Have you ever seen an obese wild animal? Look at these wildebeests in Krüger National Park in South Africa. There’s no cellulite on their thighs! Wildebeest weigh only 40 pounds at birth, but then they gain weight rapidly. By the time they’re a year old, they weigh about 200 pounds. The females reach a peak weight of about 350 pounds at 4 years of age. The males peak at 500 pounds at 5 years of age. Yet after that, their weight stays remarkably stable. Why do they stop gaining weight? Since they don’t start counting calories or taking step aerobics classes in adulthood, they must have some built-in mechanisms that regulate their weight naturally. Do humans also have in-born weight-control mechanisms? If so, why have so many people been getting so fat lately?
To keep our body weight at a normal level, we are told to engage in unnatural behaviors. We’re told to eat less and move more. Yet wild animals never limit their food portions, and they do only the amount of activity they feel like doing. I think that their secret for staying slim is that they eat the kind of food that is appropriate for their species. If you trapped some wildebeest in a pen and fed them a diet that was much richer in calories than what they ate in the wild, they’d probably get fat. That’s what has happened to human beings in industrialized societies. To cure our weight problems, we need to escape from our cubicles and start eating a more natural diet. Go play outside, and eat low-fat unrefined plant foods instead of eating animals and processed foods.
When you look at populations all over the world, you’ll notice that the people who eat a diet based on unrefined plant foods stay naturally slim and remarkably free of heart disease and diabetes and other chronic diseases. For many generations, most of the world’s population ate like that. Only the rich could afford to eat large servings of rich foods, such as meats and butter and honey, on a regular basis. As a result, only rich people suffered from obesity, gout, and atherosclerosis. Because of agricultural policies, those foods have now become cheap while fresh fruit and vegetables are still relatively expensive. As a result, the “diseases of affluence” are now a particular problem for poor people in the United States.
Capsaicin, which is the chemical that puts the heat in hot chili peppers, may encourage some kinds of cancer cells to commit suicide; but capsaicin doesn’t seem to have the same effect on healthy cells. This is just one of many ways in which chemicals that are found naturally in plants (phytochemicals) could have an anticancer effect.
Cancer isn’t just one disease. It’s a group of unrelated diseases that all result from the same sort of problem: cells behaving badly. Cancer cells don’t become the kind of cell that they’re supposed to become, and they keep dividing to make new cells long after they were supposed to stop. Sometimes, they travel through the body and settle down in places where they’re not supposed to be. All of these problems result from something going wrong in the cell’s genetic material. Either some genes have been damaged or the switches that are supposed to turn the genes on and off have been stuck in the wrong position. This problem can get started if a cell’s genes are damaged by exposure to radiation or to cancer-causing (carcinogenic) chemicals, such as those in tobacco smoke. The first line of defense against cancer is to reduce the body’s exposure to radiation and other carcinogens.
Even after a cell has gone rogue, the body has several levels of defenses that could stamp out the cancer before it is ever noticed. The first is a self-destruct mechanism that is built into the cell’s genetic instructions. This self-destruction, which is called apoptosis or programmed cell death, causes the cell to break apart into tidy fragments that are quickly and easily devoured by white blood cells. In contrast, when cells die as a result of trauma, they make a mess by spilling their contents into the surrounding fluid.
Programmed cell death plays an important role in sculpting the embryo during early development. If cells are in the wrong place at the wrong time, they get a signal to commit suicide. That’s why most people aren’t born with webbed fingers and toes. Even in a healthy adult, tens of billions of cells undergo programmed cell death every day. Programmed cell death is a natural body process that is supposed to stay in a healthy balance. If too many cells die, the result is tissue shrinkage (atrophy). If too many cells fail to commit suicide, then abnormal cells such as cancer cells can get out of control.
Programmed cell death is a complicated process that can involve several different pathways and that can be stimulated or suppressed by many different signals. However, the end result is always the same: enzymes called caspases are activated, and they break down the protein structures inside the cell. Some kinds of cancer cells fail to undergo programmed cell death because they have a deficiency of or defect in one of their caspases. These cells may need a little extra encouragement to undergo programmed cell death.
Researchers have reported that capsaicin inhibits the growth of colon tumors. Theoretically, capsaicin could have antitumor effects in other parts of the body because it is easily absorbed from the intestine and carried throughout the body by the bloodstream. One study showed that capsaicin promotes programmed cell death in a particular type of liver cancer cells. Another study showed a similar effect in breast cancer cells.
The first line of defense against cancer is to avoid radiation, carcinogenic chemicals, and the viral infections that are known to cause cells to become malignant. The second line of defense is to eat a low-fat, high-fiber, plant-based diet, which acts in several different ways to prevent cells from becoming malignant and to suppress the growth of tumors. The promotion of programmed cell death by hot peppers is just one of the ways in which a plant-based diet could help to suppress cancer.
Photo: Chimpanzee being used for space research by the U.S. Air Force in the 1960s.
The Institute of Medicine convened an ad hoc committee to answer two important questions:
Is biomedical research with chimpanzees “necessary for research discoveries and to determine the safety and efficacy of new prevention or treatment strategies?”
Is behavioral research using chimpanzees “necessary for progress in understanding social, neurological and behavioral factors that influence the development, prevention, or treatment of disease?”
The committee was asked to consider only scientific questions, not questions related to ethics or costs. The committee’s report concluded that most current use of chimpanzees for biomedical research is unnecessary and that the National Institutes of Health should put strict limits on the use of chimpanzees as research subjects. The NIH has already announced a freeze on new grants for chimpanzee experimentation.
David Sirota wrote an article that suggests that the vegetarian products that mimic meat products undermine vegetarianism by glorifying the consumption of meat. I had to laugh because I honestly couldn’t imagine Tofurkey glorifying anything. Nor do I think that rice milk glorifies cow’s milk or that a tofu scramble glorifies eggs. Yet the use of these foods does raise two important nutrition-related questions: What kind of diet is truly healthy for a human being, and how can we help people find satisfaction and delight from a truly healthy diet?
Many vegetarians depend heavily on the soy fake meats and “cheezes” because they are worried about getting enough protein in their diet. In reality, you don’t need to eat fake meat or cheeze to get enough protein. It’s practically impossible to find real cases of protein deficiency in people who were getting enough calories from any reasonable plant-based diet. To find cases of pure protein deficiency, you have to look at people who have been fed nothing but glucose intravenously, or people who have a digestive or metabolic disease, or babies who were fed some bizarre substitute for breast milk.
Plants provide all of the nutrients that are essential for human nutrition, except for vitamin D and vitamin B12. Your body makes its own supply of vitamin D if you go out in the sunshine, and vitamin B12 comes from bacteria. So there’s no nutritional need to include animal-based food in the diet. On the contrary, the less animal-based food a population eats, the lower its rates of death from heart disease, cancer, diabetes, and other chronic diseases tend to be.
So what about the refined plant-based foods that resemble animal foods? Do they pose the same health threats as real animal-based foods? The answer is a bit complicated. The health threats that they could pose depend on how closely they resemble the animal-based foods they replace.
Animal-based foods contain fat and cholesterol but no fiber. No vegan products contain any cholesterol, but some of them do contain a lot of fat and little or no fiber. Thus, they could promote weight gain and high cholesterol levels. Potato chips are vegan; but because of all that fat and salt, they’re almost as bad for you as pork rinds.
Animal-based foods contain far more protein than you need. This excess protein puts a strain on the liver and kidneys. The “high-quality” protein in dairy products, in particular, also causes the liver to release a powerful growth hormone (IGF-1) that promotes the growth of cancers. Huge servings of soy protein also promote the secretion of IGF-1, but to a lesser extent than dairy products do.
The proteins in animal-based foods are similar to but not exactly like the proteins in the human body. If they find their way into the bloodstream before they are completely broken down, they may cause the immune system to produce antibodies that go on to attack the body’s own tissues. A switch to a plant-based diet can dramatically reduce this risk. However, some of the fake animal products are based on wheat gluten, which can cause autoimmune problems in a small percentage of the population. For this reason, people with celiac disease or other wheat sensitivity cannot eat seitan.
Real meats and cheeses are high in fat but devoid of starch. The fake stuff also tends to be high in fat and low in starch. All fats are fattening, and some of the fats from plant sources are particularly powerful promoters of cancer. The plant-based diets that are truly good for human health are high in fiber and starch and low in fat.
Animals have hormones that are very much like our own. When people eat animal foods, they get a dose of these hormones, even if the animals were raised organically. Plants have different hormones. Some plants contain phytoestrogens, which are substances that have some sort of effect on estrogen receptors. However, some of the phytoestrogens are estrogen blockers or weak estrogens that compete with the body’s natural estrogens, thus decreasing the effects that our native estrogen has on our tissues.
Animals absorb toxins from their environment and store them in their fatty tissue. That’s why it’s good to eat “low on the food chain.” The processed fake meats and cheezes are low on the food chain, but you may have to consider what kinds of additives are in them.
Many people advocate the use of the fake meats and cheezes sort of as training wheels to help people adjust to a plant-based diet. My concern with that approach is that these foods can be unsatisfying because they don’t necessarily taste like the real thing. Rather than serving a food that is a dim echo of something else, why not serve something that can stand on its own? Why eat an unsatisfying soy patty when you could eat a genuine bean burrito?
I use a little bit of tofu or soy milk now and then. The “fake meat” that I use extensively is mushrooms and nutritional yeast. I make a garlicky low-fat mushroom gravy and serve it over huge mounds of mashed potatoes. I add either mushrooms or nutritional yeast to hearty stews, and nobody cares that I didn’t use a hambone.Photo by Andrea_Nguyen
Here’s an interesting article about how high levels of LDL cholesterol end up causing atherosclerosis.
The body uses cholesterol for various purposes, and it has a system for transporting cholesterol in the bloodstream. Like fat, cholesterol doesn’t dissolve in water. To transport fat and cholesterol via the bloodstream, the body puts them in packages called lipoproteins. As the name suggests, a lipoprotein contains fatty substances (lipids) as well as some protein.
Not only do fatty substances like cholesterol fail to dissolve in water, they float on top of it. That’s because they are less dense than water. They are also less dense than protein. The lipoprotein particles that are largest and contain the most fat also have the lowest density. The “bad” cholesterol that people talk about is low-density lipoprotein (LDL). These are lipoprotein particles that carry fat and cholesterol from the liver to the rest of the body. LDL is like a wheelbarrow full of fat and cholesterol traveling from the liver to the rest of the body. In contrast, high-density lipoprotein (HDL) picks up the cholesterol from the tissues and carries it back to the liver. HDL is like a mostly empty wheelbarrow picking up fat and cholesterol and taking it back to the liver.
The article explains that cholesterol is always entering and leaving the intimal layer of the arterial wall. The cholesterol is brought in by LDL and is taken away by HDL. If the cholesterol is brought in faster than it leaves, it builds up to form a deposit called an atheroma. The more LDL there is in the bloodstream, the faster the LDL particles enter the wall of the arteries. The cholesterol is likely to build up into an atheroma if there isn’t enough HDL to carry the cholesterol back out fast enough or if the LDL undergoes some chemical change within the wall of the artery before it can be removed. Here’s an article that explains the kinds of chemical changes that can occur to the LDL while its inside the arterial wall.
Why does cholesterol build up in the intima of the arterial wall but not in other kinds of tissue? It’s because the concentration of LDL is far higher in the arterial intima than in any other tissue. The probable reason for this high LDL concentration is the fact that the arterial intima is not drained by lymph vessels. LDL particles are small enough to leak through the gaps between the endothelial cells that pave the inner surface of the artery. Then, they can diffuse throughout the loose structure of the arterial intima. However, they are too big to leak through the pores in the carbohydrate-and-protein meshwork of the medial layer. Thus, they cannot make their way through to the lymphatic system, which is highly efficient at carrying lipoproteins back to the bloodstream.
Photo by Oregon State University
Diabetes is the number 1 cause of nontraumatic amputations in the United States. What’s truly outrageous is that most of these amputations are happening to people with the form of diabetes that can easily be cured, sometimes within as little as a week, by a simple change in diet. Just eat unrefined plant foods instead of animal-based foods and processed foods and cut your fat intake to 10% or less of calories.
Type 2 diabetes mellitus is cured by removing the cause, which is the fatty, low-fiber, standard American diet. People who switch to a high-fiber, low-fat (~10% of calories), high-carbohydrate (75% of calories), purely plant-based (vegan) diet become undiabetic within a surprisingly short time. (They can get even quicker results if they also start exercising.) A proper diet can even relieve the agonizing pain and dangerous numbness from diabetic neuropathy in the feet within a matter of days to weeks.
Lately, genes have been all the rage in medical research. Many people hope that genetic studies will unravel the secrets of many diseases that, strictly speaking, aren’t really genetic. Sometimes, people get so caught up in thinking about the genes that could be involved in a disease that they ignore the importance of diet to prevent and manage the disease. Yet even for a disease that is truly 100% genetic, dietary management can be important. The classic examples are the rare forms of diabetes mellitus that really are genetic. These forms of diabetes are called monogenic diabetes mellitus. Sometimes they’re called MODY, which stands for maturity-onset diabetes of the young. It is a form of monogenic diabetes, which means that it is due to a mutation in a single gene.
There are several different forms of MODY, each resulting from the mutation of a different gene. These disorders tend to be autosomal dominant, which means that if you inherit the gene from one of your parents, you have the disease. Clinically, cases of MODY tend to look like a hybrid between type 1 and type 2 diabetes. Together they account for somewhere between 1% and 5% of cases of diabetes mellitus.
Diabetes mellitus refers to several unrelated conditions that all result in high levels of sugar in the bloodstream. In the 1870s, French researchers noticed that there are two main types of diabetes mellitus. One is a catastrophic disease that tends to strike children and young adults. Before the discovery of insulin, these patients would rapidly lose weight, go into a coma, and die within a matter of days or weeks, regardless of treatment. The French researchers called it diabète maigre, or thin diabetes. English-speakers called it juvenile diabetes, then insulin-dependent diabetes, and now type 1 diabetes. In contrast, the most common form of diabetes is a much milder, reversible condition that occurs in middle-aged to elderly adults who are usually at least a bit overweight. The French called this condition diabète gras, or fat diabetes. English-speakers tactfully referred to this kind of diabetes as adult-onset, then non–insulin-dependent, and now type 2 diabetes.
If left untreated, all forms of diabetes mellitus result in abnormally high levels of a sugar called glucose in the bloodstream. In cases of type 1 diabetes, the high glucose levels result from the failure of the pancreas to produce the hormone insulin. In cases of severe insulin shortage, the body goes into a state called diabetic ketoacidosis, which is a medical emergency.
Early on, doctors noticed that people with type 2 diabetes rarely get diabetic ketoacidosis. In severe cases, they might go into a coma because their blood sugar is so high that they get severely dehydrated, but they rarely get such severe ketosis that their blood pH is affected. That’s because people with type 2 diabetes are producing some insulin. In fact, they tend to have abnormally high levels of insulin in their bloodstream. The problem is that their cells have become resistant to the effects of insulin.
MODY was discovered in the 1960s, when physicians noticed that some children had persistent, symptomless high blood sugar that didn’t progress to ordinary type 1 diabetes. In other words, the condition looked like type 2 diabetes, except that it was happening in young people who weren’t overweight. The child’s pancreas was producing some insulin, just not enough to meet the body’s needs. By the 1970s, it was clear that this problem ran in families. At present, at least 10 forms of MODY have been described, each of them linked to a different gene.
The treatment for MODY depends on what type of MODY the patient has. Genetic testing is now available for MODY1, MODY2, MODY3, MODY4, and MODY5. MODY2 is a relatively mild disease that can be managed by diet and exercise. As in ordinary cases of type 2 diabetes, the goal is to avoid or reverse insulin resistance, so that the amount of insulin the pancreas produces on its own will be enough to regulate the patient’s blood sugar naturally. Maintaining insulin sensitivity through proper diet and exercise is undoubtedly also important in managing the other, more severe forms of MODY. Patients with MODY1, MODY3, or MODY4 are usually given a sulfonylurea drug that causes the pancreas to secrete extra insulin. MODY5 is a severe condition that is usually treated as if the patient has no pancreas whatsoever; the patient is given insulin injections as well as digestive enzymes that are taken by mouth.
Eventually, doctors found that a few newborns had a condition that seemed like type 1 diabetes. This condition, called neonatal diabetes, is generally inherited as an autosomal recessive trait. To get a case of infantile diabetes, the baby has to inherit a defective version of a gene from both parents.
One of the most common symptoms of early pregnancy in human beings is nausea and vomiting. Why do so many pregnant women have so much trouble keeping food down at the very time that their need for calories and other nutrients has just gone up? Why is this problem common in women but seemingly nonexistent in pregnant females of other species? Is there something wrong with the design of human pregnancy, or is there something wrong with the food the pregnant woman is eating? I’m inclined to suspect the food, especially because morning sickness is common in the United States but rare to nonexistent in societies whose staple foods all come from plants.
Vomiting is a powerful defense mechanism. It effectively removes toxins and infectious agents from the stomach and even the upper intestines. It’s nature’s way of expelling things that shouldn’t be allowed to enter the body. This defense mechanism may be particularly important during pregnancy. Studies have consistently shown that women who vomit during early pregnancy are less likely to have a miscarriage than are those who merely feel nauseated. Perhaps it’s because the vomiting prevented things that would be harmful during early pregnancy from entering the woman’s body. Thus, it’s probably no coincidence that the nausea and vomiting associated with pregnancy tend to be most severe during the first trimester, which is the most sensitive phase of development.
In a classic article, Samuel Flaxman and Paul Sherman explained how morning sickness could end up protecting the mother and the pregnancy. They argued that morning sickness is most common when the major organ systems are developing, and the vomiting seems to be triggered by the foods and beverages that are most likely to be harmful to the mother and the pregnancy. Flaxman and Sherman pointed out that in 9 out of 9 studies, women who experienced morning sickness were much less likely to miscarry.
Flaxman and Sherman noted that many pregnant women have aversions to alcoholic and nonalcoholic (mainly caffeinated) beverages and strong-tasting vegetables, but the greatest aversions were to meats, fish, poultry, and eggs. The importance of animal-based foods in causing morning sickness also became obvious in a cross-cultural comparison. Seven societies that were free of morning sickness were significantly less likely to have animal foods as dietary staples and were significantly more likely to have only plants (mainly corn) as staple foods than were 20 societies in which women experience morning sickness.
Foodborne infectious or parasitic disease could be a serious threat to the health of a pregnant woman or her pregnancy. During pregnancy, a woman’s immune system is already somewhat suppressed, to keep it from attacking the pregnancy. As a result, pregnant women are more likely to catch serious, potentially deadly infections. Infectious and parasitic diseases are also a major threat to the developing embryo. For example, if a pregnant woman catches Toxoplasma, which is a parasite found in cat droppings or undercooked beef, the parasite infection could cause miscarriage, stillbirth, or severe birth defects.
A pregnant woman can protect her health and her pregnancy by simply avoiding the foods that are likely to make her vomit. A purely plant-based diet provides all of the nutrients that a pregnant woman needs, except for vitamin D (which she can get from sunshine) and vitamin B12 (which is made by bacteria and is available in a nice, clean tablet).
Chimpanzees eat meat for two simple reasons: they can catch it and they like it. Chimpanzees are particularly likely to eat meat during the dry season, when shortages of the foods that normally make up the bulk of theirdiet cause them to lose weight. Although the meat may be a useful source of calories during the dry season, wild chimpanzees don’t need to include meat or any other animal-based food in their diet to fulfill their needs for protein or any of the amino acids. In fact, plants provide all of the nutrients that are known to be essential for a chimpanzee, except for vitamin D (which they get from the abundant sunshine in Africa) and vitamin B12 (which comes from bacteria).
Many people think that I am silly for asking where gorillas get their protein. They tell me that I should talk about chimpanzees instead. Often, they inform me that chimpanzees are far more similar to human beings than gorillas are, as if I couldn’t tell that just by looking. These people are missing my point: gorillas are the largest and most powerful living primate and yet are the closest to following what human beings would consider a vegan diet. Chimpanzees and human beings don’t need to eat meat to grow up big and strong because gorillas grow up to be far bigger and stronger without it. Lawyers may recognize this as an a fortiori argument.
If a male gorilla, whose digestive system is practically identical to a human being’s, can get enough protein from vegetables to grow to weigh more than 400 pounds and be ten times as strong as a man, why shouldn’t I expect that a relatively puny human Olympic weightlifter could also get enough protein from a plant-based diet? My intent is to ridicule the Four Food Groups dogma that I was taught in sixth grade.
Gorillas don’t hunt or fish, and they don’t keep cows or chickens. As a result, they don’t eat meat or fish, dairy products or eggs. The only animal-source food they eat is “the other, other white meat”: termites, slugs, and other creepy-crawlies. These foods would make an insignificant contribution to the gorillas’ protein intake, which is already high because protein accounts for a high percentage of the calories in leaves.
Bugs and slugs could be a useful source of vitamin B12, a micronutrient that is made by bacteria in their intestines. Vitamin B12 is also produced by bacteria in a primate’s gastrointestinal tract. However, the vitamin may be produced so far along in the intestinal tract that it isn’t absorbed efficiently. No plants make vitamin B12, but gorillas and chimpanzees can probably get enough vitamin B12 from the bacteria in the bugs they eat and in the dirt that clings to their food. Plus, apes are not meticulous about washing their hands, if you get my drift. If you are worried about getting enough vitamin B12, you don’t have to eat dirt or bugs. You can get it in a nice, clean tablet instead.
I don’t ask where chimpanzees get their protein because chimpanzees do eat some meat. Chimpanzees probably eat less meat than just about any human population other than Buddhist monks. Nevertheless, many people want to use chimpanzees’ meat consumption as an excuse for humans to eat meat.
The fact that chimpanzees’ meat consumption is largely seasonal goes far toward explaining why human beings have always eaten meat. Chimpanzees are most likely to eat meat during the time of year when they are losing weight because their usual foods are in relatively short supply. People think of meat as a source of protein, but it’s mainly a source of calories, especially from fat. Meat is also a good source of sodium, which is in relatively short supply in the chimpanzees’ fruit and vegetable diet.
The fact that chimpanzees eat the most meat during times of food shortages suggests that their food choices follow a pattern that biologists call optimal foraging theory. Animals try to get the most calories for the least effort and without getting hurt. Optimal foraging theory explains why chimpanzees eat meat but gorillas don’t, and why chimpanzees eat more meat during times of food shortage.
Chimpanzees are mainly fruit eaters, but they also eat a lot of vegetables. The problem with fruit is that it’s seasonal. Worse yet, a fruit tree represents a rich enough source of calories that animals will fight over it. When fruit is scarce, chimpanzees can use the skills they developed in fighting over the fruit to engage in predatory behavior. Also, chimpanzees are small enough and fast enough that they are reasonably good hunters.
Gorillas, on the other hand, mainly eat leaves. There are generally plenty of leaves to go around, and a leafy plant is generally so poor in calories that it’s not worth fighting to protect. To subsist on leaves, however, you have to eat an enormous volume of food. Since leaves are so low in calories, leaf-eaters have to be good at conserving their energy. That’s why gorillas have such a placid disposition. For a gorilla, hunting is simply not worth the effort. They are too big and slow to catch very much, and they’re large enough that they’d risk injury if they got too reckless.
Chimpanzees use twigs to fish for termites, and gorillas don’t. Some people think that this fact means that chimpanzees are smarter than gorillas. I don’t. If you are a juvenile gorilla or a pregnant or nursing female gorilla, you don’t need to mess around with a little bitty twig to get a few termites. All you have to do is wait for the silverback to knock over a rotting tree. Then all of you can eat as many termites as you’d like.
Some people have argued that the balance between animal and plant foods in a hunter-gatherer society’s diet represents the optimal balance for human nutrition. I think that’s idiotic. Hunter-gatherer peoples (or should I say, gatherer-hunter peoples) tend to follow optimal foraging theory just like any other opportunistic feeder. Their goal is to survive in the short term, not to avoid breast or prostate cancer in middle or old age. The main threat to their short-term survival is starvation.
Meat represents a concentrated source of calories. The fact that a relatively high percentage of these calories comes from protein is actually a disadvantage. Hunting peoples prefer the fattiest foods. People who end up having to subsist on extremely low-fat meat, such as rabbit, are prone to a problem called fat-hunger or rabbit starvation. This problem probably results from a diet that has too much protein and not enough carbohydrate or fat. On a low-carb diet and during starvation, the body has to make its sugar supply out of protein. Perhaps the body can make only so much sugar out of protein. As long as you are eating enough fat to meet most of your energy needs, your body can make enough sugar out of protein to feed your brain. If you were eating protein but not enough fat or carbs, you could end up in serious trouble. So you could end up in trouble from a diet that is too high in protein. In contrast, it is practically impossible to avoid getting enough protein, as long as you are eating enough unrefined plant foods to get enough calories.
Famine is not a significant cause of death in the United States. In fact, people in the United States are far more likely to die of the diseases of affluence, such as heart disease and cancers of the breast and prostate. Animal-based foods and fatty processed foods are the main contributing causes of the diseases of affluence. The ability to use animals for food may have helped human beings survive to the modern era, especially in the Arctic, but animal-based foods are a major cause of death and disability in the United States today. Think about that the next time you hear someone promoting a “Paleo” diet.
Lately, lots of people have been claiming that seafood is an important part of a health-promoting diet for human beings. Some of the hype comes from the seafood industry, and some of it comes from people who simply want an excuse to eat seafood. In reality, the health benefits of the so-called pescetarian diets (a vegetarian diet plus seafood) result from the fact that they include a lot more starch and vegetables than is customary in the standard American diet, while excluding some of the most dangerous animal-based foods. The starch and vegetables are good for you. Avoiding meat and milk from mammals and meat and eggs from birds is good for you. Unfortunately, the wine and seafood and olive oil in the “Mediterranean” diet do more harm than good.
It has always struck me as illogical for people to call themselves vegetarian if they eat seafood, which is the general term used to include edible fish and shellfish. (Yes, there are some edible plants that grow in seawater, but they’re generally called sea vegetables rather than seafood.) Fish are not vegetables. They are animals. So are shellfish, a category that includes mollusks such as oysters and crustaceans such as shrimp and lobster. If you are eating animals, you’re not vegetarian.
Many people eat fish because they are afraid that a purely plant-based diet wouldn’t provide enough protein to maintain their health. That’s nonsense. Protein deficiency is simply not a real concern. As long as you get enough calories from any practical diet based on unrefined plant foods, you will automatically get enough protein—unless you have some bizarre digestive or metabolic disease.
Rather than worrying about not getting enough protein, most people should be worried about the effects of eating too much protein. When you eat more protein than you need, your body turns the excess amino acids to sugar, releasing toxic waste products such as ammonia and sulfuric acid. In contrast, burning carbohydrates and fats for energy produces just carbon dioxide and water. The toxic byproducts of a high-protein diet can harm the liver and kidneys, as well as promoting osteoporosis. One study showed that people from the North Slope of Alaska had high rates of bone loss as a result of their high-protein diet, even though their calcium intake was high because they were eating fish bones.
Seafood is animal tissue, and it has the same faults as any other animal tissue. It contains cholesterol, too much protein and fat, and no starch or fiber. Fish and other sea creatures don’t provide any essential nutrients that you can’t easily get from other sources. Plants contain all of the nutrients that are essential in human nutrition except for vitamin D (which you get from sunshine) and vitamin B12 (which comes from bacteria). Even the omega 3 fatty acids in fish oil came from the plants that were at the bottom of the fish’s food chain.
Another problem with animal tissue, including seafood, is the buildup of toxic substances, including heavy metals and fat-soluble chemicals such as dioxin. This problem is called bioaccumulation. The higher up in the food chain an animal is, the worse this problem tends to be. You can avoid this problem by eating plants instead of animals.
In short, the hype about a “pescetarian” diet is just hype. People are better off just eating plants.
Note: In my book Thin Diabetes, Fat Diabetes: Prevent Type 1, Cure Type 2, you can learn more about how a low-fat, high-fiber, high-carbohydrate diet helps people lose weight and reverses their type 2 diabetes.
