More anti-animal food fanaticism
On page 230, Campbell states in bold type: "There are virtually no nutrients in animal-based foods that are not better provided by plants."
Clearly, Campbell knows little about the nutritional content of animal foods. Animal flesh contains many nutrients that are either found in scarce amounts or entirely absent from plant foods. Here are some examples:
Creatine is used to form adenosine tri-phosphate (ATP), our ultimate source of cellular energy. Creatine availability is critical during situations when neither fat nor glucose can be processed quickly enough to form ATP, such as during the first few seconds of high-intensity physical activities like sprinting and picking up heavy objects. Creatine supplements have been shown in numerous studies to aid performance in power-oriented sports, and to improve muscular strength in patients with congestive heart failure[Kreider RB].
Creatine only occurs naturally in animal foods, with meat by far the richest source. Not surprisingly, habitual vegetarians exhibit poorer creatine status than omnivores[Maughan RJ].
Meat, along with certain species of fish and seafood, is a rich source of taurine, an important amino acid whose concentration in eggs, milk, and plant foods ranges from negligible to none[Laidlow SA][Pasantes-Morales H]. Taurine is found in high concentrations in the heart, brain, and central nervous system, where it helps stabilize the cellular response to nervous stimulation. Taurine possesses antioxidant capabilities and has been shown in double-blind clinical trials to improve cardiac function in patients with congestive heart failure[Schaffer SW][Azuma J][Azuma J].
Taurine cannot be found in plant foods. Humans are able to manufacture their own taurine but with far less efficiency than herbivorous animals, as evidenced by significantly lower blood taurine levels in vegans and rural Mexican women reporting low meat intakes[Laidlaw][Pasantes-Morales H].
Carnitine is a remarkable amino acid that plays a pivotal role in energy production, and is absolutely essential for the fat-burning process to proceed. Because of its pivotal role in energy production, high levels of carnitine are found in the heart and skeletal muscle. Clinical trials have observed markedly improved survival outcomes resulting from carnitine supplementation in patients with heart failure and coronary heart disease[Davini P][Rizos I][Singh RB][Iliceto S]. A review of the scientific literature shows that this versatile amino acid has been shown to benefit anorexia, chronic fatigue syndrome, heart disease, male infertility, sexual dysfunction and depression in aging men, and pregnancy outcomes. Exercise, even at moderate levels, can cause a significant drop in muscle carnitine levels; in patients with angina and respiratory disorders, carnitine enhances exercise tolerance[Kelly GS][Cavallini G][Gentile V].
The richest food source of carnitine, by far and away, is meat. Compared to omnivores, vegetarians repeatedly exhibit lower blood levels of carnitine[Krajcovicova-Kudlackova M][Lombard KA]. Carnitine status appears to also be worsened by the high-carbohydrate diets recommended by folks like Campbell. In healthy men receiving the same amount of dietary carnitine, blood levels of this all-important amino acid rose significantly in individuals following a high-fat, low-carbohydrate diet, while no change in carnitine levels were observed in individuals on a high-carbohydrate, low-fat diet.
Meat is the only food containing significant amounts of carnosine, an amino acid with some rather interesting and highly beneficial properties[Chan KM]. Carnosine is a potent antioxidant, being particularly effective in protecting cellular fats against free radical damage. Research shows carnosine may accelerate wound healing, boost the immune system, protect against cataracts, reduce gastric ulcer formation, rid the body of toxic metals, and even help fight against cancer[Hipkiss AR]. The most potent effect of carnosine however, appears to be its ability to prevent glycation, which, along with free-radical production, is a major contributor to degenerative illness and the aging process[Price DL, et al].
The potent anti-glycation effects of carnosine may explain why a comparison of vegetarians, vegans and meat-eating omnivores revealed the latter to have significantly lower levels of nasty glycation end-products known as advanced glycosylation end-products (AGEs) circulating in their bloodstreams. The difference could not be explained by total carbohydrate intake, blood sugar, age or kidney function, as all these variables were similar between the vegetarian and omnivorous groups[Sebekova K].
Meat, especially red meat, is the richest source of B-complex vitamins. The B vitamins perform a myriad of crucial functions in the body and requirements for these vital nutrients are dramatically increased during periods of stress, illness and physical activity. Unfortunately, the body cannot store a surplus of B-vitamins for times of increased need, so optimal amounts must be consumed on a daily basis.
Meat, especially red meat, is also a rich source of iron. Iron forms an essential component of hemoglobin, the red pigment in blood that transports oxygen from the lungs to the various body tissues. Insufficient iron intake can result in impaired immune function, decreased athletic performance and lack of energy. A double-blind Swiss study of women aged between 18-55 who had sought medical advice for fatigue, found that most of the women had low blood concentrations of iron. After four weeks, a significantly greater number of women receiving iron supplements reported a decrease in fatigue symptoms than those receiving placebo[Verdon F]. Australian women complaining of fatigue showed similar improvements when treated with either iron supplements or a high-iron diet[Patterson AJ].
Those who need to boost their iron stores should look to red meat rather than supplements or plant foods. When previously sedentary women were challenged with 12 weeks of aerobic exercise, a high meat diet protected iron stores more effectively than iron supplements[RM Lyle]. Heme iron (the form of iron found in meat) is far more easily absorbed by the body than non-heme iron from plant sources. Men and women on lacto-ovo vegetarian diets consistently exhibit lower blood levels of iron, even when consuming similar total amounts of dietary iron as omnivores[Alexander D][Hunt JR].
Animal foods are also by far and away the richest source of zinc. Apart from oysters, meat is the richest source of this mineral, with red meats again containing greater amounts of this mineral than white meats. Zinc is essential for optimal growth and repair, being involved in the actions of several vital hormones and hundreds of enzymatic reactions in the body. Zinc is essential for the formation of superoxide dismutase, one of the body's most potent antioxidants. Zinc deficiencies can result in growth retardation in children, significantly weakened immune function, poor wound healing and muscle loss, lowered testosterone levels and sperm counts, and have also been linked to depression and gastric cancer[Prasad AS][Brown KH][Siklar Z][Dardenne M][Ibs KH][Maes M][Nakaji S][Prasad AS][Hunt CD].
Overt zinc deficiencies are common to Third World countries where animal protein consumption is low. Milder, 'sub-clinical' zinc deficiencies also appear to be a common phenomenon in modernized nations. Those who follow low fat diets are at even greater risk of zinc deficiency[Retzlaff BM]
Animal foods, most notably brains and fatty fish, are the only dietary source of long chain omega-3 fats such as DHA and EPA (special algae supplements containing LCPUFA have only recently become available). Some plant foods do contain omega-3 fatty acids, but in a form known as alpha-linolenic acid (ALA). To obtain the LCPUFA the body needs, ALA must be converted endogenously to longer-chain omega-3s such as DHA and EPA. The conversion rate, however, is very low, with clinical studies repeatedly showing that omega-3 fats from plant sources to be vastly inferior to those from animal foods when it comes to boosting long-chain omega-3 status[Fokkema MR][Francois CA][Tang AB, et al].
Numerous studies have shown that vegetarians consume far lower levels of long-chain omega-3 fats--not surprising considering their avoidance of meat and fish[Rosell MR, et al]. Studies of pregnant women show that, compared to omnivores, vegetarians have significantly lower levels of DHA in their breast milk, with vegans displaying the lowest levels of all. These negative fatty acid profiles are reflected in infants, with vegan newborns displaying significantly lower red blood cell levels of DHA. This is an ominous finding, given the critical role that omega-3 fats play in healthy immune function and cognitive development[Williams C][O'Connor DL][Helland IB][Moriguchi T][Dunstan JA].
Along with lowering one's omega-3 levels, low meat intakes also increase the concentration of omega-6 fats inside the body. A high dietary and bodily ratio of omega-6mega-3 fats increases the risk of numerous diseases, including cardiovascular disease. A sizable portion of heart attacks are triggered when blood clots lodge themselves in narrowed coronary arteries and prevent the flow of blood to the heart, a process also known as arterial thrombosis. One of the early and key events in the development of thrombosis is platelet aggregation, the 'clumping together' of blood platelets. Researchers from Melbourne, Australia, compared heavy-meat-eaters, moderate-meat-eaters, lactoovegetarians and vegans and found that as meat consumption increased, platelet aggregation decreased. Heavy-meat-eaters displayed the lowest levels of platelet aggregation, while vegans displayed the highest levels.