Low-Calorie, High-Nutrient Diet May Delay Heart Dysfunction
Cardiac performance decreases with age, and typically manifests as a reduction in diastolic function, with possible changes in left ventricular systolic function. Restriction of caloric intake has been shown to increase life span in various animal studies.
Restricted caloric intake has also been shown to improve risk factors for atherosclerosis in humans, but its effect on the aging process in humans remains largely unknown.
In this study, scientists assessed diastolic function in two groups of adults: one group that had practiced caloric restriction for an average of 6.5 years, and an age- and gender-matched group that ate a typical Western diet. The Western diet group's diet averaged 2,445 calories per day, with 17 percent of the calories derived from protein, 52 percent from carbohydrates, and 31 percent from fat (including 11 percent from saturated fat). The caloric restriction diet averaged 1,671 calories, with approximately 23 percent of the calories from protein and 28 percent from fat (including 6 percent from saturated fat). The caloric restriction diet was also "nutritionally balanced," and provided at least 100 percent of the recommended daily intake for several vitamins and nutrients.
Echocardiographic imaging revealed that the standard transmitral diastolic function indexes of patients in the caloric restriction group were similar to those of younger individuals. Flow-derived diastolic function indexes were also significantly lower in caloric restriction patients, which indicated that these subjects' hearts had greater elasticity and less stiffness than Western diet patients. In addition, blood analyses revealed that concentrations of inflammation markers such as high-sensitivity C-reactive protein, transforming growth factor-B1 and tumor necrosis factor were all significantly lower in the caloric restriction group than in the Western diet group.
The researchers concluded that caloric restriction "has cardiac-specific effects that ameliorate aging-associated changes in diastolic function." They added, "These beneficial effects on cardiac function might be mediated by the effect of caloric restriction on blood pressure, systemic inflammation, and myocardial fibrosis."
Meyer TE, Kovacs SJ, Ehsani AA, et al. Long-term caloric restriction ameliorates the decline in diastolic function in humans. Journal of the American College of Cardiology