Talking food and brain health with Dr. Martha Clare Morris, lead researcher of the MIND diet study
Dr. Martha Clare Morris is a nutritional epidemiologist at Rush University in Chicago and the lead researcher of the MIND diet study. I caught up with Dr. Morris last month to discuss eating for brain health. I had questions about fish consumption, coffee, the pros and cons of drinking red wine, and what’s next for the MIND Diet Trial. Dr. Morris is not just an accomplished researcher in the field of nutrition and brain health; she is a gracious professional who generously answered all of my questions. Thank you Dr. Morris!
About the MIND Diet
The MIND diet study, as you may recall, was published in 2015 in the journal Alzheimer’s and Dementia. Dr. Morris and her colleagues created a small sensation with their paper that followed 758 dementia-free participants who kept diligent food diaries for 4.5 years.
MIND — Mediterranean-DASH Intervention for Neurodegenerative Delay — is a combination of the Mediterranean diet and the DASH diet, a diet to reduce hypertension. The researchers divided foods into 10 brain-healthy food groups and 5 brain-unhealthy ones. Participants’ diets were assessed weekly with a MIND diet score — a tally of brain healthy and unhealthy foods consumed.
Those with the highest MIND diet score, eating more brain healthy and less brain unhealthy foods, had a 53% reduction in Alzheimer’s risk. Followng the guidelines less rigorously — less brain-healthy foods, more brain-harmful ones — still had a significantly reduced risk of Alzheimer’s of 35%.
Reducing Alzheimer’s risk by 53% is equivalent to adding 7.5 years to one’s brainspan.
These numbers stunned the scientific community. Never before had a study shown such a dramatic impact of diet on Alzheimer’s risk.
(Read more about the MIND diet and the Mediterranean diet here:The Science Behind Alzheimer’s Prevention in the Brain Health Kitchen. Read more about the 10 brain healthy food groups here: MIND Diet Describes 10 Brain Healthy Food Groups.)
About Dr. Martha Clare Morris
Dr. Martha Clare Morris is Professor of Epidemiology, Director of the Section of Nutrition and Nutritional Epidemiology in the Department of Internal Medicine, and Assistant Provost of Community Research at Rush University Medical Center in Chicago. She received her doctoral degree in Epidemiology from the Harvard School of Public Health. Dr. Morris has over 20 years experience studying risk factors in the development of Alzheimer’s disease and other health problems of older persons, and in particular, how nutrition relates to these conditions. She is the Principal Investigator of a multi-center randomized trial of the MIND diet to prevent Alzheimer’s disease.
The MIND diet score
AF: I use the MIND diet score for my Brain Health Kitchen cooking class students to help them eat more brain-healthy foods. When you crafted the study with your colleagues, were you surprised to see a 53% reduction in Alzheimer’s risk in those with the best score?
MCM: I expected that it would perform at least as well as the Mediterranean and DASH diets. But even people who scored intermediate on the MIND score still had a 35% reduction in Alzheimer’s risk. They also had slower cognitive decline. So it seemed to perform more sensitively maybe because it was targeting the brain healthy foods in the index. That was surprising.
Even people who scored intermediate on the MIND score still had 35% reduction in Alzheimer’s risk.
AF: Yes, that was very good for people who can’t follow diets! It’s very optimistic for people who can’t eat perfectly all the time to show that small changes, small efforts are still helpful. I have a question about dairy intake and the MIND diet. The MIND diet puts cheese and butter in the brain unhealthy category, but makes no mention of milk and eggs. What is your position on dairy and brain health?
MCM: There’s a few things like that — fruit, dairy, eggs — we don’t make a comment on because they haven’t been specifically linked to brain health. So when people ask, I say: Well, if you enjoy fruit, continue to consume fruits. If you enjoy dairy, just be sure that it’s low-fat dairy because that will contribute to higher saturated fats. Dairy is certainly linked to better bone health, so just be cognizant of the higher calories and higher saturated fat.
Eggs and brain health
AF: Do you think there is anything in eggs specifically that you could call brain healthy, such as lutein?
MCM: Absolutely. The yolk of the eggs in particular, which people tend to think is bad for you, but that is where lutein, Vitamin E and choline are. There was milder evidence [about eggs] because of the number of studies that have even investigated lutein and choline and some of the other things in the yolk haven’t even been done. The research is more limited so it hasn’t moved up the list but there are certainly many nutrients, especially in egg yolks.
What about grains? MIND diet includes whole grains as part of a brain healthy diet.
AF: The recommendation for 3 servings of whole grains a day in the MIND diet study surprises many of my students. Nowadays many people are avoiding grains, and are under the impression that they are bad for the brain.
MCM: Well that’s because of that one book. [Wheat Belly: Lose the Wheat, Lose the Weight, and Find Your Path Back to Health by William Davis, MD.] If you look at the data, the studies that have been conducted, the Mediterranean and the DASH diets have a ton of evidence of the highest caliber studies, the randomized trials, where inflammation is actually decreased on those diets. As a society, we do make changes to the grain sources with genetic modification and more limited varieties of grains, and that is unfortunate. Whether that has impact on some individuals I think is an open question, but the data shows that whole grains have so many health benefits for so many chronic conditions.
The data shows that whole grains have so many health benefits for so many chronic conditions.
The confusion over omega-3 fatty acids
AF: Another topic that sometimes is a source of confusion among my patients and my students is omega-3’s. I know you’ve published data on fish consumption and the brain. How do you think the consumption of fish and Alzheimer’s prevention will fall out? Do you think we’ll keep it as one serving of fish per week as the optimal intake?
MCM: It’s one or more, not stop at one but that’s where the data shows a level of benefit to occur.
AF: And do you think that with each serving of fish per week the benefit goes up?
MCM: There are not many studies that support that, just one or two. It very well could be that there’s not enough studies with high fish consumers to be able to test that but I strictly go by the data. What are the best studies and what do they show? And that’s how that [recommendation] was formulated.
The higher the fish consumption, the greater the intake of omega-3 fatty acids. Now the data on omega-3 fatty acids is all over the place. There isn’t a consistent story there.
Perhaps it is because the interactions with other diet components are unknown to us so we don’t know how to get a clear picture. But from the clinical trials that have looked at omega-3 fatty acids in supplements, there are very few that have shown positive findings with slowing cognitive decline. However, we do know that DHA {docosahexaenoic acid} is one of the most important fats in the brain. Studies of neurodevelopment show that DHA is really essential for the brain. And it’s chemical structure allows for a lot more plasticity of the brain so that there is better neurotransmission. So why don’t we see a clearer association when we look at omega-3 fatty acid levels in the diet or blood in relation to cognition? My view is that we just haven’t figured out what is going on yet.
AF: And it may be different for cardio protection as well.
MCM: The cardio protection interestingly enough really has a similar picture. It’s just that the AHA {American Heart Association} and these other bodies have chosen to recommend a higher number of fish meals per week but the data is very similar to the dementia literature. The [studied] level of benefit really was at one fish meal or one seafood meal per week.
AF: Do you think the toxins in the seafood supply has anything to do with a blunted effect of improving cognition?
MCM: No. I have a paper that was published 2 years ago in JAMA {Journal of the American Medical Association} where we measured fish intake in a cohort study; everyone had agreed to donate their brains when they died. So we had brains of over 200 people and we looked at their fish and seafood consumption in relation to their brain neuropathology.
We found that higher seafood consumption of one seafood meal a week was associated with lower pathologies in the brain. We also measured brain tissue for mercury and there was no association between mercury and pathologies of the brain.
AF: That paper is so interesting because most people believe that mercury causes brain pathology. You also looked at the ApoE4 status — is that starting to become a common theme amongst teasing out which foods are brain healthy or not? Looking at them in terms of carrier status?
MCM: Yes most people if they have that data look at it. We always look at interactions by ApoE4 status.
Looking at ApoE4 carrier status and nutrition for the brain
AF: Do you think that ApoE4 carriers will benefit most by dietary interventions?
MCM: I think ApoE4 is like the omega-3’s in that we don’t really understand the implications and oftentimes with associations observed, some studies observe it with E4 positive some with E4 negative, I don’t see much consistency. We know that E4 results in greater neuropathology. So was it just that there was a lot more going on that it was easier to detect associations? That very well could be. I just always take interactions with a grain of salt.
AF: Now that 23 and Me is FDA approved, more people will be testing their carrier status. Do you think that’s a good thing or do you think it’s a little too early and we don’t know what to do with the information?
Read more about testing for APOE4, the genetic mutation for Alzheimer’s disease, here.
MCM: Yeah, we really don’t know what to do with the information. I guess if you have a genetic predisposition towards the disease it might make you motivated to pay more attention to all the prevention research and maybe follow it more so than if you didn’t have that alarming information.
AF: But if you’re going to follow a brain healthy lifestyle anyways, it probably doesn’t add anything? Except maybe worry?
MCM: The good thing about Alzheimer’s research even if there hasn’t been a huge number of randomized trials to back up what epidemiological studies are showing, is that there are benefits for multiple chronic diseases. Heart healthy diets should also be associated with slower cognitive decline and lower risk of dementia. By following these healthy lifestyle behaviors you’re knocking off these chronic diseases [because] they all have the same formula: exercise, diet, good sleep, low stress, positive social interaction. All the chronic diseases — diabetes, stroke, hypertension, heart disease, dementia — you attack them all.
By following these healthy lifestyle behaviors you’re knocking off these chronic diseases because they all have the same formula.
The next phase of the MIND diet: The MIND Diet Intervention to Prevent Alzheimer’s Disease
AF: I know that the MIND diet is going into a phase 3 trial? Has that started already?
MCM: Yes, it’s 600 people, 300 on the MIND diet, 300 on their usual diet. Both have a weight loss component that’s very mild, reducing calories by 250 kcal per day for whatever level they’re at. Our main outcome is change in cognitive function measured by a battery of 13 tests and a secondary outcome is MRI imaging of the brain looking at reductions of brain atrophy particularly of the hippocampus.
AF: Are there other biomarkers you are looking at?
MCM: We are also taking blood and urine at each of 5 visits over a three year intervention period looking at markers of oxidative stress and inflammation as well as all of the cardiovascular conditions like diabetes. So we’ll be looking at hemoglobin A1C, cholesterol levels, and measuring blood pressure.
AF: Are you looking at homocysteine?
MCM: I don’t think that made the final list. But we are measuring brain derived neurotrophic factor {BDNF} which has been associated with exercise in particular but also reduced brain atrophy and even increased neurogenesis in the hippocampus region.
AF: And will you use the same MIND diet score or have you modified that at all?
MCM: We have modified the MIND diet a little bit.
Red wine and the brain: a delicate balance.
AF: Do you still include red wine?
MCM: No, this is an older population 55-84 and we just didn’t want to mess with that. They can’t get into the trial if they have abused alcohol or are heavy alcohol consumers. It’s harder to get compliance. So these are moderate or abstaining alcohol drinkers and we just left that off the intervention.
AF: The inclusion of red wine in the MIND diet always intrigues my students.
MCM: Yeah, unfortunately people perk up over [the inclusion of red wine] but don’t realize how low the benefits are. With every drink over that very low [recommended] level, you are increasing the risk of cognitive decline and dementia as well as heart disease and breast cancer.
With every drink over that very low level, you are increasing the risk of cognitive decline and dementia as well as heart disease and breast cancer.
AF: Yes, people have a hard time sticking to 5 ounces per day. When I do my Brain Works classes we sit down and have a family-style meal at the end of the class and I actually take a marker and measure out 5 ounces of red wine for everybody so they can see how little that really is.
When will this next phase of the MIND diet [The MIND Diet Intervention to Prevent Alzheimer’s Disease] be completed?
MCM: 2021.
Coconut oil: Brain food or fad?
AF: Do you have any thoughts on the whole issue of coconut oil and the brain?
MCM: There is so little data for that [coconut oil]. A case report from an individual really caught on like wildfire but there’s no scientific evidence. There will be because there have been some trials to test it but there’s not data yet to support that. There could be; I’m not ruling it out. I just like to see the data.
{AF: The coconut oil craze is fueled in part by Dr. Mary Newport’s anecdotal account of treating her husband’s Alzheimer’s disease with coconut oil. This is the only case, to my knowledge, of successful treatment of dementia with coconut oil.}
AF: I’m glad to hear you say that because that’s what I tell people as well.
MCM: It’s very high in saturated fat and it’s very high in calories so people should be attuned to that. Just be cautious.
AF: And certainly olive oil has mountains of data behind it — you can’t even compare it to coconut oil when it comes to that. What about the ketogenic diet and some of the small studies about it’s impact on memory and cognition?
MCM: There are some trials in progress and I think it’s a good hypothesis that the ketogenic diet might be helpful for people who have dementia and an inability to take in glucose to make the brain function. But I have reservations of your non-impaired ordinary adult taking on that kind of diet.
AF: The data is just not there yet.
MCM: Right.
Coffee and the brain: What is the evidence?
AF: Do you feel the same way about caffeine or do you feel there’s enough data to make recommendations?
MCM: Caffeine is all over the place. If I could make some sense out of the data: one study showed effects only if it is 3 to 5 or more cups of coffee [consumed] a day where another finds a positive benefit at less than 1 cup a day. I mean what is that? We know it has a short-term effect as a stimulant but whether it has some long term chronic benefit to the brain, the evidence just isn’t there.
AF: You really have your work cut out for you don’t you! It’s great having a voice of reason in the whole nutrition field. It is difficult to make firm recommendations to people about what to eat and what not to eat. When you came out with the MIND diet study it was such a breath of fresh air.
MCM: Thank you.
AF: And also because it builds on what we know from the Mediterranean diet which I truly believe is probably the best way to eat. So, I imagine your eating habits have changed based on this research? Are you following the MIND diet most of the time?
MCM: I try. You know, it’s like exercise. There’s periods of your life when it’s more difficult to follow and you travel off the best path. Then you’ve just got to get yourself back there. I’d like to practice perfectly every day and I would say most of the time I do but there are times when it’s difficult.
AF: Life gets in the way. Well the great thing about what you found with the MIND diet study is that you don’t always have to be perfect to still have a risk reduction that’s significant. And I think that’s a really good message for people for whom it’s too hard to radically change their habits but they can start adding berries, eating more nuts, eating more beans, and cutting out processed food. I think that is huge.
Supplements for the prevention of Alzheimer’s
AF: Do you have an opinion on taking supplements to reduce Alzheimer’s risk?
MCM: None of the supplement trials have been designed very well. They’re all pretty much testing whether people who were already at adequate levels benefit from taking the supplement. There’s been some European trials that have targeted people who have insufficient levels of nutrients and then supplemented them and did find that effect and that was actually with folic acid. But in the US population there are maybe pockets that are insufficient with folic acid and folate because they are not eating grain. But we do fortify our grain supply with folic acid, and many European countries don’t. It is those countries that don’t [fortify their grain supply] that have shown benefits of D vitamins on cognition.
AF: Thank you Dr. Martha Clare Morris for your time.
To learn more about the MIND Diet Intervention to Prevent Alzheimer’s Disease, visit their website. And stay tuned for preliminary results from this study in the next three years.
September 21, 2022 Note: Dr. Martha Clare Morris passed away after a battle with cancer in 2020. I am indebted to her for the legacy of research she left behind after 20 years as a nutritional epidemiologist focused on Alzheimer’s prevention.
The MIND Diet Trial is currently nearing completion after some COVID-related delays.
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