Thursday, February 23, 2012

Insulin Reduces Appetite

Along the same lines as Stephan Guyenet's recent post Insulin and Obesity: Another Nail In The Coffin, a new study published in Diabetes reports that "insulin administration might be useful in curtailing overconsumption of snacks with accentuated rewarding value."

Health Day reported on the study:

"Brain insulin may act as a satiety signal during the postprandial period and is associated with decreased appetite and reduced intake of highly palatable food, according to a study published online Feb. 16 in Diabetes.

Manfred Hallschmid, Ph.D., from the University of Lübeck in Germany, and colleagues investigated the role of brain insulin signaling in the control of food intake. In two groups of healthy women, 160 IU insulin or vehicle were administered after lunch, and two hours later, the consumption of cookies of varying palatability was evaluated under the pretext of a taste test. Intranasal insulin was administered to fasted females as a control study.
The researchers found that, compared with placebo, insulin administration in the postprandial state, but not in the fasted state, decreased appetite along with intake and rated palatability of the most palatable snack offered. Intranasal insulin administration was associated with a small decrease in plasma glucose, but no effect on serum insulin concentration was seen.
"Postprandially administered intranasal insulin enhances the satiating effect of meals and reduces palatable snack intake, suggesting that insulin acts as a relevant signal in the short-term regulation of satiety in humans," the authors write. "Considering that the rewarding effect of palatable food overriding the homeostatic control of energy intake may promote obesity, insulin's potential to curb the appetite for hedonically salient, calorie-rich food deserves particular attention."
This study suggests that building meals around low-energy density foods that significantly raise insulin levels, such as potatoes, rice, and the like, could curb appetite for highly palatable snacks.

It also suggests inversely that eating meals that minimize insulin release might result in less post-meal satiety and increased appetite for snacks. 

Perhaps this provides partial explanation for the low prevalence of obesity in nations like Japan, where the cuisine revolves around a highly insulinogenic starch like white rice.

Wednesday, February 22, 2012

CDC Report: Raw Milk 150 Times More Likely To Cause Illness

Over at Food Safety News,  James Andrews reports:

"Raw milk and raw milk products are 150 times more likely than their pasteurized counterparts to sicken those who consume them, according to a 13-year review published by the Centers for Disease Control and Prevention on Tuesday. States that permit raw milk sales also have more than twice as many illness outbreaks as states where raw milk is not sold.

The CDC study, published online in Emerging Infectious Diseases, reviewed dairy-related outbreaks between 1993 and 2006 in all 50 states, during which time the authors counted 121 dairy-related illness outbreaks resulting in 4,413 illnesses, 239 hospitalizations and three deaths. 

Despite raw milk products accounting for approximately one percent of dairy production in the U.S., raw milk dairies were linked to 60 percent of those dairy-related outbreaks. In addition, 202 of the 239 hospitalizations (85 percent) resulted from raw milk outbreaks. Thirteen percent of patients from raw milk outbreaks were hospitalized, versus one percent of patients from pasteurized milk outbreaks.

Seventy-five percent of the raw milk outbreaks occurred in the 21 states where the sale of raw milk was legal at the study's onset in 1993. Today, 30 states permit the sale of raw milk, while another seven are considering raw milk legislation changes this year.

The study found that individuals under the age of 20 accounted for 60 percent of those affected by raw milk outbreaks, compared with 23 percent associated with pasteurized products. Children were also more likely than adults to become seriously ill from pathogenic bacteria in raw milk.
The differences in illness severity between raw and pasteurized milk are largely due to the pathogens present in each: People sickened from raw milk typically ingest injurious bacteria -- most commonly Salmonella or Campylobacter -- whereas pasteurized milk outbreaks more often result from "relatively mild" pathogens such as norovirus, according to the CDC."

 Read more here.

I don't endorse governmental restriction of sales of raw milk products, which from this report appear no more hazardous than alcohol, cigarettes, or many common pharmaceuticals.  If people want to take the risk of salmonella infection in order to consume raw milk, that is their own business. 

But if raw milk performs like this, it won't be long before it will lose its market.  Very quickly people will reject a disease vector like this. 

Tuesday, February 21, 2012

New Post At The Food Way: Meat-free Diet Quickly Improves Mood of Omnivores

When I used the so-called Paleolithic paradigm to guide my approach to nutrition, I embraced the idea that we (humans) have a ‘need’ to eat grass-finished meat and wild fish to get adequate amounts of long-chain omega-3 fatty acids, particularly EPA and DHA, for cardiovascular and neurological health respectively.

Like other supporters of this idea, I believed that lack of animal sources of these fats would cause depression, schizophrenia, attention deficit, and poor intelligence. It all ‘made sense’ based on the hypothesis that meat-eating provided the crucial energy and fatty acids that supported human brain evolution.

After some time I realized this hypothesis ignores the fact that meat provides only fat and protein, while the nervous system prefers glucose. The human brain uses about two-thirds of the glucose used by the entire body. Meat simply does not provide the best fuel for the brain. I now tire of reading anthropologists arguing that meat must have 'fueled' brain expansion because of its rich provision of fats. If they took a moment to study neural cell energy metabolism, they would realize that the expanding human brain needed a steady supply of non-toxic glucose (i.e. glucose not derived from protein), not found in meat or fat.

About eight months ago when preparing my presentation for the Ancestral Health Symposium I recalled that I had previously seen evidence challenging the hypothesis that humans need preformed EPA and DHA for healthy nervous system development and function.

That evidence consisted of studies showing that although vegetarians have essentially no intake of these preformed omega-3 fatty acids, they do not have deficits of  cognitive or neural function. 

Do vegetarian children suffer poor development of intelligence, and do vegetarians in general suffer any disorders that could be attributed to lack of preformed omega-3s?  Read more....