7 August 2006
The Skinny On The New Obesity Vaccine
by Serena Mackesy
One of the galling things about the obesity epidemic is the fact that so many people seem to feel empowered to make comparative moral judgments about their own superiority to others. If you've ever been a bit overweight (and, yes, I have personal knowledge of the state), you'll know exactly what I'm talking about. People so stupid you'd rather chew your own arm off rather than have to be privy to their views on spirituality, people so selfish they'd let the whole of Bangladesh drown rather than turn their air-conditioner down a couple of notches, people so vain they wax their eyebrows, for heaven's sake; who sit there secure in the knowledge that their possession of a bony tush will get them into heaven. Fat people are slackers, after all. Fat people are greedy. I know it's hard, but if they'd only try a bit; perhaps if they would exercise a little self-control...
Well, yes, okay. We all know - it's been rammed down our throats (along with all those fast-food commercials) enough - that the growing weight of the average citizen is a big, big problem. We all know that obesity carries all sort of major health penalties, aside from the depression brought on by being patronized by some walking osteoporosis farm with a face like a sucked lemon. And, yeah, I'll happily put a hand in the air and admit that I got my Neolithic-Goddess physique partly from my Mum and partly from eating more than I exercise. But then again, I'm a writer, and what writers do is sit staring day-in day-out at a computer screen, interspersed with bouts of spectacular Hemingway-style drunkenness.
But come on, Skeletor: the issue is a lot more complicated than simple moral turpitude. If it weren't, then you'd see the same levels of obesity in the rich as you do in the poor; the developed world wouldn't be seeing soaring rates of depression along with their ever-expanding backsides; and Kentucky Fried Chicken wouldn't spend tens-of-millions a year on getting some of the world's best psychological brains to persuade us that a bucket of special recipe will fill the yawning gaps in our lives.
So I had to fight a powerful urge, this week, to punch the air and shout "yesssss!" followed by a trip down to the street to find the nearest thin person and go "Nyyaaaaah!" when the Scripps Research Institute in California announced it had just carried out the first successful trials of an immunopharmacotherapeutic (spell that, Paris Hilton!) vaccine against obesity. That's right, a vaccine against obesity. An injection which physically blocks the laying-down of fat, which might just suggest that the source of the problem is, in fact, at least partly physiological, rather than moral.
The substance involved is called ghrelin. And of course they've only tested it on rats so far (the science world's need to rush into publication does tend to mean that we get our hopes up rather prematurely these days), but this is an astonishing, potential-filled breakthrough in our basic understanding of psychophysiology; and no doubt our email will be filling up with utllimatee phhrameccuttical spams any day now.
As opposed to immunology, which introduces foreign bodies into our systems to stimulate our immune response, immunopharmacotherapy is the art of harnessing antibodies in our own immune systems to direct the body's own immune response against specific targets. Interestingly, other areas under research in this field include nicotine and cocaine addiction. Ghrelin is a naturally-occurring hormone first identified in 1999, and which is known to help regulate energy balance in the body. It also, however, is the substance that is responsible for the retention of stored energy as fat. It is very useful, for instance, in dealing with the effects of famine: slowing down fat metabolism, encouraging eating and promoting fat retention. But the problem is that dieting effectively replicates the conditions of famine, stimulating the production of high levels of ghrelin in the body. And hence the grim cycle of yo-yo feast and famine so familiar to many of us who struggle with our weight. It's not just simple greed that makes you think about food all the time when you're depriving yourself of it. It's your hormones. Your body is protecting itself against the very thing you're trying to do to it, i.e. make it lose weight; and in a world where food supply is not a problem and opportunity and encouragement to fall off the wagon is everywhere, it has become a self-sabotaging mechanism for millions of us.
But here's the thing: ghrelin only does this when it's stored in your central nervous system. Bombing about in your blood, it just regulates your energy levels and makes it easier to get through the day. The trick the Scripps team came up with was to find a way to block the uptake of ghrelin into the brain. When they achieved this in the rats, the results were unarguable: while their intake of food remained unchanged, both weight gain and stored fat were significantly decreased. While the control rats continued to pork-up, the ghrelin rats started fishing in the backs of their wardrobes for the little-bitty rat bikinis they never thought they'd wear again.
So: hooray. No doubt, as happens whenever someone comes up with, say, a breakthrough in the treatment of lung cancer, there will be vested-interest spokespeople coming out of the woodwork spouting about how we "shouldn't see this as a license", but the fact remains: as human beings we are big bags of chemicals and, free will aside, it's the chemicals that drive us. Of course this isn't a free ticket to give up exercise and loll about eating tortilla chips in front of the soaps. Being fat is only one of the side-effects of a sedentary lifestyle and we should all be taking what steps we can to combat it. But anything that can help those of us who were not given the bodies and appetites of supermodels to stop beating-up on themselves every time they pass a plate-glass window has to be a good thing, doesn't it?