8/09/2009

Intermittent Fasting: Amazing health benefits




Intermitent Fasting: Amazing health benefits

Intermittent fasting and calorie restriction are two ways of reducing your calorie intake to obtain health benefits (1).

Intermittant fasting might be accomplished by eating every other day, for example, while calorie restriction means eating every day, but eating less. In both cases, you have to make sure your intake of micronutrients is optimal, and your physician agrees, as for any sane dietary choice.

On the scientific side:
Both calorie restriction and intermittent fasting produce significant health and longevity benefits in shorter-lived mammals such as mice, and at least significant health benefits in primates, including humans.


Far more research has been accomplished for calorie restriction, and uncertainty remains as to whether intermittent fasting is as good, definitely increases longevity, has a preferred method of practice, or whether it could even be harmful to long-term health if done incorrectly.


It seems plausible that calorie restriction and intermittent fasting produce their benefits in similar but different ways, based on research in lower animals, but I know of no research confirming this in mammals.


From the point of view of actively practicing either intermittent fasting or calorie restriction, intermittent fasting is much easier for anyone whose eating habits interact with those of other people, or who is already fairly set in his ways with good dietary habits.


You just don't eat some days - very simple, and few other changes to the routines of life are needed.

Starting to practice calorie restriction, on the other hand, requires greater effort and more thought in terms of changing your diet. It's not hard, especially given the good resources available to walk you through the obvious pitfalls, but it isn't as simple as just saying "I'm not eating right now."


So the traditional trade-off in labor and knowledge:
Intermittent fasting is usually much easier to introduce into your life, but has far less scientific support or a body of research to indicate the optimum methodology.
Calorie restriction requires more initiative to organize, but has a great weight of science backing it up, and a wide range of resources based on decades of practical experience.
Given what I know of human nature, I suspect that intermittent fasting will rapidly become more popular than calorie restriction as soon as it accumulates a little more research in mammals than presently exists.


(1)Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems

by Mattson MP, Wan R. Laboratory of Neurosciences,

National Institute on Aging Intramural Research Program,

Baltimore, MD 21224, USA. mattsonm@grc.nia.nih.govJ Nutr Biochem. 2005 Mar;16(3):129-37.


ABSTRACT

Intermittent fasting (IF; reduced meal frequency) and caloric restriction (CR) extend lifespan and increase resistance to age-related diseases in rodents and monkeys and improve the health of overweight humans. Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity.

Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke.


The beneficial effects of IF and CR result from at least two mechanisms--reduced oxidative damage and increased cellular stress resistance. Recent findings suggest that some of the beneficial effects of IF on both the cardiovascular system and the brain are mediated by brain-derived neurotrophic factor signaling in the brain. Interestingly, cellular and molecular effects of IF and CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting shared mechanisms.


A better understanding of the cellular and molecular mechanisms by which IF and CR affect the blood vessels and heart and brain cells will likely lead to novel preventative and therapeutic strategies for extending health span.