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Did you know that your brain is more than 60 percent fat? And that eating the right fats can help keep your brain mentally sharp as you age? That’s because fatty acids are the main building block of myelin, the protective covering around nerve calls, and they play a key role in brain health.
A new study published in Neurology links a diet low in omega-3 fatty acids, particularly those found in fish, such as DHA, to greater risk for memory problems in seniors. Lack of this crucial nutrient seemed to shrink the brain, with the researchers reporting that those with the lowest levels of DHA and other fatty acids in their blood had smaller brain volumes than those with higher DHA levels.
In the study of 1,575 older adults (average age 67), low levels of DHA were also linked to worse scores on tests of visual memory, processing, and abstract thinking. Since DHA is the most abundant fat in the brain, it makes sense that skimping on this “smart fat” would impair mental function.
Here’s the skinny on more intriguing research findings about fat.
There’s a fat that makes you thin. Until three years ago, scientists thought that only babies have brown fat, but new research shows that adults have it too—in small amounts in the upper back, the side of the neck, the indentation between the collarbone and shoulder, and along the spine. Brown fat is metabolically active and torches calories like a furnace.
For this to happen, you have to activate the brown fat, which happens naturally when you’re cold and (at least in mice) during exercise. In one study, brown fat burned 250 calories in three hours. Researchers are now trying to figure out how to jump start brown fat to help us lose weight.
Most people gain about an average of one gram of fat per day. A gram doesn’t even seem worth mentioning--it’s the equivalent of 0.0053 ounces. But that miniscule amount has a way of adding up over time. Between your 25th and 50th birthdays, it will amount to a 20-pound weight gain. Think of that when you reach for a snack!
A typical adult has about 50 billion fat cells. They’re everywhere except your eyelids, parts of the esophagus, and in men, the penis. Here’s the good news: after puberty, you usually won’t gain any more fat cells. However, if you pack on more pounds, your fat cells can balloon up to 10 times their usual size.
Fat cells live for an average of ten years. Although about 150 of your fat cells die every day, they’re quickly replaced by new fat cells. A single fat cell can store only half a millionth of a gram of fat, which means it takes four million fat cells to store the calories consumed in a single Tic Tac.
A fat belly may shrivel the brain. A 2011 study compared the brain size of lean and obese people of similar ages and backgrounds. Obese people had more water in their amygdala, a part of the brain involved in feeding behavior, and had smaller orbitofrontal cortices, a region involved in impulse control. These brain changes may raise the risk for future overeating, New Scientist reports.
Whole grains help flatten your belly. In a study published in American Journal of Clinical Nutrition, Penn State researchers compared 25 obese adults eating whole grains to 25 obese adults eating refined grains, while on a diet. Over 12 weeks, both groups dropped an average of eight to 11 pounds, but the whole-grain group shed double the fat in the belly area. Good sources include whole-grain cereal, oatmeal, brown rice and barley.
It’s possible for normal-weight people to be obese. So-called normal-weight obesity means that the person has a high percent of body fat, particularly in the belly, which is linked to increased risks of heart disease and type 2 diabetes. A team of Mayo Clinic researchers report that up to 30 million Americans may fall into this category.
High body fat in normal-weight men and women nearly quadruples risk for metabolic syndrome, a cluster of heart attack risk factors that includes high blood sugar, high triglycerides, and high blood pressure. The #1 warning sign that you could be at risk is a large waist: more than 35 inches for women; or above 40 inches for men.
A high-fat diet may causes new brain cells to sprout: A new study from Johns Hopkins suggests that a high fat diet can stimulate formation of new brain cells, in mice, and that turning off these new cells stops weight gain even when the animals ate more of their high-fat diet. The big question is: can this happen in humans? If so, it may lead to new approaches to weight control.
Fat Isn’t Making Us Fat: After decades of hearing that the problem is our high-fat diets, we’re now getting a new message: What’s driving the obesity epidemic is overindulgence in high-glycemic load carbohydrates (think sugar-sweetened cereals, donuts, white bread and pastries), says integrative medicine pioneer Andrew Weil, M.D. Powerful evidence backs that up: Multiple studies have shown that 40 percent of the calories in the super heart-healthy Mediterranean diet come from fat, principally olive oil that doesn’t raise cholesterol levels