Scientists Say Common Virus Could Cause Obesity

[Islander]

no author
21 Aug 2007

Scientists at the 234th national meeting of the American Chemical Society in Boston, Massachusetts this week presented the results of a study that suggests a common virus could be partly responsible for the obesity (http://www.medicalnewstoday.com/info/obesity/how-much-should-i-weigh.php) epidemic that is sweeping across America and other nations. They hope their findings will develop antiviral medication to treat "viral obesity".

According to the National Institutes of Health (NIH), some 97 million adult Americans are obese. Obesity increases risk of many illnesses, including type 2 diabetes (http://www.medicalnewstoday.com/info/diabetes/), heart disease, stroke (http://www.medicalnewstoday.com/articles/7624.php), and osteoarthritis.

So far scientists have shown that genetic predisposition increases risk of obesity, as do other contributory factors including over-eating, eating foods high in fat, lack of physical exercise, genetics, and some medications.

In this latest study, researchers used lab experiments to show that infection with a common virus that causes respiratory and eye infections in humans, called human adenovirus-36 (Ad-36) turns adult stem cells (http://www.medicalnewstoday.com/info/stem_cell/) retrieved from fat tissue into fat cells. But stem cells that were not exposed to Ad-36 did not turn into fat cells.

Read more: http://www.medicalnewstoday.com/articles/80205.php

[Islander]

A Google search on "VIRUS-INDUCED OBESITY" will turn up a collection of further information. Additionally, one of the members of mercola.com, Kolibakoliba, today posted this:

"Many attempts have been made to explain this epidemic of obesity, and some creative explanations have been advanced. Clearly, simple behavioral changes in diet and lifestyle are not entirely sufficient to explain the epidemic. One potential explanation of the “epidemic” is that truly it is an epidemic due to infectious causes, specifically VIRUS-INDUCED OBESITY, at least in part. Indeed, the 5 animal viruses and 3 human viruses that have been shown to cause obesity .

The obesogenic animal viruses include canine distemper virus, Rous-associated virus type 7, Borna disease virus, scrapie agent, and SMAM-1. The first 4 viruses attack the central nervous system to produce obesity. SMAM-1, an avian adenovirus from India, acts directly on adipocytes and is the only animal virus that is associated with human obesity. The 3 human adenoviruses, adenovirus (Ad) 36, Ad-37, and Ad-5, that are associated with obesity also affect adipocytes directly.

These viruses stimulate enzymes and transcription factors that cause accumulation of triglycerides and differentiation of preadipocytes into mature adipocytes. Ad-5 and Ad-37 have been shown to cause obesity in animals. Ad-36 has been studied the most and is the only human adenovirus to date that has been linked with human obesity. Ad-36 causes obesity in chickens, mice, rats, and monkeys and was present in 30% of obese humans and 11% of nonobese humans. In twins discordant for infection with Ad-36, the infected twins were heavier and fatter than their co-twins.

The growing body of evidence demonstrating that viruses produce human obesity supports the concept that at least some of the worldwide epidemic of obesity in the past 25 years is due to viral infections. In my opinion dysproportional intake of macronutrients and and micronutrient malnutriton may lead to inadequate (insufficient) immune responses to obesogenic viruses and subsequently to increased susceptibiliy to other obesogenic factors."

http://tinyurl.com/3g7q9n7

[mellowsong]

I've been reading about this...it's fascinating!

[Reesacat]

Although the XMRV virus theory of CFIDS/ME is now being thought to be due to a laboratory contaminate rather than actual infection, many of us had a viral type illness onset and 40 lb weight gain.

[Islander]

More from Koliba: "@Islander, thank you for your interest. I´d like to add, that not only virues but also some intracellular bacteria, (e.g. chlamydia) have been reported possibly to promote obesity.

For example, several studies showed that C. pneumoniae IgG, but not IgA, antibody positivity was associated with a higher BMI, which implies that past and/or current C. pneumoniae infection would be associated with changes in BMI. Recent finding that elevated serum chlamydial lipopolyscharide (cLPS) levels were associated with an elevated BMI strengthens the link between chlamydial infection and obesity. A lack of association between total LPS and BMI suggests that the association between infection and an elevated BMI may be specific to certain pathogens, and not to, for example, Gram-negative bacteria in general.

C. pneumoniae is capable of infecting and surviving in monocytes/macrophages, and along with them it may have ‘access’ to adipose tissue, where it may further infect adipocytes. Recently, persistent C. pneumoniae infection, but not Aggregatibacter actinomycecomitans infection, has also be shown to induce liver steatosis (one of the components of metabolic syndrome) in ApoE-deficient mice. Thus, C. pneumoniae infection in adipose tissue could promote production of inflamma- tory molecules from both macrophages and adipocytes, and even accumulation of fat inside both cell types.

Chlamydial infection might also generally promote inflammation and increase the levels of serum inflammatory markers. Increased levels of inflammatory markers again may contribute to development of obesity and inflammation-related conditions such as decreased insulin sensitivity, type 2 diabetes, metabolic syndrome, cardiovascular disease and cancer. Since it is well known that chlamydial chlamydial species have a tendency to cause persistent infection,impaired immune response might predispose not only to acute infections but also to persistence of infection."

I think it's worth checking certain mercola.com articles several times a day just to see the comments from KolibaKoliba and Sayer Ji.

(http://tinyurl.com/3g7q9n7)http://tinyurl.com/3g7q9n7

[Reesacat]

Fascinating.