Zooming HEALTH
OUR BODIES CARRY TRILLIONS of microorganisms. Many live in our gastrointestinal tracts, where they break down nutrients or produce useful compounds like vitamins. But you’d never expect the tiny bugs in your belly to shape your mood, would you? That’s what the latest science is suggesting.
In experiments at McMaster University’s Farncombe Family Digestive Health Research Institute, anxious mice became more confident after a transplant of gut microbes from bolder mice. And vice versa. “It suggests that our resident bacteria have the ability to alter the brain chemistry and the function of the brain,” says Dr. Stephen Collins, a gastroenterologist involved in the work, which is supported by the Canadian Institutes for Health Research. Collins’ team has also changed anxiety levels of mice by giving them selected probiotics.
IT SEEMS FAT PEOPLE really are jolly. British researchers followed almost 2,000 overweight and obese people in their 50s and older. They discovered that, over a span of four years, the group (14 per cent) who lost weight ended up a lot less happy than their pudgier peers – even though their hearts were healthier. Unexpected? The researchers suggest the dieters could have become disappointed when their life wasn’t magically transformed with the weight loss, and that day-to-day problems didn’t disappear as the pounds came off. Plus, certain aspects of dieting, like avoiding temptation and even skipping social outings that revolve around food, can be frustrating.
The take-home message isn’t to stay heavy, but rather to be realistic – and stay positive. “I suspect that the more people believe they’re will--
At the University of California, scans of humans have proven that when different bacteria species become dominant in the gut, there are changes in brain regions controlling emotion and sensation. Bacteria may be producing substances that travel to the brain and affect its function – like tryptophan, which is used by the brain to make the mood stabilizer serotonin. The vagus nerve seems to be a potential pathway, and even our immune system may be involved. “There are multiple mechanisms,” says Collins.
The million-dollar question: can we alter our mental function by manipulating our microbes? Can better bacteria make us happier? Collins is now investigating people with irritable bowel syndrome who also have anxiety or depression. The conditions often go hand-in-hand, and he wants to find out if the selected probiotic bacteria that perked up the mice will improve the moods of this group.
It’s unlikely we can blame gut bacteria as the source of all psychiatric problems. But they may play a role, says Collins, and this research may help us develop new approaches to treatment. “It opens a number of possibilities.” fully depriving themselves of something they want, whether it’s food, television or affection, the more bitter they become,” says Brian Wansink, a professor at the Dyson School of Applied Economics and Management at Cornell University in Ithaca, New York. Wansink co-led an experiment that showed people who were primed to think negatively ended up reaching for more indulgent foods to console themselves. The reverse was also proven: people who think happy thoughts are more likely to make healthy food choices, and eat less.
This is a mind-over-matter technique that anyone can do, says Wansink. “Simply ask yourself just one or two things you’re really thankful for. As grumpy as we feel, there are always positive things that have happened,” he says.
“There are a lot of little tricks you can use,” adds Wansink, whose book, Slim by Design: Mindless Eating Solutions for Everyday Life, recently hit the shelves. But if you want to stay on a real high as your weight dips low, try a dose of gratitude right before meals. “That’s an easy intervention.”