Continue eating the 12 Smart Foods that are essential for better brain health, and avoiding foods that decrease cognitive performance. As soon as you are ready, for a truly sharper brain and even stronger protection against cognitive dysfunction and memory loss, take the next step.
If we want to address the number one cause of cognitive dysfunction and memory loss—and abnormal blood sugar regulation—then we need to stop brain-killing insulin resistance. The easiest way to improve insulin sensitivity is to choose foods with a low sugar load, also known as a low glycemic load. A food’s glycemic load refers to how high a person’s blood sugar shoots up after eating a serving of it (glyc = sugar, and emia = blood level). Glycemic load is divided into three categories: low, medium, and high. (See this page for lists of foods by glycemic load.)
Studies have shown that if you have insulin resistance, then eating even something as simple as breakfast can have a serious impact on your brain function. If you begin your morning with a high glycemic load meal (think pancakes, toast, cereal, bagels, pastries, orange juice), you will immediately decrease your cognitive function. It’s not a great way to start your workday (or any day), right? But the reverse is true, too, and it’s good news: eating low glycemic load foods and giving that breakfast a makeover (whole fruit with plain yogurt, eggs, or a protein- and fiber-rich smoothie) can improve your brain function, and your blood sugar control. A study of middle-aged, overweight women with insulin resistance found that eating a low glycemic load breakfast improved their cognitive function.
If you’ve been following dietary trends, no doubt you’ve encountered the term glycemic index—a numbered value that indicates how quickly and how high your blood sugar rises after eating a specific quantity of a specific carbohydrate, ranked as high, moderate, and low. After the glycemic index concept was introduced, it became quite popular in the dieting community, like calorie counting, since some saw it as a way to simplify and speed weight loss. The diet mantra was to avoid the “high GI” foods (because they were packed with sugar, the thinking went). People were encouraged to choose low GI, in the hope that the pounds would fall away. (Some food companies label products as “low GI” to attract diet watchers.)
Unfortunately, the glycemic index concept is not that simple. Though the index can be extremely useful when it is properly interpreted, it isn’t the best decision-making tool, in part because it’s quite impractical in the real world and easy to misuse. For example, the index rates pasta as a “moderate” GI food but carrots as “high.” The average person might think that pasta, therefore, is a healthier (less “sugary”) choice than carrots, but that’s a gross misunderstanding of the data—and it leads people to false conclusions.
The index was largely developed as a research tool by Dr. Jennie Brand-Miller, a scientist at the University of Sydney in Australia, to help assess how foods impact blood sugar. Typically, researchers measure blood sugar levels after an individual consumes 50 grams of carbohydrates from a single food. That would be about 1 cup of cooked pasta, a portion that for most people would be pretty small. (You can easily eat twice that amount.) By contrast, to get 50 grams of carbs from carrots, you would have to eat nearly nine large carrots in one sitting, which most people couldn’t do if you paid them.
Nutrient-dense carrots are good for you, and, like most vegetables, they have a very low impact on blood sugar. Avoiding them because they appear “high” on the glycemic index is a mistake, as carrots have a glycemic load of 4, which is low. As you’ll discover in a moment, glycemic load—not glycemic index—is the gauge you should be using. Beets are another food with a high glycemic index but a low glycemic load. Their sugar impact per serving is low, so yes, eat your beets!
As it turns out, adding more fiber, especially from beans, is an effective way to improve glycemic control. The irony is that some people, including those who follow a Paleo diet, avoid beans because they are high on the glycemic index, but beans most definitely do not behave the way sugar does in the body!
I interviewed Dr. Brand-Miller, and we discussed the scientific merits of the glycemic index but also how it falls short in offering ordinary people usable information. To make the data more useful, she explained, researchers added another layer of information and started calculating a food’s glycemic load, which estimates how quickly and how high your blood sugar rises after you consume a standard (real-world) portion of it. That makes it far easier to choose foods that will help you achieve blood sugar control. And that is why the glycemic load (GL) of a food has become my favorite tool for making blood sugar control easy. (I also refer to it as a food’s “sugar load.”)
A selection of low and medium glycemic load foods you can enjoy every day is found on this page, along with a chart of high glycemic load foods you should limit or avoid if you’re trying to control blood sugar. For more extensive glycemic index and glycemic load lists, visit the University of Sydney website www.glycemicindex.com.
Here are some other factors to consider as you make your food choices.
The more active and fit you are, the trimmer you are; and the more fiber you eat, the more glycemic load you can tolerate without causing a rise in blood sugar or insulin. However, the proof is in the testing. If your fasting blood glucose level is less than 95 mg/dL, and your insulin level is less than 5 µIU/mL, then your food choices and active lifestyle are working well for you.
At the other end of the spectrum, most people with metabolic syndrome and poor blood sugar control will need to avoid all foods with a glycemic load of more than 10 (as indicated in the charts; 10 to 19 is considered a “medium” load food) to restore normal blood sugar and insulin regulation. If you fall into that category now or if you’re sliding down that slope, you can do something about it now, and as you get healthier and increase your fitness through better eating and regular physical activity, you will be able to manage occasional indulgences.
Your activity level also influences your response to glycemic load, meaning that the more active you are, the less your blood sugar will rise after you eat a specific amount of carbs. As an example, an athlete exercising twenty or more hours per week can eat a great deal more pasta and maintain normal blood sugar than a person sitting at their desk all day who struggles to exercise even two or three hours each week. If you enjoy eating pasta and need to improve your blood sugar control, then spaghetti becomes a great incentive to exercise!
As a general guide:
• If you exercise less than 7 hours per week, then choose mostly foods from the low glycemic load list.
• If you are highly active (more than 7 hours of aerobic activity per week), you likely will tolerate 1–2 servings of medium glycemic load foods daily.
Scientists debate how accurate the glycemic load tables are for users, and a recent study showed that people’s blood sugar responses can vary by 20 to 30 percent. While scientists might quibble over a few points, generally the glycemic load tables are still useful if they can predict your response within 70 to 80 percent. Of interest, the two biggest factors that create variability in glycemic load response are blood sugar control and levels of inflammation, factors that this book will help you to improve, which will also make your use of these tables more reliable.
Sally’s Better Brain Story: Low Sugar Load Foods
When I first met Sally, a new patient, she looked older than her age, which was sixty. But more than anything, she looked worried.
She’d been struggling with her weight—she’d tried at least a dozen diets as well as exercise programs, but the number on the scale seemed stuck. What worried her more than her weight, however, was that she felt she was losing her memory. She forgot details from meetings at the marketing firm where she worked. She had trouble remembering names of new clients. She was constantly misplacing her glasses and cell phone. Her brain felt sluggish. And what really scared her was that her mom, who had been diagnosed with Alzheimer’s disease several years ago, had been transferred to a nursing facility the previous year. Would she wind up the same way?
We went over Sally’s test results—including fitness and nutrition evaluations, as well as cognitive function scores—to come up with a plan. Her cognitive scores put her in the lower half for her age group, making her job responsibilities a real challenge. She also had elevated blood sugar and insulin levels, and from reviewing her eating plan, I could see why. She had been following a low-fat, high-carb eating plan, with lots of whole grains: whole-grain cereal for breakfast with nonfat milk, a sandwich for lunch, a granola bar for a midafternoon snack, and some protein with brown rice or whole-grain pasta for dinner, followed by a fat-free cookie for dessert. Sally thought her choices were in keeping with a healthy diet and would lead to weight loss, but she was actually sabotaging those efforts and compromising her brain health as well.
To help transform her brain function, Sally needed to pick foods with a low sugar load. I asked her to avoid eating any foods for the next month that had a glycemic load of more than 10. She didn’t have to diet, but she had to limit her sugar load at each and every meal, and she also had to eat more healthy fats. She was to take a good-quality supplement as well (discussed in Chapter 5). And I wanted her to go for a walk, either in the morning or after work, for at least twenty to thirty minutes five days per week for the first month.
“That’s it?” she said, with some surprise. “I already work harder than that every day.” But as I told her, what she was doing wasn’t working, so she agreed to give my plan a chance.
At the end of thirty days, she had lost five pounds. She looked more youthful, and her fasting blood sugar and insulin levels were totally normal. We repeated her cognitive function test, and she was now in the top twenty-fifth percentile for executive function, a 50 percent improvement. All those “healthy” whole grains and low-fat foods she had been eating had sent a large glycemic load into her bloodstream, causing her insulin levels to surge and her tissues to stop responding, making her insulin resistant. That resistance had made her brain cells unable to use the overly abundant glucose in her bloodstream. Choosing to avoid foods with a high glycemic load was the key that unlocked her from mental prison. With those accomplishments in place, we talked about ways she could step up her fitness, and additional supplements that she should consider to protect her brain over the long term—all part of the Better Brain Solution. Now almost ten years later, Sally looks and feels younger and is as mentally sharp as ever.
What the numbers mean:
0–9.9 = a low glycemic load food
10–19.9 = a medium glycemic load food
20+ = a high glycemic load food
(You may find some slight variation on numbers in other sources.)
Most of the vegetables and fruits, and all the nuts and clean protein sources, are low in glycemic load. Beans have a low glycemic load, and eating legumes actually offsets a jump in blood sugar caused by other foods, such as bread or pasta. It provides a gradual release in blood sugar over hours—exactly what you’d like from eating food.
For nearly two decades, the mantra I have shared with my patients is for them to eat more clean protein, healthy fat, vegetables, fruits, beans, and nuts—with extra spice and herbs for flavor. The glycemic load tables will help you clarify which foods to enjoy more often.
| Food Source | Serving Size | Glycemic Load |
| BEVERAGES | ||
| Tea and coffee, unsweetened | 1 cup | 0 |
| Milk, almond | 1 cup | 0 |
| Milk, skim | 1 cup | 9 |
| Milk, whole | 1 cup | 9 |
| Milk, soy | 1 cup | 9 |
| Wine, red or white | 5 oz. | 0 |
| Beer | 12 oz. | 3 |
| CEREALS | ||
| Oatmeal, cooked, steel-cut | 1 cup | 9 |
| SNACKS | ||
| Chocolate, dark (70–85% cocoa) | 1 oz. | 4 |
| Guacamole | ¼ cup | 0 |
| Hummus (chickpea salad dip) | 1 oz. (30 g) | 0 |
| FRUIT | ||
| Apple | 1 medium | 6 |
| Apricots | 1 cup | 6 |
| Blueberries, wild* | 1 cup | 1 |
| Blueberries, commercially raised* | 1 cup | 4 |
| Cherries | 1 cup | 4 |
| Grapefruit | 1 small | 3 |
| Grapes | 1 cup | 5 |
| Mango | 1 cup (120 g) | 8 |
| Orange | 1 medium | 4 |
| Peach | 1 large | 5 |
| Pear | 1 medium | 5 |
| Pineapple | 1 cup | 7 |
| Plum | 1 cup | 5 |
| Strawberries | 1 cup | 3 |
| Watermelon | 1 cup | 4 |
| LEGUMES (BEANS) | ||
| Beans, black | ½ cup | 7 |
| Beans, kidney | ½ cup | 7 |
| Beans, white | ½ cup | 9 |
| Chickpeas | ½ cup | 8 |
| Lentils | ½ cup | 6 |
| Soybeans (edamame) | ½ cup | 3 |
| NUTS | ||
| Almonds | 1 oz. | 0 |
| Cashews, salted | 1 oz. | 3 |
| Hazelnuts | 1 oz. | 0 |
| Macadamias | 1 oz. | 0 |
| Peanuts (actually a legume) | 1 oz. | 0 |
| Pecans | 1 oz. | 0 |
| Pistachios | 1 oz. | 0 |
| Walnuts | 1 oz. | 0 |
| VEGETABLES | ||
| Asparagus | 1 cup | 3 |
| Avocado (Florida or California) | ½ fruit | 0 |
| Beet | 1 cup | 6 |
| Bell pepper, green | 1 cup | 2 |
| Bell pepper, red or yellow | 1 cup | 3 |
| Bok choy | 1 cup | 0 |
| Broccoli | 1 cup | 0 |
| Cabbage | 1 cup | 0 |
| Carrot | 1 cup | 2 |
| Cauliflower | 1 cup | 0 |
| Celery | 1 cup | 0 |
| Mixed greens, lettuce, and raw spinach | 1 cup | 0 |
| Peas, frozen or fresh | 1 cup | 5 |
| PROTEIN SOURCES | ||
| Eggs, steak, chicken, salmon, pork | 6 oz. | 0 |
| SMART FATS | ||
| Olive, avocado, almond, and coconut oils | 1 Tbsp. | 0 |
| Avocado (Florida or California) | ½ fruit | 0 |
*The glycemic load discrepancy between blueberry varieties is because wild are small and tart, but commercially raised are modified to be larger, juicier, and sweeter.
For these foods, generally limit your portions to not more than one or two servings per day. You should notice that two commonly eaten foods, potatoes and bananas, are in this medium glycemic load group.
These foods are fine for your birthday but not every day. You should avoid them most of the time. You likely won’t be astonished to learn from this chart that a doughnut or a candy bar is high, but you may notice a few surprises, too: whole-wheat bread and white bread have the same high glycemic load (20), a bagel is even higher (34), and “healthy” granola cereal is nearly (literally) off the charts (36). Also notice that none of the proteins, vegetables, fruits, beans, and nuts have a high glycemic load. You won’t miss much avoiding high glycemic load foods.
There is one more step you can take to improve insulin sensitivity and cognitive performance, and that is fasting—avoiding calorie intake for a prolonged period of time.
When we fast, we divert energy from digestion to higher purposes and accomplishments that are often attributed to greater mental clarity. Many historical figures and spiritual leaders, from the ancient Greeks to biblical figures to Gandhi, embraced the practice of fasting for a wide variety of reasons, and its use as a form of political protest continues to this day. Fasting has long played a major role in most of the world’s religions (Christianity, Judaism, Islam, Buddhism, Hinduism, and more) and is incorporated into many holidays and rituals.
The traditional fast entails avoiding all food and sources of calories for anywhere from twenty-four hours to several days. Hydration with liquids including herbal infusions, tea, and broth, as well as water, is essential during a fast. To end the fast, start with water or broth, then progress to a broth or soup with vegetables. Gradually return to eating normally, with foods that are easy to digest. After a fast, most people report feeling more mindful and connected to the foods they consume. Fasting will not only improve some aspects of cognitive function but help us appreciate food and eating as well.
Partial intermittent fasting is a bit different from the traditional model, but it shows promise for improving blood sugar control as well as cognitive performance, especially for those who may be dealing with cognitive impairment.
One of the benefits of prolonged fasting is that without calorie intake, you eventually exhaust your blood sugar supplies and start burning fat to make energy for cells, which forms molecular compounds called ketones. Many of your tissues can use ketones very effectively, especially your brain.
The challenge is that the longer you have to fast, the harder it is to follow, but for some individuals it’s worth doing. “Partial intermittent fasting” is one of the more recent twists on this dietary practice (and is the basis of a number of popular weight-loss diets). Instead of the traditional twenty-four-hours-or-more fast, partial intermittent fasting can have many variations—for example, a fifteen-to-eighteen-hour calorie fast done two or three days per week, or for up to twenty-one to twenty-eight days. And it works for more than weight control.
Recent studies have shown that partial intermittent fasting can be as effective—and sometimes more effective—in improving cognitive performance than traditional fasting; plus it also improves blood sugar control. Avoiding calories (especially carbohydrates) for at least fifteen to eighteen hours will initiate ketone formation and shift fuel usage from glucose (sugar) to ketones (a molecular by-product of fat-burning). The brain’s energy-producing factory, the mitochondria, then uses those ketones for fuel. Simply put, in ketosis, cells convert fat rather than sugar into energy, and the brain seems to like that.
At least in studies of mice, extending the time between feedings (without overall calorie restriction) to induce ketosis has shown several brain benefits. Researchers have noted that such intermittent fasting in mice stimulates the ability to handle brain oxidative stress, enhances the ability to memorize new information (neural plasticity), and induces actual brain growth through increased brain-derived neurotrophic factors and heightened brain cell mitochondrial function.
A second form of partial intermittent fasting is to limit calorie intake for one day to 500–800 very-low-carb calories, get into ketosis, then eat as much as you want the next day. During a three-week period, this method of alternating fasting (25 percent of calories) and feasting (175 percent of calories) every other day has been shown to improve insulin resistance and decrease markers of oxidative stress. The limitation was that the improvements in insulin resistance were about as equally effective as interval exercise training for twenty minutes three times per week. You’d have to decide for yourself, but to get the same results, I would find it much easier to add sixty minutes per week of interval exercise than to fast with only 25 percent of my normal calories every other day.
Yet another form of intermittent fasting is to follow an intense and extremely low carb diet for four or five days every month, basically changing the cellular fuel from glucose to ketones for several days in a row each month. During the four-to-five-day fast, carbs make up less than 10 percent of all food sources, with a modest amount of protein, and nearly 70 to 80 percent of calories during the fast are from pure fat. During this high-fat, ultra-low-carb eating plan, typical meals would include:
• Shakes with coconut milk, green leafy vegetables (like kale), and protein powder, and without any fruit or sugar
• Animal protein stir-fry with green leafy vegetables, like spinach, with ample cooking fat
• Liver, bacon, pâté, and other animal protein sources
• Nuts and seeds, avocados, coconut
• Avoiding all fruits, potatoes, grains, beans, and products with sugar
• Adding extra oil to everything you cook
Since the 1920s, and especially with recent protocols at all major epilepsy treatment centers, many people with difficult-to-control epilepsy have shown a marked improvement in seizure control by shifting their brain fuel from glucose to ketones. However, for epilepsy control, they follow this type of very-low-carb, moderate-protein, very-high-fat diet all the time, not intermittently. In particular, the brain is able to use ketones, which include the molecular compounds beta-hydroxybutyrate, acetoacetate, and, to a lesser degree, acetone. Based on the benefits shown for people with epilepsy, researchers have tried these same protocols for people with mild cognitive impairment and dementia.
In a small study, twenty-three older adults with mild cognitive impairment were randomly chosen for either a very-low-carb or a high-carb diet for six weeks. Those on the very-low-carb diet who showed signs of ketone formation (as evidenced by ketones being present in the urine and blood) showed improvements in not only their memory scores but also in their waistline and in their fasting insulin and glucose levels. This strategy appears to be effective for those with established cognitive decline, and it seems related to improving blood sugar and insulin control, but it was limited to those willing to follow this restrictive regimen. And we don’t know yet whether this type of change yields long-term or only short-term gains.
While a person with epilepsy might be highly motivated to avoid a devastating seizure, a healthier person won’t be inclined to adopt this restrictive fasting regimen long-term—it’s tough to do. The difficulty in following this plan is a big reason why I have designated partial intermittent fasting as a Step 3 option, not Step 1 or 2. Another reason is that the long-term benefits aren’t confirmed. They appear promising but are still being studied.
A Better Way for Women to Fast
One of my friends and medical colleagues, Dr. Anna Cabeca, an obstetrician/gynecologist from Emory University, has been studying the impact of partial fasting regimens for women to address menopause symptoms. Her clinical experience has been that women have much more trouble tolerating fasting with higher meat and fat intake, when they become physiologically acidotic (a state of increased acidity in the blood that may occur with ketosis). Typically, eating animal proteins, eggs, dairy, and grains makes us “acidic,” meaning that we’re forcing the body to eliminate acid in the urine to keep the blood acidity balanced; eating vegetables, beans, and nuts has the opposite effect. With prolonged acidosis, people lose bone mass and muscle mass and may initially report fatigue and brain fog.
There may be a gender difference in how we respond to fasting. After 100,000 years of history, men may adapt better to an eating plan focused on animal protein intake mixed with fasting, while women may do better with far more plant foods mixed between fasting states. Vegetables, fruits, nuts, and beans make us alkaline. Loading up on vegetables and beans the night before fasting ensures an alkaline fasting state, and Dr. Cabeca has found that having her menopausal patients do a vegetable feast before an overnight prolonged fast improves many aspects of their quality of life and makes fasting far more tolerable.
When I talk to my clinic patients about fasting, we review the partial intermittent fasting options:
1. Fasting overnight for 15–18 hours (basically skipping breakfast) 2–3 days per week
2. Very-low-carb fasting every other day
3. Very-low-carb fasting 4–5 days per month
Thus far, in these short-term studies, all three approaches seem similarly effective. However, the vast majority of my patients say the first option—to skip breakfast (fast for fifteen to eighteen hours) two or three days per week—is the easiest to follow, and I predict that this approach would probably be the easiest for you, as well.
With the fifteen-hour overnight fast, there are two options. Option one is hydration (water, tea, herbal infusions, or broth), but no meaningful calories. A friend and colleague, Dr. Kellyann Petrucci, M.S., N.D., made this very popular with her Bone Broth Diet, as she has people limit their calorie intake to only bone broth for eighteen-plus hours two days per week.
Another, even easier-to-follow variation of fifteen-to-eighteen-hour fasting was developed by another colleague, Dave Asprey, who created the Bulletproof Diet. He asks people to eliminate all carbs and protein for fifteen to eighteen hours most days, just having coffee and fat for breakfast (see “Bulletproof Coffee” box, this page). The advantage of adding fat to your coffee is that because you are adding 300 to 400 calories, you don’t get hungry, but without carbs or protein, you go into ketosis as if you didn’t consume any calories at all, minus the hunger.
To get the most benefit from adding fat to your coffee, you don’t dump in half-and-half or cream and stir well. Instead, you use a medium-chain triglyceride (MCT) oil and clarified butter (ghee) and mix the fats with the coffee in a blender. MCTs, typically derived from coconut oil or palm oil, are a special form of saturated fat that has shorter chains than the saturated fats that come from meat, eggs, and palm oil. MCT oil breaks down pretty quickly into ketones and provides a very effective fuel source not only for people with epilepsy but also for competitive athletes who participate in long-distance sports and don’t want to run out of fuel. While a person typically runs out of glycogen (sugar stored in chains in muscle cells) within 90 to 120 minutes with exercise, nearly all of us have enough fat stores to be used as fuel all day long, giving a big advantage to using fat as fuel for long-distance sports.
Because MCT oils break down into ketones, they are also being used as supplements for people with mild cognitive impairment and dementia. In 2009 Samuel Henderson (vice president of research and development for the biotech company Accera) and his research team evaluated 152 subjects with mild to moderate Alzheimer’s disease in a ninety-day randomized study—in other words, nobody knew who was getting what. Instead of having the participants fast to create ketones, researchers gave them an MCT oil supplement or a look-alike placebo, initially ten grams of MCT oil per day during week one, then twenty grams per day for the remaining ninety days. Those getting MCT oil had a clear increase in ketone levels (especially beta-hydroxybutyrate, which is used readily by the brain as fuel), and their cognitive function improved compared to the placebo-treated group.
The biggest downside was that at the dosage of twenty grams daily, 25 percent of the MCT-treated subjects had diarrhea, more than four watery stools per day, sometimes with urgency and crampiness. This discomfort might be worth it for someone with established memory loss (a scary if compelling diagnosis) if they got a boost in brain function, but it’s far harder to tolerate if you are looking for a bit of cognitive edge in your daily, healthy life. You’d have to decide for yourself if you’d prefer to generate ketones through fasting, or tolerate the gastrointestinal issues by adding a hefty dosage of MCT oil, about 1.5 tablespoons every day.
The other major concern with this study is that while there were some benefits for people with the ApoE2 and ApoE3 genotypes, 20 percent of the population with at least one ApoE4 gene showed no benefit. Those are precisely the individuals who have a 300 percent greater risk for developing Alzheimer’s disease, and that’s an unfortunate and frustrating finding because they are the group most desperately in need of a solution like this.
I personally know of one exception—and it’s a striking one. In researching this book, I spoke to Dr. Mary Newport, a physician from Florida who was famous in a way that she would have preferred not to be: her husband was diagnosed more than a decade ago with premature Alzheimer’s disease, and she was researching treatment options. All the medications available had failed him, and Mary was looking for additional options. Though he carried an ApoE4 gene, she tried him on a series of products, including coconut oil, later MCT oil, and finally beta-hydroxybutyrate (the primary ketone in MCT oil), finding moderate improvement with all of these treatments. Mary has spoken at a variety of physician meetings during the last decade and published articles related to her trials. Her husband’s initial success clearly shows that although he had the ApoE4 gene, some individuals are still able to benefit from this type of plan, at least in the short term.
For some reason not yet known, the majority of people with memory loss and the ApoE4 gene are not able to use ketones effectively as brain fuel. Thus, if you have an ApoE4 genotype, it is much more important to prevent cognitive decline and maintain excellent blood sugar and insulin regulation. As noted in the study above, consuming MCT oil does not appear to be highly effective once memory loss has occurred, although partial intermittent fasting may still have other benefits for this high-risk population. For people with an ApoE4 gene, see additional tips to prevent cognitive decline in Chapter 10.
Dave Asprey suggests how to make Bulletproof Coffee with MCT oil; he started the trend toward mixing organic, super-clean, mold-free coffee with butter and MCT oil. Always use a blender. If you pour MCT oil into hot coffee, the fat will float to the top and you may burn your tongue trying to drink it.
Start with 8 ounces of hot coffee, 2 teaspoons of MCT oil, and 1–2 tablespoons of butter or organic ghee. Ghee is essentially dairy free (no dairy protein), so people with dairy intolerance are able to use it without side effects.
First, pour hot water into the blender to warm the container; once that is done, pour the water out. Next, add the hot coffee and MCT oil and blend carefully (taking precautions so it doesn’t splatter). Add a bit of butter (or ghee, organic clarified butter) to the mixture, making a nice, creamy suspension. MCT oil by itself is a bit bland, so blending in ghee adds flavor and richness. The minute amount of dairy protein in regular butter provides lasting foam formation when you blend the coffee, creating a cappuccino effect, so if you truly want foam, you need to use real butter. You can gradually increase the MCT oil to 20 grams daily over time.
A much simpler way to fast and not go hungry (and avoid putting coffee in a blender) is to add organic heavy cream to coffee. Two tablespoons provide 103 calories and less than 1 gram of carbs. If you are otherwise fasting, have one or two cups of coffee with fat, and you’ll reach ketosis—start burning fat and making ketones. Using MCT oil as a fat offers a big boost in ketone levels and especially for people with MCI, might make preparing their coffee in a blender worth it.
Note: This chart compares 20 grams of MCT oil to 20 grams of butter, half-and-half, or heavy cream per one 8-ounce cup of coffee; in relevant studies of MCT oil, the amount specified is 20 grams of fat. I’ve also included 30-gram listings for half-and-half and heavy cream, which is a standard prepackaged single-serving size. Aim to keep carbohydrate grams to less than 1 if you are trying to get into ketosis.
If you don’t want to add fat to your coffee, another alternative to taking MCT oil is to drink an elixir loaded with the ketone compound beta-hydroxybutyrate. Whereas MCT oil is converted into ketones, there are now products available that provide the ketones themselves. Popular with athletes and often sold in a powdered form (users compare the taste to Tang), these drinks are fairly expensive, at around four dollars per serving. These products have just started to be studied, however, and there is a concern that the initial ketone elixirs may be contaminated with other products that might cause harm. If you want to test this type of elixir, ensure that the product is pure beta-hydroxybutyrate, without acetone or formaldehyde by-products.
Coconut products (such as coconut milk and the meat of the coconut) and oil are different from MCT oil. “MCT oil” and “coconut oil” are not interchangeable terms, as coconut oil has only about one-fourth to one-eighth the concentration of medium-chain triglycerides compared to pure MCT oil. MCT oil is usually concentrated from coconut oil or palm oil. The MCT oil used in Dr. Henderson’s study was more than 95 percent caprylic acid and caproic acid, which are shorter versions of medium-chain triglycerides. For those of you into biochemistry (or if you just want to understand the significance of molecular chain-length in this context): medium-chain triglycerides include caprylic acid with 8 carbon chains, caproic acid with 6, capric acid with 10, and lauric acid with 12. Here’s the key fact: the shorter chains—in this case, caprylic and caproic acids—are better at forming ketones.
Coconut oil has only about 25 percent of these shorter MCT forms and is more than 50 percent lauric acid. It also has a wide variety of other fatty acids, including 223 mg (0.223 grams) per tablespoon of omega-6 fatty acids—part of the reason it has such a low smoke point for cooking, meaning it tolerates only cooking temperatures below 350°F. (It’s a myth that you can safely cook at high heat with coconut oil, because it can convert to a damaged fat at temperatures above 350°F.)
If the goal is to produce ketones to be used as brain fuel, then MCT oil appears to be a better choice than coconut oil, as it has anywhere from four to eight times the potency of coconut oil. Yet consuming coconut oil is associated with several health benefits:
• The primary oil component in coconut oil is lauric acid, which, once digested, is very effective at killing microbes and fighting infections. It is often used by natural health practitioners to help remove GI pathogens.
• Coconut oil boosts metabolism (calorie burning) in highly active people, as the medium-chain fats are great for athletes to use as fuel, especially for prolonged exercise sessions, which is why athletes often combine coconut milk with their workout protein shakes.
• Coconut oil generally appears to be beneficial for cognitive function and for people with neurological disease, as the medium-chain triglycerides will help to form ketones—less than pure MCT oil does, but far more than other oils.
Despite these benefits, coconut oil is still controversial because eating more coconut products increases cholesterol levels. Coconut oil and coconut products are made of 90 percent saturated fat, much more than is found in butter (64 percent) or beef fat (40 percent). Consuming coconut products daily raises LDL and total cholesterol by 40 to 70 points. That said, it increases healthy HDL levels as well and may even improve the healthy total cholesterol/HDL ratio. Another cholesterol benefit of consuming coconut products is that they increase LDL particle size (considered good); thus, although a conventional physician might be concerned by the shift in your cholesterol profile, the net change on cholesterol profiles may be more beneficial than problematic.
My concern, however, is we do not have any clinical outcome studies that show eating coconut is either neutral or beneficial, and at least one clinical study using coconut products showed that they decreased artery function and worsened HDL inflammation. For those reasons, I don’t recommend coconut oil to my patients with established heart disease.
Skip the Coconut Water
I’m hesitant to suggest coconut oil for people with heart issues but I’m even more concerned about the highly popular coconut water—for anyone. A typical 11-ounce serving of coconut water has 12.5 grams of sugar, nearly 1 tablespoon, without any meaningful fiber. This is akin to drinking apple juice instead of eating an apple, which is far more sugar than I’d recommend for anyone. When some of my patients with diabetes started using coconut water as a sports drink during their regular workout activities, such as during a tennis match, they almost immediately went from well-controlled blood sugar to poorly controlled—and the only change was a few servings of coconut water daily. Plain water is a much better choice. If you can find unsweetened coconut water (without sugar), then it’s fine to enjoy it.
My recommendation is that if you are in good health, or if you have neurological issues like memory loss, and especially if you are trying to follow a ketogenic diet, then it is likely smart to eat more coconut products. However, if you have established heart disease or are being treated by your doctor for abnormal cholesterol problems, I’d recommend that you consult with your doctor, avoid coconut oil in general, and enjoy the many other heart- and brain-friendly fats. Other fats to consider beyond coconut oil would be avocado and avocado oil, nuts and nut oils, dark chocolate, wild cold-water fish, and of course olives and olive oil.
If instead of pure coconut oil you are using coconut products, use coconut milk as well as coconut flour and meat, as they also provide fiber, flavonoids, and other vitamins and minerals. I remain enthusiastic that someday coconut products will be shown to have clinical benefits, which is why despite the lack of proven benefit, you’ll notice that I use coconut flour and coconut milk in several of my recipes (see Chapter 10).
An overnight fast with nothing to eat after seven or eight p.m. a couple of days per week seems the easiest type of partial intermittent fasting to try first, allowing you some form of fat, in particular with your coffee or tea for breakfast, to suppress hunger. The evening before your partial fast, eat a big salad, extra vegetables, or bean-vegetable soup to help induce a more alkaline state. Don’t eat anything else until noon.
Despite the potential health benefits of partial intermittent fasting, I have designated it as Step 3 of my food plan for several reasons. It is harder to follow than adding foods that are proven to enhance brain function (things like dark chocolate, berries, greens, coffee/tea, and red wine), as in Step 1, and more difficult than choosing foods that have a low sugar load, as in Step 2. Second, the limitations are that we don’t know if this type of fasting intervention will work over the long term (as in years), or for just the thirty to ninety days they have been studied to date. Furthermore, we don’t know which type of intermittent fasting is the most effective, although the initial data suggest that they all work.
Finally, although partial intermittent fasting and adding MCT oil to generate an elevation in ketones has been shown to help people with dementia and mild cognitive impairment over the short term, we simply don’t know if they help people who are relatively healthy with normal brain function—those of you trying to optimize your current brain function and prevent future memory loss.
If you want to try Step 3, I leave it up to you to decide if following one of these fasting regimens matches your lifestyle. Certainly, doing Steps 1 and 2 will take you a long way toward achieving better brain health. Step 3 has the potential to take you even further.
The recipes starting on this page feature the brain-boosting foods at the heart of Steps 1 and 2. Weigh the fasting options in Step 3 as well as the use of MCT oil—all of which will improve your blood sugar and insulin control. You can start on those recipes now, and perhaps they will inspire you to try some of your own brain-boosting food combinations.
Now, to the second pillar of the program: key nutrients for brain health.