Intermittent Fasting: A Heart Healthy Dietary Pattern?

Dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to improve cardiac health. Intermittent fasting is another type of popular dietary pattern that is based on timed periods of fasting. Two different regimens are alternative day fasting and time-restricted eating. Although there are no large, randomized control trials examining the relationship between intermittent fasting and cardiovascular outcomes, current human studies that suggest this diet could reduce the risk for cardiovascular disease with improvement in weight control, hypertension, dyslipidemia, and diabetes. Intermittent fasting may exert its effects through multiple pathways, including reducing oxidative stress, optimization of circadian rhythms, and ketogenesis. This review evaluates current literature regarding the potential cardiovascular benefits of intermittent fasting and proposes directions for future research.

Comparison of total 12-lead QRS voltage in a variety of cardiac conditions and its usefulness in predicting increased cardiac mass.

Echocardiography provides a more accurate method to determine increased cardiac mass than does electrocardiography. Nevertheless, most offices of physicians do not possess echocardiographic machines, but many possess electrocardiographic machines. Many electrocardiographic criteria have been used to determine increased cardiac mass, but few of the criteria have been measured against cardiac weight determined at necropsy or after cardiac transplantation. Such was the purpose of the present study. Cardiac weight at necropsy or after transplantation was determined in 359 patients with 11 different cardiac conditions, and total 12-lead electrocardiographic QRS voltage (from the peak of the R wave to the nadir of either the Q or the S wave, whichever was deeper) was measured in each patient. Even in hearts with massively increased cardiac mass (>1,000 g), the total 12-lead QRS voltage was clearly increased (>175 mm) in only 94%, but this criterion was superior to that of previously described electrocardiographic criteria for "left ventricular hypertrophy." Hearts with excessive adipose tissue infrequently had increased total 12-lead QRS voltage despite increased cardiac weight. Likewise, patients with fatal cardiac amyloidosis had hearts of increased weight but quite low total 12-lead QRS voltage. In conclusion, 12-lead QRS voltage is useful in predicting increased cardiac mass, but that predictability is dependent in part on the cause of the increased cardiac mass.

The effects of caloric restriction on health and longevity.

OPINION STATEMENT: There is increasing evidence that restricting caloric intake may have considerable health benefits in humans. Significant evidence in non-primate animals demonstrates that caloric restriction increases average and maximal life span. However, historically, caloric intake reduction in humans has been involuntary and accompanied by poverty, malnutrition, poor sanitation, and a lack of modern health care. As a result, caloric restriction in people typically has been accompanied by a reduction of both average and maximal life span. Conversely, improvements in standards of living usually are accompanied by an increased food supply and resultant improved health and longevity. The majority of the world is now in a new era where an abundance of caloric intake and its associated obesity are causing widespread chronic illness and premature death. What would happen if one were to institute caloric restriction with high-quality nutrition within an environment of modern sanitation and health care? This review argues that improved health and improved average life span would quite likely result. A lengthening of maximal human life span with this combination is perhaps possible but by no means certain.

Revisiting niacin: reviewing the evidence.

Atherogenic dyslipidemia, defined by a cluster of lipoprotein abnormalities, including low high-density lipoprotein cholesterol (HDL-C) and elevated serum triglycerides, represents an important potential target for reducing cardiovascular risk. This has paved the way for revisiting niacin as a therapy in preventing progression of atherosclerosis. Niacin remains the safest and most effective agent for raising HDL-C and is a logical choice to target atherogenic dyslipidemia. While the clinical efficacy of niacin has been known for many years, it is only with development of newer formulations, which have lower side-effect profiles and improved compliance, that the potential for this agent been fully realized. In this review, we will examine some of the reasons that niacin can have important implications for reducing progression of atherosclerosis. We will first examine the different formulations and their variability, not only in side-effect profiles, but also in clinical efficacy. We will then consider the theoretical evidence for the benefit of HDL-raising produced by niacin on atherosclerotic progression. Finally, we will review clinical data suggesting the benefit of niacin on cardiovascular outcomes.