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Immune Function

Immune function refers to comprehensive mind/body processes that protect against accident, disease, and misfortune. Most medical research on natural immunity to disease is focused on blood and lymph factors, liver and spleen functions, and other physiological mechanisms. While all diseases and disorders result from weakened immunity, a category of immune-deficiency diseases has emerged which are increasingly be treated with diet and nutrition. See AIDS. Antioxidants, Arthritis, Cancer, Chronic Fatigue, Fibromyalgia, Hiziki, Phytoestrogens, Seeds, Selenium, Soy Foods, Vegetables, Women’s Health.


• Soy Foods Enhance Immunity Against Cancer

In a laboratory study, Chinese researchers reported that a diet high in daidzein, an isoflavone found naturally in soy foods, increased nonspecific immunity, activated humoral immunity, and enhanced cell-mediated immunity. “These results demonstrate for the first time that daidzein at high doses enhances several immunologic functions and suggest a novel approach to understanding the mechanism(s) by which soy foods may contribute to observed cancer prevention.”

Source: R. Zhang et al., “Enhancement of Immune Function in Mice Fed High Doses of Soy Daidzein,” Nutrition and Cancer 29(1):24-28, 1997.


• High Vitamin E Diet Enhances Immune Function

In a laboratory study of the effects of diet on immune function, researchers in Japan reported that a high vitamin E diet increased interleukin 2 production in the spleens of rats, improved decreased cellular immune function caused by aging, and enhanced macrophage functions and lymphocyte responsiveness.

Source: S. Sakai and S. Moriguchi, “Long-Term Feeding of High Vitamin E Diet Improves the Decreased Mitogen Response of Rat Splenic Lymphocytes with Aging,” Journal of Nutrition Science and Vitaminology 43(1):113-22, 1997.


• Foods High in Carotenoids Enhance Immunity to Cancer

In a placebo-controlled study of 25 healthy men, cancer researchers in England reported that a diet rich in carotenoids positively influenced cell factors involved in the initiation and regulation of immune responses involved in tumor development. “These findings suggest that moderate increases in the dietary intake of beta-carotene can enhance cell-mediated immune responses within a relatively short period of time, providing a potential mechanism for the anticarcinogenic properties attributed to beta-carotene.”

Source: D. A. Hughes et al., “The Effect of Beta-Carotene Supplementation in the Immune Function of Blood Monocytes from Healthy Male Nonsmokers,” Journal of Laboratory Clinical Medicine 129(3):309-17, 1997.


• Diet and Natural Immune Function

In Humanity at the Crossroads, Michio Kushi and Alex Jack offer a comprehensive view of the human immune function, especially its dietary and nutritional foundation. “Human natural immunity includes 1) adaptation to the environment; 2) maintenance of existence; 3) continuous biological and spiritual evolution, especially involving the quality and scope of consciousness.” The eight key components of immune function include:

     1. Intuition and Instinct, including avoidance of danger, caution of abrupt, dramatic change, and seeking a middle way between extremes

     2. Consciousness, including the sensory, emotional, intellectual, social, and philosophical or spiritual levels. Through the exercise of this judgment, natural selection involving attraction or repulsion, and absorption or expulsion, are constantly being made for certain tendencies, objects, behaviors, or persons. As long as these levels of consciousness are working, extremes can be avoided without exposing us to danger.

     3. Autonomic Response. In addition to the central nervous system, which mainly serves to produce and exercise consciousness, autonomic nerves—sympathetic and parasympathetic—function to react imme­diately to surrounding stimuli. Through autonomic control, the necessary balance and harmony with the stimulus can be maintained for preserving and supporting the life of the organism.

     4. Body Surface Protection and Reaction, including the skin and sweat glands which serves to protect the internal environment and reacts by contraction and expansion according to the nature of the stimuli.

      5. Internal Liquid Protection, including acid/alkaline balance and buffer reactions in the saliva, stomach, and small intestine (including secretions from the liver and pancreas).  These digestive liquids minimize and neutralize poisonous chemical and biological factors, including the undesirable action of microorganisms, in addition to normal food decomposition and digestive functions. Proper chewing facilitates the immune process. The more we chew, the more saliva is produced. Saliva accelerates these protective functions, enhancing other digestive secretions and related nervous activities.

      Further, immunoglobulin A (IGA) existing in the internal fluids secreted throughout the digestive system (and in other systems such as the reproductive system) as well as on intercellular fluids can act as a protective agent from toxic substances that have entered from outside the body or that have been produced inside the body. The pro­tective functions of IGA in the mouth cavity together with saliva and in the wall surface around and in between numerous villi in the small intestine are especially active in neutralizing and minimizing the un­desirable activities of viruses, bacteria, and other microorganisms.

     6. Blood and Intercellular Fluid Protection and Reaction. Within the bloodstream, there are constant balancing mechanisms and buffer ac­tions to neutralize strong toxic acid compounds, changing them to weak acids through the mobilization of minerals in the body. These minerals are normally supplied in the daily diet, but if additional minerals are required for this buffer action, stored minerals are used. As a result, weakening of the bones often arises following the consumption of excessive amounts of acid-pro-ducing foods such as meat, dairy, and sugar. In children, this is the chief cause of tooth decay. In older people, chronic weakening of the bones from improper diet can lead to a po­tentially crippling condition known as osteoporosis.

        Further, white-blood cells protect from undesirable viral and bacterial invasion. White-blood cells known as lymphocytes have various kinds of cells, such as B-cells and T-cells. These cells coordinate the maintenance of normal conditions by either neutralizing or harmoniz­ing the poisonous effects of invading viruses or other microorganisms. Among their functions there are antagonistic-complemental relations constantly working as well-known helpers and suppressors. Among the group of T-cells, antagonistic-complemental relations between T4 cells and T8 cells are one of the balancing and harmonizing activities relating to undesirable viruses and microorganisms.

      Because lymphocytes can exist within the body’s intercellular fluids—that is, outside the bloodstream—these actions also arise within this location. In addition, when foreign substances such as undesirable viruses or bacteria enter the blood and intercellular fluids, antagonistic and com­plementary factors can naturally be produced. These are called anti­bodies. The purpose of antigen production is to balance and harmonize foreign substances and maintain continuous body functions. According­ly, the presence of antibodies can be an indication of the activity of un­desirable viruses or other microorganisms within the individual.

     7. Lymphatic Protection. After the blood and intercellular fluids nourish various body cells, they are collected in the lymph system. A great number of lymph nodes form a network throughout the body for cleaning undesirable wastes. If the collected fluids contain a great amount of undesirable poisonous wastes, various kinds of minerals are mobilized into the lymph nodes to make drastic action or cleaning. This action often results in the swelling of the lymph nodes. If such poisonous effects continue for some period, chronic swelling of lymph nodes and the spleen and ineffectiveness in the function of the lymphatic system arises as in the case of lymphoma. In connection with this function, the surgical removal of some im­portant lymph nodes such as the tonsils also directly contributes to the inefficiency of lymphatic functions and a general weakening of the natural immune system.

     8. Cellular Protection. Each cell of the human body has its own protective function to maintain its identity and existence. Cell membranes act for direct protection from undesirable physical stimuli and chemical invasion. Firm bonding of several elements in DNA and RNA is not easily impaired unless the power of foreign substances and stimuli far exceeds the protective mechanism. Cell membranes and intercellular fluids also serve to protect the nucleus of the cell.

     Each cell is constantly rejuvenated by the energy and nutrients that are being supplied through blood and intercellular fluids. Accordingly, if the quality of blood and intercellular fluids changes substantially, the quality of cells also inevitably changes. Such changes arise not only in the cell membrane and intercellular fluids, but also possibly in the nucleus of the cell.

      “These eight aspects of natural immunity do not function completely independently,” the authors conclude. “Each acts to ensure its integrity, and yet all are inter­related and united as a whole. The decline of natural immunity—leading to TB, AIDS, the human variant of mad cow disease, or other immune-deficiency or infectious condition—is not the result of a sudden failure, defect, or ineffectiveness in one or more of these immune functions. It is the result of partial or total failure or decay of all of them, usually over a period of time.

     “The primary origin of natural immune deficiency is cloudiness in intuition and instinct. The decline of intuitive and instinctive judgment causes us to observe abnormal life-styles and dietary practices that exceed the natural limitations of our environment, climate, constitution, or condition. A-dopting imbalanced ways of life and eating, in turn, results in the further decay and weakening of other levels of the natural immune system.

      “While the primary origin of immune deficiency is the decline of intui­tive-instinctive response, the biological cause of natural immunity is improper dietary habits. In other words, when intuitive-instinctive judg­ment is not exercised naturally in our daily eating, the decline of our natural immunity begins, and harmful viruses and bacteria in our en­vironment can easily affect either some or all of the systems of the body.”

Source: Michio Kushi and Alex Jack, Humanity at the Crossroads (Becket, MA: One Peaceful World Press, 1997).



In developing countries or poor areas that suffer from chronic malnutrition and epidemic disease, vaccinations can save lives in the short run and are part of a temporary humanitarian solution. However, in the long run, vaccinations may weaken the body’s natural immunity and can increase the risk of serious disease in the future. Childhood immunization, in particular, is regarded as unhealthy and largely unnecessary by many people, including some scientists and physicians. With the emergence of new drug-resistant microbes, the efficacy of vaccines, inoculations, and immunizations is being reexamined in the medical community. See Infectious Disease, Potato.


• Risks of Vaccination

A researcher examines the risks of vaccinations for measles, whooping cough, diphtheria, German measles, mumps, polio, and other childhood diseases.

Source: Jamie Murphy, What Every Parent Should Know about Childhood Immunization, Earth Healing Products,  1993.


• Do Vaccines Cause Disease?

A researcher brings a new perspective to many provocative issues such as the vaccine-AIDS connection, medical statistics and claims, the track record of the Salk vaccine for polio, and the short- and long-term consequences of DPT, the standard vaccine given schoolchildren.

Source: Walene James, Immunization: The Reality Behind the Myth, Greenwood, 1995.


• Vaccines Counterproductive

Applying evolutionary principles to the entire scope of modern medical treatment, an expert on infectious disease came to the paradoxical conclusion that many scientific strategies to combat infectious disease—such as hospitalization, vaccination, and antibiotics—may actually be increasing the incidence of disease.

     In his book on infectious diseases, Paul W. Ewald, a biologist at Amherst College, shows that the virulence of potentially harmful microorganisms rapidly increases in a clinical setting and that many vaccines and drugs are counterproductive. By killing off the milder strains of microbes, they strengthen the stronger ones, which are then able to multiply better, spread more rapidly, and cause more serious damage.

     Ewald cites current statistics showing that 1 in 20 patients in the United States—and 1 in 7 intensive care patients—acquires an infection in the hospital; one third of all pneumonia is acquired in the hospital, and one third of all these cases die; and hospital-acquired infection now ranks among the ten leading causes of death in modern society. Increasingly, he explains, hospital-caused infections are untreatable because the clinical setting favors the rapid evolution of drug-resistant species of microorganisms, and for many conditions, such as tuberculosis, there is currently no effective remedy.

      “The present efforts to control infectious diseases generally do not involve assessment of evolutionary stability,” he explains. “Rather, researchers focus on vulnerable aspects of a pathogen, such as biochemical components that can be used in a vaccine . . . If the individuals in a pathogen species always wore the same uniform, identifying and destroying them would be as easy as it was with smallpox. But most parasites practice guerrilla warfare . . . vaccines generated against sexually reproducing parasites like malaria, or mutation-prone viruses like HIV and influenza can be expected to provide partial and unstable solutions. Vaccination has already nullified easy adversaries. We are now left with the more wily ones, which probably will evade our vaccination efforts by changing their coats.”

     Rather than mass, multiple, broad-based vaccination campaigns to eradicate harmful microbes, Ewald suggests that we “use our knowledge about them to make them evolve into less dangerous organisms.” Many current vaccines, he suggests, are unsafe and ineffective. In addition to occasionally causing “severe damage to those it is supposed to protect,” the whooping cough vaccine, for example, produces increased virulence. If new vaccines do not take natural selection and the survival of the fittest into account, he concludes, “our vaccination efforts may backfire. We may be introducing large numbers of benign organisms into environments that will favor their evolutionary transformation into dangerous organisms.”

Source: Paul W. Ewald, Evolution of Infectious Disease (New York: Oxford University Press, 1994).



Impotence, or the failure to achieve or hold an erection, affects between 50 and 75 percent of men over 65 in modern society. Arteriosclerosis, or hardening of the arteries leading to the penis, is the principal cause, while reactions to drugs are implicated in 25 percent of cases, and nerve damage or other disorder can also lead to this affliction. See Infertility, Sexual Vitality.


• Links with a High-Fat Diet

In a study of 440 impotent men, researchers found evidence of arterial lesion in the penises of 53 percent. “Our results indicate that much of the increase in impotence with age is associated with arteriosclerotic changes in the arteries and cavernous tissue,” the investigators concluded. “Impotent patients should follow the regimens [diets] recommended to patients with more severe arteriosclerosis of other sites.”

Source: R. Virag, P. Bouilly, and D. Frydman, “Is Impotence an Arterial Disorder?” Lancet I:181-84, 1985.


Incan Diet

The World Health Organization has set up a database on traditional plants used in healing at the University of Illinois. The “lost crops of the Incas” are being rediscovered and reintroduced around the world. In a recent study, the National Research Council singled out quinoa, a small grain that is high in protein; nunas, a bean that resembles roasted peanuts; and other cereals, legumes, and roots as nutritious additions to urban diets and valuable sources of farm income in developing nations. See Agriculture.

Source: William K. Stevens, “Rediscovering the Lost Crops of the Incas,” New York Times,  October 31, 1989.



Indoles are a group of phytochemicals that stimulate enzymes that inhibit tumor formation in the human body. Found in broccoli, cabbage, cauliflower, and other cruciferous vegetables, they appear to block estrogen and protect against breast cancer. See Phytochemicals.


Infectious Disease

Infectious diseases were the leading cause of death in the 19th and early 20th centuries. With the advent of modern miracle drugs, infectious diseases virtually disappeared. But in recent years, tuberculosis, malaria, cholera, and pneumonia have began to come back in new drug-resistant forms, and new epidemics, ranging from AIDS to mad cow disease, have emerged. New holistic approaches are needed to offset this trend. See AIDS, Candida, Drug-Resistance, Genetically Engineered Food, Immune Function, Immunizations, Malaria, Natto, Onion, Parsley, Potato, Sea Vegetables, Xenotransplants.


• Most Infectious Diseases Animal Based

In a study of plague and other human diseases, a historian concluded that nearly all of the distinctive infectious diseases of civilization have been transferred to human populations from animal herds used primarily for food. “Measles, for example, is probably related to rinderpest and/or canine distemper; smallpox is certainly connected closely with cowpox and with a cluster of other animal infections; influenza is shared by humans and hogs.” The researcher noted that today humans share 26 diseases with poultry, 42 with pigs, 46 with sheep and goats, and 50 with cattle.

Source: William H. McNeill, Plagues and Peoples (Garden City, N.Y.: Anchor Press/Doubleday, 1976), p. 51.


• Diet and Infectious Disease

Two holistic educators present a multifactoral dietary and environmental approach to several dozen new viral and bacterial diseases, including AIDS, new drug-resistant strains of tuberculosis and pneumonia, Ebola, hepatitis C and E, strep A infections, lyme disease, and mad cow disease. This study includes a useful checklist of factors that increase or decrease risk for the new epidemics and looks at the impact of global warming on the spread of infectious disease.

Source: Michio Kushi and Alex Jack, Humanity at the Crossroads (Becket, MA: One Peaceful World Press, 1997).


• Household Cleaning Spreads Germs

Contrary to conventional wisdom, the worst “hot zones” for bacteria in the house are not the toilet seat or bathroom, but kitchen sponges and dish clothes, the kitchen sink drain area, kitchen faucet handles, cutting boards, and refrigerator handles. In a study of 15 typical households, University of Arizona researcher Dr. Charles Gerba reported that “the more tidy the household, the more widespread the bacteria.” “Neat housekeepers use contaminated sponges all over, spreading bacteria everywhere,” he found.

Source: “Germs, Germs Everywhere,” Parade Magazine, September 13, 1998.


• Environmental Origin of New Viral Epidemics

In India, Kyasanur Forest Disease (KFD), a severe hemorrhagic disease, first appeared in the mid-1950s. Initially it affected monkeys and then spread into the human population. A generation ago, scientists would have declared the KFD virus a mutant organism that had arisen randomly and that had to be destroyed by any means necessary. Today, the approach is more sophisticated.

      “Ecological factors, including deforestation, cattle grazing, and an increased opportunity for tick density were probably responsible for the appearance of this disease, which has persisted as an endemic infection since that time,” contends Thomas Monath, in Emerging Viruses, an anthology of current articles in the field. “The virus was probably circulating silently in ticks and rodent hosts; ecological changes provided an opportunity for amplified transmission, and human encroachment in this altered environment led to the emergence of epidemic disease.”

      Social, cultural, and environmental measures will be more important in reversing this epidemic than medical treatment. In Central and South America, the rain forests are being felled for timber, livestock production, mining, and ranching. The environmental movement has focused on how this is contributing to global warming by increasing the buildup of carbon dioxide in the atmosphere. An equally dangerous consequence of the loss of the tropical rain forests and biodiversity is the effect on microorganisms. Following ecological imbalance, selective forces may favor more virulent strains of microbes, which may emerge and disseminate around the world.

      In an essay “Global Change and Epidemiology” in Emerging Viruses, Thomas E. Lovejoy notes that populations of North American migratory birds that hibernate in the tropical forests have declined dramatically in the last decade. “This may occasionally upset the average bird watcher, but what does it mean to the rest of us? It turns out that most of those migratory passerines are very dependent on insect populations at the time they are raising young and are a major evolutionary influence on insect behavior and ecology. So even something as far fetched as conversion of Central American forest to cattle pasture could, in the end, have a major impact on the way viruses and other pathogens associated with birds or insects might behave in North America.”

     Increasingly ecology is seen as the key to understanding the development of animal and human epidemics. “Introduction of viruses into the human population is often the result of human activities, such as agriculture, that, cause changes in natural environment,” explains Stephen S. Morse, a virologist at Rockefeller University, in Emerging Viruses. He explains that herbicides introduced into the Latin American pampas led to the rise of Argentine hemorrhagic fever beginning in 1960. The chemical sprays altered the ecology and led to the creation of a new mouse which was the carrier of the deadly virus.

Source: Stephen S. Morse, editor, Emerging Viruses (New York: Oxford University Press, 1993).


• Lyme Disease Caused by Ecological Imbalance

In the United States, the recent emergence of Lyme disease offers some parallels. As forests gave way to urban development, weedy grasses and shrubs proliferated, providing new habitats for rodents. As bears, wolves, and other predators disappeared, deer populations grew. The end result was a dramatic increase in infectious ticks that gave rise to Lyme disease. From the first cases reported in 1975 in Connecticut, the disorder has spread to 46 states. “The ‘greening’ of the United States has led to suburban living where a deer may be as common as a squirrel,” explains public health researcher Marc Lappé. “Unfortunately, deer are one of the intermediate hosts for adult ixodid ticks that also carry the Lyme organism.”

Source: Marc Lappé, Evolutionary Medicine (San Francisco: Sierra Club Books, 1994).


• Cholera Transmitted by Contaminated Food

In a study of the spread of cholera from Peru to other Latin American countries, researchers in Argentina reported that 22 food products were contaminated including yogurt, cream cheese, marmalade, mayonnaise, refined pasta for empanadas, meat sausage, meat and spinach ravioli, margarine, milk dessert, lettuce, tuna fish, ricotta cheese, and sterilized milk. Most of the foods, moreover, could tolerate the growth and persistence of the cholera bacillus for up to three months.

Source: D. Dobosch et al., “The Role of Food in Cholera Transmission,” Medicina 55(1):28-32, 1995.


• Virus Mutation and Nutritional Deficiency

In the first study of its kind, scientists found that viruses can mutate and become lethal as a result of nutritional deficiencies in their hosts. In experiments at the University of North Carolina, scientists found that a human virus normally harmless in mice mutated and damaged the hearts in mice suffering from a lack of selenium (found naturally in whole grains and vegetables). The altered virus then was capable of infecting and damaging the hearts of mice on a well balanced diet. Dr. Melinda A. Beck, who directed the research, speculated that nutritional deficiencies may cause viruses and bacteria to become more virulent and be a factor in the evolution of influenza, hepatitis, meningitis, and other human illnesses.

     In the study, researchers used Coxsackle viruses which are related to the type of viruses associated with sore throats, colds, aches and inflammation, as well as polio and some types of heart disease, meningitis, and diabetes. "Perhaps virus evolution does depend on what we eat or what we do not eat," a commentary in the journal concluded.

Source: M. A. Beck et al., “Rapid Genomic Evolution of a Non-Virulent Coxsackievirus B3 in Selenium-Deficient Mice Results in Selection of Identical Virulent Isolates,” Natural Medicine 1(5):433-36, 1995.



Fertility problems are commonly related to diet and environment. Caffeine causes delayed conception in women, while pesticides, PCBs, and other industrial chemicals decrease sperm concentrations in men. See Chemicals, Sexual Vitality.


• Plant Foods Improve Male Fertility

Comparing the dietary intake of antioxidants among 10 fertile and 48 infertile men, researchers from the University of Rochester found that infertile men were twice as likely to eat less than five servings of fruits and vegetables a day compared to fertile men. Men with low consumption of these foods also had lower sperm motility.

Source: V. Lewis et al., “Dietary Antioxidants and Sperm Quality in Interfile Men,” Annual Scientific Meeting of the American Society for Reproductive Medicine, October 2006.


• Organic Food Increases Sperm Counts

Danish researchers reported that organic farmers and other men who regularly consumed organic foods had nearly twice the sperm count of men employed in other occupations who consumed ordinary, primarily chemically grown foods.

Source: T. K. Jensen et al., “Semen Quality Among Members of Organic Food Association in Zealand, Denmark,” Lancet 347:1844, 1996.


• Natural Approach

Several macrobiotic educators discuss the origin, cause, and dietary approach to infertility and other reproductive disorders. In men, they assert, infertility is associated with intake of too much sugar and sweets, producing weak sperm, while in women it is caused primarily by dairy and other high-fat foods that block the fallopian tubes.

Source: Michio Kushi with Charles Millman, A Natural Approach—Infertility/Reproductive Disorders,  (Tokyo & New York: Japan Publications, 1988); Aveline Kushi,  Cooking for Health—Infertility/Reproductive Disorders, Japan Publications, 1988.


• Synthetic Estrogens Result in Global Decline in Fertility

Environmental scientists and medical researchers warned that hormone-mimicking chemicals are making the environment “a virtual sea of estrogen” that is emasculating animals and humans. By inhibiting natural hormones, industrial chemicals and estrogen disrupters interfere with the functioning of the liver, brain, pancreas, adrenals, and ex orders.

     Mimicking the effects of estrogen, the female sex hormone, the chemicals are feminizing men, leading to reduced sperm production, testicular cancer, prostate cancer, and undescended testicles in baby boys. A sharp increase in these symptoms has been observed in many parts of the world including the Great Lakes, Denmark, Britain, Malaysia, and Indonesia. In France, researchers reported a 30 percent reduction in viable sperm in the last 20 years, and a 50 percent drop in semen quality and a 19 percent decrease in semen volume over the last half century.

     The estrogen disrupters include synthetic estrogens used extensively in the livestock industry, DES prescribed to pregnant women from 1948 to 1971, PCBs, and DDT.

Source: Erik Lindala, “Chemical Pollutants Linked to Male Infertility,” Alternatives 21(3):11, 1995.



A compress made with leafy green vegetables, tofu, or sea vegetables is traditionally used in Far Eastern healing to reduce inflammation.


• Kombu Plaster

In his book on home remedies, educator Michio Kushi explains how to make a kombu plaster and other seaweed compresses and their energetic effects.

Source: Michio Kushi, Basic Home Remedies (Becket, MA: One Peaceful World Press, 1994).


 • Seaweeds Reduce Inflammation

Japanese scientists reported that sujiaro-nori, an edible green alga, exhibited strong anti-inflammatory effects such as reducing the inflammatory reaction in edema formation in a mouse ear in laboratory experiments and in human leukocytes.           

Source: Y Okai, "Potent Anti-Inflammatory Activity of Pheophytin A Derived from Edible Green Alga, Enteromorpha Prolifera," International Journal of Immunopharmacology 19(6):355-8, 1997.



Intelligence is believed to result from a balance of nurture and nature. In addition to constitutional strengths, intelligence is associated with proper diet, parental support, cultural vitality, and musical and artistic expression. See Breast-feeding, Children’s Health, Fluoridation.


• Macrobiotic Children Have Higher IQs 

In a study of mental development and I.Q., macrobiotic and vegetarian children were significantly brighter and more intelligent than ordinary youngsters their age.

     The test group consisted of 28 children in the Boston area between two and eight years old, with a mean age of four years old. The mean I.Q. was 116 for the group as a whole, or 16 percent above average. The children’s mean mental age was found to exceed their mean chronologic age by approximately a year. The macrobiotic children’s I.Q.’s and mental ages were slightly higher than the other vegetarians.

      “In the judgments of both the pediatrician and psychologic technician, the children as a group were bright,” the researchers concluded. They speculated, however, that the brightness may be due to better education on the part of the macrobiotic and vegetarian parents, not to diet.

Source: J. T. Dwyer et al., “Mental Age and I.Q. of Predominantly Vegetarian Children,” Journal of the American Dietetic Asociation 76:142-47, 1980.



Irradiation is used on food to kill bacteria, insects, and molds. Massive doses of ionizing radiation are commonly used, e.g., 100,000 rads, the equivalent of approximately ten million medical X-rays. Radioactive wastes from nuclear weapons and power plants are used to irradiate many common foods, including fruits and vegetables, herbs, spices, teas, pork, poultry, white potatoes, wheat, and wheat flour, in order to prolong freshness and shelf life. The FDA approved irradiation in 1986, but irradiated foods are banned in New York, New Jersey, and Maine and by several countries including Germany, Denmark, Sweden, Australia, and New Zealand.


• Radiolytic Products

Scientific studies indicate that irradiation can produce complex chemical changes in food including the creation of radiolytic products; reproductive disorders; chromosomal abnormalities; and up to 50 percent reduction in nutrients.

Source: Food and Water, RR1, Box 68D, Walden VT 05873; (800) EAT-SAFE.


• Danger of Irradiation           

Studying the complex chemical changes irradiation produces in food, scientists have found reproductive damage and chromosomal damage in rodents, monkeys, and children tested with irradiated food. An Indian study found chromosomal abnormalities in undernourished children given irradiated wheat. Irradiation also reduces the nutritional value in foods, especially vitamins A, C, E, and B complex. Japanese researchers reported that the vitamin C content of irradiated potatoes was almost 50 percent lower than normal.

Sources: S. S. Epstein and J. Gofman, "Irradiation of Foods," Science 223:1354, 1984. M. Colby and S. S. Epstein, "Risks of Radiation: Too Many Questions about Food Safety," USA Today, January 22, 1992, A 11. M. F. Jacobson and S. Schmidt, "Food Irradiation. Zapping Our Troubles Away?" Nutrition Action, April 1992, 5-7.


• Cancer Risk Increased

Irradiating meat could increase the risk of cancer. "Irradiation produces formaldehyde in mutagenic doses," reports George L. Tritsch, cancer research scientist at Roswell Park Cancer Institute in Buffalo. "This can be ignored only by individuals with less than a decade of life expectancy, about the minimum time needed to produce clinical cancer after a mutagenic or carcinogenic insult."

     Irradiation also does not kill the bacteria spores responsible for botulism, which is fatal. Further, while radiation kills 90 to 99 percent of the bacteria in meat, "the remaining viable organisms are, by definition, radiation-resistant and no research has been done on what these bacteria and their progeny populating the intestines would do to man. These mutants may be heat-resistant, antibiotic-resistant, etc. No one knows."

Source: "Irradiating Meat Could Increase the Risk of Cancer,” The Buffalo News, September 19, 1997.



Iron is an essential mineral found in animal foods, green leafy vegetables, sea vegetables, and other staple foods. Iron from plant-quality sources is safer and metabolized better in the body than that from animal sources. See Dairy, Meat, Heart Disease, Soy Foods, Vegetarians.


• Excess Iron Increases Risk of Heart Disease

Excess iron in the blood may be a primary cause of heart disease and double the risk of heart attacks in men. Finnish researchers theorized that iron in the bloodstream accounts for the higher rate of heart attacks in men than in young women, whose iron levels decline during menstruation. About 50 percent of the dietary iron in the Finnish study came from animal food sources.

Source: “High Stored Iron Levels Are Associated with Excess Risk of Myocardial Infarction in Eastern Finnish Men,” Circulation 86:803-11, 1992.


Ishizuka, Sagen

At the end of the 19th century, Japanese physician and philosopher Sagen Ishizuka, M.D., published the results of many years’ research and study, outlining a broad theory of human physiology, food, health, sickness and medicine based on the dynamic balance between sodium and potassium in the environment and diet. On the basis of his own work as a military doctor in China and general practitioner in Japan, as well as readings in anthropology, he concluded that whole cereal grains contained the ideal balance of nutrients and should form the foundation of the human diet, supplemented with beans, vegetables, seeds and nuts, and a small amount of fish or game depending on the climate, region, and season of the year.  In Tokyo, he set up a free clinic and was known as “Dr. Daikon” and “Dr. Miso Soup.”  He helped thousands of people recover from tuberculosis, diphtheria, and other modern diseases that had entered Japan with the modern diet.

Sources: Sagen Ishizuka, Kagakuteki Shoku-Yo (A Chemical Nutritional Theory of Long Life), 1897 (Tokyo: Nippon C.I., 1975), and Shokumotsu Yojoho: Ichimei Kagakuteki Shoku-Yo Tai Shin Ron (A Method for Nourishing Life Through Food: A Unique Chemical Food-Nourishment Theory of Body and Mind), 1898 (Tokyo: Nippon C.I., 1974). 



Isoflavones are a class of natural compounds found in a variety of plant-quality foods that have strong anticancer effects. Principal isoflavones include genistein and daidzein. Similar in chemical structure to estrogens, isoflavones are capable of blocking the uptake of estrogen in the breasts, prostate, and other organs sensitive to hormones. They are particularly found in soybeans. Isoflavones are a type of phytoestrogen. See Genistein, Immune Function, Kuzu, Leukemia, Phytoestrogens, Prostate Cancer, Soy Foods, Tempeh, Wine.


• Dietary Sources

In a study of dietary sources of genistein and daidzein, natural isoflavones with strong antitumor properties, scientists reported that kuzu (kudzu), soybeans, miso, fava beans, lupine (a legume), and psoralea (Indian root bread) are excellent food sources for both these metabolites and may help protect against cancer.

Source: P. B. Kaufman et al., "A Comparative Survey of Leguminous Plants as Sources of the Isoflavones, Genistein and Daidzein: Implications for Human Nutrition and Health," Journal of Alternative and Complementary Medicine 3(1):7-12, 1997.


Isoflavone Content of Selected Soy Foods

                                                 Genistein        Genistin

            Soybeans                         4.6                   18.2

            Soy powder                 200.6                  968.1

            Soy milk                           1.9                    94.8

            Tofu                                13.9                  137.7

            Miso                               38.5                    71.7

            Natto                           229.1                  492.8

            In micrograms/gram


• Soy Foods May Protect Japanese from Cancer

In a study of soy-related sources of genistein, an isoflavone with chemopreventive properties, and genistin, its beta-glucoside conjugate, researchers found that the daily consumption of these foods in Japan averaged 1.5-4.1 and 6.3-8.3 mg/person respectively. "These levels are higher than those for Americans or Western Europeans, whose mortality rates for breast, colon, and prostate cancers are greater than the Japanese," the study concluded.

Source: M. Fukutake, "Quantification of Genistein and Genistin in Soybeans and Soybean Products," Food Chemistry and Toxicology 34(5):457-61, 1996.


• Isoflavones Protect Vegetarians from Chronic Disease

In a study of isoflavones, German scientists reported that a large group of naturally occurring low molecular weight substances that are present in grains, vegetables, fruits, seeds, nuts, and the stems, leaves, flowers, bark, and roots of most plants have a wide range of positive effects on preventing chronic diseases.

     The researchers especially singled out 3-hydroxyflavone, 3’,4’-dihytdrox-yflavone, 2’,3’-dihydroxyflavone, fisetin, apigenin, and luteolin for their capacity to inhibit the growth of normal and tumor cells, especially the growth of small blood vessels. This process, known as angiogenesis, is involved in rheumatoid arthritis, psoriasis, diabetes complications, and cancer. Compared to people eating animal food, vegetarians excrete 30 times more genistein, a principal phytoestrogen, in their urine, a barometer of protection against chronic disease.

Source: T. Fotsis et al., “Flavonids, Dietary-Derived Inhibitors of Cell Proliferation and in Vitro Angiogenesis,” Cancer Research 57:2916-21, 1997.



A type of phytochemicals found in kale, broccoli, brussel sprouts, cauliflower, and other cruciferous vegetables that inhibit cancer development.

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