A Lot on Your Plate
by Women’s Brain Health Initiative:
ADOPTING THE MIND DIET FOR BRAIN HEALTH.
The MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay) was developed in 2015 to prevent Alzheimer’s dementia by nutritional epidemiologist Dr. Martha Clare Morris and her colleagues at Chicago’s Rush University Medical Center and Harvard T.H. Chan School of Public Health.
Founded on the premise of “diet as a medicine,” this eating plan is a hybrid of the DASH (Dietary Approaches to Stop Hypertension) diet and Mediterranean diet and includes evidence-based recommendations to consume foods and nutrients that improve brain health.
The MIND diet, DASH, and Mediterranean diet all emphasize intake of fruits and vegetables, lean meats, fatty fish, unsaturated fats, and plant-sources of protein (e.g., nuts, beans, and lentils). Where they differ is in their nutrient- and food-specific recommendations.
THE DASH DIET
This diet was designed to reduce blood pressure and recommends lowering intake of sodium, saturated fat, and added sugars, while increasing intake of nutrients and food components known to decrease blood pressure (e.g., potassium, calcium, magnesium, fibre, protein). Daily recommendations include intake of grains, fruits, vegetables, fat-free or low-fat dairy products, lean meats, poultry, and fish.
THE MEDITERRANEAN DIET
This diet came about in efforts to describe eating patterns within countries by the Mediterranean Sea, like Greece, France, Spain, and Italy, where there are relatively low rates of cardiovascular disease. While there are several “Mediterranean-like” diets that have been studied over the years, key recommendations include daily consumption of fish, unprocessed whole grains, olive oil (or other plant oils), fruits, and vegetables.
THE MIND DIET
This hybrid diet borrows elements from the DASH and Mediterranean diets and emphasizes intake of nutrients that improve brain health and address risk factors for Alzheimer’s disease (AD).
COMPONENTS OF THE MIND DIET
There are 14 dietary components to the MIND diet. The original version included one serving of wine per day as a brain-healthy food, but it has since been removed based on current evidence that suggests risk of wine (alcohol) consumption outweighs potential benefits.
9 BRAIN-HEALTHY FOODS TO EAT
EVERY DAY
whole grains (three servings)
green leafy vegetables (at least 1 serving)
other vegetables (at least 1 serving)
MOST DAYS
nuts
beans and legumes
TWICE A WEEK
berries
poultry
ONCE A WEEK
oily fish
OLIVE OIL (if adding fat to meals)
5 UNHEALTHY FOODS TO LIMIT
RED MEATS (less than 4 servings per week)
BUTTER AND STICK MARGARINE (less than 1 tablespoon/day)
CHEESE (less than 1 serving/week)
PASTRIES AND SWEETS (less than 1 serving/week)
FRIED OR FAST FOODS (less than 1 serving/week)
The MIND diet offers more flexibility for meal plans when compared to the DASH and Mediterranean diets, with only three foods to incorporate daily: whole grains, green leafy vegetables, and other vegetables.
Moreover, with its guidance to consume plant sources of protein like nuts, beans, and legumes most days and limit intake of butter and cheese, the MIND diet is easily adapted for vegetarians and vegans.
A key distinguishing factor of the MIND diet from its predecessors is that berries are the only fruit to make it on the list of brain-healthy foods, with a specific recommendation to consume berries twice a week.
Though all fruits are good sources of nutrients that may be consumed when following the MIND diet, research has shown that berries have direct benefits to brain health through antioxidant and anti-inflammatory activity, and improvements to cognitive function.
RESEARCH HIGHLIGHTS ON THE MIND DIET & BRAIN HEALTH
The effect of the MIND diet on brain function and disease is a burgeoning area of research. The earliest studies published in 2015 in Alzheimer’s & Dementia from the Rush Memory and Aging Project showed that high adherence to the MIND diet was linked to slower cognitive decline and 53% lower risk of AD.
This finding was comparable to the effect of the Mediterranean diet (54% lower risk of AD) and higher than that of the DASH diet (39% lower risk of AD). Encouragingly, findings showed that even moderate adherence to the MIND diet appeared to be protective against AD (35% lower risk of AD), suggesting that there was some “wiggle room” when adopting brain-healthy eating habits. A similar trend was not seen for the Mediterranean or DASH diets.
THERE WAS ALSO EVIDENCE OF GREATER PROTECTION FROM AD THE LONGER THE MIND DIET WAS FOLLOWED, SUGGESTING THAT ADOPTION OF MIND DIET HABITS IN EARLY ADULTHOOD WAS BENEFICIAL.
Since 2015, the MIND diet has been examined alongside a number of lifestyle and environmental factors. Here are some highlights:
THE MIND DIET CAN IMPROVE COGNITION.
A study published in Journal of the American Geriatrics Society in 2017 by Dr. Claire McEvoy et al. showed that there is an association between the MIND diet and cognitive function in older adults, with greater adherence showing better cognition and lower risk of cognitive impairment. Data were drawn from the nationally representative Health and Retirement Study in the United States.
BEING PHYSICALLY ACTIVE WHILE ON A MIND DIET PROVIDES ADDED BENEFITS FOR BRAIN HEALTH.
A study published in Alzheimer’s & Dementia in 2021 by
Dr. Thomas Holland and colleagues showed that there is a synergistic relationship between the MIND diet, physical activity, and brain health.
Among participants without cognitive impairment, those with high adherence to the MIND diet who also engaged in high levels of physical activity showed better memory and cognition scores and slower rates of decline in global cognition over time when compared to those with high adherence to the MIND diet and low rates of physical activity. Data was drawn from the Memory and Aging Project.
THE MIND DIET MAY MAINTAIN COGNITIVE FUNCTION EVEN AMONG THOSE WITH BRAIN PATHOLOGIES.
A 2021 study published in Journal of Alzheimer’s Disease by Dr. Klodian Dhana and colleagues looked at the final set of cognitive tests and brain pathologies (e.g., accumulation of protein deposits in the brain) post-mortem among 569 participants of the Memory and Aging Project. Participants with a higher MIND diet score had better global cognitive functioning prior to death.
In fact, there was a group of participants with high MIND diet scores with enough protein deposits in the brain to constitute AD who were symptom-free and did not have a clinical diagnosis when they were alive. Authors pointed to this as preliminary evidence that the MIND diet has a protective effect on memory and thinking even as brain diseases progress.
THE MIND DIET MAY LOWER RISK OF DEATH FROM ALL CAUSES.
A longitudinal cohort study by Dr. Janie Corley looked at the dietary patterns of 882 participants in Scotland. Published in Public Health Nutritionin 2022, data showed that during a 12-year follow-up, participants with the top third of MIND diet scores had a 37% lower risk of death from all causes when compared to those with the bottom third of the MIND diet score.
Similar trends were not seen for those following a Mediterranean-type diet or traditional dietary patterns. Corley suggested that public health recommendations based on the MIND diet may help to promote longevity.
To date, most research on the MIND diet has been observational, that is, based on trends seen in cohort studies or population studies. Findings based on interventions, like randomized controlled trials, are needed to prove whether the MIND diet is specifically responsible for the positive health outcomes noted in previous research.
A groundbreaking three-year randomized control trial, known as the “Mediterranean-DASH Intervention for Neurogenerative Delay (MIND) Study: Rationale, Design and Baseline Characteristics of a Randomized Control Trial of the MIND Diet on Cognitive Decline” study, is currently underway. Led by the two research centres that developed the MIND diet, Rush University and the Harvard T.H. Chan School of Public Health, the study will test the effects of the MIND diet on cognitive decline among 604 participants without cognitive impairment who are overweight and have suboptimal diets.
Data collection concluded in 2021, and analyses are ongoing to examine the role of the MIND diet on a host of outcomes including cognitive function, changes in brain volume, and cardiovascular risk factors. Researchers are hopeful that findings from the trial may be the basis for future prevention and treatment of brain diseases and many other health conditions.
So while the research isn’t fully conclusive in terms of the how the MIND diet affects brain health, it does seem promising, so you may want to give this flexible approach to eating a try.
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Origins of the MIND Diet
The Rush Memory and Aging Project is an ongoing longitudinal study (with more than 1,000 participants) that examines genetic and environmental risk factors for Alzheimer’s dementia. A diverse group of participants without a dementia diagnosis have been recruited primarily through retirement communities in the Chicago area of the United States from 1997 onward (recruitment and research is ongoing).
Participants complete annual clinical evaluations, assessments of risk factors (e.g., exercise), blood tests, and provide consent for organ donation at the time of death (i.e., spinal cord, muscle and nerve, brain) so that declines in motor and cognitive function may be documented through a variety of measures. In 2004, an optional food frequency questionnaire was added, providing data that formed the basis of the MIND diet.
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Hold the Wine!
Although on the original list of brain-healthy foods, wine was removed from the MIND diet for the study “Mediterranean-DASH Intervention for Neurogenerative Delay (MIND) Study: Rationale, Design and Baseline Characteristics of a Randomized Control Trial of the MIND Diet on Cognitive Decline” (a randomized controlled trial from 2017-2021). This trial was led by research centres at Rush University and Harvard University, who developed the MIND diet.
Unlike the other nine brain-healthy components in the MIND diet where there are no known risks of consuming the recommended amounts, there is accumulating evidence that suggests having even one glass of wine per day (or an equivalent amount of alcohol) can lead to adverse health outcomes.
For example, extensive data has shown an association between low to moderate consumption of alcohol and an increased risk of developing breast cancer. According to a review published in Current Breast Cancer Reports in 2014 by Dr. Jasmine McDonald and colleagues, there is an estimated 30 to 50% increase in breast cancer risk from consuming one to two drinks per day.
Alcohol consumption has also been linked to sleep disturbances and suppressed cardiovascular recovery during the first three hours of sleep. A 2018 study in JMIR Mental Health by Dr. Julia Pietilä and colleagues showed that sleep disturbances were shown with just one drink of alcohol, and disturbances were more pronounced with more alcohol consumption. Emerging data also suggests that if you increase daily wine consumption to one glass a day from half a glass the impact on your brain volume would be equivalent to aging two years.
This finding was from a 2022 study published in Nature Communications showing that among 36,678 healthy middle-aged and older adults, alcohol intake was negatively associated with brain volume measured by MRI. This relationship was evident even among those who consumed one to two units of alcohol (e.g., 0.5–1 glass of wine) per day.
Given the strong evidence identifying health risks of low wine/alcohol consumption, it is not surprising that health experts do not recommend that non-drinkers introduce wine/alcohol into their diet. In fact, the recent release of Canada’s Guidance on Alcohol and Health in January 2023 states that “even very small amounts of alcohol can be harmful to people’s health and well-being.” The bottom line is that if you drink, reducing your intake by any amount is beneficial.
Berries are low calorie and nutrient dense when compared to other fruit, with high levels of vitamin C, manganese, vitamin K, potassium, and fibre. Berries are the richest source of polyphenols in fruit, with about triple that of plums, cherries, and apples.
In a review published in Neural Regeneration Research in 2014, Dr. Selvaraju Subash and colleagues explained that research shows polyphenols have both antioxidant and anti-inflammatory functions in the body, and are neuroprotective because they can cross the blood-brain barrier and minimize oxidative stress and tissue damage in the brain.
Polyphenols and other active compounds in berries have been linked to a range of health benefits including possibly improving motor function, cognitive function, and regulating blood sugar.
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