High-fat diet can disrupt our biological clock
American pharmaceutical giant Eli Lilly and Company has agreed to plead guilty and pay $1.415 billion for promoting its drug Zyprexa for uses not approved by the Food and Drug Administration (FDA), the Department of Justice announced. This resolution includes a criminal fine of $515 million, the largest ever in a health care case, and the
Full Post: Eli Lilly to pay $1.415 billion for off-label promotion of Zyprexa
Indulgence in a high-fat diet can not only lead to overweight because of excessive calorie intake, but also can affect the balance of circadian rhythms - everyone’s 24-hour biological clock, Hebrew University of Jerusalem researchers have shown.
The biological clock regulates the expression and/or activity of enzymes and hormones involved in metabolism, and disturbance of the clock can lead to such phenomena as hormone imbalance, obesity, psychological and sleep disorders and cancer.
While light is the strongest factor affecting the circadian clock, Dr. Oren Froy and his colleagues of the Institute of Biochemistry, Food Science and Nutrition at the Hebrew University’s Robert H. Smith Faculty of Agriculture, Food and Environment in Rehovot, have demonstrated in their experiments with laboratory mice that there is a cause-and-effect relation between diet and biological clock imbalance.
To examine this thesis, Froy and his colleagues, Ph.D. student Maayan Barnea and Zecharia Madar, the Karl Bach Professor of Agricultural Biochemistry, tested whether the clock controls the adiponectin signaling pathway in the liver and, if so, how fasting and a high-fat diet affect this control. Adiponectin is secreted from differentiated adipocytes (fat tissue) and is involved in glucose and lipid metabolism. It increases fatty acid oxidation and promotes insulin sensitivity, two highly important factors in maintaining proper metabolism.
The researchers fed mice either a low-fat or a high-fat diet, followed by a fasting day, then measured components of the adiponectin metabolic pathway at various levels of activity. In mice on the low-fat diet, the adiponectin signaling pathway components exhibited normal circadian rhythmicity. Fasting resulted in a phase advance. The high-fat diet resulted in a phase delay. Fasting raised and the high-fat diet reduced adenosine monophosphate-activated protein kinase (AMPK) levels. This protein is involved in fatty acid metabolism, which could be disrupted by the lower levels.
In an article soon to be published by the journal Endocrinology, the researchers suggest that this high-fat diet could contribute to obesity, not only through its high caloric content, but also by disrupting the phases and daily rhythm of clock genes. They contend also that high fat-induced changes in the clock and the adiponectin signaling pathway may help explain the disruption of other clock-controlled systems associated with metabolic disorders, such as blood pressure levels and the sleep/wake cycle.
After you eat a burger and fries or other fat-filled meal, a protein produced by the liver may send a signal that fat is on the way, suggests a report in the December issue of the journal Cell Metabolism, a Cell Press publication. Researchers have found in mice that the liver produces a protein called
Full Post: Adropin protein produced by the liver sends signal that fat is on the way in response to high-fat foods
Scientists at the University of Texas at Austin have identified pathways by which a reduced-calorie diet and exercise can modify a postmenopausal woman’s risk of breast cancer. The results, presented at the American Association for Cancer Research’s Seventh Annual International Conference on Frontiers in Cancer Prevention Research, suggest that both caloric restriction and exercise affect
Full Post: Reduced-calories and exercise can modify a postmenopausal woman’s risk of breast cancer
Diabetes and high levels of blood sugar may be linked to abnormalities in a person’s body clock and sleep patterns, according to a genome-wide association study published today in the journal Nature Genetics. The research suggests that diabetes and higher than normal blood sugar levels could partly be tackled by treating sleep problems, say
Full Post: Body clock and sleep patterns linked to diabetes and high blood sugar
French scientists have found a drug they say tricks the body into burning off fat - and it even works on a high-fat diet. Reducing calorie consumption by about 20% has been shown to slow down the aging process, improve endurance and protect against diet-induced obesity and metabolic diseases such as diabetes. Last year researchers
Full Post: New drug tricks the body into burning off fat
The immune system’s battle against invading bacteria reaches its peak activity at night and is lowest during the day. Experiments with the laboratory model organism, Drosophila melanogaster, reveal that the specific immune response known as phagocytosis oscillates with the body’s circadian rhythm, according to Stanford researchers who presented their findings at the American Society for
Full Post: Research suggests that immunity is stronger at night