When unhealthy foods hijack overeaters' brains

By LAURAN NEERGAARD, AP Medical Writer

WASHINGTON – Food hijacked Dr. David Kessler's brain. Not apples or carrots. The scientist who once led the government's attack on addictive cigarettes can't wander through part of San Francisco without craving a local shop's chocolate-covered pretzels. Stop at one cookie? Rarely. It's not an addiction but it's similar, and he's far from alone.

Kessler's research suggests millions share what he calls "conditioned hypereating" — a willpower-sapping drive to eat high-fat, high-sugar foods even when they're not hungry. In a book being published next week, the former Food and Drug Administration chief brings to consumers the disturbing conclusion of numerous brain studies: Some people really do have a harder time resisting bad foods. It's a new way of looking at the obesity epidemic that could help spur fledgling movements to reveal calories on restaurant menus or rein in portion sizes.

"The food industry has figured out what works. They know what drives people to keep on eating,"
Kessler tells The Associated Press. "It's the next great public health campaign, of changing how we view food, and the food industry has to be part of it."

He calls the culprits foods "layered and loaded" with combinations of fat, sugar and salt — and often so processed that you don't even have to chew much. Overeaters must take responsibility, too, and basically retrain their brains to resist the lure, he cautions. "I have suits in every size," Kessler writes in "The End of Overeating." But, "once you know what's driving your behavior, you can put steps into place" to change it.

At issue is how the brain becomes primed by different stimuli. Neuroscientists increasingly report that fat-and-sugar combinations in particular light up the brain's dopamine pathway — its pleasure-sensing spot — the same pathway that conditions people to alcohol or drugs. Where did you experience the yum factor? That's the cue, sparking the brain to say, "I want that again!" as you drive by a restaurant or plop before the TV.

"You're not even aware you've learned this," says Dr. Nora Volkow, chief of the National Institute on Drug Abuse and a dopamine authority who has long studied similarities between drug addiction and obesity. Volkow is a confessed chocoholic who salivates just walking past her laboratory's vending machine. "You have to fight it and fight it," she said. Conditioning isn't always to blame. Numerous factors, including physical activity, metabolism and hormones, play a role in obesity. And the food industry points out that increasingly stores and restaurants are giving consumers healthier choices, from allowing substitutions of fruit for french fries to selling packaged foods with less fat and salt.

But Kessler, now at the University of California, San Francisco, gathered colleagues to help build on that science and learn why some people have such a hard time choosing healthier: _First, the team found that even well-fed rats will work increasingly hard for sips of a vanilla milkshake with the right fat-sugar combo but that adding sugar steadily increases consumption. Many low-fat foods substitute sugar for the removed fat, doing nothing to help dieters eat less, Kessler and University of Washington researchers concluded.

Then Kessler culled data from a major study on food habits and health. Conditioned hypereaters reported feeling loss of control over food, a lack of satiety, and were preoccupied by food. Some 42 percent of them were obese compared to 18 percent without those behaviors, says Kessler, who estimates that up to 70 million people have some degree of conditioned hypereating.

Oily fish 'can halt eye disease'

People with age-related macular degeneration (AMD) should eat oily fish at least twice a week to keep their eye disease at bay, say scientists.

Omega-3 fatty acids found in abundance in fish like mackerel and salmon appear to slow or even halt the progress of both early and late stage disease.

The researchers base their findings on almost 3,000 people taking part in a trial of vitamins and supplements.
The findings are published in the British Journal of Ophthalmology.
An estimated 500,000 people in the UK suffer from AMD, which destroys central vision.

Protective
Experts have already suggested omega-3 may cut the risk of getting AMD by a third, and now this latest work suggests these fats also benefit patients who already have the disease.

These findings appear to be consistent with previous research that has shown that eating omega 3 poly-unsaturated fats as part of a balanced diet may help prevent the development of age-related macular degeneration
A spokeswoman from RNIB

Progression to both dry and wet forms of advanced AMD disease was 25% less likely among those eating a diet rich in omega-3 fatty acids.

People with advanced AMD who also consumed a low-GI diet, eating of foods that release their sugar more slowly, and who took supplemental antioxidant vitamins and minerals like vitamin C and zinc appeared to reduce their risk of disease progression by even more - by up to 50%.

Substituting five slices of wholegrain bread for white bread every day out of a total intake of 250g of carbohydrate might cut out almost 8% of advanced age related macular degeneration over five years, say the authors.

Surprisingly, however, the supplements were counterproductive for those with early AMD, negating the benefits of omega-3 fats, and even appeared to increase the risk of disease progression.
Those who took all the antioxidant vitamins plus zinc, and who a high daily intake of beta carotene - found in yellow and green vegetables - were 50% more likely to progress to advanced disease.

The researchers at Tufts University, Boston, believe omega-3 fatty acids offer protection against AMD by altering fat levels in the blood after a meal that can be damaging to the body.

'Moderation'
But they say it is not clear whether patients should also consider taking supplements as well as omega-3 because of their mixed findings.

They suggest that eating two to three servings of fatty fish, such as salmon, tuna, mackerel, shellfish, and herring every week, would achieve the recommended daily intake (650mg) of omega-3, substantially cutting the risk of both early and late stage AMD.

The UK's Food Standards Agency says people should eat at least two portions of fish a week including one of oily fish.
But they caution that too much oily fish is bad because it can contain low levels of pollutants that can build up in the body.
Most people can safely eat up to four portions a week, but girls and women who might have a baby and those who are pregnant or breastfeeding should limit their intake to two portions a week.

A spokeswoman from RNIB said good nutrition was very important for both general and eye health.
"These findings appear to be consistent with previous research that has shown that eating omega-3 poly-unsaturated fats as part of a balanced diet may help prevent the development of age-related macular degeneration, the main cause of severe sight loss in the UK. "RNIB hopes that this will further highlight why looking after your eyes should be a key motivation in maintaining a healthy lifestyle," she said.

Weekly curry 'may fight dementia

Eating a curry once or twice a week could help prevent the onset of Alzheimer's disease and dementia, a US researcher suggests.

The key ingredient is curcumin, a component of the spice turmeric.

Curcumin appears to prevent the spread of amyloid protein plaques - thought to cause dementia - in the brain.

But the theory, presented at the Royal College of Psychiatrists' annual meeting, has been given a lukewarm reception by UK experts.

“ If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia ”
Professor Murali Doraiswamy Duke University
Amyloid plaques, along with tangles of nerve fibres, are thought to contribute to the degradation of the wiring in brain cells, eventually leading to symptoms of dementia.

Professor Murali Doraiswamy, of Duke University in North Carolina, said there was evidence that people who eat a curry meal two or three times a week have a lower risk of dementia.

He said researchers were testing the impact of higher doses - the equivalent of going on a curry spree for a week - to see if they could maximise the effect.

Animal studies

Professor Doraiswamy told the meeting: "There is very solid evidence that curcumin binds to plaques, and basic research on animals engineered to produce human amyloid plaques has shown benefits."

"You can modify a mouse so that at about 12 months its brain is riddled with plaques.

"If you feed this rat a curcumin-rich diet it dissolves these plaques. The same diet prevented younger mice from forming new plaques.

"The next step is to test curcumin on human amyloid plaque formation using newer brain scans and there are plans for that."

Professor Doraiswamy said a clinical trial was now underway at the University of California, Los Angeles, to test curcumin's effects in Alzheimer's patients.

He said research had also examined turmeric's therapeutic potential for treating conditions such as cancer and arthritis.

Good diet

He stressed that eating a curry could not counter-balance the increased risk of dementia associated with a poor diet.

“ Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why ”
Dr Susanne Sorensen Alzheimer's Society
However, he said: "If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia."

Professor Doraiswamy predicted it might be possible to develop a curry pill which had the same therapeutic effect.

However, Rebecca Wood, of the Alzheimer's Research Trust, stressed that people would need to eat a lot of curry - over 100g of turmeric curry powder - to get a clinical dose of curcumin.

She said: "Professor Doraiswamy's unpublished research applies only to animal models; his hypothesis has not been confirmed in human clinical trials.

"We look forward to the results of the human curcumin trial at UCLA."

Dr Susanne Sorensen, of the Alzheimer's Society, said: "Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why.

"Alzheimer's Society is keen to explore the potential benefits of curcumin in protecting the brain and we are conducting our own research into this area.

"A cheap, accessible and safe treatment could transform the quality of life of thousands of people with the condition."