Developmental Biology - Fasting|
Intermittent Fasting & Living Longer
Alternating between fasting and eating may trigger metabolic switching...
For many people, the New Year is a time to adopt new habits as a renewed commitment to personal health. Newly enthusiastic fitness buffs pack into gyms and grocery stores are filled with shoppers eager to try out new diets.
But, does scientific evidence support the claims made for these diets? In a review article published in the Dec. 26 issue of The New England Journal of Medicine, Mark Mattson PhD, professor of neuroscience at the Johns Hopkins University School of Medicine, concludes intermittent fasting does work.
Mattson has studied the health impact of intermittent fasting for 25 years and adopted it himself about 20 years ago. He writes that "intermittent fasting could be part of a healthy lifestyle." His new article is intended to help clarify the science and clinical applications of intermittent fasting in ways that may help physicians guide patients.
Intermittent fasting diets fall into two categories:
(1) daily time-restricted fasting, which narrows eating times to 6-8 hours per day, and
(2) intermittent fasting, with one moderate meal two days a week or 5:2.
An array of animal and some human studies show how alternating between times of fasting and eating supports cell health, Probably by triggering "metabolic switching" an age-old adaptation to periods of food scarcity. Switching occurs when cells use up highly accessible stores of sugar-based fuel, and begin converting fat into energy through a slower metabolic process.
Studies show "switching" improves blood sugar regulation, increases resistance to stress and suppresses inflammation. As most Americans eat three meals a day plus snacks, they don't experience "metabolic switching," or its benefits.
Mattson notes four studies in both animals and people found intermittent fasting decreased blood pressure, blood lipid levels and resting heart rates.
Evidence is also mounting that intermittent fasting can modify risk factors associated with obesity and diabetes. Two studies at the University Hospital of South Manchester NHS Foundation Trust — of 100 overweight women showed those on the 5:2 intermittent fasting diet lost the same amount of weight as women who restricted calories. But, they did better on measures of insulin sensitivity, while reducing more belly fat than those in the calorie-reduction group.
More recently, preliminary studies suggest intermittent fasting could also benefit brain health.
A multicenter clinical trial at the University of Toronto in April 1919, found that 220 healthy, non-obese adults who maintained calorie restricted diets for two years, showed improved memory in a battery of cognitive tests.
Far more research needs to be done to prove any effects of intermittent fasting on learning and memory. But if that proof is found, fasting - or a pharmaceutical equivalent that mimics fasting - may help stave off neurodegeneration and dementia.
"We are at a transition point where we could soon consider adding information about intermittent fasting to medical school curricula alongside standard advice about healthy diets and exercise," Mattson adds.
Acknowledging that researchers do "not fully understand the specific mechanisms of metabolic switching — and that some people are unable or unwilling to adhere to fasting regimens," Mattson believes with guidance and patience, most people can incorporate these practices into their lives. It takes some time for the body to adjust to intermittent fasting, and get beyond hunger pangs and irritability. "Patients should be advised that feeling hungry and irritable is common initially and usually passes after two weeks to a month as the body and brain become accustomed to new habits," he explains.
Mattson suggests physicians advise patients to gradually increase their duration and frequency of fasting periods over several months, instead of "going cold turkey." As with all lifestyle changes, it's important for physicians to understand the science so they can communicate potential benefits and challenges, and offer support.
Evidence is accumulating that eating in a 6-hour period and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-based energy, with increased stress resistance, increased longevity, and a decreased incidence of diseases, including cancer and obesity.
Rafael de Cabo PhD and Mark P. Mattson PhD.
This work was supported by the Intramural Research Program of the National Institute on Aging, National Institutes of Health.
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Dec 26 2019 Fetal Timeline Maternal Timeline News
The Benefits of Intermittent Fasting CREDIT Johns Hopkins Medicine.