5 Reasons Intermittent Fasting Is Good for Cardiac Health

The easy availability of various foods from across the world, the increased consumption of processed foods, and the marketing of lip-smacking snacks as fillers between meals are just a few of the challenges to following healthy eating practices.

A lot of undue focus is being laid on exotic, fancy diets, while tried and tested eating habits are being overlooked.

Of those, fasting is one of the most ancient ones engraved in human history.

Surprisingly, however, whenever fasting is mentioned, it mostly invites the same eye-rolling response.

It is misunderstood as another name for starvation.

But am I endorsing starving oneself? No! There is a type of eating plan that periodically switches between fasting and feasting in a periodic way that is gaining traction of late.

This article highlights five reasons, among many, why intermittent fasting should be practiced more often.

Tried and tested fasting practice

In the 1980s, a new concept of fasting gained popularity that centered on when to eat instead of what to eat.

This form of fasting has come to be known as intermittent fasting (IF).

In prehistoric times, humans practiced IF inadvertently when they were dependent on hunting and gathering for food before they learned to farm.

As hunting for food had a lot of inherent determinants, humans had to survive and thrive for long periods without eating.

This practice of episodic eating is akin to the recent fasting trend—intermittent fasting.

IF is supported by decades of studies showcasing its capability to ward off diseases such as obesity, diabetes, cancer, and neurodegenerative disease (Gotthardt et al., 2016; Duan et al., 2003; Dorff et al., 2016).

Most of the research has been conducted on rodents, and it is yet to be firmly ascertained if these outcomes of IF hold true in humans also.

Globally, millions are suffering from these diseases, which makes it even more important to learn more about IF and its potential benefits.

This involves knowing what it is, how it can best be followed, the most effective time window and length of fasting, and its variations. 

Easy to follow

The concept of intermittent fasting will not be unfamiliar to anyone who is au courant with the latest health and fitness trends.

Typically, IF entails dividing a day into a large window of fasting (no food at all) and a short window of “feasting” (normal eating).

In other models of IF, fasting and feasting windows are in units of days in a week rather than hours in a day.

Among the popular protocols defining the fasting and non-fasting windows are 16:8 (16 hours fasting and 8 hours non-fasting in a day), alternate-day fasting (24 hours fasting followed by 24 hours non-fasting), and 2:5 (two days fasting and five days non-fasting in a week).

Although the concept of fasting has existed across the globe in different forms as part of religious and cultural practices, it is only recently that IF has started gaining traction among health enthusiasts and scientists.

Better results than traditional dieting

One may ask, How is IF different from good old calorie restriction (CR) when it comes to a diet plan? While CR focuses on how much to eat (aiming to restrict calorie intake), IF specifies when to eat, allowing normal calorie intake in the non-fasting window. CR regulates metabolic parameters, whereas IF, without reducing calorie intake, signals the body to act differently.

Of course, mindful eating—avoiding junk and processed food—is common to both.

A recent study has evinced the following beneficial impacts of IF on human health (Trumpfeller, 2020):

• Weight loss
• Belly-fat reduction
• Better night’s sleep
• Increased longevity
• Maintained muscle mass
• Reduced oxidative stress
• Increase in cell turnover
• Improved mood and energy levels
• Prevention of cancer and neurological, cardiovascular, and metabolic disorders

Scientifically proven

The increasing popularity of IF prompted me to dive deep into the science behind it.

In the process, I came across the term metabolic switching, which illustrates the alteration of signaling pathways that occurs during IF (Anton et al., 2018).

While following IF, during fasting, our liver converts its glycogen stores into glucose, which is released into the bloodstream to maintain high blood-glucose levels.

After 12–36 hours, a metabolic shift takes place in which the body starts consuming fat stores as a source of fuel.

This energy-source transition influences metabolic pathways, resulting in weight loss and the prevention of diseases.

The energy-source flipping may improve body composition even though the causes of this switch are still unclear.

At the hormonal level, IF regulates appetite through ghrelin, a “hunger hormone,” and leptin, a “satiety hormone” (Ravussin et al., 2019).

Reduced ghrelin and increased leptin cause our bodies to consume fewer calories, resulting in weight loss.

Heart health

IF aids in maintaining a healthy heart and preventing cardiovascular diseases. Below are the mechanisms involved in preventing heart diseases:

1. The major mechanism through which fasting appears to lower the risk of cardiovascular disease involves improved insulin sensitivity.

One of insulin’s main functions is to stimulate uptake of glucose from the blood by cells that eventually get used as fuel.

With decreased insulin sensitivity (insulin resistance), cells require larger quantities of insulin as signals, and even then they cannot use up all the glucose from the blood, causing high blood-sugar levels.

In a 2008 study, the American Journal of Cardiology also observed that fasting is associated with a dramatic reduction in the risk of heart diseases (Horne et al., 2009).

A few reports establish a strong association between insulin resistance and heart diseases (Adeva-Andany et al., 2019; Ormazabal et al., 2018).

Fasting, by giving a break to the system, reduces glucose and thereby insulin in the blood, thus eliminating (temporarily) exposure to the stimulus and resetting the sensitivity.

2. Autophagy, which is induced by limiting nutrients, is a cellular-level housekeeping process in which damaged cell components, including misfolded proteins, are destroyed and reused.

If these misfolded proteins accumulate, it leads to proteinopathy, a condition observed in many cardiovascular conditions such as aging-induced cardiac hypertrophy and heart failure (Sandri & Robbins, 2014).

By inducing autophagy, IF plays a pivotal role in combating age-associated decline in cardiovascular health (Abdellatif et al., 2018).

A study done on rodents and fruit flies demonstrated that IF-induced autophagy dampens cardiac aging by attenuating (via deactivating mTOR and activating AMPK) myocardial collagen deposition, oxidative stress, inflammatory markers, and more (Zhang et al., 2018).

3. Another way in which IF helps improve heart health is by lowering blood pressure.

A study on animals who were kept on an IF diet showed decreased blood pressure and heart rate (Mager et al., 2006).

Recently, the same effectiveness of IF on blood pressure was seen on human group also (Wilhelmi de Toledo et al., 2019).

4. IF seems to affect the biochemical profiles of lipids, which in return changes lipid parameters and maintains good heart health.

Levels of total cholesterol, triglycerides, and low-density cholesterol are found to be decreased, therefore limiting the risk of coronary heart diseases (Bhutani et al., 2013).

This study was done on humans and demonstrates the effectiveness of intermittent fasting on the human heart.  

Summary 

• Intermittent fasting, a dietary intervention, is based on the principle of time-based restriction of food intake. 

• Due to its effects of increased insulin sensitivity, enhanced autophagy, and reduced blood pressure and lipid stores, IF seems to be a promising dietary intervention in not only cardiovascular but also other chronic diseases like obesity and aging-related diseases that are associated with insulin resistance.

• It looks like IF presents a better alternative to conventional dieting (effectively, calorie restriction) as it mimics the biochemical benefits of CR without the associated risks such as decreased immunity and low libido.

• IF is more viable as it doesn’t rely on “superfoods” with exorbitant prices and the fasting window includes the sleeping hours: an early dinner and a late brunch are all it would take to implement IF into your daily routine.

• Intermittent fasting has surely helped several including me to lose weight, and I shall be expecting to benefit from its long-term heart health advantages.

References

Abdellatif, M., Sedej, S., Carmona-Gutierrez, D., Madeo, F., & Kroemer, G. (2018). Autophagy in cardiovascular aging. Circ. Res. 123(7), 803–824.

Adeva-Andany, M. M., Martínez-Rodríguez, J., González-Lucán, M., Fernández-Fernández, C., & Castro-Quintela, E. (2019). Insulin resistance is a cardiovascular risk factor in humans. Diabetes Metab. Syndr. 13(2), 1449–1455.

Anton, S. D., Moehl, K., Donahoo, W. T., Marosi, K., Lee, S., Mainous, A. G., Leeuwenburgh, C., & Mattson, M. (2018). Flipping the metabolic switch: Understanding and applying health benefits of fasting.” Obesity (Silver Spring) 26(2), 254–268.

Bhutani, S., Klempel, M. C., Kroeger, C. M., Trepanowski, J. F., & Varady, K. A. (2013). Alternate day fasting and endurance exercise combine to reduce body weight and favorably alter plasma lipids in obese humans. Obesity (Silver Spring) 21(7), 1370–1379.

Dorff, T. B., Groshen, S., Garcia, A., Shah, M., Tsao-Wei, D., Pham, H., Cheng, C.-W., Brandhorst, S., Cohen, P., Wei, M., Longo, V., & Quinn, D. I. (2016). Safety and feasibility of fasting in combination with platinum-based chemotherapy. BMC Cancer 16, article 360.

Duan, W., Guo, Z., Jiang, H., Ware, M., & Mattson, M. P. (2003). Reversal of behavioral and metabolic abnormalities, and insulin resistance syndrome, by dietary restriction in mice deficient in brain-derived neurotrophic factor. Endocrinology 144(6), 2446–2453.

Gotthardt, J. D., Verpeut, J. L., Yeomans, B. L., Yang, J. A., Yasrebi, A., Roepke, T. A., & Bello, N. T. (2016). Intermittent fasting promotes fat loss with lean mass retention, increased hypothalamic norepinephrine content, and increased neuropeptide y gene expression in diet-induced obese male mice. Endocrinology 157(2), 679–691.

Horne, B. D., May, H. T., Anderson, J. L., Kfoury, A. G., Bailey, B. M., McClure, B. S., Renlund, D. G., Lappé, D. L., Carlquist, J. F., Fisher, P. W., Pearson, R. R., Bair, T. L., Adams, T. D., Muhlestein, J. B., & for the Intermountain Heart Collaborative Study. (2009). Usefulness of routine periodic fasting to lower risk of coronary artery disease among patients undergoing coronary angiography. Am. J. Cardiol. 102(7), 814–819.

Mager, D. E., Wan, R., Brown, M., Cheng, A., Wareski, P., Abernethy, D. R., & Mattson, M. P. (2006). Caloric restriction and intermittent fasting alter spectral measures of heart rate and blood pressure variability in rats. FASEB J. 20(6), 631–637.

Ormazabal, V., Nair, S., Elfeky, O., Aguayo, C., Salomon, C., & Zuñiga, F. A. (2018). Association between insulin resistance and the development of cardiovascular disease. Cardiovasc. Diabetol. 17, article 122.

Ravussin, E., Beyl, R. A., Poggiogalle, E., Hsia, D. S., & Peterson, C. M. (2019.) Early time-restricted feeding reduces appetite and increases fat oxidation but does not affect energy expenditure in humans. Obesity (Silver Spring) 27(8), 1244–1254.

Sandri, M., & Robbins, J. (2014). Proteotoxicity: an underappreciated pathology in cardiac disease. J. Mol. Cell Cardiol. 71, 3–10.

Trumpfeller, G. (2020, February 25). 16 benefits of intermittent fasting. Simple. https://simple.life/blog/intermittent-fasting-benefits/

Wilhelmi de Toledo, F., Grundler, F., Bergouignan, A., Drinda, S., & Michalsen, A. (2019). Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. PLoS One 14(1), e0209353.

Zhang, S., Ratliff, E. P., Molina, B., El-Mecharrafie, N., Mastroianni, J., Kotzebue, R. W., Achal, M., Mauntz, R. E., Gonzalez, A., Barekat, A., Bray, W. A., Macias, A. M., Daugherty, D., Harris, G. L., Edwards, R. A., & Finley, K. D. (2018). Aging and intermittent fasting impact on transcriptional regulation and physiological responses of adult drosophila neuronal and muscle tissues. Int. J. Mol. Sci. 19(4), 1140.