The secret to eating for better brain health 🧠

Guest Dr Annie Fenn, author of Brain Health Kitchen, shares her top tips

I have something special for you today, a guest post by

Annie Fenn, MD

.

Dr Annie’s substack Brain Health Kitchen was one of the very first I signed up to, and I’m really pleased to have her here sharing her brilliant insights on eating for better brain health.

I highly recommend subscribing, she’s kindly offering Second Brain readers a 25% discount.

And if you leave a comment below, you’ll be in the draw to win a copy of her book, The Brain Health Kitchen (open to UK and US readers).

(Plus, there’s a bonus free PDF too, scroll to the end).

Over to you, Annie! So great to have you here.

Hi, I’m Annie, a physician, culinary instructor, and author of The Brain Health Kitchen: Preventing Alzheimer’s Through Food. It’s a pleasure to be a guest writer on Second Brain this week! I became a huge fan of Dr. Emily’s work when I discovered Genius Gut: The Life-Changing Science of Eating for Your Second Brain. Then, when I discovered her Substack, Second Brain, I knew that our paths must surely someday cross.

My mission at Brain Health Kitchen is to help you take care of your brain while still eating delicious food. And, as all you gut brain foodies already know, Emily is passionate about sharing cutting-edge science (and amazing recipes, too), for both your gut and your brain. Today, Emily and I are not only waving to each other from either side of the pond, we are saying hello from our different perspectives of the gut-brain axis. Be sure to check out Emily’s guest post this week on my Substack: Should You Be Taking Probiotics For Your Brain?

Here’s the thing: The more I learn about brain health, the more I realize that your friendly gut microbiota are driving the boat. In fact, I will let you in on a little secret. When I was doing research for my book about the most science-based way to eat for a healthy brain, gut science shaped my brain food guidelines. Not only did fiber (or fibre, as Emily would say) gain a prominent spot in my 4F’s of Brain Healthy Food (more on that below), what we know about cultivating a diverse and resilient community of gut microbiota is baked into my Brain Health Kitchen Food Pyramid.

Yes, my brain health food pyramid is actually a gut health eating plan, too. Let’s take a walk through the pyramid and I'll show you around. 

Excerpted from The Brain Health Kitchen: Preventing Alzheimer’s Through Food by Annie Fenn, MD @Artisan Books 2023

The Brain Health Kitchen Food Pyramid 

The BHK pyramid reflects the most studied brain-protective dietary patterns in one graphic. While you may often read that one diet is superior to another with regard to fending off age-related cognitive decline; that’s not true. There are several dietary patterns that have been proven to protect the brain. One of the most successful is the Mediterranean diet (MeDi), based on traditional foods eaten in the countries that surround the Mediterranean Sea. In fact, all the dietary patterns that have solid data to say they reduce dementia risk are based on the MeDi. The MIND diet (which stands for Mediterranean-DASH Intervention for Neurodegenerative Decline), is the most highly regarded MeDi spin-off. Following the MIND diet closely has been shown to reduce the risk of developing Alzheimer’s or another type of dementia by as much as 53%.

Yes, it is simply incredible that one could slash their risk of developing dementia in half just by changing up what they eat. What’s even more incredible is that many brain health experts, including myself, think this number could be higher. Read on to learn why I altered the MeDi and MIND dietary recommendations slightly based on the latest research.

Find a downloadable guide to the BHK pyramid and food guidelines at the end of this post!

The Brain-Healthy Food Groups

The MIND diet, which was published in 2015, defined 10 brain-healthy food groups: vegetables, leafy greens, whole grains, berries, beans and legumes, nuts, fish and seafood, poultry, extra-virgin olive oil, and red wine. Since then, there’s been ample data to confirm that some of these food groups need to be dropped (I am looking at you, red wine) while others deserve a spot (fermented food!). Here’s how I tweaked the classic guidelines based on the decade of gut and brain health data published after the MIND diet study came out.

Here’s what I changed:

1. Vegetables: While MeDi and MIND guidelines recommend eating one serving of vegetables a day, I increased that to three servings. The reason? I am thinking of your friendly gut microbiota. They need two things you get from vegetables: fiber and flavonoids—those polyphenol compounds integral to both gut and brain health, as Emily shared recently. I recommend shooting for 3 servings of vegetables a day. One serving is 1 cup (raw) or ½ cup (cooked).

2. Leafy greens: The MeDi includes leafy greens as part of the vegetable kingdom, which it is, but for the purposes of brain health, the MIND diet singles it out as a distinct food group. Here’s why: Eating a generous serving of green leafy vegetables daily has been shown to be an independent factor in aging with a healthy brain. That’s one reason I upped the recommendation from one serving to two servings a day. One serving size is one cup (raw) or ½ cup (cooked) greens. The other reason is to help everyone hit target fiber requirements for the day. As Emily pointed out, 90% of us aren’t getting enough fiber each day.  

3. Berries:  If I ask you to name a top brain food, chances are blueberries will come to mind. And it’s true, all the blue, black, red, and purple berries have solid data to say that eating them regularly protects the brain from aging. They provide key polyphenols called anthocyanins that cross the blood brain barrier and block oxidative stress. Data from the Nurses’ Health Study showed that women who ate ½ cup berries every day performed better on memory tests than those who ate them a few times a week.That’s one reason I increased the twice-weekly berry eating recommendation (from MeDi and MIND) to daily. And besides, who doesn’t love berries? Not only are they delicious and can fill the craving for sweets, they are an important source of fiber and polyphenols.

4. Nuts and seeds: The recommendation to eat four ¼ -cup servings of nuts a week comes straight from the cardiology literature: doing so reduces the risk of having a heart attack or stroke. In the brain health world, we say “what’s good for the heart is good for the brain.” Reducing cardiovascular risk factors is a huge factor in also reducing dementia risk. In the BHK pyramid, I added seeds because they provide all the same spectrum of gut and brain health benefits as nuts, including plenty of fiber and monounsaturated fats, along with a good dose of protein.

5. Fish and seafood: Emily recently discussed how crucial omega-3 fatty acids are for gut health. In the dementia-prevention world, it’s just as important to consume enough good-quality fish and seafood to provide the brain with marine-based omega-3s: DHA and EPA. Not getting enough of these has been associated with an increased risk of age-related cognitive decline. MIND diet goes with one or more (3- to 4-ounce) servings of fish and seafood a week. MeDi guidelines recommend eating two to three servings weekly. In the BHK pyramid, I align with MeDi’s guidelines of two to three servings per week.

6. Poultry: Both MeDi and MIND recommend including two or more (3- to 4-ounce) servings a week of poultry (chicken, turkey, etc) in a brain-healthy diet, while limiting red meat to less than four 3-ounce servings a week. What about eggs, you may be asking? Egg recommendations aren’t included in either guideline. More on that, below.

   
   In the BHK pyramid, I grouped all of these animal products into one rung of the ladder: poultry, meat, and eggs. This reflects current data that suggest including good-quality unprocessed meat may actually be good for the brain. The BHK recommendations for this food group is to enjoy up to 4 servings of meat or poultry a week. Those following plant-based diets can eliminate this food group entirely, but should speak to their healthcare provider about taking supplements to fill in the gaps they may lead to certain deficiencies (namely vitamin B12, iron, and marine-based omega-3s).

   Eggs can be complicated when it comes to brain health. They provide brain health nutrients (choline, lutein, omega-3 fats) along with a good dose of protein. Plus, this 2024 study showed that egg consumption was linked to less Alzheimer’s pathology in the brain. Yet some people will have a too high LDL cholesterol if they eat too many eggs. Prolonged elevated LDL cholesterol is one of the Lancet Commission’s modifiable risk factors for dementia. That’s why I recommend tailoring egg consumption to a person's individual health profile. Someone who is having difficulty getting lipids to target levels could have impaired clearance of the cholesterol in eggs (and other cholesterol-rich foods). Cholesterol “hyperresponders” (an estimated 15% of people) should limit egg intake based on their current lipid profiles. As for the other 85% of us, eating up to an egg a day is likely to benefit your brain health.
   

7. Fermented food: Even though fermented food has a long tradition in the MeDi, there are no specific recommendations for consuming these probiotic-rich foods. The MIND diet doesn’t address ferments at all. I added it to the BHK pyramid based on the growing evidence that including lacto-fermented food in a brain healthy diet helps cultivate a healthy gut. In fact, in this well-known study out of Stanford, researchers looked at the gut diversity and colony counts of participants who upped their fiber intake compared to those who introduced fermented foods. While they both were beneficial to the gut eventually, eating fermented foods was more efficient in getting the gut bugs in tip top shape. 

   
   

   Caveat: participants in the high fiber group bumped up their fiber intake from 21 to 45 grams per day; those in the high fermented group went from on half-serving to six servings of fermented food a day. That’s a lot of fermented food! In my guidelines, I recommend eating one or more servings of fermented food each day.

Source: Wastyk, et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021.

9. Red wine: Drinking a moderate amount of red wine has been widely touted as a habit that contributes to brain longevity. It holds a permanent spot in the MeDi pyramid and was designated as the tenth brain-healthy food group in the MIND diet study. So why did I move it off the BHK pyramid and onto my list of foods to limit or avoid? The data has been moving in the direction to say that no amount of alcohol is considered good for the brain. Then, when the U.K Biobank study was released in 2021, the impact of drinking alcohol (including red wine) became crystal clear. Brain shrinkage was evident starting at four drinks a week, well under the definition of moderate drinking (one drink a day for women, two drinks a day for men). Not drinking at all gives brain volume the greatest edge: nondrinkers enjoy more robust brain volume and a lower risk of Alzheimer's and other dementias. 

   
   Instead of recommending that you drink red wine, I replaced it with drinks that we know are brain-healthy like filtered coffee, tea (especially green tea), and water. If you drink, however, red wine does provide a decent dose of polyphenols. But I recommend getting your polyphenols from the wide array of colorful plant foods instead. When it comes to alcohol and the brain, I advise a LOW or NO policy of no more than four alcoholic beverages in a week.

Here’s where my guidelines match the MeDi and MIND guidelines:

As for the food groups whole grains, bean and legumes, and extra-virgin olive oil, my guidelines are aligned with the MeDi and MIND ones. It’s the gut-friendly nature of grains and legumes that makes them also indirectly beneficial for the brain. Both provide a fiber-rich substrate on which the microbiota thrive. They both their magic for the brain in other ways, too, like helping lower harmful LDL cholesterol in the bloodstream and keeping blood sugar stable, both of which are factors in long term brain health. 

The brain health benefits of extra-virgin olive oil have been well-documented. I recommend using it for almost all of your cooking oil needs. For high heat (above 375ºF or 190ºC), I advise using an oil with a higher smoke point, such as avocado or pecan oil. 

There’s No One Perfect Brain-Healthy Diet

As the science of brain-healthy eating evolves, we are finding that there’s not just one perfect way to eat to protect your brain. Many dietary patterns can be tweaked for optimal brain health. I created the Brain Health Kitchen pyramid to be inclusive of many dietary proclivities, including pescatarians, omnivores, vegetarians, vegans, whole food plant-based (WFPB), and traditional ethnic dietary patterns (African-, Latino-, and Asian-American Heritage Diets). (Strategic supplementation is encouraged for those limiting or totally avoiding animal products to avoid deficiency in B vitamins (especially B12), choline, lutein, and marine-based omega-3 fatty acids). 

For Both the Gut and the Brain, Fiber is Queen

As you can see, fiber, Emily’s favorite macronutrient features prominently throughout the pyramid. And it holds a coveted spot in my 4F’s of Brain Health Food: brain-friendly fats, flavonoids, fiber, and fit. 

Whether you are focused on optimal gut health or protecting your brain from age-related cognitive decline, you can’t go wrong paying attention to both ends of the gut-brain axis. 

Bhk Food Guidelines And Pyramid

10.6MB ∙ PDF file

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Thanks for having me over to Second Brain! I am happy to answer any questions you may have. 

Xoxo

Annie

Emily here!

A huge thank you to Annie for sharing so much useful knowledge!

I’m really grateful to Annie for being with us today, I know you’ll have loved this guest post as much as I have.

To win a copy of Dr Annie’s brilliant book, The Brain Health Kitchen (open to UK and US readers), just leave a comment, ask a question, or say hi - you’ll be automatically entered in the draw.

Chat soon,

Emily xx

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