Is calorie restriction stressful?

Yes, but it seems to be a good stress. Restriction of food intake to the degree that it extends life span is associated with same protective mechanisms mobilized by stress. In another research conducted by the same university, results indicate that at least one

inflammatory reaction, an edema, is attenuated by food restriction (60 percent of adlibitum calories) and are consistent with the hypothesis that food restriction enhances a potentially protective glucocorticoid activity. (Journals of Gerontology, Series A, Biological Sciences & Medical Sciences. 50(2):B79-82, 1995)

The mechanism of action of caloric restriction remains unknown; owever, data suggest that cellular functions are altered in such a way that destructive by-products of metabolism are reduced, and defense or repair systems are enhanced by this nutritional manipulation. (Clinics in Geriatric Medicine, 11(4):553-65, 1995))

The amount of oxidative damage increases as an organism ages and is postulated to be a major causal factor of senescence. Restriction of caloric intake lowers levels of oxidative stress and damage, retards age associated changes, and extends the maximum life span in mammals. Animal and human studies suggest potential benefits of dietary restriction, exercise, antioxidants, hormones and deprenyl.

Does deprenyl mimic at least some of calorie restriction effects? Probably, thinks Dr. Masoro. "Dietary restriction protects against oxidative damage and oxidative damage is probably an inevitable component of fuel use." So does deprenil, though in rather narrow way. Deprenyl (selegiline) is a neuroprotective drug an inhibitor of brain monoamine oxidase B (MAO-B). That means it inhibits a very particular enzyme promoting oxidation of the brain chemical monoamines, which are very important in many vital functions, including cognition.

Dietary restriction was found to retard age associated decline of sensory and movement coordination, and improve performance of aged mice on learning problems. "Studies in aged calorie restricted mice indicated that lowering of protein oxidation by calorie restriction could be reversed within a time frame of three to six weeks. These findings suggest that the beneficial effects of dietary restriction upon brain function and life span may depend upon its ability to acutely reduce steady state levels of oxidative stress." (Archives of Biochemistry & Biophysics, 333(1):189-97, 1996)

More on the topic

Dietary restriction and life span

Can Adults Benefit from Calorie Restriction?

Is calorie restriction stressful?

References