You may have noticed that our food culture is obsessed with “superfoods.” We’re all looking for that one game changer that’s going to fix all of our health problems and make us feel like a million bucks. We’re encouraged to reach for pills we can pop to make everything better. Minimal effort with maximum results. Don’t get me wrong, superfoods (and medications, when you need them) are great. But we got it a little twisted because no one food is capable of meeting that expectation. There aren’t three hundred thousand plants on Earth so that we could pick just one and gorge ourselves on it.
There’s no perfect food—they all have strengths and weaknesses. I’m the first to admit that there are weaknesses to the healthy foods I’m promoting in this book. It goes back to our conversation from Chapter 4. Too much of a good thing can hurt you. If all you ate was kale, you would be incredibly unhealthy.
When we focus on superfoods alone, we miss out on diversity of plants. Superfoods are cool, but I will take plant-based diversity over superfoods every day of the week.
Remember that food is not just a bunch of individual components, it’s an entire package. Do the benefits outweigh the negatives? Bring food into your life that’s more positive than negative. When we do that, we get the best from our diet. That’s where plant-based diversity comes in—each plant might not be individually perfect, but the positives far outweigh the negatives, and when you consider them collectively you have a diet perfectly tailored to support a healthy gut microbiota and overall health.
That said, we can focus on diversity of plants and at the same time incorporate foods that are true nutritional powerhouses to get the best of both those worlds. These turbocharged foods can be our “best friends,” but they shouldn’t be our only friends.
Here are my favorite Fiber Fueled foods, conveniently organized into an acronym to make them easy to remember. These are the foods I try to sneak in as often as possible, but they are most powerful in combination and when you eat them with more plant varieties.
F GOALS
F: Fruit & Fermented
G: Greens & Grains
O: Omega-3 Super Seeds
A: Aromatics (onions, garlic)
L: Legumes
S: Sulforaphane (broccoli sprouts and other cruciferous veggies)
In Chapter 6, we celebrated fermented foods for their increased nutritional value, prebiotics, probiotics, and enrichment with postbiotics. They also add further plant-based diversity to our diet. Remember that our goal is to add a small serving of fermented foods to our daily routine.
But there’s a second “F” in our F GOALS and that’s fruit. There’s an inordinate amount of fear of fruit out there, particularly in the fitness community where I’ve seen or heard many personal trainers say, “Fruit has sugar, and excess sugar can lead to weight gain.” Folks, we shouldn’t look at any food only through the lens of its individual components because it will cause us to make conclusions that are flat-out wrong. We need to look at whole foods. The sugar in fruit is by no means the same as processed sugar. It’s packed in with everything else in the fruit, including vitamins and minerals, phytochemicals, and fiber.
And no, eating whole fruit does not cause “weight gain.” It’s actually quite the opposite. It doesn’t cause diabetes, either, for that matter. Instead, it actually can protect against it. For example, as sweet as berries may be, they actually lower blood sugar and insulin release after a meal. Whether you are diabetic or looking to avoid sugar for another reason, don’t make the mistake of lumping natural sugar in whole fruit in with added or processed sugars. You absolutely should be eating fruit! It can help you lose weight and control your diabetes.
I could write an entire book about the health benefits you’ll find in fruit. In Chapter 4 we learned that apples are an excellent source of prebiotic fiber, healthy microbes, and numerous beneficial polyphenol phytochemicals contributing to reduced risk of heart disease, stroke, lung cancer, diabetes, asthma, and weight loss. Oranges have vitamin C and antioxidant flavonoids and anthocyanins that protect against hypertension, high cholesterol, kidney stones, and iron deficiency. Nice, right?
So apples and oranges are great, but let me tell you about my deep and abiding love for berries: blueberries, blackberries, raspberries, strawberries, and the lesser known acai and goji berries. Give me all of them!
Berries come in incredible colors: blue, purple, red, and pink. The color actually comes from a phytochemical (remember, “phyto” means “plant-based”) called anthocyanins. Without anthocyanins, blueberries would be green! That’s why immature blueberries aren’t blue, because the anthocyanins haven’t come in yet. Anthocyanins are pretty magical. They help protect against cancer, and they also boost cognition. For example, in one study women who ate just two servings of strawberries or one serving of blueberries per week postponed cognitive decline and made their brain behave like it was thirty months younger. In another study, two servings of berries a week yielded a 23 percent less chance of developing Parkinson’s. And when wild blueberries were given to kids, they saw almost immediate improvements in cognitive performance that increased based upon the dose of blueberries. I recently took a grueling eight-hour exam to renew my board certification in internal medicine. Guess what I was eating all day? Blueberries.
But let’s not ignore the fiber content. In a one-cup serving of strawberries, blueberries, blackberries, and raspberries, you’ll find 3, 4, 8, and 8 grams of fiber in each, respectively. Considering that the average American is only getting 15 or 16 grams of fiber in a day, a simple handful of berries can make a big difference. I love popping a couple of handfuls of berries as an afternoon snack or when I have a sweet tooth.
In Chapter 4 we discussed the merits of whole grains, such as reduced risk of coronary heart disease, cardiovascular disease, and total cancer as well as lower likelihood of death from all causes, respiratory diseases, infectious diseases, diabetes, and all non-cardiovascular, non-cancer causes. That was just one study.
It’s pretty straightforward from my perspective. Drop the refined grains, no doubt. I’m with you 100 percent. But if you want a healthy microbiota, whole grains are at the foundation of building a healthy gut. And the numerous studies cited in Chapter 4 support it.
There’s a second important “G” in the house, and that’s greens. There is so much plant-based diversity when it comes to greens: collards, kale, arugula, spinach, romaine, bok choy, watercress, Swiss chard, broccoli raab, mustard greens, sorrel, escarole, kohlrabi, and more. And there are varieties within these foods, too. For example, kale varieties include curly, lacinato (aka dinosaur or Tuscan kale), Redbor, or Siberian. Even the leaves of some favorite root veggies like beet, turnip, dandelion, radish, and carrots are edible and offer more variety in the green category.
When we assess the health benefits of food, nutrient density is a key concept. The idea is to get the maximum amount of nutrients—vitamins, minerals, phytochemicals, fiber—per calorie consumed. This becomes a simple formula: nutrient density equals nutrients divided by calories. So if you think about oil, for example, it’s high in calories and low in nutrients. Poor nutrient density. Or potato chips. High in calories, low in nutrients. This is a pretty straightforward, logical approach, right?
We call it the ANDI score, which stands for Aggregate Nutrient Density Index and was developed by the legendary Dr. Joel Fuhrman, one of my personal health heroes. The score is from 1 to 1,000, with 1 being the worst. For example, cola, corn chips, and vanilla ice cream got the lowest score. Sounds about right. As for the high performers, there were five with a perfect 1,000 score—kale, collards, mustard greens, watercress, and Swiss chard. Bok choy, spinach, arugula, and romaine were the next four highest scores. In other words, greens were the top nine foods on the list. This wasn’t a list restricted to just greens. All foods were eligible, yet greens hold a monopoly at the top.
The absurd amount of nutrient density in greens is a present from Mother Nature. You get tons of nutrients packaged with almost no calories, so you can literally eat as much as you want. It’s getting your nutrients served without the calories! For example, an entire pound of leafy greens has only 100 calories. That’s about one egg or two bites of steak. I’ve stopped worrying about portion size ever since I transitioned to a plant-based diet, but if you do continue to consume high-calorie foods after reading this book, know that you can throw unlimited amounts of greens in there to get more nutrients in your diet without compromising calories.
Let’s highlight a few examples of this nutrient density hard at work:
Kale: Kale contains antioxidant phytochemicals lutein and zeaxanthin, which are required by the eyes to prevent macular degeneration. It also contains beta-carotene, which reduces the risk of getting cataracts.
Collard greens: You can’t live in Charleston, South Carolina, and not love collard greens. But what’s beautiful is that they can sneak nutrients in on even the most unsuspecting Southern palate. Turns out that collards bind bile acids in the intestines and eliminate them in our stool. This helps to lower cholesterol and reduces carcinogenic secondary bile acids.
Spinach: You may recall that Popeye got his superhuman strength by popping a can of spinach. Popeye was created in 1929, so this was incredibly forward-thinking. And it’s true! Just one cup of cooked spinach offers 36 percent of your daily value for iron and 11 percent for protein, not to mention a bonus of vitamins A and K, calcium, magnesium, potassium, and manganese. Oh, and 4 grams of fiber.
Arugula: Arugula is a cancer destroyer. It has a unique mix of phytochemicals like thiocyanates, sulforaphane, and indoles that may help fight some of our most deadly cancers—prostate, breast, colon, ovarian, and cervical. We’ll come back to sulforaphane in a minute.
Bok choy: Bok choy is great for your bones, offering critical minerals like iron, zinc, and magnesium in combination with vitamin K.
Romaine: If you’re looking for healthy skin and to reverse aging, grab some romaine. The vitamins A and C in romaine help to lay down fresh collagen to prevent wrinkles and neutralize oxidizing free radicals. The result is glowing, radiant skin with improved elasticity.
I absolutely adore this category because I feel like these foods have it all—they are nutritious, delicious, versatile, and unique. But before I jump in, a few words on omega-3 and omega-6 fatty acids. You’ve heard of different fat types: trans, saturated, monounsaturated, polyunsaturated. These omega-3 and -6 fats are polyunsaturated fats, and they’re considered “essential” because our body is not capable of intrinsically making them so we are required to get them from our diet. If you don’t consume them, you develop a deficiency, which can lead to sickness.
Generally speaking, polyunsaturated fats are considered healthy and are important for many functions in the body. But you’ve probably heard about omega-3s more than omega-6s. Part of the reason why you’ve heard so much about omega-3s is that the modern Western diet provides an excessive amount of omega-6s and an inadequate amount of omega-3s. The ratio of omega-6s to omega-3s is a marker of health. Traditional cultures are thought to have evolved with a nearly even mix between omega-6s and omega-3s, while most Westerners are functioning with a ratio between 15 and 16.7 to 1 of excess omega-6s. It’s a ratio that when skewed can promote disease: cardiovascular disease, cancer, osteoporosis, and autoimmune diseases. Our goal is to balance this ratio, which means that we need an influx of omega-3s in our diet.
And I know just where we can find them—omega-3 super seeds. To be specific, I’m referring to three types of seeds that contain plant-based omega-3s: flaxseeds, chia seeds, and hemp seeds. While each offers the omega-3s, there are differences between each so let’s break it down a little bit.
Flaxseed: Flaxseeds are an excellent source of omega-3 alpha-linolenic acid (ALA), with 2,300 milligrams of ALA per tablespoon of flax. But it is also an excellent source of soluble fiber, which is part of the reason why it’s a traditional remedy for constipation. You get all the goodness that comes with prebiotic fiber as discussed in Chapter 3. Flax is also particularly rich in lignans, which are plant chemicals that strongly protect against hormonal cancers like breast and prostate cancer.
Chia seeds: You’ll find lignans in chia seeds as well, though the levels are higher in flax. Chia has ever so slightly more omega-3s (2,400 vs. 2,300 milligrams per tablespoon) and significantly more fiber (5 grams in chia vs. 3 grams in flax). Chia seeds are 40 percent fiber by weight, making them one of the top sources of fiber in the world. This is mostly soluble fiber, which is the prebiotic kind. You can see the soluble fiber on display if you stir a tablespoon of chia into a quarter cup of liquid and within ten minutes you’ll find a viscous gel. Chia seeds can absorb ten to twelve times their weight in water. Let them sit in water for a few hours and you’ll make chia pudding, which is nutritious and has a texture resembling tapioca pudding.
Hemp seeds: Last but not least are hemp seeds. They’re, ahem, different from flax and chia. Okay, let me just get this out of the way. Yes, hemp seeds come from the same plant as marijuana. But they’re legal! They don’t contain THC, the psychoactive part of cannabis. So they won’t get you high, but they will get you healthy. Hemps seeds have about 40 percent of the omega-3 ALA that you find in chia and flax, but less fiber. When you think of hemp seeds, think of protein. Hemp seeds are unique in that they are complete protein, meaning they contain all of the essential amino acids. So hemp seeds are a one-stop shop for both essential fats and amino acids.
I love throwing omega-3 super seeds in my smoothie. Honestly, I’ll often put all three in at the same time. They go well with oatmeal or in some cases on a fresh salad. And you’ll find a mouthwatering recipe for chia pudding (Zesty Lemon Chia Pudding) in Chapter 10, “The Fiber Fueled 4 Weeks.”
There are a few other sources of plant-based omega-3s to be aware of—walnuts, firm tofu, and edamame have a decent amount of ALA, although much less than flax or chia. Beans and Brussels sprouts have a small amount, as well.
These are the flavor foods! Think of a heavenly, slow-simmered Italian sauce heavily laden with garlic, onions, and basil.
The great flavor that you get with onions and garlic is because they’re both allium vegetables. Others in this category with similar benefits are leeks, shallots, chives, and scallions. At baseline, allium vegetables are jam-packed with nutrients: vitamins B1, B2, B3, B6, C, E, K, folate, iron, magnesium, phosphorus, sodium, and zinc. Jam. Packed.
But then we get into the really good stuff. Allium contains aromatic organosulfur compounds that are responsible for their smell, their taste, and their health benefits. For example, when fresh garlic or onions are chopped or crushed, an enzyme called alliinase is activated and converts alliin into allicin. It takes ten minutes for the enzyme to activate the allicin, a compound that has antibacterial, antifungal, antiparasitic, and even antiviral properties. The stronger the smell, the better it is for your health. To allow allicin to activate, CHOP, then STOP and wait for ten minutes before cooking with alliums. The allicin appears to target the bad guys like multidrug-resistant enterotoxigenic E. coli and Candida albicans. And it promotes the growth of Bifidobacteria and other healthy microbes in the gut. It’s worth noting that alliums are also an excellent source of prebiotic fiber.
Allium veggies also have potent anticancer activity, particularly against gastric and prostate cancer. There are two layers to the anticancer activity. First, the organosulfur compounds like allicin detoxify carcinogens, block tumor growth, and prevent blood flow to the tumor. Second, allium veggies contain at least twenty-four different flavonoid phytochemicals, such as quercetin. Red onions have the added benefit of anthocyanidins. The flavonoids have anti-inflammatory effects that may help protect us from cancer.
These antioxidant compounds also appear to be beneficial for Alzheimer’s dementia and heart disease.
Legumes are among the healthiest foods on the planet. And they are dirt cheap! They are at the foundation of a healthy gut microbiota, offering prebiotic fiber and resistant starches in spades. Please don’t pass up the opportunity to build your gut on these irreplaceable foods. See Chapter 4 for more information on legumes.
Plants are like my children. I love all of them, and I can see the beauty in their individuality. But if there’s one I love the most, this is the one. I have been waiting eight chapters to talk to you about cruciferous vegetables and their super chemical sulforaphane.
We all know broccoli, kale, arugula, cabbage, cauliflower, and Brussels sprouts as healthy foods. But what’s so special about them? They’re part of a family of vegetables that we refer to as cruciferous. There are at least forty family members, but they share a common lineage. Through billions of years of plant evolution, they evolved a common defense system using an enzyme called myrosinase to convert glucosinolates into “toxic” compounds. The myrosinase and glucosinolates are stored in separate compartments within the plant, so under normal circumstances they don’t mix. But when an insect or invading herbivore—like yours truly—starts mashing on the plant, they’ll break the separating chambers, mix the chemicals, and set off a chemical reaction leading to the production of isothiocyanates (ITCs) like sulforaphane. It’s conceptually similar to a bomb. So what happens when the bomb goes off and these ITCs are released? Cancer is cured, inflammation is squashed, hearts get healthy, blood sugar comes down, fat gets burned, and hormones get balanced. ITCs are powerfully health promoting. This is yet another example where a plant’s defense mechanism can also do double duty as our defense against cancer cells.
Let’s talk about my favorite isothiocyanate—sulforaphane. You get sulforaphane from cruciferous vegetables like broccoli, Brussels sprouts, kale, and cabbage. In 1992, Dr. Paul Talalay, a true pioneer in the field of cancer prevention, opened Pandora’s box when he first published on the cancer protective effects of sulforaphane. Since that time there have been hundreds of laboratory, animal, and some human studies (many by Dr. Talalay himself, who recently passed away at age ninety-five) suggesting that sulforaphane may be the driving force behind these incredibly healthy foods. Here’s what we have learned about sulforaphane, this medicinal phytochemical:
Protects us from cancer by seven mechanisms: inhibits the production of carcinogens, activates enzymes to detoxify the carcinogens that are produced, shuts down blood flow to the tumor (which is needed to fuel growth), inhibits cancer cell migration and invasion, promotes self-destruction of cancer cells (apoptosis), and even regulates cancer development through epigenetics.
Undermines lung, colon, breast, prostate, skin, pancreatic, liver, throat, and bladder cancer, osteosarcoma, glioblastoma, leukemia, melanoma—and potentially more.
Shuts down the pro-inflammatory pathways that get activated by bacterial endotoxin.
Works as a powerful antioxidant to detoxify free radicals and reduce cellular damage.
May benefit Parkinson’s, and recovery from stroke, concussion, or other brain trauma.
Reduces amyloid beta plaques and improves cognitive impairment in Alzheimer’s patients.
Improves mood, as well as anxiety and depression.
Boosts brain function, improving memory and focus.
Regulates the immune system, ameliorating autoimmune diseases like experimental multiple sclerosis and rheumatoid arthritis.
Flips the body into fat-burning mode to promote weight loss, amazingly by reducing pathogenic bad bacteria in the gut and limiting bacterial endotoxin release in addition to other mechanisms.
Combats bacterial and fungal infections. In one study, twenty-three out of twenty-eight pathogenic bacterial and fungal species were inhibited.
Protects the heart by improving lipids, lowering blood pressure, inhibiting platelet aggregation, and even directly suppressing inflammation in the arteries.
Improves insulin sensitivity to correct type 2 diabetes.
Repairs the damage of diabetes, correcting diabetic heart and kidney damage.
Protects the liver and kidneys from the damage done by some chemotherapeutic drugs.
Believe it or not, I could keep going. So how does sulforaphane interact with our gut microbiota? We saw above that sulforaphane is capable of reducing levels of pathogenic bacteria and bacterial endotoxin release. But there’s so much more. In another study, sulforaphane corrected gut dysbiosis by increasing healthy gut microbes, increasing butyrate release, and repairing the intestinal lining to reverse leaky gut by upregulating tight junction formation. Mind. Blown. What I’m saying here is that part of the way sulforaphane works its absolute magic is by tag teaming with SCFAs to create the most powerful gut-healing superhero duo of all time.
It’s all about the cruciferous veggies, specifically broccoli, Brussels sprouts, cabbage, cauliflower, and kale. But there is one food that dominates all others in terms of offering more sulforaphane: broccoli sprouts. These are essentially immature broccoli, where the seed has just recently hatched and we have the earliest thing beyond a seed. The concept is the same as bean sprouts or alfalfa sprouts. Broccoli sprouts can produce ten to one hundred times more sulforaphane than mature broccoli. What this means is that you can either eat massive quantities of fully mature broccoli or a small amount of broccoli sprouts and achieve the same effect.
Broccoli sprouts have a bitter, peppery flavor, but it’s that bitterness that is blasting cancer cells on your behalf. And note: Taking a supplement instead just can’t match the effect of the broccoli sprouts. In a study comparing broccoli sprouts to a supplement, the real thing dominated. Whole foods win, yet again! If the taste bothers you, try using broccoli sprouts in a smoothie, soup, or larger salad.
I’m pretty sure you now understand why sulforaphane deserved its own category. Honestly, there may be no single food that represents the idea of “Food Is Medicine” better than broccoli sprouts. But mushrooms and seaweed deserve a quick shout-out as a bonus category.
Shrooms deserve mention because they are entirely unique—they’re not even plants! They’re fungi, but let’s make them honorary plants because they sure behave as such. They contain prebiotic beta-glucan, which strengthens the immune system to prevent infections and even cancer. Several types even offer unique protection against breast cancer. Eating one button mushroom per day is associated with a 64 percent reduction in breast cancer risk. One beautiful thing about mushrooms is the variety: white, cremini, oyster, portobello, maitake, reishi, cordyceps. Each offers its own unique blend of health benefits. So in addition to plant-based diversity, I advocate for toadstool diversity!
Seaweed deserves a little more respect. It’s not a weed, it’s a vegetable. It just so happens to come from the ocean. And what’s cool is if we’re talking about plant-based diversity, seaweed is a fantastic way to add it because, not only is it high in fiber, but it actually has several unique types of fiber that you won’t find in terrestrial plants—ulvans, xylans, agars. Naturally, these are prebiotic fibers. Brown algae, such as kelp or wakame, contain a unique compound called fucoxanthin that helps reduce the accumulation of fats, promotes weight loss, improves insulin sensitivity, and improves blood lipid profiles. Sea veggies are also an excellent source of iodine for thyroid health and vitamin B12.
Since sea veggies and algae aren’t a traditional part of the American diet, you may be at a loss for where to start with them. No worries. Let’s do a quick little run-through of some options and how to incorporate them.
Nori: These are the crisp sheets that can be softened to make sushi rolls. They’re a lightweight, nutritious snack as is, but can also be broken into “flakes” and sprinkled on your salad for some added crunch.
Kelp/Kombu: Generally sold in dried strips and “meaty” versions, kelp adds a nice umami flavor to savory soups, like the Biome Broth you’ll find in Chapter 10, “The Fiber Fueled 4 Weeks.” The Japanese even drink kombu tea.
Wakame: A delicate, lightly sweet seaweed that makes a nice addition to miso soup, or combine it with crunchy veggies like cucumber to make a delicious seaweed salad.
Spirulina: A nutrient-dense blue-green algae found in powder or tablet form that’s very high in iron, calcium, protein, B vitamins, and chlorophyll. Sprinkle it into your smoothies and enjoy its deep color.
Okay, so we have our list of foundational foods and now it’s time to shift our eating. Be conscious of the fiber and FODMAP content on the F GOALS list. It’s no coincidence that these are high-fiber, high FODMAP foods. As we’ve discussed, FODMAPs aren’t the enemy, they’re our friend. But whenever we’re adding in fiber and FODMAPs, we want to go low and slow to grow—that’s the motto.
To view the 60+ scientific references cited in this chapter, please visit me online at www.theplantfedgut.com/research/.