Eat to Beat Your Diet

CHAPTER 1

The Surprising Science of Fat, Health, and Disease

If the word “fat” triggers a strong emotion when you hear it, you’re not alone. Our language is filled with words like “overweight,” “obese,” and “heavy” that can bring about judgment, discomfort, disappointment, and even fear. We wince when we see the fat on our frame in the bathroom mirror. It makes us feel less healthy. Even in the grocery store, we feel a negative reaction when we see a rind of fat on a cut of meat in the butcher section. Fat has a bad reputation—but I’m here to tell you that fat is not the villain we’ve made it out to be.

The truth is, fat is one of the most important tissues in your body. It stores the fuel that your heart needs for pumping, your liver needs to detoxify your blood, and your kidneys need to remove waste and extra fluid from your body. In fact, fat is essential to every organ’s functioning. Without any body fat, you would look skeletal and haggard—ultraskinny is a shocking look—and if you stopped eating, you’d run out of life-sustaining energy and die within a couple of months. If you had no food, your body could draw on its fuel reservoir of fat to help you survive—which would be depleted to zero in nine weeks for a woman and seven weeks for a man of average build.ⁱ

Fat insulates you like a sweater when you are exposed to the cold, and it cushions and prevents your internal organs from rupturing if you take a fall. More surprising, science has revealed that fat itself is an actual organ. It releases hormones and chemical signals that control your brain, heart, immune system, and virtually all your body’s health systems. Fat is not to be feared but rather respected, although we do need to keep it under control.

The Problem with Excess Fat

Excess body fat is a true villain when it comes to your well-being, even in slender people. A common misconception is that you only need to worry about body fat if you are overweight. In reality, even if the number on the scale says “you’re healthy,” you can have too much fat. Medical research shows that everyone needs to be concerned about the amount of body fat they carry inside their frame.

Whether you have a large body or a small one, excess body fat grows… like a cancer. Just like a tumor, fat needs a blood supply to nourish its mass. To grow larger and become dangerous, growing fatty tissue must take on an ever-increasing blood supply by recruiting new blood vessels through a process called angiogenesis—just like a cancer does. Tumors are angiogenesis-dependent, and so is burgeoning fat.

This property of fat has been confirmed using the very tools of cancer research. Scientists at the University of Massachusetts Medical School obtained chunks of belly fat from people undergoing gastric bypass surgery for morbid obesity. They placed tiny pieces of fat in a plastic dish, bathed them with liquid nutrients, and observed what happened. Within four days, new blood vessels began sprouting outward like branches from a tree as the fat attempted to feed itself. This is shown in the two photos from the study (Figure 1.1). The dark mass in the left panel is a piece of fat with a starburst of growing blood vessels radiating outward. In the right panel is a close-up view: you can see the individual blood vessel cells organizing themselves into tiny tubes.ⁱⁱ

Once fat improves its blood supply, more oxygen and nutrients flow to feed the cells. But also like a tumor, fat cannot grow if its blood supply is impeded. Researchers have shown in the lab that body fat will actually shrink if angiogenesis is inhibited, and this leads to weight loss.¹ Administering a drug that inhibits angiogenesis can starve fat tissue and cause slimming of the body, even when there is no change in diet.² Cutting off the blood supply to tumors is an effective way doctors treat cancer. Now this strategy, called antiangiogenesis, can be applied to controlling body fat.

The best news, however, is that you don’t need drugs to cut off fat’s blood supply. This approach has been borrowed to study the effects of food because many foods contain natural chemicals that can cut off the blood supply to fat and shrink it. Green tea, for example, contains a bioactive compound called epigallocatechin-3-gallate (EGCG), which is a potent angiogenesis inhibitor.³ Clinical studies have tested extracts from green tea and shown that people drinking them have reduced abdominal fat and waist circumference.⁴ Researchers at Inha University in Korea examined 10,030 subjects in the Korean Genome and Epidemiology Study and found that women who consumed four or more cups of green tea per week had a 44 percent decreased risk of abdominal obesity.⁵ All this to say:

You can eat to beat fat.

Eat to Fight Fat

We’ve known for centuries that eating less will help you lose weight, but the unexpected good news is that we’ve now identified certain foods that when eaten can help burn away excess fat. These foods improve your metabolism, which is vital to your health. You read that correctly: eating the right foods can actively promote fat loss and improve your metabolism. Even better, many of the same foods improve your body’s health defenses, too. A triple win.

If you are reading this book because you want to lose weight, chances are you have tried dieting before. You may have lost weight temporarily but soon gained it back, since most diets are just too hard to follow for long. You might have felt discouraged by diets that are all about restriction and elimination because you found them onerous and depriving. That’s completely understandable. We naturally prefer to enjoy our life and not fear food. So, you may be asking, “Is there a way I can combat fat while embracing and enjoying food?”

The answer is “Yes!” I am going to show you how.

In the chapters ahead, you will learn how you can fight harmful fat, improve your metabolism, and eat for pleasure—all at the same time. And I will show you exactly how to put the latest research to work in your daily menu.

Choosing the right foods can take your health to the next level. In my previous book, Eat to Beat Disease, I gave a comprehensive primer on your body’s health defense systems. Since then, medical research has greatly expanded our understanding of the many ways our health defenses are linked to our body fat, and vice versa. What this means is that eating to boost your health defenses can also help rein in your body fat. The harm caused by excess body fat also directly hinders the body’s health defense systems, making you more vulnerable to disease. In this first chapter, I will lay out, for the first time ever, the fascinating connections among food, fat, and your five health defenses. So let’s take a closer look at how each of these systems does its job and how they interact with your body fat.

Heroes of Health: Fat and Your Five Defense Systems

The Angiogenesis System

The prefix “angio-” refers to blood vessels, and “-genesis” refers to growth. Your body is filled with sixty thousand miles of blood vessels that form your circulation—enough to encircle the world twice. These are the highways and byways for blood and everything that’s carried within it. Your angiogenesis defense system delivers oxygen and nutrients to every cell in your body. When your blood vessels are healthy, your organs are healthy. This defense system maintains just the right number of blood vessels at all times.

If you are injured and need to heal, or if you are building more muscle, or if you are pregnant and nurturing new life, your angiogenesis system springs into action to grow blood vessels wherever they are needed: just the right amount, not too few and not too many. On the flip side, the system also can adjust itself to prevent too many blood vessels from forming or prune away excess vessels. In short, to maintain good health, you need your angiogenesis system to be operating to groom your circulation.

More than seventy diseases can occur when your angiogenesis system is weakened and there are either excessive or insufficient blood vessels. Some of the most common diseases include obesity, cancer, diabetes, arthritis, and even Alzheimer’s disease. Insufficient angiogenesis leads to wounds that do not heal or an oxygen-starved heart and brain and organ failure. Excessive blood vessels, on the other hand, can leak fluid and bleed, causing organ damage. If this should happen in your eyes, leaking vessels can cause vision loss in conditions like age-related macular degeneration and diabetic retinopathy.

Cancer can thwart your angiogenesis defenses by recruiting new blood vessels to bring nutrients and oxygen to cancer cells. This allows tumors to grow and spread (metastasize). A robust, fortified angiogenesis defense prevents this from happening. Without a new blood supply, a tumor cannot expand beyond 2 to 3 millimeters (about 1/10th of an inch) in diameter, roughly the size of the tip of a ballpoint pen. If a cancer does manage to hijack the angiogenesis system, however, new blood vessels sprout into the tumor and nourish cancer cells, fueling the tumor’s ability to invade surrounding organs and lethally spread. Cutting off the blood supply to shrink tumors is the basis for cancer treatments called antiangiogenic therapy.

The same principle also applies to fat. The heftier the fat mass, the more blood vessels are needed to keep it nourished. Cut off the blood supply to a mass of fat, and it can’t grow larger.

Unlike cancer, however, blood vessels were already baked into your fat from the time you were born. In studies of people with severe obesity, the bigger their waistline, the more blood vessels were present and feeding their fat.⁶ The need for blood flow in fat is critical. As I mentioned earlier, a chunk of belly fat removed during surgery and placed in a plastic dish of nutrients will quickly sprout new vessels in an attempt to feed itself.

More than one hundred foods can fortify your body’s angiogenesis defenses by either stimulating or inhibiting blood vessel growth. Beyond green tea, foods like turmeric, soybeans, ginseng, and broccoli all prevent unwanted blood vessels from supplying nourishment to cancer cells, and they suppress the growth of fat cells, too.⁷ Other foods that support your angiogenesis defenses, such as fruit skins, barley, and even sea bass, can stimulate helpful new circulation for healing. Here’s the remarkable part: angiogenesis-inhibiting foods do not starve your organs, and angiogenesis-stimulating foods do not provoke cancer growth. Your body is designed so that when it comes to responding to healthy foods, it takes just what it needs, nothing more, nothing less.⁸

The Regeneration System

Your body contains cells whose job is to constantly regenerate and repair your internal organs. These are your stem cells, also called progenitor cells. They have the amazing ability to morph into any type of cell depending on your body’s needs. You were born with 750 million of these progenitors that are stored in your bone marrow, skin, and fat. Throughout life, your stem cells are spurred into action when a damaged organ needs to be repaired or when it grows—like muscle or fat.

The stem cells enter your bloodstream and circulate to the location where they are needed, then they home in to the organ, where they regenerate the tissue. This can occur literally anywhere in your body, such as your intestines, nerves, blood vessels, muscles, bones, liver, lungs, testes, ovaries, and even your heart and brain. Your blood cells and your immune system are constantly replenished by stem cells to keep them fresh and ready for action.

Your fat contains special stem cells called preadipocytes. These cells are essential for health. Preadipocytes create hormone-releasing fat cells—adipocytes—that help your metabolism process blood sugar and blood lipids. The hormones also influence your reproductive system, which in turn communicates with your fat.⁹ Your preadipocytes also produce the protective fat padding that safeguards your organs as you jostle through life.

The problem comes when your diet causes your preadipocytes to become overly active and create too many fat cells. Too much fat disrupts your hormones, so your preadipocytes need to be reined in. Foods such as blueberries, goji berries, and turmeric have restraining power over preadipocytes, taming them so that they do not create too many new fat cells.¹⁰

Another type of stem cell that lives in your fat is called the adipose stromal cell (ASC). These special cells live in the lacework of connective tissue that is embedded within a mound of fat. ASCs have a talent: they are master builders of blood vessels, the ones needed for healthy fat tissue to thrive. When they are overly active, however, ASCs can create an undesirable blood supply that nourishes and expands the fat around your waistline, under your chin, or anywhere in your body.

Medical researchers have tapped into the power of ASCs by pulling them out of a person’s fat and injecting them elsewhere in their body in order to tap into their regenerative power. Researchers collect ASCs using liposuction, the same procedure performed by plastic surgeons for body sculpting. The stem cells are harvested and cultivated like seedlings before being reinjected directly into the organ that needs to be healed. This ASC therapy is being tested in clinical trials to regenerate heart muscle in patients with heart failure, to regenerate brain cells in those with Parkinson’s disease, and to regrow nerves in people suffering from severe spinal cord injury.¹¹ Significant clinical improvements have been seen in patients receiving ASCs for all of these conditions.ⁱⁱⁱ

In a landmark case, a young man suffered a catastrophic fall that severed his spinal cord at neck level, leading to quadriplegia, a state of paralysis in which he could not move his arms and legs. He received an experimental injection of his own ASCs into his spinal cord to see if they could regenerate his nerves.¹² Within months after the treatment, he began regaining movement, the progress of which is shown in Figure 1.2. The vertical axis shows a measure of his ability to move. The horizontal axis shows the time after ASC treatment. The boxed line represents the patient’s arms. The diamond line represents his legs. The improvement he experienced over forty-eight months following spinal cord regeneration led to a reversal of his paralysis—an unprecedented feat of medical science!

Remarkably, many foods can trigger regeneration in organs without adding more body fat. In fact, some foods can cause regenerative healing at the same time as they inhibit preadipocytes from creating more fat. Mushrooms, barley, cacao, omega-3-containing foods, and coffee and tea have been shown to coax more stem cells to be released into the bloodstream to promote regeneration, but, as you’ll soon learn, these are also foods that fight fat.¹³

The Microbiome System

Your microbiome is a health defense made up of 39 trillion bacteria, along with viruses and fungi. These organisms live mostly in your lower gut but also on your skin and in every bodily orifice. Bacteria in particular are surprisingly essential for your well-being. They fine-tune your metabolism, lower blood sugar, reduce cholesterol levels, suppress inflammation, and enhance immunity. Your microbiome also speeds up wound healing and influences your emotional well-being by sending signals to your brain that instruct it to release crucial mood-enhancing hormones such as oxytocin, serotonin, and dopamine.

When your microbiome is disrupted, your physical and mental health can fall apart. A growing body of evidence shows that dysbiosis, the state in which your microbiome is damaged, is associated with an array of diseases including obesity, cardiovascular disease, cancer, autoimmune conditions, irritable bowel syndrome, Alzheimer’s disease, depression, schizophrenia, amyotrophic lateral sclerosis, and even autism. Your gut’s bacterial makeup can even influence the success of cancer therapy. Whether or not your microbiome is healthy can be a matter of life and death.¹⁴

Your microbiome is tied to your body fat. Researchers from the Washington University School of Medicine in St. Louis studied fifty-four pairs of twins of different body sizes and checked their microbiomes by collecting fecal samples. They found that twins with lean body types had a different mix of gut bacteria than twins who were obese.¹⁵ Lean subjects also had differences in more than three hundred bacteria genes compared to their obese counterparts.¹⁶

The diversity of bacteria in your gut is also important. As a general rule, the greater the diversity, the better your health. Lean individuals have a more diverse microbiome than people who are obese. What’s important is that you can influence your microbiome directly through the foods you eat. People who consume more plants in their diet have more diverse species of bacteria in their gut than those who shy away from fruits and vegetables.

One particular bacterium, Akkermansia mucinophila, is an especially important player among the trillions of bacteria in your body. Akkermansia plays a key role in controlling body mass and metabolism, as well as immunity. Researchers have discovered that people who are lean have more Akkermansia in their gut than obese people.¹⁷ Even among people who are overweight, those with more Akkermansia have a smaller waist-to-hip ratio and their fat cells are smaller in size.¹⁸ Foods like pomegranate, cranberry, turmeric, green tea, and chili pepper help Akkermansia grow in the gut because these foods make the intestines secrete more mucous, creating a welcoming environment where this bacterium thrives. Those foods can even help cancer patients respond to immunotherapy treatments because Akkermansia plays a role in the immune destruction of cancer cells.¹⁹

Your microbiome began to develop while you were a fetus in your mother’s womb, but it is shaped by your experiences and food choices throughout life. You “pick up” and swallow bacteria without knowing it from touching your pets; from hugging family members and friends; from objects you handle at school, work, restaurants, and shops; and while you are on vacation. What you eat directly influences your gut bacterial health. When you eat plant-based foods, the dietary fiber feeds your microbiome. When they are content and well fed, these bacteria produce three notable metabolites—acetate, butyrate, and propionate—known as short-chain fatty acids. These fatty acids are responsible for many of the health benefits of your microbiome, including streamlining your metabolism and lowering blood cholesterol.

Foods that contain lots of dietary fiber are called “prebiotic” because they nourish your inner biota, your gut bacteria. Leafy green vegetables; fruits like apples, pears, and kiwifruit; mushrooms; whole grains; and nuts like walnuts and macadamia are just some examples of prebiotic foods. “Probiotic” foods are those that contain live bacteria that contribute to the gut ecosystem. They are fermented foods such as kimchi, sauerkraut, pickles, yogurt, kefir, miso, tempeh, and cheese. Fermented foods that contain fiber, such as kimchi and sauerkraut, which are made from pickled cabbage, are both prebiotic and probiotic. The products made and released by the bacteria as they grow in the fermented foods are known as “postbiotics,” and these aid your metabolism, too.

The DNA Protection System

Your DNA is a six-foot-long folded ribbon of genetic material coiled inside every single one of your 40 trillion cells (very similar to the number of bacteria in your body!). This ribbon contains your genetic code, the instructions for cells to make the proteins your body needs to stay alive. But less than 2 percent of your DNA is used to guide the creation of proteins. Most of your DNA is used to coordinate the inner workings of the two hundred different types of cells in your body to keep them functioning for health.

Your DNA is a defense system that protects your genetic code against the damage that can be wreaked by everyday exposures, including ultraviolet radiation from the sun; radon from the ground; microplastics in your drinking water; and chemicals released by wall paint, carpets, and furniture. These environmental forces create highly reactive atoms known as free radicals. These atoms behave like rogue samurai warriors slashing at your DNA. Left unrepaired, the damaged DNA can create mutations that lead to abnormal cells and, ultimately, to cancer.

Excess body fat also creates free radicals inside your body and increases the risk for cancer-causing mutations.²⁰ Harmful free radicals are also created by emotional distress; lack of sleep; physical inactivity or extreme physical activity; and eating ultraprocessed food, grilled meats, and chemical preservatives.

Fortunately, damaged DNA is capable of repairing itself. Without this health defense, you would not be here to read this book. You can dial up (or dial down) the strength of the repair mechanisms with the foods you eat. Foods like kiwifruit, carrots, beans, strawberries, and omega-3-rich seafood can boost DNA repair.

Besides repair, parts of your DNA can be switched on or off by your diet, lifestyle, and environment. These are called epigenetic changes. Such changes can protect your health by turning on useful genes or by blocking harmful ones. For example, when parts of your DNA called tumor suppressor genes are turned on, they protect you against prostate, breast, and colon cancer. Foods like soy, cabbage, kale, Brussels sprouts, broccoli sprouts, turmeric, and green tea can switch on these protective genes.²¹

Another type of epigenetic change, called methylation, is associated with lowering body mass. In methylation, the function of a gene is changed by a chemical structure, called a methyl group, which is inserted right into your DNA. The effect is like jamming a screwdriver into a conveyor belt. It halts the manufacturing of certain proteins that cause belly fat to grow and that disrupt your metabolism.

Methylation affects the function rather than the structure of your DNA. It is an extra move in the health defense playbook of DNA. A study by scientists at the Norwegian University of Science and Technology compared the DNA of sixty lean and sixty obese women who were between twenty-three and thirty-one years old. They found there were ten specific sites in the DNA that were more methylated—helpfully blocked—in people who are lean compared to those who are obese.²²

Another link between DNA and fat was discovered by researchers at the Carlos III Health Institute in Madrid, Spain.²³ They tracked the changes in the DNA of 131 obese children, boys and girls between four and nine years old. The children were placed on a personalized version of the Mediterranean diet for one year, along with a supervised physical activity program. Their DNA and physical characteristics were examined at four and twelve months. At both points, the diet and lifestyle interventions led to a decrease in total body fat. When the researchers examined their DNA, they found that those with more DNA methylation had less abdominal fat, smaller body mass, a better metabolism, and more weight loss.

One more way that your DNA defends your health is through structures called telomeres. These are protective caps that prevent your DNA from fraying at its ends. As you age, telomeres shorten like the burning wick of a candle. Anything that slows the shortening process also slows cellular aging. Regular exercise and good-quality sleep, for example, can slow telomere shrinkage, which is why both are important for health.

People with a high body mass have a faster erosion of those crucial telomeres. Children and adolescents who are overweight have shorter telomeres compared to their counterparts who are lean.²⁴ In adults and the elderly, the impact is even more profound. The Health, Aging and Body Composition Study led by the University of California San Francisco examined 2,721 people in their seventies and measured their body composition and telomere length.²⁵ Subjects with a lower percentage of body fat and less belly fat had longer telomeres. The good news is that certain foods have been discovered to slow telomere shrinkage. Many of these foods are common in Mediterranean-and-Asian-style eating patterns, and they can also fight body fat, helping your DNA take care of itself—and you.

The Immune System

By far, the most familiar of your body’s five defense systems is your immune system. It protects you from external invaders like bacteria and viruses swirling around in your environment. It also protects you from invaders lurking within your body, like cancer cells. Healthy immunity repels disease regardless of its source.

Seventy percent of your immune system is in your intestines, where it communicates with your gut microbiome. Part of your immune system is also embedded in your fat. Like the rest of your body’s defenses, your immune system is strongly influenced by the foods you eat.

Your immune system has two main parts: the innate system and the adaptive system. Innate immunity is swift acting and reacts in the same way each time, like a blunt instrument. This part of your immune system causes inflammation, a necessary and brief response when defending your body against invaders. The second part, adaptive immunity, is smarter but slower acting. It is trained to recognize enemies and then develops sophisticated responses to handle each threat. This is where T cells and natural killer cells (also known as large granular lymphocytes) work together to tackle invaders, and where immune B cells learn to produce antibodies. Adaptive immunity is activated inside your body in response to viral infections, a vaccine injection, or a bee sting, or when your immune system is trained by cancer treatments, known as immunotherapy, to seek out and destroy cancer cells. Together, the elements of these two parts of the immune system function like an army of super soldiers, each with its own special weapons and tactics for detecting, destroying, and clearing out invaders from the fortress of your body.