Are you healthy?
There's an interesting op-ed in New Scientist this week. A psychiatrist and a political scientist make the point that "health" is a loaded term; while in principle we all want to be healthy, it's a word that has been co-opted by those with agendas to push:
Health now means more than the absence of disease or presence of a positive state of bodily flourishing. In 2010, health also describes an ideological and commercial tool, used to make moral judgements, convey prejudice, sell products, or even to exclude groups of people from healthcare.It's an interesting point — "health" is so self-evidently something that we all care about that if you have an agenda (be it making money by pushing pills, or getting funding for a stadium for your favourite sports team) you can sanctify it simply by pitching it as being all about promoting good health.
It's not hugely controversial to propose that unscrupulous individuals use push-button marketing to make their profit-making schemes seem saintly; there's a lot of greenwashing going on these days, and a lot of money in alternative medicine. But is it possible that imbuing the concept of health with moral value is actively damaging?
In case you've just returned from a decade down a mine shaft, we currently appear to be in the middle of a global epidemic of obesity. It's hard to open a newspaper without reading about frantic attempts to deal with the problem, or to convince people that the problem exists. And we're surrounded by exhortations to eat less and exercise more, couched in the language of sin: gluttony and sloth are the only options on the menu.
According to Nature news (the RSS news feed of the journal Nature), animals in human care are also fatter today than they were 20 years ago. It's not just people who are packing on the pounds: our pets are also gaining weight. And before you write it off as fat folks feeding Fido far too much, the effect extends to all animals living in proximity to humans, including feral rodents and laboratory animals.
It's easy to see kids crashing out on the sofa and eating too many burgers as receiving their just deserts for not living a virtuous, abstemious, physically gruelling lifestyle — but it may be deeply misguided and an example of our expectations of health being infected by misplaced moralizing. The "gluttony and sloth" model for the obesity epidemic can explain pets being over-fed by their overweight owners, but the further away from the sinners we get, the more tatty the picture: urban rats? Laboratory primates? (Lab animals are not generally over-indulged by their owners.)
There are alternate models for the obesity epidemic. Environmental contamination by endocrine disrupting chemicals might be one direction to look in. Another might be the AD36 adenovirus:
Nikhil Dhurandhar, an obesity researcher at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, has shown that a human adenovirus called AD36 raises body-fat levels in animal models such as chickens and rodents. What's more, he found that obese humans were three times more likely to be infected with the virus than non-obese people -- and heavier individuals in both groups tended to be infected. Dhurandhar reported these findings in a 2005 paper.The link between AD36 and obesity is suggestive but not yet conclusive, and there are criticisms of the research; it treads on dangerous ground. In particular, many large corporations would love to see the obesity epidemic pinned on something other than their own sub-standard food products (just as coal mines would like to blame climate change on solar output fluctuations).
But the news currently paints a very interesting picture — and one that backs up that New Scientist op-ed about the ideological rhetoric surrounding our definition of health. If AD36 is responsible for the obesity epidemic, then we're not going to cure ourselves through exercise and crash diets: we're going to need vaccine research and epidemiologists instead. But as long as we view obesity as a symptom of moral failure rather than a disease, we're not going to get research into effective treatments.
There is an urgent need for more research. Someone needs to start routinely sampling lab animals, pets, and feral rodents for AD36, and establish whether there is indeed a correlation between AD36 levels and the prevalence of obesity. A next step would be to isolate AD36, infect seronegative lab animals, and see if it induces obesity. If such a link is confirmed, we then need research to establish the underlying mechanism — in fact, it would be the start of the job, not the end.
Edit: Let me clarify: some of the work has already been done. In case you're wondering how an Adenovirus could make us fat, here's the abstract of a paper on that topic (Stem Cells. 2008 Apr;26(4):969-78. Epub 2008 Jan 17):
Abstract: Human adenovirus Ad-36 is causatively and correlatively linked with animal and human obesity, respectively. Ad-36 enhances differentiation of rodent preadipocytes, but its effect on adipogenesis in humans is unknown. To indirectly assess the role of Ad-36-induced adipogenesis in human obesity, the effect of the virus on commitment, differentiation, and lipid accumulation was investigated in vitro in primary human adipose-derived stem/stromal cells (hASC). Ad-36 infected hASC in a time- and dose-dependent manner. Even in the presence of osteogenic media, Ad-36-infected hASC showed significantly greater lipid accumulation, suggestive of their commitment to the adipocyte lineage. Even in the absence of adipogenic inducers, Ad-36 significantly increased hASC differentiation, as indicated by a time-dependent expression of genes within the adipogenic cascade-CCAAT/Enhancer binding protein-beta, peroxisome proliferator-activated receptor-gamma, and fatty acid-binding protein-and consequentially increased lipid accumulation in a time- and viral dose-dependent manner. Induction of hASC to the adipocyte state by Ad-36 was further supported by increased expression of lipoprotein lipase and the accumulation of its extracellular fraction. hASC from subjects harboring Ad-36 DNA in their adipose tissue due to natural infection had significantly greater ability to differentiate compared with Ad-36 DNA-negative counterparts, which offers a proof of concept. Thus, Ad-36 has the potential to induce adipogenesis in hASC, which may contribute to adiposity induced by the virus.
Let's not forget that the AD36 epidemic hypothesis could fall at any of these hurdles. AD36 might just be a random interloper, a suspect fingered by a statistical fluke (a false positive, in other words), and promoted by researches on the payroll of the junk food industry. However, it would be unpleasantly ironic if it turns out that our culture's moralizing fixation on the association between obesity and sinfullness — painting it as the just the reward of sloth and gluttony, and only legitimately to be avoided by drudgery and self-denial — has allowed a dangerous viral pandemic to rage undetected for decades.
But it wouldn't be the first time that moral prejudices based in traditionalist religious views have encouraged the spread of a lethal infectious agent.
 I'm not taking aim at herbalism here — many of our most effective pharmaceuticals are based on drugs of botanic origin, and not all herbal remedies that are shown to work have been commercialised as allopathic pharmaceuticals. However, I have a problem with homeopathy or biofield therapy; both of these are based on models that just plain don't work — they don't match what we know of biology and chemistry these days (although their internal models were still plausible in the 19th century).
 I'm overweight, and not terribly happy about it. I know when it happened, too: in October 1990 to March 1991 my body weight shot up by about 15%, and I've been unable to shed it since. My weight is annoyingly stable (regardless of dietary changes and exercise), and I'd love to pin the blame on a virus; that'd open up new possibilities for fixing it.
 Let's not underestimate the lethality of the obesity epidemic. Obese people are more likely to suffer from diabetes, cardiovascular disease, and joint damage. These are all contributors to premature morbidity and mortality. In fact, the total years of life lost to premature mortality among 2-3 billion victims of an obesity virus would be similar to the years of life lost due to diseases such as AIDS or malaria (which are significantly more immediately lethal, but infect a smaller pool).