Noticias

Comiendo Saludable

http://www.whfoods.com/genpage.php?tname=foodspice&dbid=90

5 Mayo 2010

Los prebióticos mejoran el desequilibrio de la flora intestinal, por lo que pueden tratar el exceso de grasa y de peso.

El mayor o menor rendimiento energético de los alimentos, es decir, las calorías totales que el organismo aprovecha, depende de la calidad de la microbiota o flora intestinal. Así lo revelan diversas investigaciones que advierten, además, de cómo el desequilibrio de ésta (disbiosis) afecta al metabolismo de los nutrientes en lo relativo a la gestión y el almacenamiento de la energía. Estos datos novedosos pueden acreditar la protección o predisposición a la obesidad de muchas personas afectadas por esta enfermedad crónica y significarían que la selección de alimentos es clave para mejorar el conjunto de bacterias que viven en el intestino. Los prebióticos como la inulina destacan entre las sustancias de los alimentos esenciales para este fin.

Distintos estudios, en su mayoría realizados con animales, han demostrado la relación estrecha entre el microbioma -conjunto de genes de los microbios que conviven con el ser humano- y los efectos sobre el metabolismo energético y, por ende, sobre una de las causas de la génesis de la obesidad. La mayor parte de los resultados coinciden en señalar que algunas mezclas de bacterias de la microbiota o flora intestinal pueden proteger o, por el contrario, predisponer a la obesidad. Estos vínculos han llevado a la opinión médica y científica a considerar el papel de prebióticos y probióticos, en la selección y cantidad adecuada para que resulten terapéuticos, como elementos clave para invertir la composición anómala de la flora intestinal en caso de desequilibrio y tratar, en cierta medida, la acumulación de grasa y de peso.

El intestino humano es un complejo ecosistema microbiano que contiene cerca de 100 trillones de microorganismos. Según las investigaciones, algunos de ellos son más eficientes en la extracción de la energía de los nutrientes ingeridos por los alimentos. Esto se traduce en un mayor metabolismo energético, que podría conducir a un mayor depósito de grasa y un riesgo aumentado de obesidad. Diversos ensayos clínicos en humanos, adultos y jóvenes han comprobado que las poblaciones de microbios en el intestino son diferentes entre personas obesas y delgadas.
En 2006, la revista “Nature” publicó un artículo dirigido por un equipo de expertos de la Washington University School of Medicine (St Louis, Estados Unidos), que asociaban la obesidad a un aumento en la concentración de bacterias del género “Firmicutes” y una reducción proporcional en la de “Bacteroidetes” -los dos grupos bacterianos más abundantes en el intestino humano-, al constatar diferencias sustanciales entre sujetos obesos y delgados. Es más, cuando los individuos obesos consumieron una dieta con alimentos seleccionados con cuidado, perdieron peso y, de forma paralela, su microflora se invirtió hacia un mayor equilibrio. Así lo comunican también especialistas de la Université catholique de Louvain (Bruselas, Bélgica) en un ensayo hecho público el pasado mes de diciembre en la revista médica especializada “Current opinión in pharmacology”.

Los prebióticos naturales más conocidos son la inulina y la oligofructosa, ambos clasificados como fructo-oligosacáridos (FOS). La industria alimentaria y la farmacéutica, que lideran el ranking de oferta de complementos o métodos para perder peso, extraen estos hidratos de carbono de reserva de las plantas y los añaden a alimentos o los venden como prebióticos para complementar la dieta. En los envases se destacan sugerentes mensajes como “vientre plano”, “mejora los trastornos digestivos y el exceso de gases” y similares. Pero no todos los productos son efectivos ni seguros.
Se puede aumentar de manera significativa el aporte diario de prebióticos si se plantean a diario recetas con hortalizas y frutas.
Son numerosos los alimentos vegetales ricos en inulina que, según la temporada, se pueden escoger para configurar un menú rico en prebióticos. Este hidrato de carbono de reserva que se considera un tipo de fibra soluble, sobresale en la composición de verduras de invierno como el cardo y la achicoria; de primavera como la alcachofa, los espárragos y el rábano; de verano como los tomates, y otras disponibles todo el año en sus distintas variedades, como las cebollas y los ajos, frescos o en bulbo. También destacan los plátanos.

Pero el consumo de prebióticos a través de los alimentos es escaso, apenas unos 800 miligramos diarios frente a los 2-6 gramos recomendados, según estudios de hábitos de alimentación de la población general. Dado que la disbiosis intestinal se conoce como una causa de hinchazón abdominal, estreñimiento crónico y enfermedad inflamatoria intestinal, puede estar justificado recurrir a los alimentos enriquecidos en estos componentes o a los complementos dietéticos como método seguro para compensar la deficiencia. Entre los alimentos enriquecidos destacan las galletas, zumos y otras bebidas, derivados lácteos o panes especiales tipo molde. De un modo natural y sencillo, se consigue un aumento significativo del aporte diario de prebióticos si se plantean a diario recetas con algunas de las hortalizas y frutas citadas.

Las siguientes aumentan los recursos culinarios, ya que destacan por ser muy sabrosas y diferentes a las tradicionales. Las cebollas se pueden rellenar de pescado o de carne, al igual que los espárragos, cuyo resultado es un plato jugoso y muy vistoso. La mayoría de las verduras se comen cocidas, si bien las hojas más tiernas de muchas se pueden agregar crudas en las ensaladas, como la de achicoria combinada con frutas y frutos secos, o la de cardo. Se pueden emplear como ingrediente de una pizza o de un original entrante de alcachofa con queso fresco.

http://www.consumer.es/web/es/alimentacion/tendencias/2010/04/22/192578

Do you have friends who say that they feel physically sick and develop headaches, heart palpitations, nausea and dizziness when they eat sugar or anything with high fructose corn syrup? Do you know others who report feeling tired, bloated and nauseous when they eat meat or saturated fats, especially fatty meats processed with nitrates? Do you know people who say that they feel less energetic or alert when they eat processed foods or who feel nervous, shaky and irritable when they drink something with an artificial sweetener in it? Do you know people who develop rashes and congestion when they eat or drink various foods or who feel depressed and fatigued when they eat refined white flour or carbohydrates?

A reader recently wrote puzzled about a strange phenomenon she was seeing among a large and growing number of healthy, nondiabetic young women. They complain of feeling jittery, dizzy and sick the rest of the day after consuming “too much sugar,” she said. When she pins them down, they define “too much sugar” as the amount in a scoop of ice cream or can of soda — yet they say they have to “detox for a week because of ‘all that sugar’,” she wrote. “Detox … from sugar?” They’ve become so afraid of sugar that if they enjoy even the smallest treat, it ruins their entire day, she lamented. “What is going on here? Are all of these people losing their minds because of the hysteria they’re being whipped into? Could you shine a sane light onto this sucrophobia?”
There is a name for the ill health effects reported associated with our modern diet.
It’s called the nocebo effect and it’s far more widespread than many people realize.

Nocebo

The nocebo effect is negative stepsister of the placebo effect, where we feel good after eating foods, taking a remedy or doing something we believe is healthy.
With the nocebo effect, people can experience real and extraordinary physical and mental symptoms of illness, even paralysis, when they believe they’ve eaten or been exposed to something they think or fear could be harmful. The nocebo effect is behind most fears of unseen dangers lurking around us, especially in our food, and explains how people can sincerely believe that something is making them sick … even when there is no biological basis for their symptoms. When we’re told, or know, there is no scientific basis for what we’re experiencing, it’s still hard to believe that our minds can be that powerful.

Psychologists have cautioned that public health and nutrition information, or simply reading about scary diseases, triggers the nocebo effect. The growing trend to issue precautionary advice concerning health risks, even when there is no evidence for any credible risk to people’s health, can also feed the nocebo effect. Fears are not benign and the nocebo effect can have real and harmful effects and there are growing examples in the medical literature.

Dr. Nicholas Christakis, M.D., Ph.D., MPH, professor of medical sociology at Harvard Medical School, described the phenomena where healthy people develop anxiety about a perceived danger, then, being around others who are anxious, serves to heighten one’s own sense of fear. In other words, fear is contagious. “Mass hysteria,” also called “mass psychosomatic reaction” or “mass sociogenic illness,” is an epidemic of physical symptoms without biological basis that spread through a group of people, often young women, who share beliefs about their fears and symptoms. The Canadian Medical Association Journal noted that these events are common. Besides disrupting lives and communities, they can also place enormous burdens on emergency and public health services to care for people suffering from a mass psychosomatic reaction.

The preventive health movement, concerns over health risk factors, and being inundated by health information and health warnings has not only changed our entire concept of what it means to be healthy, it is transforming us into a nation of worried well. Although we have the greatest supply of nourishing food and we’re healthier and freer from serious illnesses than ever before, we’re more worried than ever about our health. Even benign aches and pains and symptoms that are part of normal human experience can be misinterpreted as signs of something wrong. The nocebo effects of healthism costs all of us, too. The worried well account for one-third of all primary care visits and incur healthcare costs 14 times higher than average.

Nocebo means “I will harm,” Jack Dini wrote in the Hawaiian Reporter last week. His article, “The Nocebo Effect — Think Sick and You’ll Be Sick,” gave a fascinating list of examples of nocebo. For example:
● In a study in the early 1980s, 34 college students were told an electric current would be passed through their heads, and the researchers warned that the experience could cause a headache. Though not a single volt of current was used, more than two-thirds of the students reported headaches.
● Drinking water fluoridation was first introduced in Grand Rapids, Michigan in 1945. Calls began coming in to city offices from people complaining of sore gums and peeling tooth enamel. One woman even claimed that all her teeth had fallen out. These calls arrived in early January, when some press reports had stated that fluoridation would begin, but some weeks before the actual advent of fluoridation on January 25.
● Call it fear of spraying. In one study researchers spewed distilled water from planes over residential neighborhoods without telling anyone what the spray contained. The intent was to gauge public phobia of chemicals. Sure enough, the experimenters were soon deluged with complaints from frightened folks who claimed the spray was causing cows to abort, dogs to shed and children to get sick…
● A Paris household blamed three installed cell phone antennas in their area for causing headaches, nosebleeds and a metallic taste in the mouths of some residents. The one problem with this complaint—the antennas were never activated.

Nocebo and healthy eating

Most troubling is how nocebo is used on unsuspecting consumers. The nocebo effect is not only well recognized in medicine and science research, it’s well-recognized by marketing professionals. Nocebo is why fear has become the most widely used political and marketing technique, especially when it comes to food and health. Fear sells. This natural human phenomenon has been the bread-and-butter for proponents of various alternative diets and nostrums over the decades.

Sadly, it’s hard for people to differentiate fear-based marketing from science and to see how the effects of nocebo and placebo have influenced what they’ve come to believe is food that is healthy and unhealthy for them. Nocebo-driven fears hurt people’s health and well-being, leave them less able to enjoy foods, and cost them normal relationships with food.

While there is no sound evidence that any food is actually harmful (excluding, of course, rotted, germ-ridden foods and people with severe allergies or rare metabolic disorders), from the age of two, people are being scared into believing that they’ll develop cancer or another chronic disease, get fat, and die prematurely if they eat “unhealthy” foods or are exposed to ‘chemicals’.

One of the most troubling and powerful examples of the use of the nocebo effect is in a food curriculum for elementary children across the country to scare them into believing that conventionally-grown foods, animal products, fats, sugars and processed foods poison their bodies and will give them cancer, heart disease and dementia, and cause them to be fat, have acne and deviant behaviors, and make them feel less energetic or able to learn.
What may be surprising is that these unsupported nocebo/placebo dietary tenets — such as metabolic typing, enzyme, healthy, macrobiotic or intuitive eating — are not really new. They resurface every generation, different renditions of the same basic fears, with new names and twists. And each new generation is largely unaware that these alternative beliefs are not grounded in science and have failed to hold up in clinical research time and again.
These tenets have in common the belief that chronic degenerative diseases of aging, such as cancers, type 2 diabetes and heart disease, are caused by unhealthy diets or processed foods and a build-up of toxins. Conversely, they hold that chronic diseases can be prevented and optimal wellness achieved by all-natural diets rich in antioxidants, “healthy” fats and fiber; whole foods made without added sugars, salts or preservatives; and flushing toxins from the body by drinking lots of water or detoxification.

Nocebo is also behind beliefs that each person should eat “in tune with their body and how foods make them feel.” The belief is that every body has different dietary needs for optimal health, maximum energy and mental clarity; to naturally control food cravings and maintain a healthy weight, strengthen immunity and slow down the aging process. The restrictive eating encouraged by the nocebo avoidance effects of ‘unhealthy’ foods are also weight loss techniques, and not surprisingly, eating intuitively is most intensely marketed to people concerned about their weight.
These nostrums, remember, have not been supported in scientific research. They are correct about one thing, though: there is no “one size fit all” diet. But that’s only because eating a certain way doesn’t matter as much as many think. People around the world have a wide range of diets with no consistent relationships to health or lifespans.The most common cause of poor nutrition and deficiencies isn’t eating “bad” foods, but eating too few calories and trying to restrict eating.

The origin of beliefs of diet and degenerative disease date back at least to the 1920s and 30s when a couple of dentists theorized that the “modern” diets of more developed countries were associated with degenerative diseases — diseases that were seldom seen among under developed regions of the world. Their theories have repeatedly failed to hold up to scientific scrutiny, however, which has noted they’d failed to account for the fact that people in more industrialized countries live longer and have different hereditary characteristics. Poor people in remote underdeveloped countries don’t live long enough to get degenerative diseases of aging.

By the 1950s, theories that eating according to one’s individual autonomic nervous system balance gave way to Dr. Roger Williams’ theory of optimal diets according to “biochemical individuality” and metabolic profiles. Another dentist, Dr. William D. Kelley, originated the metabolic typing diet by the 1960s. His assistant, William L. Wolcott, continued to develop metabolic typing in the 1980s, which promoted that every person had unique dietary requirements according to their metabolic type.

Through the use of questionnaires and other suggestive techniques, people are guided to think about how certain foods make them feel when they eat them, and to believe that this is their body telling them what they should eat. (Based on the answers to their “metabolic typing” profile, for example, people are divided into protein types, carbo types or mixed types, and told what type of personalities they have, their food cravings and what foods they should avoid and what foods are supposed to be best for them.) Invariably, of course, what foods their body is telling them they should eat is always ‘healthy’, based on the same underlying fears of modern diets as causing degenerative diseases and weight gain.

One holistic health counselor of “integrative nutrition” describes what can be learned by getting in touch with how your body feels when you eat certain foods and eating intuitively. Based on Wolcott’s 60 questions, carbo types, for instance, are described as characteristically having a “weaker appetite, higher tolerance for sweets, type A personalities, caffeine dependency” and should avoid foods high in fat (and use oils sparingly), heavy proteins, caffeine, sugar and “thyroid suppressing foods.” They are encouraged to eat whole grains, fruits and vegetables. For protein, they can eat “sustainable seafood, lighter chicken and turkey meats, pasture-raised eggs, low-fat dairy (if tolerated), tempeh, tofu and beans.” To feel more energetic and alert all day, she also advises drinking more water. “I don’t mean some water — I mean a lot of water. Eight 12 ounce glasses a day at least” to keep your system “healthier and better flushed.” And eat more fiber for more energy, she says, to lose that heavy feeling from food not processed effectively.

Nocebo and health frauds

These unsound dietary beliefs become even more dangerous when they become unsupported clinical guidelines or public health policies to prevent diseases. Or worse, when they’re used in treatments.

Kelley’s diet became part of a treatment regimen for cancer, as outlined in his Newsletter on Cancer Remedies in 1980. Kelley was convicted of practicing medicine without a license in 1970 and had his dental license suspended for five years in 1976, reported Dr. Saul Green, Ph.D., former professor of biochemistry at Sloane-Kettering Cancer Institute and a board member of the National Council Against Health Fraud. Still, Kelley continued to promote his methods through his “International Health Institute” in Dallas, where “certified metabolic technicians” administered his metabolic typing questionnaires and produced long computerized instructions for diets and supplements, detoxification and healthy lifestyle changes.

Kelley’s regimen was duplicated in the cancer regimen of Dr. Nicholas Gonzales, M.D., who has been found guilty of professional negligence and incompetence more than once. Proponents of the Kelly and Gonzalez regimen believe that toxins from sources such as processed foods and environmental pollution are responsible for human cancers, according to the National Cancer Institute. "If these toxins could be neutralized and eliminated from the body, proponents believe, both early and established cancers would be halted, and general health would be restored."

As Dr. Green explained, Kelley’s and Gonzales’ regimen was based on the discredited theory that cancer is caused by the growth of ectopic germ cells in the wrong place and a lack of digesting enzymes. Kelley invented a Malignancy Index based on a patient’s “metabolic classification as a sympathetic dominant, parasympathetic dominant or a balanced metabolizer,” and his cancer treatment was supposed to clear the body of toxins. Concerning his diet, wrote Dr. Green:
Kelley initially proposed a strict vegetarian diet, but later advocated that diet must be tailored to each patient's need. He developed ten basic diets with 95 variations. These ranged from pure vegetarian to exclusively meat. The diets forbade processed foods, pesticide residues, milk, soy beans, peanuts, food concentrates, white sugar and white rice. It allowed almonds, low protein grains and nuts, yogurt, "organic" raw vegetable and fruit juices, salads and whole grain cereals….
Kelley/Gonzalez diets are not unique and have been referred to variously as nutritional, enzyme, metabolic, holistic, macrobiotic, nontoxic and oxidative. Advocates of these diets also recommend "all natural foods" grown without pesticides or chemical fertilizers, and prepared without added sugar, salt, artificial coloring or preservatives. They also recommend large vitamin doses, mineral and glandular supplements and amino acids.

But no one has ever identified those supposed toxins in processed foods, said Dr. Green. Such beliefs are not grounded in science, but from fears of unseen and misunderstood chemicals. Nor has any credible evidence ever surfaced that they poison the body and lead to cancer, or that pancreatic enzyme deficiency is related to cancer, or that enzymes supplied from animal or vegetable sources can replace human enzymes, or that pancreatic enzymes seek out and kill cancer cells. Nor have Kelly or Gonzales every produced evidence that their regimens are more effective than placebo for cancer, he said. In fact, their claims are biologically implausible.

Memorial Sloan-Kettering Cancer Center has cautioned that nutritional metabolic therapies — such as Kelley’s metabolic typing based on claims that a “healthy natural diet” of whole foods, fresh fruits and vegetables, vitamins and detoxification practices to flush toxins from the body can help the body heal naturally — show no evidence of efficacy. They can, however, cause life-threatening complications while deterring people from seeking medical care that can help them.

National Center for Complementary and Alternative Medicine (NCCAM) actually put Gonzales’ pancreatic proteolytic enzyme treatment to the test in a clinical trial begun in November, 1999 at the Herbert Irving Comprehensive Cancer Center at Columbia University in New York. Because most patients refused randomization, the trial was changed in 2001 to a controlled, observational study with participants allowed to volunteer for the regimen. The results were just published in the Journal of Clinical Oncology and reported that those on the Gonzales enzyme regimen did considerably worse than those receiving chemotherapy, living one-third as long and with poorer quality of life. Even more troubling, the patients did worse than average patients with pancreatic cancer in the SEER Database. Regardless of the weaknesses in this study, the bottom line is that the dietary interventions were unable to demonstrate any benefits.

There have been a string of null studies recently published that disprove (again) many popular beliefs about healthful eating in tune with one’s body’s natural healing and that prevents degenerative diseases of aging. Since the media has largely ignored them, upcoming posts will take a look.