Butter Leads To Lower Blood Fats Than Olive Oil
High blood fat levels normally raise the cholesterol values in the blood, which in turn elevates the risk of atherosclerosis and heart attack. Now a new study from Lund University in Sweden shows that butter leads to considerably less elevation of blood fats after a meal compared with olive oil and a new type of canola and flaxseed oil. The difference was clear above all in men, whereas in women it was more marginal.
The main explanation for the relatively low increase of blood fat levels with butter is that about 20 percent of the fat in butter consists of short and medium-length fatty acids. These are used directly as energy and therefore never affect the blood fat level to any great extent. Health care uses these fatty acids with patients who have difficulty taking up nutrition in other words, they are good fatty acids.
“A further explanation, which we are speculating about, is that intestinal cells prefer to store butter fat rather than long-chain fatty acids from vegetable oils. However, butter leads to a slightly higher content of free fatty acids in the blood, which is a burden on the body,” explains Julia Svensson, a doctoral candidate in Biotechnology and Nutrition at Lund University.
The greater difference in men is due to, among other things, hormones, the size of fat stores, and fundamental differences in metabolism between men and women, which was previously known. This situation complicates the testing of women, since they need to be tested during the same period in the menstruation cycle each time in order to yield reliable results. Read more
Fruit Flies Can Shed Light On High Cholesterol, Obesity In Humans
How do fruit flies get high cholesterol and become obese? The same way as people do – by eating a diet that’s too rich in fats.
More importantly, according to two new studies led by a University of Utah human geneticist, fruit flies use the same molecular mechanisms as humans to help maintain proper balances of cholesterol and a key form of stored fat that contributes to obesity. The findings mean that as researchers try to learn more about the genetic and biological processes through which people regulate cholesterol and fat metabolism, the humble fruit fly, also called Drosophila, can teach humans much about themselves.
“Not a lot is known about these regulatory mechanisms in people,” says Carl S. Thummel, Ph.D., professor of human genetics at the U of U School of Medicine and senior author on the two studies. “But we can learn a lot by studying metabolic control in fruit flies and apply what we learn to humans.”
High cholesterol and obesity, which affects an estimated 25 percent to 30 percent of the U.S. population, are linked to heart disease, diabetes, and other diseases that take huge tolls on health and add billions of dollars to the nation’s medical bills. Understanding the processes that regulate cholesterol and fat in humans could be critical for addressing those health risks in people, Thummel believes.
The two studies identify a nuclear receptor, DHR96, which plays a critical role in regulating the balance or homeostasis of cholesterol and another fat molecule called triacylglycerol (TAG). Nuclear receptors are proteins that sense the presence of chemical compounds within cells. DHR96 corresponds closely to a nuclear receptor in humans, called LXR, that is known to regulate cholesterol levels.
In a study published Dec. 2 in Genes & Development, Thummel and colleagues at the U of U and two Canadian universities show that DHR96 helps regulate cholesterol in fruit flies by binding with this compound. When this binding occurs, it allows DNA to be read, which switches genes on and off that help maintain proper levels of cholesterol, according to Thummel, who also holds an H.A. and Edna Benning Presidential Endowed Chair in Human Genetics. Read more