Kimberly Pierpont, a registered dietitian nutritionist at The Ohio State University Wexner Medical Center, pointed out some nutritional highlights.
“The brain is susceptible to oxidative stress,” she said. “Fruits and vegetables contain antioxidants that protect the brain by capturing free radicals and preventing oxidative damage. This can reduce age-related memory loss and decrease the risk of neurological disorders.”
Whole Grains
A 2023 review associated whole grains with enhanced mood and a lower incidence of anxiety and depression. It also linked them to higher GMV.
Examples of whole grains are brown rice and breads and pastas labeled “100 percent whole grain” or “100 percent whole wheat.” Refined grains, such as white rice and white bread, do not fit into a healthy category, as they lack fiber and contain only a small fraction of the nutrients in whole grains.
Ms. Pierpont explained that bran, the outer layer of the whole grain, contains folate. Folate continues to benefit the mind throughout the lifespan, as it maintains cognitive function and repairs DNA, which is important because most neurons in the brain are not replaceable.
Nuts
An additional 2020 review found that nut intake produced a more noticeable cognitive benefit in people at higher risk of cognitive impairment than those who are not. Studies on walnuts had more consistently positive results, but further research is necessary to prove they offer more cognitive advantages than other nuts.
“Nuts contain polyphenols which are antioxidants,” continued Ms. Pierpont. “Polyphenols protect the brain by capturing free radicals and preventing oxidative damage. They have also been found to improve blood flow to the brain.”
Extra Virgin Olive Oil
Extra virgin olive oil may help prevent the development of dementia and delay cognitive decline, stated another 2023 review. It contains high levels of healthy fat—monounsaturated and polyunsaturated fatty acids—as well as phenolic compounds. These nutrients may have a neuroprotective effect that underlies the benefits.
Fatty Fish
A 2021 review found that higher intake of fatty fish was associated with a lower risk of Alzheimer’s disease, and moderate intake of fish in childhood and adolescence may have some cognitive advantages.
Fatty fish contain an omega-3 fatty acid called docosahexaenoic acid (DHA). DHA and other fatty acids are the essential building blocks of the brain, according to Ms. Pierpont. They are required to keep the brain functioning normally. Salmon, herring, and sardines contain the highest levels of DHA.
Spices
A 2020 study associated spicy food intake with higher cognition and reversed biomarkers for Alzheimer’s disease in cerebrospinal fluid. This suggested that a diet rich in cayenne pepper, which contains the compound capsaicin, has the potential to change the pathology in the brain associated with Alzheimer’s disease.
Eggs
An intake of about one egg per week was associated with a slower memory decline in later life compared to eating little or no eggs, found a 2021 study. While it was not clear if increasing the weekly servings of eggs resulted in an additional benefit, the results offer support for the protective effect of eggs on memory, particularly after age 70. Eggs contain choline, tryptophan, and lutein, nutrients that may enhance cognition.
Moderate Dairy
A 2018 review found regular intake of fermented dairy products, such as yogurt, have the potential to contribute to protection against dementia and cognitive decline. The fermentation of lactic acid bacteria generates nutrients that may be responsible. Compounds in Camembert cheese, which is fermented, may help protect against Alzheimer’s disease.
Legumes
A 2015 research article includes legumes in a list of brain foods. Legumes like beans, peas, and lentils are good sources of vitamins needed to synthesize neurotransmitters that influence mental health, such as serotonin.
What Foods Are Brain Foes?
Processed Meat
A statistically significant link may exist between processed meat and a risk of depression. An association between processed meat consumption and all-cause dementia and Alzheimer’s disease may also be present.
Sugar
Chronic excess sugar consumption has long-lasting negative effects on mood, memory, object recognition, and concentration. Refined sugar may be a major contributor to cognitive decline and dementia.
Saturated Fat
The NMH study noted that prior research linked saturated fat to decreased learning and memory, as well as smaller GMV. Although for some time, cardiologists have advised people to limit saturated fat for heart health and cholesterol, this has been a topic of controversy in more recent years.
Is It Ever Too Late to Improve Diet?
Authors of the NMH study urged the adoption of a healthy diet in childhood. The assumption is that the earlier in life people start, the more mental and cognitive benefits they may receive. However, if someone waits until late in life to improve their eating habits, is it worthwhile?
It is never too late to improve your diet, Eric Ciappio, a registered dietician at Balchem Human Nutrition & Health, told The Epoch Times in an email.
“In nutrition, we strongly recommend that people adopt healthy dietary patterns early in life to help achieve their health goals. That said, just because you haven’t had a perfect diet doesn’t mean that you can’t make changes today,” he said. An older adult can still receive benefits from healthy dietary changes.
