EAST LANSING, Mich. (UPI)
Obesity and immunity may be linked through hormone activity, two studies by researchers at Michigan State University. The studies, both published in the Proceedings of the National Academy of Sciences, examined the link between the neuroendocrine system and white blood cell function. "These two studies, while not directly related, show that the neuroendocrine system plays a big role in both the immune system and obesity," lead scientist for both studies Pamela Fraker said in a statement. The first study discovered leptin -- a hormone produced by fat cells that control how much food is eaten and how quickly energy is burned -- also supports white blood cell production, which in turn enhances immune function. "This is a brand new role for leptin," Fraker said. "It appears that most obese people may be somewhat immunosuppressed. This finding shows us that the body's resistance to leptin plays a role in that, too." The second study found corticosteroids produced naturally in the body do not suppress the immune system in the way prescription steroids -- such as inflammation-reducing prednisone -- do. "With the pharmacological versions of steroids, you lose some immune function," Fraker said. Copyright 2008 by United Press International
The Nutrition Transition and Obesity
Obesity in the developing world can be seen as a result of a series of changes in diet, physical activity, health and nutrition, collectively known as the 'nutrition transition.' As poor countries become more prosperous, they acquire some of the benefits along with some of the problems of industrialized nations. These include obesity.
Since urban areas are much further along in the transition than rural ones, they experience higher rates of obesity. Cities offer a greater range of food choices, generally at lower prices. Urban work often demands less physical exertion than rural work. And as more and more women work away from home, they may be too busy to shop for, prepare and cook healthy meals at home. The fact that more people are moving to the city compounds the problem. In 1900, just 10 percent of the world population inhabited cities. Today, that figure is nearly 50 percent.
That is not to say that rural areas are immune. Increased mechanization of farm activity leads to reduced physical activity at the same time that more food -- but not necessarily a better variety of foods -- becomes available. Many rural farmers have given up subsistence farming of multiple crops that provide a more balanced diet in favour of a single, high-yielding cash crop.
Importing poor eating habitsAnother element of the nutrition transition is the increasing importation of foods from the industrialized world. As a result, traditional diets featuring grains and vegetables are giving way to meals high in fat and sugar.
Some critics blame industrialized countries for producing leaner cuts of meat for their own citizens but selling the high-fat remainders elsewhere. Turkey tails and mutton flaps (cuts of skin, fat and little meat) are sold to the developing world, for instance, despite the fact that 80 percent of the energy in these items come from fat.
Cities--with their greater choice of food and less active lifestyle--are increasingly home to obesity. A woman shops in a market in Turkey. (FAO/22457/R. Messori)
And as food companies watch incomes rise in the developing world, they are setting their sights on new markets. From Mexico to Morocco, the same foods that jeopardize health in wealthy countries are now tempting poor ones.
Other dietary changes are taking place regardless of outside influences. In China, when per capita income grew fourfold after the economic reforms of the late 1970s, the consumption of high-fat foods soared. And while incomes grew, the income needed to purchase a fatty diet decreased. In 1962, a diet containing 20 percent of total energy from fat correlated with a per capita GNP of US$1 475. By 1990, a GNP of just $750 correlated with the same diet.
In a number of countries, globalization has changed the face of obesity. In Mexico and Brazil, for example, where overweight used to be a sign of wealth, it now often marks poverty. The increased availability of foods at lower prices mean the poor have access to a richer diet. While the elite can choose to adopt a healthy lifestyle, the poor have fewer food choices and more limited access to nutrition education.
The cost of a poor dietThe underweight and overweight share high levels of sickness and disability, shortened life spans and reduced productivity. Obesity increases the risk of chronic diseases such as diabetes, hypertension, heart disease, stroke, gall bladder disease and a number of cancers.
And the developing world risks suffering the lion's share of the growing disease burden. For instance, the number of people with obesity-related diabetes is expected to double to 300 million between 1998 and 2025 -- with three-quarters of that growth projected in the developing world.
For nations whose economic and social resources are already stretched to the limit, the result could be disastrous.
To read about FAO's viewpoint on obesity, click here.
FAO links:
FAO's Food and Nutrition Division FactFile: Majority of people to live in cities by 2005 Focus Archive
External links:
World Health Organization: Controlling the global obesity epidemic University of North Carolina (UNC): What is the nutrition transition? UNC: Nutrition transition and its health implications in the developing world
Obesity in the developing world can be seen as a result of a series of changes in diet, physical activity, health and nutrition, collectively known as the 'nutrition transition.' As poor countries become more prosperous, they acquire some of the benefits along with some of the problems of industrialized nations. These include obesity.
Since urban areas are much further along in the transition than rural ones, they experience higher rates of obesity. Cities offer a greater range of food choices, generally at lower prices. Urban work often demands less physical exertion than rural work. And as more and more women work away from home, they may be too busy to shop for, prepare and cook healthy meals at home. The fact that more people are moving to the city compounds the problem. In 1900, just 10 percent of the world population inhabited cities. Today, that figure is nearly 50 percent.
That is not to say that rural areas are immune. Increased mechanization of farm activity leads to reduced physical activity at the same time that more food -- but not necessarily a better variety of foods -- becomes available. Many rural farmers have given up subsistence farming of multiple crops that provide a more balanced diet in favour of a single, high-yielding cash crop.
Importing poor eating habitsAnother element of the nutrition transition is the increasing importation of foods from the industrialized world. As a result, traditional diets featuring grains and vegetables are giving way to meals high in fat and sugar.
Some critics blame industrialized countries for producing leaner cuts of meat for their own citizens but selling the high-fat remainders elsewhere. Turkey tails and mutton flaps (cuts of skin, fat and little meat) are sold to the developing world, for instance, despite the fact that 80 percent of the energy in these items come from fat.
Cities--with their greater choice of food and less active lifestyle--are increasingly home to obesity. A woman shops in a market in Turkey. (FAO/22457/R. Messori)
And as food companies watch incomes rise in the developing world, they are setting their sights on new markets. From Mexico to Morocco, the same foods that jeopardize health in wealthy countries are now tempting poor ones.
Other dietary changes are taking place regardless of outside influences. In China, when per capita income grew fourfold after the economic reforms of the late 1970s, the consumption of high-fat foods soared. And while incomes grew, the income needed to purchase a fatty diet decreased. In 1962, a diet containing 20 percent of total energy from fat correlated with a per capita GNP of US$1 475. By 1990, a GNP of just $750 correlated with the same diet.
In a number of countries, globalization has changed the face of obesity. In Mexico and Brazil, for example, where overweight used to be a sign of wealth, it now often marks poverty. The increased availability of foods at lower prices mean the poor have access to a richer diet. While the elite can choose to adopt a healthy lifestyle, the poor have fewer food choices and more limited access to nutrition education.
The cost of a poor dietThe underweight and overweight share high levels of sickness and disability, shortened life spans and reduced productivity. Obesity increases the risk of chronic diseases such as diabetes, hypertension, heart disease, stroke, gall bladder disease and a number of cancers.
And the developing world risks suffering the lion's share of the growing disease burden. For instance, the number of people with obesity-related diabetes is expected to double to 300 million between 1998 and 2025 -- with three-quarters of that growth projected in the developing world.
For nations whose economic and social resources are already stretched to the limit, the result could be disastrous.
To read about FAO's viewpoint on obesity, click here.
FAO links:
FAO's Food and Nutrition Division FactFile: Majority of people to live in cities by 2005 Focus Archive
External links:
World Health Organization: Controlling the global obesity epidemic University of North Carolina (UNC): What is the nutrition transition? UNC: Nutrition transition and its health implications in the developing world
No comments:
Post a Comment