High-Fat Diet May Raise Cancer Risk
Over the last 10 years studies have shown that being obese and eating a high-fat, high-calorie diet can raise the risk of many types of cancer. Now a new study published in Nature may have discovered the mechanism by which that happens.
Research on mice suggests that by boosting stem cell production in the gut – and also by inducing other cells to mimic stem cells – a high-fat diet could increase the risk of colon cancer.
The study team fed healthy mice a diet of 60% fat for 9 months (a much higher proportion of fat than the 20-40% fat content of the average American diet). The mice gained 30-50% more body mass and developed more intestinal tumors, compared with healthy mice on a normal diet.
When they examined the mice’s gut tissue, researchers found the ones fed a high-fat diet had many more intestinal stem cells than the mice on a normal diet. More significantly, the team noticed that the boosted population of stem cells had a very distinctive feature – they could operate independently of the cells around them.
Under normal circumstances, stem cells interact with support or “niche” cells that surround them. These niche cells regulate stem cell activity and signal to them when it is time to differentiate into tissue-specific cells.
But the stem cells from the intestines of mice on the high-fat diet were so independent of their niche cells that, when cultured outside the body, they could produce “mini-intestines” much more readily than stem cells from normal-fed mice.
These findings are important because scientists already know that intestinal stem cells are often the cells of the gut that develop and accumulate mutations that give rise to cancer.
Sourced from: Medical News Today, High-fat diet may raise cancer risk by changing gut stem cells
Published On: Mar 4th 2016
What Not to Say to Someone Who Has Lost Weight
Offering encouragement and support is what good friends do. But sometimes the best of intentions have a way of backfiring on us.
Researchers from Harokopio University in Athens, Greece found that certain kinds of encouraging advice given to people who have lost weight may actually have the opposite effect.
They surveyed 289 people who successfully lost weight and kept it off for more than a year, and 122 people who lost weight, but then regained it shortly afterwards. Participants were asked detailed questions about their diet, physical activity and the kinds of support they received from friends and family.
Oddly, the results showed that people who regained weight reported receiving more support overall from their family and friends. Hoping to solve the puzzle of why that was, investigators dug deeper, looking at each question participants answered about the kinds of support they got.
The results: Support for the “regainers” often came in the form of do-and-don’t reminders – people who regained weight reported more frequently than the weight maintaining group that their friends and family reminded them not to eat high-fat foods, or reminded them to be physically active.
Those who maintained weight loss more often reported that their friends and families simply engaged in helpful activities with them, such as eating healthy or low-fat foods with them.
The study authors theorize support with the best intentions may be perceived negatively, as criticism and meaningless reminders, by the person already struggling to cope with managing a weight problem.
Sourced from: Live Science, The Surprising Things You Shouldn’t Say to Someone Who’s Lost Weight
Published On: Mar 4th 2016
Obesity Linked to Impaired Memory
There seems to be no end to the dangerous health consequences of being overweight.
As if high blood pressure, heart disease, stroke, diabetes, gout and some forms of cancer were not enough – obesity may have neurological consequences associated with reduced function in certain parts of the brain.
A study from University of Cambridge found the effects in the frontal lobes specifically – which are the seat of intelligence – and the hippocampus, which is critical for memory formation.
The study team looked at 50 volunteers aged 18 to 35, with Body Mass Indexes (BMIs) ranging from 18 (underweight) to 51 (extremely obese). They were asked to perform a computerized memory test which involved moving food items around complex scenes, like a desert with palm trees – hiding them in various locations, and indicating afterwards where they had hidden them.
Participants with higher BMI performed significantly worse on the tests, apparently because of an impaired ability to bind the different elements of the task – such as spatial location and the identity of the objects – into coherent and vivid memories. Earlier studies on both animals and humans show that obesity has a significant impact on brain structure and function.
This new study adds to the growing body of evidence suggesting that the mental deficits associated with obesity are present early in life. The researchers did include a caveat to their study. It did not take conditions like hypertension and sleep apnea into account – both of which usually occur with obesity, and are also known to impact mental function.
Sourced from: The Guardian, Obesity linked to memory deficits
Published On: Mar 4th 2016