Eating to Prevent Alzheimer’s: Q and A with Dr. Annie Fenn
The author of The Brain Health Kitchen breaks down the best diet for Alzheimer's prevention
Annie Fenn, doctor, chef, and founder of Brain Health Kitchen, a cooking school focused on preventing cognitive decline, didn’t retire after 20 years as an Ob/Gyn practicing menopausal medicine with the intention of taking a deep dive into brain health. “I didn’t choose to become a culinary educator and voice for Alzheimer’s prevention,” she writes in her new book The Brain Health Kitchen: Preventing Alzheimer’s Through Food, “Alzheimer’s chose me.”
Dr. Fenn’s mother was diagnosed with early stage Alzheimer’s disease in 2015, prompting Dr. Fenn to scour all the medical literature available on how to eat to prevent decline. She parlayed her newfound expertise — and her passion for food and cooking — into a gig at a local hospital teaching cooking classes focused on preventing dementia, and soon launched Brain Health Kitchen. Zeroing in on ten food groups with neuroprotective properties, Dr. Fenn developed an eating plan that she describes as a “plant-heavy version of the MIND and Mediterranean diets,” both of which emphasize plant-based foods and healthy fats, and both of which have been proven in numerous studies to significantly reduce the risk of Alzheimer’s.
More than one in nine people aged 65 and older have Alzheimer’s, according to Dr. Fenn, and if you are a 45-year-old woman, your lifetime risk for developing Alzheimer’s is close to 1 in 5. As she puts it in her new book, which is chock full of brain-healthy recipes, “food choices sit at the core of the Alzheimer’s epidemic, but food is also at the heart of the solution.” Here, Dr. Fenn offers guidance on what to eat — and what not to eat — to help stave off dementia and keep your brain younger, longer.
CoveyClub: Many believe that cognitive decline is a normal part of aging — but you say that this a myth, and that the number one dementia-reducing behavior is a brain-healthy dietary pattern. How did your experience treating perimenopausal and menopausal women — and your experience with your own mother — reinforce this for you?
Dr. Fenn: It’s really not normal to have significant cognitive problems as we get older. The one thing that does happen with age is it takes a little bit longer to retrieve memories, but they’re still there. And so I think we just have to be very gentle with an aging brain and avoid multitasking, really pay attention to the things that we’re doing one at a time. When I was practicing medicine, I would see perimenopausal women come in with very concerning memory loss, and then at a different point in their cycle the symptoms would all resolve. So hormonal fluctuations also have an impact on cognitive function, but that’s reversible.
When my mother was diagnosed with mild cognitive impairment (MCI), we basically went through her kitchen and threw away all of her ultra-processed food. And we had her eat very, very carefully just from the MIND Diet, in the hopes that it would slow down progression. I will tell you that it’s eight years later, and she does have Alzheimer’s, and she is deteriorating, but she’s still at home, still functioning at an independent level in terms of daily tasks. And that’s better than we ever dreamed — we thought for sure by now she would have to be in an institution with full-time care.
CoveyClub: If, as you claim, “brain health begins in the kitchen,” what is the number one food choice you can make to bolster brain health and prevent cognitive decline?
Dr. Fenn: Well, there’s not just one food, it’s really a way of eating. And that’s where the money is in terms of the studies that show how people can age really successfully: It’s their dietary pattern. I love the concept of dietary pattern, too, because it lets people off the hook — you don’t have to eat perfectly all the time. You do need to reach for brain healthy foods most of the time. That being said, there are a few brain healthy food groups that really stand above the other ones: Berries, leafy greens, and seafood.
There’s so much data to show that eating berries — two servings a week at minimum — can really protect the brain and help people perform better in terms of their memory as they get older, as well as prevent Alzheimer’s and other types of dementia. Certain nutrients in berries are specifically brain healthy: They are the flavonoids, substances that make the berries purple, black, red, or blue. And these flavonoids, particularly anthocyanins (the darker the berry, the more anthocyanins), protect the brain from oxidative stress, the type of inflammation that people get as they age.
Studies also show that people age more successfully if they consume a certain amount of leafy greens: about a cup and a half a day of raw leafy greens, or about half that cooked. Greens contain a whole complement of different micronutrients and vitamins, including vitamin K, which is very important for clearance of oxidative stress in the brain. They also provide a lot of fiber, a one-of-a-kind secret ingredient in a brain healthy diet. Fiber serves to lower blood cholesterol levels, reduces the risk of diabetes, and also cultivates a healthy gut microbiome, which we’re learning more and more is important for brain health.
Seafood is an interesting category because we know there are certain omega three fatty acids that are absolutely crucial for long term brain health and Alzheimer’s prevention. We know this because people who have diets that are really low in these types of omega-3s have a greater risk of Alzheimer’s disease. There are three types of omega-3 fatty acids – DHA, EPA, and ALA. You can get ALA from plant-based foods like chia seeds or walnuts, but it’s the DHA and the EPA that are really important for protecting the brain. These fatty acids actually become incorporated into the membranes of nerve cells. They are reparative and anti-inflammatory at the cellular level. That’s why including fish or seafood at least once a week has been shown to reduce Alzheimer’s risk. If you’re vegetarian or vegan and don’t eat seafood, I would recommend taking a supplement that provides these really important omega-3 fatty acids.
CoveyClub: The Mediterranean and MIND diets already highlight fruits and vegetables (along with whole grains, beans and legumes, and healthy fats like olive oil and nuts). Why did you opt to increase the plant content and decrease the servings of food from animals in your Brain Health Kitchen guidelines?
Dr. Fenn: Number one, I want people to get more fiber in their diet. A lot of the data that we’re looking at in terms of Alzheimer’s prevention is correlating with what we’re learning about gut health. It’s important to have a lot of fiber to feed the trillions of microbiota that live in our intestinal tract. The microbiota, in turn, create neurotransmitters that perform important functions in the brain. They also create short-chain fatty acids, which cross the blood-brain barrier and act as anti-inflammatory particles in the brain. Increasing leafy greens from the standard recommendation of one cup a day to two cups a day is an easy way to boost fiber intake.
Certain vegetables are particularly important to brain health: the cruciferous vegetables, for example, like broccoli, Bok choi, cabbages, and Brussels sprouts. They provide a certain antioxidant called sulforaphane and are also very rich in protein, which everyone needs as they get older. So I increased the amount of other vegetables (the non-leafy-green vegetables) from one cup a day to three, and I recommend including cruciferous vegetables in your weekly vegetable intake. Another reason I’m upping the plants is there’s been a lot of research in the last couple years about the importance of flavonoids. It’s easy to figure out which foods have more flavonoids — they’re the most colorful fruits and vegetables at the grocery store. Consuming a flavonoid-rich diet can reduce your risk of Alzheimer’s by as much as 50%. And when you look at the literature about vegan and vegetarian diets, there’s a lot of data that shows they reduce your risk of cardiovascular disease and stroke, both risk factors for Alzheimer’s and dementia.
I’m not saying that you shouldn’t eat any animal products at all. But I would like to see the plant foods — whole grains, beans, vegetables, leafy greens, nuts and seeds — move to the center of the plate. And whatever animal protein you consume, whether it be chicken, some sort of high quality meat or seafood, to be more of a side dish. A good rule of thumb: three quarters of your plate should be plant foods. That turns a traditional American way of eating upside down because we’ve always put the animal protein in the center of the plate.
CoveyClub: We’re talking about preventing Alzheimer’s — and cognitive decline in general — but can following a brain-healthy diet actually improve cognitive function?
Dr. Fenn: Yes, and this was shown in the MIND Diet Study that was published in 2015 out of Rush University. What they found was that people who adhere closely to the MIND Diet actually improve their cognition — they did better on memory tasks during the study than those following a Mediterranean diet. So the beauty of following a brain healthy eating pattern is that not only does it help you age better, more gracefully, with a smarter, sharper brain, but it also helps you in the present time to deal with cognitive tasks.
CoveyClub: Once a person is diagnosed with Alzheimer’s, can eating brain-healthy food reverse any of the damage — or at least slow disease progression?
Dr. Fenn: As far as we know, Alzheimer’s is not reversible. There seems to be a tipping point where the proteins that accumulate in the brain — and the inflammatory process — get to a point where they cannot be reversed. However, there’s a lot of data looking at MCI, an early stage of cognitive decline that sometimes goes on to Alzheimer’s and sometimes does not. Some cases of MCI are reversible — like memory loss caused by extreme mental stress, untreated depression, excessive drinking, or nutrient deficiencies, for example. For those who have the type of MCI associated with Alzheimer’s disease, researchers are looking at eating a Mind Diet or Mediterranean dietary pattern to slow down that process. And so far, the results are very positive.
CoveyClub: What happens in the brain of someone with Alzheimer’s, and how, biologically-speaking, do the brain-health foods we’ve discussed prevent these things from happening?
Dr. Fenn: We used to think that Alzheimer’s just happened to people in their 70s or 80s, that their brain function goes off a cliff. Now we know Alzheimer’s starts 20 to 30 years before the first symptoms. And it’s not just one thing that causes it. The older thinking on Alzheimer’s was these people develop amyloid protein in their brain, and it forms all these plaques and then the brain doesn’t function at all. That is part of it. But now we know it’s a multifactorial disease, much like heart disease. The root cause of Alzheimer’s comes from chronic inflammation in the brain that accrues over decades, and this inflammation can be from a variety of different sources, such as air pollution and the inflammatory particles we get from the foods that we eat. So that’s one theory why eating health-promoting foods and getting rid of inflammatory foods can really help your brain function longer. Animal data suggests that certain foods can actually put a dent in that amyloid plaque. But our bodies have a disposal system to get rid of it too — this is where high quality sleep and exercise come in. They can actually stimulate your brain to clean up the plaque that develops.
CoveyClub: We’ve talked about some of the most important neuroprotective foods to include in our diets — let’s delve into the inflammatory ones, the ones that accelerate brain aging. If we want to increase what you refer to as our “brainspan” — or years of brain-healthy living — what foods should we be avoiding?
Dr. Fenn: There’s a lot of data that shows that ultra-processed foods can lead to dementia. Foods like frozen pizza and other frozen meals which include a lot of factory-produced ingredients to preserve them. Even foods like roasted nuts and energy bars can rack up these inflammatory particles as part of the processing. That’s why it’s really important to read labels, and make sure you’re not consuming a food product that has added sugar, artificial sweeteners, or any other type of artificial ingredients. I also recommend limiting high–saturated fat dairy products. We know from independent studies that the higher the amount of saturated fat is in your diet, the greater your risk of Alzheimer’s disease.
CoveyClub: There’s much confusion about which oils are healthy and which are detrimental. Which oils should be the go-tos for brain-healthy cooking — and for dressing food — and which ones should be avoided?
Dr. Fenn: It’s actually quite simple if you look at the data. We know that extra virgin olive oil is the primary cooking oil in the Mediterranean diet, and that people in those countries enjoy a lower risk of heart disease and Alzheimer’s. Extra virgin olive oil is really the only cooking oil — besides some nut oils — that provides polyphenols, anti-inflammatory substances that are really important for long-term brain health. Studies show that when you give people with MCI high quality extra virgin olive oil, it can reverse some of their symptoms. And that’s probably because polyphenols have a potent effect on clearing inflammation from the brain. So I recommend using extra virgin olive oil as the primary cooking oil in your kitchen. You can cook with it up to about 375°F. After that, there’s this misconception that it turns into something toxic, which is not true. Those polyphenols, however, are delicate and will be damaged by heat. For cooking with high heat, such as direct grilling or roasting in an oven above 375°F, use an oil with a higher smoke point, like avocado or nut oils, which also provide nutrition for the brain.
Coconut oil is confusing because it has been marketed as a brain healthy food. It has a delicious flavor, is really nice in baked goods, and you can use it for high-heat cooking, but coconut oil is 94% saturated fat, which is too high for it to have a larger role in my kitchen. The problem with coconut oil is that if you use a lot of it, it raises your LDL cholesterol, the cholesterol we’d like to keep really low. There is a direct correlation between your LDL cholesterol and your risk of Alzheimer’s disease, as well as cardiovascular diseases.
CoveyClub: Your recipes incorporate many fresh herbs and spices — can you address the brain-boosting benefits of these ingredients?
Dr. Fenn: You may not think of herbs as leafy greens, but they are. And microgreens actually have a higher complement of flavonoids and other nutrients that we consider brain healthy. So they’re particularly good for nutrient density and they also can just add a lot of flavor, color, and nuance to your meals. Spices are also really important to a brain healthy diet. There’s some data to show that certain spices are anti-inflammatory — especially the ones that start with a C, like cinnamon, cumin, and curcumin, which is the active ingredient in turmeric. If you do use these spices, it’s helpful to cook them in a little bit of oil, which helps absorb their antioxidant properties better in the body.
CoveyClub: One thing that surprised me as I read through Brain Health Kitchen was that how we cook our food can be just as important in staving off cognitive decline as which foods we choose to eat. Can you explain why?
Dr. Fenn: Cooking techniques are really important. Applying heat to food creates inflammatory particles called AGE’s (advanced glycation end products) that get absorbed into the bloodstream and cross the blood-brain barrier. AGE’s accumulate in brain cells and set off oxidative stress. Cooking over direct heat, such as grilling or searing a piece of steak or fish, actually increases AGE formation. The other problem is it causes the nutrients in the food to dissipate. For example, if you overcook salmon, you will notice a white film on it — that’s the albumin or protein seeping out. In that protein layer is where your vitamin D is, where the omega-3 fatty acids are. When you use the brain-friendly cooking techniques — braising, steaming, pressure cooking, slow cooking, indirect grilling (using a cedar plank, for example) — you retain more nutrients and are less likely to rack up inflammatory particles.
CoveyClub: We’ve talked about what to eat and how to cook it. But what we choose to drink affects the brain, too, right?
Dr. Fenn: The good news is that drinking coffee and certain types of tea are overall proven to be very good for the brain. The caveat is if you take your coffee and add creamer that has lots of processed ingredients and you add a lot of sugar, then you’ve converted that antioxidant-rich beverage into a brain-unhealthy drink. So coffee is best consumed black and unsweetened, or perhaps with a small amount of plant milk. We actually have lots of studies that show that you can reduce the risk of Alzheimer’s and dementia with a healthy coffee drinking habit. And the same goes for tea — particularly black, white, green, and oolong teas, which all come from the Camelia sinensis plant.
Avoid ultra-processed sugary drinks, such as soda pop, energy drinks, and sweet tea — anything that has an artificial or sugar-sweetened component. Stick to tea, coffee, and water, mostly water. I’m not a big fan of juicing because I look at it as consuming fruits and vegetables without any fiber, so it hits your bloodstream like sugar. And then there’s alcohol. Alcohol is tricky because it has this health halo for being protective when it comes to brain health (especially red wine, which is high in antioxidants). But in 2022, just as my manuscript was going to print, this big study came out of the UK which found that what we consider moderate drinking — one drink a day for women or two drinks a day for men — actually causes the brain to shrink faster compared with people that don’t drink alcohol at all, or drink very lightly. Brain volume is an incredibly important marker for brain health as you get older — it’s how many neurons you have, it’s how many synapses you have, it’s the connections between your neurons, it’s your memories, it’s your intellectual capital. Based on what we know now, in 2023, people should limit their alcohol intake to up to four drinks a week — or no drinks.
CoveyClub: Finally, one more thing I found fascinating in Brain Health Kitchen was the notion that how we combine our brain-friendly foods can actually enhance their beneficial effects. What are the drawbacks of no-fat and no-carb diets, and how does adding fat or fiber-rich, whole grain carbs to a meal amplify its nutritional value?
The only low-carb diet I would recommend would be one where you get rid of all the junky carbs in your diet. The problem with carbohydrates, especially in the US, is that most people consume carbohydrates in the form of all-purpose white flour, pastries and sweets, which are devoid of nutrients and hit your bloodstream like sugar, so they’re impeding your metabolic health. But it’s not a good idea to eliminate all the whole grains in your diet, because whole grains are incredibly nutrient dense and provide a lot of flavonoids and fiber to provide diversity for your gut microbiota.
Low-fat diets are not a good idea either: There has to be a certain amount of fat in the diet to help you absorb all these nutrients from the plant foods that you’re eating. If you look at the overall dietary pattern for brain health, it’s not a low fat diet at all. It’s a diet that’s rich in monounsaturated fats with some polyunsaturated fatty acids, and fewer amounts of saturated fat. I think of extra virgin olive oil — which is primarily monounsaturated fat (about 80%) with some polyunsaturated fatty acids (about 15%) and a small amount of saturated fat (around 5%) — as the secret sauce of the Mediterranean diet that’s really helping you make all these nutrients from the plant foods more bioavailable. It also makes your food more interesting, satiating, and delicious.