Connect with us

Ecology

Two for One: How Our Brains Reward Us Twice for Every Meal

Editor

Published

on

[ad_1]

food reward dopamine

Feel the dopamine. (Credit: Syda Productions/Shutterstock)

Food. It’s probably on your mind quite a bit this holiday season, whether you’re anticipating festive meals or dreading the pounds you might pack on during a bout of epicurean overindulgence.

Though tips on managing our cravings for all things sweet and fatty abound, it’s also worth remembering that the odds are stacked against us when it comes to resisting the call of another slice of pie.

Our brains respond to food, and even the sight or thought of it, with a heady rush of chemicals aimed at convincing us to eat. It’s a relict of bygone days when a steady food supply was no guarantee and the best strategy was to stuff ourselves every chance we got. Our brains evolved to deliver a rush of neurotransmitters to both motivate us to and reward us for eating. Is it any wonder we still enjoy it so much?

Double Feature

And it turns out that we actually get not one but two chemical rewards for satiating ourselves. Using a new imaging technique, a team of researchers led by scientists at the Max Planck Institute for Metabolism Research in Germany have discovered that our brains release the neurotransmitter dopamine in response to a tasty snack both when the food hits our mouths and after it’s entered our stomachs — a real twofer.

With a modified version of a Positron Emission Tomography (PET) scan, the researchers were able to track the movement of dopamine through the brains of 12 participants who had just been given something to eat. Dopamine is part of the brain’s reward system, and it’s released both when we see or think about food and when we actually eat it. The researchers gave the participants either something tasty to eat (a milkshake, of course) or a bland control food (a “tasteless solution”) and watched to see when and where the neurotransmitter appeared.

Dopamine blossomed in the participant’s brains as soon as the milkshake hit their tastebuds, as expected. It was concentrated in areas involving reward-value signaling, memory and inhibitory control, among others — again, no surprise. But, 15 to 20 minutes after the milkshake had gone down the hatch, the researchers found another wave of dopamine in people’s brains. Even more odd, it was in totally different regions than the first rush. This time around, the dopamine appeared in regions related to higher cognitive functions, compared with the more primal areas stimulated in the initial release of the neurotransmitter.

Further analysis picked out another trend: If people had been craving the milkshake, the first rush of dopamine was quite strong, but the second was much smaller. If they hadn’t been craving the milkshake as much, the first release was small, but the second was larger. In short, the people who really wanted a milkshake got a bigger reward when it first hit their tongues. The less milkshake-happy saw a smaller reward at first, but they got a more substantial dopamine hit later on.

The work was published Thursday in Cell Metabolism.

From Tongue to Stomach

It’s a bit of an oversimplification, but the double whammy reflects the fact that our mouths and our stomachs like food for two different reasons. Our mouths like food because it tastes good, and our stomachs like it because it’s full of nutrients. So when we taste something good, our brains reward us with dopamine. And, when our stomachs get the stuff they need to fuel our bodies, they also send signals to the brain telling it to release a chemical “thank you.”

The researchers think that the people who craved milkshakes got more dopamine upfront because their payoff was bigger, and then less later on in an attempt to curb overeating. Those who got a bigger hit later on were seeing their bodies respond to the nutritional value of the food: Their stomachs were simply telling their brains “This is good! Let’s get more!” by rewarding the behavior. It’s proof that our bodies do reward us for eating food that’s good for us, not just stuff that tastes good.

Though the response has been observed in mice, this is the first time it’s even been found in humans. The discovery has implications for how we treat obesity, the researchers say, as it seems that the more we crave food, the less we get rewarded for it later on when our stomachs are counting nutrients. By choosing meals that favor in-the-moment gratification — things with high sugar and fat content — over long-term satisfaction, we’re also forgoing that second dopamine hit, the one actually related to nutritional content. The result could be choices that are less healthy.

If anything, it’s also a reminder that less immediately-satisfying foods do have their own reward. We just have to wait a little to get it.

[ad_2]

Source link

قالب وردپرس

Ecology

Today’s letters: ‘Visionary’ plans don’t always work in Ottawa

Editor

Published

on

By

The opinion piece written by Tobi Nussbaum, CEO of the NCC, declares that a “bold, visionary transit plan” would showcase the capital.

As a long-term resident of Ottawa, I’ve had it with visionary plans. In the 1950s, the streetcars serving Ottawa so well were sent to the scrapyards. In the early ’60s, Queensway construction bulldozed established neighbourhoods and ripped the city apart. Later in the decade, the downtown railway station, which could have formed the hub of a commuter network, was relocated to the suburbs. These actions, in the name of “progress,” were undertaken with the “vision” to make Ottawa a car-reliant city.

Now we have an LRT, built just in time for most people to realize that they do not have to go downtown as they can work from home.

Current thinking is pushing a new “link” between Ottawa and Gatineau, with yet more expensive and disruptive infrastructure projects being touted, including a tramway or another tunnel under the downtown core.

Continue Reading

Ecology

That was then: Biggest earthquake since 1653 rocked Ottawa in 1925

Editor

Published

on

By

A regular weekly look-back at some offbeat or interesting stories that have appeared in the Ottawa Citizen over its 175-year history. Today: The big one hits.

The Ottawa Senators were playing a Saturday night game against the Montreal Canadiens at the Auditorium, the score tied 0-0 halfway through the second period. Sens’ rookie Ed Gorman and the Habs’ Billy Boucher had just served penalties for a dustup when the building began to make “ominous creaking sounds.” A window crashed to the ground.

Nearby, at Lisgar Collegiate, all eyes were on teenager Roxie Carrier, in the role of Donna Cyrilla in the musical comedy El Bandido. She had the stage to herself and was singing “Sometime” when the building rocked, the spotlight went out, and someone in the audience yelled “Fire!”

At a home on Carey Avenue, one woman’s normally relaxed cat suddenly arched its back, rushed around the room two or three times, spitting angrily, and climbed up the front-window curtains.

Continue Reading

Ecology

Ottawa delays small nuclear reactor plan as critics decry push for new reactors

Editor

Published

on

By

TORONTO — Canadians will have to wait a little while longer to see the federal government’s plan for the development of small nuclear reactors, seen by proponents as critical to the country’s fight against global warming.

Speaking at the opening of a two-day virtual international conference on Wednesday, the parliamentary secretary to the minister of natural resources said the plan will lay out key actions regarding the reactors. Its launch, Paul Lefebvre said, would come in the next few weeks.

“We’re still putting the finishing touches on it,” Lefebvre said. “The action plan is too important to be rushed.”

Small modular reactors — SMRs — are smaller in size and energy output than traditional nuclear power units, and more flexible in their deployment. While conventional reactors produce around 800 megawatts of power, SMRs can deliver up to 300 megawatts.

Proponents consider them ideal as both part of the regular electricity grid as well as for use in remote locations, including industrial sites and isolated northern communities. They could also play a role in the production of hydrogen and local heating.

“SMRs will allow us to take a bold step of meeting our goal of net-zero (emissions) by 2050 while creating good, middle class jobs and strengthening our competitive advantage,” said Lefebvre.

Natural Resources Minister Seamus O’Regan had been scheduled to speak at the conference but did not due to a family emergency.

Industry critics were quick to pounce on the government’s expected SMR announcement. They called on Ottawa to halt its plans to fund the experimental technology.

While nuclear power generation produces no greenhouse gas emissions, a major problem facing the industry is its growing mound of radioactive waste. This week, the government embarked on a round of consultations about what do with the dangerous material.

Dozens of groups, including the NDP, Bloc Quebecois, Green Party and some Indigenous organizations, oppose the plan for developing small modular reactors. They want the government to fight climate change by investing more in renewable energy and energy efficiency.

“We have options that are cheaper and safer and will be available quicker,” Richard Cannings, the NDP natural resources critic, said in a statement.

Lefebvre, however, said the global market for SMRs is expected to be worth between $150 billion and $300 billion a year by 2040. As one of the world’s largest producers of uranium, Canada has to be part of the wave both for economic and environmental reasons, he said.

“There’s a growing demand for smaller, simpler and affordable nuclear technology energy,” Lefebvre said.

Joe McBrearty, head of Canadian Nuclear Laboratories, told the conference the company had signed a host agreement this week with Ottawa-based Global First Power for a demonstration SMR at its Chalk River campus in eastern Ontario. A demonstration reactor will allow for the assessment of the technology’s overall viability, he said.

“When talking about deploying a new technology like an SMR, building a demonstration unit is vital to the success of that process,” McBrearty said. “Most importantly, it allows the public to see the reactor, to kick the tires so to speak, and to have confidence in the safety of its operation.”

Continue Reading

Chat

Trending