Diet and the Brain: From Ultraprocessed Foods to the Farmers Market

Kathrin LaFaver, MD; Madhureeta Achari, MD


August 31, 2023

This transcript has been edited for clarity.

Kathrin LaFaver, MD: Hello. My name is Kathrin LaFaver. I'm a neurologist in Saratoga Springs, New York. I have the pleasure today to be talking to Dr Madhureeta Achari, who is joining us from Houston, Texas, on the topic of nutritional neurology. Thank you, Reeta, for joining us.

Madhureeta Achari, MD: Kathrin, thank you so much for this opportunity and for inviting me to do this. I really appreciate it.

Nutritional Neurology

LaFaver: In the base of introduction, you have a very interesting career. You have special training in epilepsy and neuroimaging, and you have been in private practice for over 20 years. One of your special interests has been the field of nutrition and neurology. Tell us what got you interested in this topic.

Achari: Neurologists have always been involved in nutrition. If you look at the first vitamin that was discovered, which is vitamin B1, it's called B1 because it was the first one. Deficiency causes beriberi. The symptoms of beriberi can be cognitive issues, including mental fog and peripheral neuropathy.

As you go down the list of other micronutrients and vitamins that have been discovered, the predominant or first manifestations tend to be neurologic, with folic acid and its importance for spinal cord development; vitamin B6; and, of course, vitamin B12. We know that deficiencies in these things cause clear neurologic issues that are treatable.

I grew up at a time when we thought food was supplemented and so things should be much better for us, and yet we know that people still have these deficiencies. I think neurologists are nutritionists by definition. We do it so easily and as such a known part of our lives that we may not actually fully realize how often we're involved in it.

LaFaver: Yes, that is true. I think, especially for vitamin B12, we do check this quite a bit in different scenarios. Could you give me some other examples from your practice where you came across nutritional deficiencies that are less commonly known or encountered?

Achari: Sure. What has been interesting for me, and all of us who are taking care of patients, is that our diets have changed significantly. In the modern world, people have very specialized and unique diets, and some of them are quite restrictive. Some of them are for health reasons and some of them are for fashionable reasons. Either way, we have many different diets now, so people eat differently.

The first case that really got me looking into nutrition in much greater detail was an attorney who, for a year or so, had been going to the medical center because of brain fog. I'm in Houston, Texas. I have the good fortune of having three different medical schools, three different departments of neurology, and fabulous neurologists. He was having trouble keeping track of the things being said in depositions. He would pick up the reading material that he'd seen yesterday and really had a hard time continuing and figuring out where he left off. His brain wasn't working as sharply as it should have been, and he had this weird numbness and tingling.

He went to our institutions. Everybody did a fabulous job, and almost everything was done, including spinal taps and nerve biopsies, and nothing could be found. I like interesting and strange cases, so he was referred to me. He came in with two banker's boxes full of records, and I thought, Everybody has seen him. There's no way I'm going to add anything. Like all good neurologists, we take it all home and we look through it all. Really, everything had been done.

I called him the next morning and I said, "Have you done anything different? Have you started welding? Are you in a warehouse? Could it be some sort of toxin exposure? What are we missing here?"

He said, "I haven't done anything different." I put the phone down and a few minutes later he called me back and he said, "Dr Achari, the one thing different is that 6 months before all these symptoms began, I started a gluten-free diet." He eliminated all grains — all of them — from his diet.

A B1 level was done once during an earlier evaluation, and it was just barely within normal range, so nobody thought anything of it. The thing was, he would occasionally cheat and that was probably around the time that the original level was done, because it has a waxing/waning presentation. We did his B1 level again and it was very deficient. I gave him B1 injections, B1 orally, found a good source of wheat flour in Utah for him, and taught him how to bake bread. I put good, whole grains back into his diet in appropriate quantities and made sure he wasn't eating what most of us get in the grocery store, which is added gluten to everything, which was making him feel sick. There was a reason he went to this diet.

Once we got him on good, whole grains without dough conditioners and added gluten, he did very, very well. He recovered fully and went back to practice. For a year, he sent me a loaf of bread once a month. I haven't received that in a while, so I'm sure he's doing well. He doesn't have to think about his neurologist anymore. That's my B1 deficiency story.

Then, 50% of the American public is actually vitamin C deficient, right? Those data come from NHANES, which is the nutritional assessment survey done by the CDC. [Editor's note: The NHANES reference data show nearly 42% as vitamin C deficient.] Those measurements are actually serum and good blood level measurements. In my next case, I'll tell you about vitamin C.

I saw a 22-year-old woman who had epilepsy, and she was convinced that she was getting rash and abdominal pain from her antiseizure medicine. She had been taking the same medicine this whole time. She came to see me and we went through everything. The generic formulation had not changed. Nothing about the drug had changed, yet she's having this abdominal pain and rash. She also had some joint pain and gum bleeding. There were other things that pointed to scurvy.

I didn't know at that time — this was about 20 years ago — that you could order a vitamin C level. I had to call the lab and ask how to do it. She went and got her blood work done. Her level came back and it was zero. I thought that clearly something had gone wrong with the test. When I called the lab, the phlebotomist actually checked their own level after seeing that the vitamin C level came back a zero. It was low, but it wasn't zero, so it was a legitimate result. We did repeat her level and it really was zero.

I asked her what was going on. Well, she was working as a waitress in a restaurant, living by herself, and she was only eating canned soup. She would work all night, sleep, get up in the morning, and have canned soup. Canned soup doesn't have any vitamin C despite having little beans, potatoes, and carrots pictured on the label. That is my vitamin C story. We gave her vitamin C. Actually, she went back to school and got her degree in nutrition. She's doing very well.

Vitamin and Micronutrients to Check

LaFaver: Thanks for these very illustrative stories. As you said, we always feel that nutritional deficiencies are not something we should commonly see in our society, but we actually do. For many reasons, people might have to restrict their diets.

After having so much experience with this, do you have a specific panel of vitamins or micronutrients that you usually check, or can you give us any advice in that regard?

Achari: Sure. It is an ever-evolving list of things that I check. When we check levels, the question that we have to ask ourselves is, what does that serum level actually say about the intracellular level? More and more work is being done in the biochemistry literature and the International Journal of Chemistry in helping us understand this, so we're getting more data.

For instance, the brain uses more vitamin C than any other tissue in the body, which is new data for me. I'm now increasing the amount of vitamin C I'm giving people, so Linus Pauling was probably right. I check all the ones that we typically do: B1, B12, folic acid, B6. I also do vitamin B2, 25-hydroxy vitamin D, vitamin E, selenium, zinc, and copper. Those are the big ones.

I'm working right now to figure out what is the best way to measure iodine. I've seen a case of goiter and it presented as cognitive decline with thyroid deficiency. The interesting thing — and this is a new subject for me — is that we've stopped using iodized salt. We now use additive-free salt, such as kosher salt, Himalayan salt, or sea salt. That iodine was added to salt for a very clear reason. Since we're moving away from iodized salt, now I'm asking patients, "What kind of salt are you using?"

I never thought I'd be doing these things as a neurologist, but those are the main levels that I check. Certainly, you can add more micronutrients as you need for your specific patient. I also occasionally will check a biotin level and a niacin level, depending on what the patient's particular diet or symptoms are. That's what I'm doing right now.

Preventing Nutritional Deficiencies: The Fermented Five

LaFaver: That's very helpful. Let's shift gears a little bit. How can we prevent these nutritional deficiencies in the first place? There's been so much interest in preventive neurology, especially as it pertains to common problems such as stroke and dementia.

We were just talking about the literature coming out about how our highly ultraprocessed food is related to increased risks for dementia and so on. I'd be really interested in hearing your perspective on that.

Achari: There are data now that ultraprocessed foods represent up to 75% of the products in our grocery stores, so it's very difficult for us as individuals, and then our patients, to try to eat as best we can. When we go to the grocery store, only 25% of all the things in front of you are not ultraprocessed. I think that also is contributing to things.

We know that with diets rich in ultraprocessed foods you have an increased risk for cognitive decline, dementia, stroke, all-cause mortality, and cancer. It's just really bad for you. I try really hard to inform patients without frightening them into thinking that they cannot eat anything. Food is actually good for you. How do I get you to eat real food? That's the first challenge in prevention.

Source really matters. I focus on nutrition. We have the MIND diet and the DASH diet. We have several dietary guidelines. Unfortunately, the MIND diet, which is more of a European Mediterranean diet, doesn't translate very well to someone from Southeast Asia, Vietnam, or North Africa.

The other thing that I try to do is get a sense of what my patients are actually eating. I have them do a photo diary for about 2 weeks of everything that they eat, and then we try to enhance that. Whatever they're doing, we're trying to get a better source, out of the grocery store and into maybe a farmers market or someplace where the quality can be better. We also have to keep in mind access to good foods. Not everybody can find good foods where they live. It is difficult, but you can always add a little bit, whether it's whole grains or good dairy. You can do these things.

We know that a large amount of work is happening right now about the gut microbiome. There's a focus on good, fermented foods, the little bits eaten every day. I like a variety of things. For my patients, I have my fermented five, which is fermented grain. Many cultures have fermented grain. In the European cultures, there's bread, so sourdough bread or normal bread. The idea of day-old bread getting hard is because it's properly made. There shouldn't be anything in bread other than good flour, salt, water, and yeast. In Ethiopia, they eat injera. In India, they have fermented pancakes called dosas. Many cultures use fermented products, such as kimchi and yogurt. All over the world, they use these things.

There is fermented dairy in the form of yogurt, kefir, labneh, or whatever you would like. There's also fermented fruit, fermented vegetables, and fermented leaves. If we try to incorporate some of these things from the grocery store, there are many good companies doing cold fermentation.

The first approach to good nutrition is good sources and a wide variety of foods that are culturally relevant. That's what makes it easier for our patients. I think that's the biggest thing. I check levels, and for most of these micronutrients, I like to hold people at a high-normal range. We have a range of vitamin D of 30-100 nmol/L, and we know, out of a paper on multiple sclerosis through the Department of Defense data, that 80-100 nmol/L, or higher than 80 nmol/L, is where we want our vitamin D levels. We have good data that we can use biomarkers to help us. 

The Farmers Market

LaFaver: Wonderful. I love your approach, especially the very practical things of having people journal their food for you and then look at that. I think that's very helpful. Maybe we should all be more hands-on with patients to help them to make those transitions. I think this is wonderful. If anyone is looking for additional resources or practical advice on making these diet changes for patients, are there any additional resources you want to share?

Achari: There are easy cookbooks. This is not just for patients, but it's for us as physicians. We are hurried. We shortchange our lives and therefore we shortchange our nutrition. Regardless of everyone thinking that this is a very cognitive specialty, those of us who've been through residency training and see patients on a daily basis know that it is physically also demanding. Making sure that we are getting what we need is important. Eating well is important for us.

I think it's important to familiarize yourself with things like the MIND diet. There are books by Michael Pollan that tell you about what's happening to food. That's really the way to get started with this. Every association has a diet, including the American Heart Association, the American Stroke Association, and the American Diabetes Association. Everybody's got a diet, but no one diet fits all. It's important to understand how to enrich and enhance your diet and move away from ultraprocessed foods. I wish there were shortcuts, but there just aren't any.

Tomorrow morning at 8:00, I'll be meeting three of my patients at the farmers market. I tour them through the farmers market because that's where I shop. I know that this is impractical for most people, but I've arrived at this place after 20 years of doing this. During that time, we will talk about things like how to buy small amounts of produce so you are not wasting things in the refrigerator. There's a good pickle vendor. Where do you get your meat? How do you get your eggs? They become connected again with farmers and what's local in their area, and basically — I'm going to sound very crunchy-granola — the earth. We are of the earth.

We've all been talking about this. We have more medications available to us now. We have more "food" available to us now, calories available, and yet we are ever sicker. We are sicker now than we've ever been, in a sea of calories and a sea of pharmaceuticals. I think if we're going to look at prevention, we need to also look to ancient cultures. We are all here because their diets were good and allowed us to exist. I just got back from Egypt, and 50,000 years ago they were eating a balanced diet, something of everything. That's why I would like to encourage going back to the past, because it worked.

If neurologists can take just a little bit of time — it doesn't take very long for somebody these days to create a pictorial food diary — so you have an idea of what's going on, and then start that conversation. I do the nutritional counseling myself just because I live in Houston and we're the most culturally diverse city in the country. I've learned all these dishes — how to cook, how to prepare, and then how to change. Just starting that conversation of getting people away from ultraprocessed foods… If there's a farmers market in your area, I think that's what I would ask people to do.

LaFaver: Wonderful. Thank you so much for sharing all this great advice. I absolutely love how you spread your knowledge in very small and large ways. I didn't mention at the beginning that this year you are also the president of the Texas Neurological Society. You also do so much teaching and advocacy for the American Academy of Neurology. I think this is really wonderful advice. Thank you so much for sharing your knowledge, and have a wonderful rest of your day.

Achari: Kathrin, thank you so much again for the opportunity. I hope this has been helpful. I really enjoyed it.

Follow Kathrin LaFaver on X (formerly known as Twitter) @LaFaverMD

Follow Medscape on Facebook, X (formerly known as Twitter), Instagram, and YouTube


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.