Make us your home page
Instagram

Today’s top headlines delivered to you daily.

(View our Privacy Policy)

Study: Hunger keeps you hungry — and healthy

Many experiments have demonstrated that eating about 30 percent less than needed to keep up with the body's energy needs extends longevity and improves health in animals ranging from the humble earthworm to rhesus monkeys. Humans who try calorie restriction appear to reduce their risk of heart disease and diabetes, and improve their immune function. There's even some evidence that calorie restriction reduces the risk of Alzheimer's disease — in mice and monkeys, at least.

Why does calorie restriction produce this effect? No one knows for sure, but researchers at the University of Alabama at Birmingham have conducted experiments that lead them to suspect that it's the hunger produced by calorie restriction that confers benefits, not the reduction in food intake itself.

The scientists found that hunger triggers a cascade of hormonal signals that may counter age-related mental decline in mice genetically altered to develop Alzheimer's pathology. To test the idea, they gave the mice a synthetic form of ghrelin, the hormone that produces the sensation of hunger. The mice who received the ghrelin avoided the age-related cognitive decline more often than those that didn't receive the treatment.

"Hormonal hunger signaling may represent a new way to combat Alzheimer's disease, either by itself or combined with caloric restriction," said lead author Inga Kadish, assistant professor at the School of Medicine at the University of Alabama at Birmingham.

The mice in the study were divided into three groups. One consumed a diet with about 20 percent fewer calories than typical. The other two groups ate normally, but one group received the synthetic ghrelin to produce a sense of hunger. The memory of the mice was tested by having them swim in a pool of milky water that obscured the view of a platform they could climb on to get out of the water. The mice could find the platform faster if they remembered the visual cues located around the perimeter of the pool. Mice receiving synthetic ghrelin found the platform 26 percent faster than their normally fed peers, and the group on a calorie-restricted diet found it 23 percent faster.

Ghrelin creates hunger signals by acting on the hypothalamus, a part of the brain that influences growth, development, reproduction and metabolism. A new study just published online in Nature has found that the hypothalamus may function as a "fountain of youth" capable of slowing the aging process. "What's exciting is that it's possible — at least in mice — to alter signaling within the hypothalamus to slow down the aging process and increase longevity," said senior author Dongsheng Cai.

The researchers injected gonadotropin-releasing hormone (GnRH) into the brains of the aging mice and found that the hormone promoted the production of new neurons — a process that declines with age. The mice also showed a reduction in other signs of aging, such as a decrease in muscle strength, skin thickness and the ability to learn. They also lived about 20 percent longer.

Might this treatment have affected the activity of ghrelin too? No one knows yet, but you can boost the production of ghrelin in your body simply by eating less. The Cooking Channel may be offering good advice with its slogan: "Stay hungry."

Tom Valeo writes about health matters. He can be reached at tom.valeo@gmail.com.

Study: Hunger keeps you hungry — and healthy 05/21/13 [Last modified: Wednesday, May 22, 2013 11:09am]
Photo reprints | Article reprints

© 2017 Tampa Bay Times

    

Join the discussion: Click to view comments, add yours

Loading...
  1. Jones: Bucs need success to get national respect

    Bucs

    Tampa Bay Times columnist Tom Jones offers up his Two Cents on the world of sports.

    No respect

    Tampa Bay Buccaneers head coach Dirk Koetter walks the field during the second day of mandatory minicamp at One Buccaneer Place in Tampa, Fla., on Wednesday, June 14, 2017. LOREN ELLIOTT   |   Times
  2. Hopes fade after landslide destroys Chinese village (w/video)

    World

    Crews searching through the night in the rubble left by a landslide that buried a mountain village under tons of soil and rocks in southwestern China found 15 bodies, but more than 110 more people remained missing.

    Vehicles and people line a road leading to the site of a landslide in Xinmo village in Mao County on Saturday in southwestern China’s Sichuan Province. More than 100 people remained missing after the village was buried under tons of rocks and soil.
  3. Rookie Jake Faria dissatisfied with performance in Rays' loss to Orioles

    The Heater

    ST. PETERSBURG — The rookie pitcher walked to his locker Saturday after tossing the fourth quality start in as many tries to begin his career. He held the potent Orioles bats to three runs and for six innings gave his team a chance to win.

    Orioles third baseman Manny Machado tags out the Rays’ Mallex Smith at third after a rundown in the first inning.
  4. Thousands converge in two St. Pete locations celebrating LGBT rights

    Human Interest

    ST. PETERSBURG — Tom Rockhill didn't know what to expect Saturday, but by noon people were knocking on the door of his bar Right Around the Corner in Grand Central.

    (From left to right) Emma Chalut 18, gets a rainbow sticker on her cheek from her sister Ellie, 15 both of Jacksonville before the annual St. Pete Pride parade in downtown St. Petersburg on Saturday. This year the route was changed from the Grand Central and Kenwood area to Bayshore Drive.
[EVE EDELHEIT   |   Times]
  5. Retired Florida Supreme Court Justice Parker Lee McDonald dies

    TALLAHASSEE — A former Florida Supreme Court justice, who wrote a decision that prevented lawyers from excluding jurors because of their race, has died.

    Former Florida Supreme Court Justice Parker Lee McDonald died Saturday, the court said in a statement. He was 93.