The research, conducted in a mouse model, suggests how lifestyle and genetics converge. The researchers found that animals with an APC mutation, the most common genetic mutation found in humans with colorectal cancer, developed cancer faster when fed a high-fat diet.
The mice with APC mutations developed benign growths called adenomas. In humans, adenomas are common in the intestine and are routinely removed during colonoscopies. These growths normally take decades to turn into malignant adenocarcinomas. Yet the adenomas in these mice quickly turned cancerous when given high-fat diets.
The scientists randomly divided 292 male mice into two diet groups. One group received a naturally sourced diet that was lower in purified sugars and fat, and higher in protein and fiber than the other diet. The mice in each diet group were then divided into three sub-groups based on how often they had access to food. The first group of mice had access to food around the clock. A second group of mice was fed 30 percent less calories per day than the first group. The third group was meal fed, getting a single meal that added up to the exact number of calories as the round-the-clock group. Both the meal-fed and calorie-restricted mice learned to eat quickly when food was available, resulting in longer daily fasting periods for both groups.
The scientists tracked the mice’s metabolic health through their lifespans until their natural deaths and examined them post-mortem. Meal-fed and calorie-restricted mice showed improvements in overall health, as evidenced by delays in common age-related damage to the liver and other organs, and extended longevity. The calorie-restricted mice also showed significant improvement in fasting glucose and insulin levels compared to the other groups. Interestingly, the researchers found that diet composition had no significant impact on lifespan in the meal fed and calorie restricted groups.
One of my neighbors is a mouse researcher. I bet he’s really excited this weekend.
The NIH webpage on caloric restriction and fasting diets is here.
Confirming and extending previous observations, the researchers showed that prolonged social isolation leads to a broad array of behavioral changes in mice. These include increased aggressiveness towards unfamiliar mice, persistent fear, and hypersensitivity to threatening stimuli. For example, when encountering a threatening stimulus, mice that have been socially isolated remain frozen in place long after the threat has passed, whereas normal mice stop freezing soon after the threat is removed. These effects are seen when mice are subjected to two weeks of social isolation, but not to short-term social isolation — 24 hours — suggesting that the observed changes in aggression and fear responses require chronic isolation.
Though the work was done in mice, it has potential implications for understanding how chronic stress affects humans.
Get out of the house. Socialize with friends and family. Leave the cell phone at home.
Social media is not social. It’s a serious public health problem for the brainwashed masses with addictive behaviors.
Read the source article here.
For example, when offered chocolate for just one hour per day, the animals will compulsively ‘binge’, consuming as much chocolate in one hour as they would over a whole day if it was continually available. They also showed inflexible behaviours, similar to those seen in addiction, choosing to wait for chocolate while ignoring freely available standard chow. Yet, at the same time, the chocolate did not seem to satiate hunger as well as regular food.
The team found that animals on the high fat or chocolate diet also changed their daily routines. They were more likely to eat during the daytime — mice are usually nocturnal and feed at night — and they ate shorter more frequent ‘snacks’ rather than larger, longer-spaced meals.
We had friends over for dinner on Saturday. While at the store shopping for provisions I saw some gelato on sale for 99 cents.
$0.99! The only flavor on sale was chocolate. I bought some.
The next night I had to have some chocolate gelato. Because it was there!
The mice have proven what I already know.
Read the source article here.
In the latest study, the researchers paired sets of mice together and then removed one mouse from each pair and subjected them to a mild amount of stress. They then returned the stressed mouse to the pair and observed the brains of both mice. The results showed that the stressed mouse experienced changes in a group of neurons located in the hippocampus, a brain area that plays a central role in memory and emotional response. The brain of the other mouse that hadn’t been stressed, but was now in the presence of its stressed partner, rapidly showed the same neuronal changes in its hippocampus. In effect, the brains of the unstressed mice mirrored the brains of the stressed mice.
Perhaps as could be expected, both in earlier research and in anecdotal evidence in humans, the animal models tended not to do great on the American-style diet. A couple of the strains became very obese and had signs of metabolic syndrome. Other strains showed fewer negative effects, with one showing few changes except for having somewhat more fat in the liver. With the Mediterranean diet, there was a mix of effects. Some groups were healthy, while others experienced weight gain, although it was less severe than in the American diet. Interestingly, these effects held, even though the quantity of consumption was unlimited.
The results demonstrated that a diet that makes one individual lean and healthy might have the complete opposite effect on another. “My goal going into this study was to find the optimal diet,” Barrington said. “But really what we’re finding is that it depends very much on the genetics of the individual and there isn’t one diet that is best for everyone.”
Read the source article here.
This is the first research study I’ve come across exploring genetics and diet. This supports a belief I have about diet. Eat what your ancestors ate.