Cardioprotection by Intermittent Fasting in Rats

[Bo Bolund]

Cardioprotection by Intermittent Fasting in Rats
Ismayil Ahmet, MD, PhD*; Ruiqian Wan, PhD*; Mark P. Mattson, PhD; Edward G. Lakatta, MD; Mark Talan, MD, PhD

Background— Intermittent fasting (IF), a dietary regimen in which food is available only every other day, increases the life span and reduces the incidence of age-associated diseases in rodents. We have reported neuroprotective effects of IF against ischemic injury of the brain. In this study, we examined the effects of IF on ischemic injury of the heart in rats.

Methods and Results— After 3 months of IF or regular every-day feeding (control) diets started in 2-month-old rats, myocardial infarction (MI) was induced by coronary artery ligation. Twenty-four hours after MI, its size in the IF group was 2-fold smaller, the number of apoptotic myocytes in the area at risk was 4-fold less, and the inflammatory response was significantly reduced compared with the control diet group. Serial echocardiography revealed that during 10 weeks after MI (with continuation of the IF regimen), the left ventricular (LV) remodeling and MI expansion that were observed in the control diet group were absent in the IF group. In a subgroup of animals with similar MI size at 1 week after MI, further observation revealed less remodeling, better LV function, and no MI expansion in the IF group compared with the control group.

Conclusions— IF protects the heart from ischemic injury and attenuates post-MI cardiac remodeling, likely via antiapoptotic and antiinflammatory mechanisms.

...
Because the IF regimen used in the present study results in an overall reduction in calorie intake and hence, a lower BW, the relative contributions of fasting and caloric restriction components of this diet to improved outcomes after MI are not known. Previous studies suggest 2 general mechanisms by which IF and caloric restriction increase life span and protect neurons against injury One mechanism involves reduced levels of oxidative stress as the result of reduced mitochondrial oxyradical production, and the other mechanism involves induction of expression of stress resistance genes, such as those that encode protein chaperones and growth factors. Caloric restriction may exert its beneficial effects primarily by reducing oxidative stress, whereas IF may act primarily by a stress resistance mechanism. Reduced oxidative stress and increased cellular stress resistance therefore likely underlie the cardioprotective effects of IF in the present study.

http://www.circ.ahajournals.org/cgi/...ll/112/20/3115

[Mike ODonnell]

Good study link.

whereas IF may act primarily by a stress resistance mechanism. Reduced oxidative stress and increased cellular stress resistance therefore likely underlie the cardioprotective effects of IF in the present study.

There it is right there...our bodies want to learn how to get stronger through periods fasting...vs people who eat all day long and will never give their body the needed stimulus to learn how to protect itself.