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Michael: Why do we like talking to people? Of course not everybody does, but most of us enjoy interacting with other human beings, at least occasionally. It just.. feels good. But why? why does it feel good?

Well, according to research published this week, it's because of a compound that's released in a part of your brain that controls motivation and reward, and responds to social interaction. Biologists often call this compound the 'bliss molecule,' but it's actually a lot like... Pot.

It all begins with a hormone and neurotransmitter that we've told you about before... oxytocin. It's been found to promote trust, relaxation, psychological stability, and romantic attachment, as well as hope women give birth. It even plays a role in the bond you feel between you and your dog. But it's most famous for it's role in making you care about other people.

High oxytocin levels are most often observed in women during breastfeeding, between couples in the first 6 months of their relationship, as well as during and after sex. Previous studies have shown that people given extra doses of oxytocin are better at detecting emotional cues in facial expressions. They also express greater concern for and sexual attraction to their partners, and show fewer signs of attraction to anybody else. 

How oxytocin does all this stuff however, was something of a mystery. But we now know that a key player is anandamide. Anandamide is an endocannabinoid. That means it activates the cannabinoid receptors in the brain. And if you think that sounds a lot like cannabis, there's a reason for that.

The active ingredient in marijuana is tetrahydrocannabinol, which attaches to the same receptors in your brain, and socially it has pretty similar effects. It makes you feel less hostile, and also makes you really want to talk to people like, about anything. Maybe about that cool dream you had, or about how clouds are like, totally incredible.

An international group of neuroscientists found that social contact made the brains of mice produce more anandamide. Meaning, being around other mice was rewarding them by making them feel calm and fulfilled, as well as making them want to be around other mice even more.

They did this by isolating the mice first for 24 hours. Then half the mice were reunited with all of their mouse friends, and the other half stayed in isolation. The mouse brains were then removed, and flash-frozen so they could be tested for anandamide. They also looked at mice that were missing a gene that codes for the enzyme that breaks down anandamide. 

When given a choice between two kinds of bedding, the mice tended to prefer the type they had with other mice even though they'd spent the same amount of time with the other type in a cage by themselves. Mice who had the usual set of genes and therefore could break down anandamide didn't choose the social bedding as often.

So oxytocin triggers the production of anandamide, which stimulates the cannabinoid receptors, which makes you feel all chill and good about being around other people. Researchers hope this can be used to treat certain kinds of social anxiety or even the social effects of some autism disorders.

So that's what makes you happy, here's something that'll probably make you sad. We're all tired of hearing how bad it is to eat sugar. I mean, it's delicious and if you cut back on calories elsewhere, you can afford to have that candy bar, right? I mean calories are calories. Turns out no, they're not.

In a paper published this week in the journal Obesity, researchers at UC San Francisco showed that sugar isn't necessarily bad for you because it has so many calories, it's just bad for you because it's sugar.

They studied 43 young people between the ages of 9 and 18, all of whom were medically obese and suffering from some kind of metabolic disorder like hypertension or high triglyceride levels, which are a sign of fatty liver. For nine days, the subjects were given food with the same number of calories that they were used to eating, but with almost no sugar. They were not feeding the kids healthy food; this was starchy, fatty food like pizza and potato chips.

The goal was not to make them lose weight, in fact if the subjects started losing weight, the researchers fed them more, because their goal was to keep their weight stable to see how their bodies responded to no longer needing to metabolize sugar. An in just 9 days - again, eating the same number of calories as they always ate, and staying at the same weight the subjects' health improved across the board.

Their blood pressure decreased, their cholesterol levels went down, their blood sugar and insulin levels dropped dramatically and their liver function got better. Because, it turns out, your body doesn't metabolize all calories in the same way. Sugar turns to fat in your liver where too much of that fat can lead to inflammation and scarring. So I know you've heard it a thousand times, but maybe stay away from the candy bars.

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