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How Much Fat Should You Eat?


The amount of information and advice swirling around us on how much and what kind of fat to eat is enough to make a person dizzy. We're told some fats are bad for us (saturated fats and trans-fats) and others are good for us (monounsaturated fats, polyunsaturated fats and omega-3 fats). Some diet experts, such as Dr. Dean Ornish, suggest a low-fat diet. Others, such as the Atkins diet, promote a high-fat diet. According to the following studies, however, even too much of a good thing may be too much:

Rats Fed High-Fat Diet Experienced Decreased Brain Function: In a recent study, scientists report that rats fed a high-fat diet experienced brain injury that resulted in reduced brain activity. After documenting the short- and long-term effects of a high-fat diet, researchers concluded that a high-fat diet triggers reduced brain activity. Rats that were fed a diet with the amount of fat consumed in a typical American diet not only gained weight, they also experienced a swelling of the hypothalamus, the part of the brain that regulates weight. In addition, scientists detected damage to (and even loss of) weight-regulating neurons.

Fat Causes Grey Brain Matter to Shrink: For some time now, obesity has been considered a key factor in the development of medical conditions such as heart disease, diabetes and cancer. Adding to that list, researchers have found compelling evidence linking obesity with memory loss in dementia and Alzheimer's patients. Being obese or even overweight can age grey matter-the thinking part of our brains-by as much as 16 years.

Along the same line, researchers at the Karolinska Institute in Sweden found the risk of dementia to be 71 percent higher for overweight individuals than for people of normal weight. In addition, scientists have discovered that consuming too many fatty and sugary foods actually changes the way we think. In other words, eating an excess amount of junk food causes the brain to crave more of the same. There is a light at the end of the tunnel, however; subjects of the study who lost weight also improved brain function.

High-Fat Diet Changes Dopamine Levels: A high-fat diet wreaks havoc with dopamine levels in the brain, according to Mitchell Roitman, a researcher at the University of Illinois at Chicago. Rats fed a high-fat diet experienced a significant reduction in dopamine levels over a six-week period. Commenting on the link between dopamine levels and obesity, Roitman said, "Previous research has demonstrated reduced dopamine transporter numbers in association with obesity and exposure to a high fat diet. Our research shows that these changes lead to major differences in the way dopamine functions in the brain."

Could Stem-Cell Research Retard the Growth Of Fat Cells? Scientists at the University of Texas Health Science Center at Houston have discovered a stem-cell marker produced in mice and in human adults associated with obesity and weight gain. The marker, called delta-decorin, shows up on adipose cells. Commenting on the link, Alexes Daquinag, PhD, coresearcher and postdoctoral fellow at the UTHealth Medical School, said, "In obesity, you have an overgrowth of white adipose tissue. It is made of adipocytes (fat cells) and one way to stop obesity is to target the progenitor cells-adipose stem cells." Although the research is still in its preliminary stages, the discovery of this stem-cell marker may eventually lead to weight-loss drugs that target fat.

Cutting all fat out of our diet isn't a viable option because healthy fats help manage mood, provide energy and create a sensation of satiety. But given this research, if we are to optimize our health and well-being, we will need to make healthy choices (replacing bad fats with good ones) and manage the amount of fat we consume so that we experience none of the downside and all of the benefits.

Photo Credit:  Muffet on Flickr.

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