Ice cream and other foods with certain types of saturated fat may encourage overeating. The fat interferes with the brain, interrupting signals that tell the body it is full, according to a new study from the University of Texas Southwestern. If you’ve been enjoying a lovely weekend with Ben&Jerry’s, stop right there!

UT Southwestern conducted a study on the effects of different types of fats on the hypothalamus and other parts of the brain. “Normally, our body is primed to say when we’ve had enough, but that doesn’t always happen when we’re eating something good,” said study author Dr. Deborah Clegg, assistant professor of internal medicine at UT Southwestern. What they found was that certain fatty acids blocked hormone signals from insulin and leptin, hormones that regulate weight and appetite.

The study examined the effects in rats. The animals received equal amounts of different types of fats. The first group of rats was fed a diet high in palmitic fatty acids, the second monounsaturated fatty acids, and the third with oleic fatty acids. These groups were then divided further into two groups. In the first group, fats were directly injected into the bran via the carotid artery, while the second group of rats received fats via a tube.

“We found that the palmitic acid specifically reduced the ability of leptin and insulin to activate their intracellular signaling cascades,” Dr. Clegg said. “The oleic fat did not do this. The action was very specific to palmitic acid, which is very high in foods that are rich in saturated fat.”

Oleic acids are naturally-occuring “good” fats found in foods such as olives and some types of soybeans. Palmitic acid, in contrast, is a type of saturated fatty acid typically found in foods high in animal fats, such as beef, butter, and cheese. These types of fats are intended for long-term energy storage, but when a person consumes a diet high in palmitic acid it can accelerate obesity.

“What we’ve shown in this study is that someone’s entire brain chemistry can change in a very short period of time,” Dr. Clegg said. The study showed that the effects of these types of fats can last as long as three days.

“Our findings suggest that when you eat something high in fat, your brain gets 'hit' with the fatty acids, and you become resistant to insulin and leptin,” she said. “Since you’re not being told by the brain to stop eating, you overeat.”

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It may be in your best interest to postpone surgery until regular OR hours. According to a study appearing in The Journal of Bone and Joint Surgery, patients with after-hours operations have 24 percent more unplanned follow-up operations than those who went under the knife during regular office hours.

“Although everyone wants to be treated immediately… it is not always best to rush a patient to the OR in the middle of the night,” explains Dr. William M. Ricci MD, Associate Professor of Orthopaedic Surgery at the Washington University School of Medicine.

The study followed 203 patients who underwent orthopaedic surgery—surgery on bones and joints. While there was no significant difference between radiation exposure, healing time or actual treatment, there was a noticeable disparity between operations that occurred between the daytime and nighttime shifts.

All operations used intramedullary nail fixation to mend tibial or femoral fractures. This is a procedure in which a rod, or “nail”, is used to set the bone. The day was divided into two shifts—the morning shift between 6:00 a.m. and 4:00 p.m., and the night shift thereafter.

Second shift patients had shorter operations, but they also had more follow-up operations and more nail removal surgeries—27percent versus 3 percent for patients whose surgeries occurred during regular office hours. Dr. Ricci believes that much of this can be attributed to the long hours many surgeons put in.

“The reality is that the on-call night surgical team may not be well rested as it is likely they had just finished a normal day shift,” Ricci says. Ricci, who is also chief of the Orthopaedic Trauma Service in the Department of Orthopaedic Surgery at W.U., also explains why non-emergency operations should wait.

“We in the healthcare industry don’t have unlimited resources,” Ricci says. “Many hospitals in the U.S. do have a dedicated night team of orthopaedic surgeons who otherwise are without daytime responsibilities. There are surgical teams on-call for those instances when treatment must be immediate.”

Ricci believes giving orthopaedic surgeons more time to operate on trauma patients can help reduce the risk of minor complications from nail fixation surgeries. He encourages patients to wait for surgery if possible, but insists that actions be taken immediately in urgent situations: “Naturally, when the medical condition is emergent and time is a critical factor, immediate surgery should proceed regardless of time of day.”

Hopelessness may increase your risk of stroke, according to new information from the University of Minnesota. Researchers found that higher levels of hopelessness are linked with accelerated development of early atherosclerosis in middle-aged women.

Atherosclerosis causes plaque to build up on the insides of arteries, reducing the flow of oxygen-rich blood to organs and other parts of the body. Arteries in the neck can thicken, a condition called carotid artery intimal-medial thickening (IMT). Atherosclerosis increases risk of heart attack and can block blood flow to the brain and lead to stroke.

Science has explored the connection between hopelessness and IMT in men and women with cardiovascular disease, but little was known about the link in healthy women. “This is the first study to suggest that hopelessness may be related to subclinical cardiovascular disease in women without clinical symptoms of heart disease,” said Susan A. Everson-Rose, Ph.D., M.P.H., associate professor of medicine at the University of Minnesota and co-author of the study.

Data for the study was collected from two sites in Chicago and Pittsburgh, using the Study of Women’s Health Across the Nation (SWAN). Five hundred and fifty-nine women (average age 50) living in the city participated in the study. Participants appeared to be in good health, showing no signs of cardiovascular disease.

SWAN used questionnaires to measure the association between IMT and hopelessness frequency using an eight-point scale, asking participants about personal goals and future life expectations. Scores of five and above were considered “high.” Ultrasounds were then used to measure the thickness of arteries in the neck.

Participants with the highest hopelessness scores showed an average of .06 mm greater thickening than their hopeful counterparts (.02 mm is equal to roughly one year’s thickening). Researchers discovered that hopelessness triggered a hormonal release in response to mood change that can amplify the effects of atherosclerosis and the thickening of neck arteries.

Researchers plan to continue exploring the unique relationship between hopelessness and cardiovascular disease in future studies. “These findings suggest that women who experience feelings of hopelessness may have greater risk for future heart disease and stroke,” Everson-Rose said. "We look forward to examining the longitudinal relations between hopelessness and heart disease risk in women."