Long-term caloric restriction
Objectives: We determined whether caloric restriction (CR) has cardiac-specific effects that attenuate the established aging-associated impairments in diastolic function.
Background: Caloric restriction retards the aging process in small mammals; however, no information is available on the effects of long-term CR on human aging. In healthy individuals, Doppler echocardiography has established the pattern of aging-associated diastolic impairment, whereas little change is observed in systolic function.
Methods: Diastolic function was assessed in 25 subjects (age 53 +/- 12 years) practicing CR for 6.5 +/- 4.6 years and 25 age- and gender-matched control subjects consuming Western diets. Diastolic function was quantified by transmitral flow, Doppler tissue imaging, and model-based image processing (MBIP) of E waves. C-reactive protein (CRP), TNF-alpha and TGF-beta1 were also measured.
Results: No difference in systolic function was observed between groups; however, standard transmitral Doppler flow diastolic function indexes of the CR group were similar to those of younger individuals, and MBIP-based, flow-derived diastolic function indexes, reflecting chamber viscoelasticity and stiffness, were significantly lower than in control subjects.
Blood pressure, serum CRP, TNF-alpha, and TGF-beta1 levels were significantly lower in the CR group (102 +/- 10/61 +/- 7 mm Hg, 0.3 +/- 0.3 mg/l, 0.8 +/- 0.5 pg/ml, 29.4 +/- 6.9 ng/ml, respectively) compared with the Western diet group (131 +/- 11/83 +/- 6 mm Hg, 1.9 +/- 2.8 mg/l, 1.5 +/- 1.0 pg/ml, 35.4 +/- 7.1 ng/ml, respectively).
Conclusions: Caloric restriction has cardiac-specific effects that ameliorate aging-associated changes in diastolic function. These beneficial effects on cardiac function might be mediated by the effect of caloric restriction on blood pressure, systemic inflammation, and myocardial fibrosis.
SOURCE: J Am Coll Cardiol
EDITOR’S NOTE: The middle-aged adults in the calorie restriction group maintained an average blood pressure (102/61) that in Western society is normally characteristic of a pre-teen.