Alimentação ruim produz comportamentos nocivos e diversas inflamações
Bad Eating Habits Produce Inflammation and Changes in Behavior
Saturday, October 11, 2008 by: Maryann Marshall (see all articles by this author)
The hypothalamus is a cone shaped gland, about the size of an almond, attached to the pituitary gland and lying near the brain stem. It is the mechanism which helps the body maintain homeostasis – the tendency toward a stable, constant state of equilibrium. The hypothalamus regulates body temperature, hunger, thirst, fatigue, anger, sexual desire, blood pressure, water balance, and circadian cycles. The nervous system and endocrine system communicate through the hypothalamus.
A protein called IKKbeta/NK-kappaB is normally present in the hypothalamus in large quantities. However, it is not generally released into body tissues. This substance is used by macrophages and leukocytes, triggering inflammation throughout the body. It is as if the immune system tries to attack and destroy an invader which is not there. Researchers speculate it may have been an important element in a the body’s first line of defense against pathogenic invaders at some time in the distant past.
In the present day, it is activated by a different mechanism. A high fat diet releases IKKbeta/NK-kappaB from the hypothalamus. When they fed mice a high-fat diet, activity in the pathway which releases this protein doubled. It increased even more in mice genetically prone to obesity. Release of this protein results in resistance to insulin and leptin. Resistance to these hormones hold a key to the development of diabetes and heart disease. These researchers feel they have discovered a "master switch" for the diseases caused by overeating. Inflammation and obesity are intertwined.
Insulin is the hormone produced by the pancreas which stimulates the cells to take up glucose and stops use of fat as an energy source.
Leptin plays a key role in regulation of appetite, metabolism, and reproductive function. It is a hormone that normally helps regulate appetite, and insulin, and helps convert food into energy. Produced by fat cells, it signals the body to shut off the appetite and encourages physical activity to burn off energy. Leptin also regulates insulin. At night, when the body is at rest, leptin is decreased by the presence of melatonin.
Oddly, in obese people, large quantities of leptin are found circulating in the blood. It is now thought that IKKbeta/NK-kappaB produces leptin resistance. In the study, when the protein was active, the mouse’s body ignored signals from leptin. Stimulating its release made the mice eat more, while suppressing it made them eat less.
"Knocking out" the gene controlling this pathway through genetic engineering kept mice eating normally and prevented obesity, even though a high fat diet was available to them. Such genetic engineering cannot be done in people.
The ultimate goal: to identify a selective and effective suppressor of the pathway to target related neurons. The researchers believe a drug, or even gene therapy, might work.
With gene therapy, a virus or other so-called vector is used to carry corrective DNA into the body, but the approach is still highly experimental.
Other scientists are leery of these conclusions. The complexity of the controls governing human metabolism, appetite and the laying down of fat has become clear over recent years. If some drugs target this pathway, they may well interfere with some other part of the immune system.
Not all fats are guilty of stimulating the pathway described above. It is suspected that the mice studied were fed a diet similar to the Standard American Diet (SAD). This diet is typically high in saturated fats and simple carbohydrates.
Another study out of UC Irvine, reported in the October 8 issue of Cell Metabolism, demonstrated a different mechanism affecting hunger. An unsaturated fat, oleic acid – found in olive oil, avocados and nuts – triggers a compound, called oleoylethanolamide (OEA), in the small intestine which curbs hunger pangs. Oleic acid, transforms into OEA by the action of cells in the upper region of the small intestine. After several minutes, OEA activates nerve endings which carry a hunger-curbing message to the brain. The signals activate a brain circuit (in the hypothalamus) that increases feelings of fullness. The process can take up to twenty minutes. Previous studies found that increasing OEA levels can reduce appetite, produce weight loss and lower blood cholesterol and triglyceride levels.
Your choice of foods, beyond fat content, can affect the inflammation level in your body. Regular consumption of anti inflammatory foods may lead to reduction of inflammation on your body. Following is a list of foods which have been found to have anti inflammatory action:
Green Onions/Spring Onions
Acerola (West Indian) Cherries
Herbs and Spices
Cayenne Peppers/Chilli Peppers
Cocoa (at least 70% cocoa chocolate)
Nuts and Seeds
Extra Virgin Olive Oil
Did you ever notice the way people approach buffet food bars? A study, reported in the June issue of the journal Obesity, analyzed the habits of people at all-you-can-eat Chinese restaurants.
Trained observers recorded the height, weight, sex, age, and behavior of 213 patrons at 11 restaurants. Various seating, serving, and eating behaviors were then compared across BMI levels. Dramatic differences were observed depending on the person’s body mass index (BMI).
Obese people found ways to make the food more convenient to eat. Thus they tended to eat in excess. Rather than surveying the food bar to decide what they want, they were more than three times as likely to seize a plate and start filling it. They used larger plates. They chose seats an average of 16 feet closer to the food bar. Facing the food bar was a preferred position.
Those with lower BMI were twice as likely to sit in a booth, rather than at a table. They put a napkin in their lap and chose to eat with chopsticks rather than a fork more frequently. Each bite was chewed longer by normal weight people compared to those who had higher BMI.
Appetite is a very complex subject. However, we do know that poor food choices and attitudes and habits surrounding food both contribute to and perpetuate overeating and its resulting chronic illnesses.
Cell Press (2008, October 3). Brain Pathway Responsible For Obesity Found: Too Many Calories Send Brain Off Kilter. ScienceDaily. Retrieved October 6, 2008, from http://www.sciencedaily.com/releases/20…
University of California – Irvine (2008, October 7). How Fatty Foods Curb Hunger. ScienceDaily. Retrieved October 8, 2008, from
About the author
Six years ago, her eldest son suffered a severe brain injury in an auto accident. His journey to wellness continues today. The family struggles through the government and medical labyrinth to assist his healing through prayer, nutrition, herbs, and other natural methods. Maryann is currently writing a book about the accident and its aftermath. You can read it in progress at: http://MiracleBoyArif.blogspot.com/ .
Her websites can be found at: http://www.agglom.com/agglom/36788/Mary….