By Charlotte Harbour, 4th Year BSc Nutritional Therapy student
Autophagy is nothing new.
Although the word was coined in the 1970s, this ancient bodily process has been at work for as long as we’ve been living. Autophagy is derived from Greek words that literally dentate “self- devouring” to conveniently align with the oxford dictionary definition of “consumption of the body’s own tissue as a metabolic process occurring in starvation and certain diseases”.
In Spring 2018, internet searches for autophagy reached peak popularity. This may be due to increased public discussion of the process and press coverage on benefits such as anti-aging. Whatever the reason, it’s always fantastic to see conversations on emerging topics being had around the digital sphere.
With that said, as Nutrition students who will ultimately become professionals – we should continue to stay abreast of trending topics so that we are able to deliver evidence-based advice to those around us seeking answers from well informed individuals. This will become particularly prevalent when working with clients who ask about the latest food trends and whether they are as “sensational” or “dangerous” as the media suggests.
Like most things, there is typically a balance – and autophagy is no exception.
Autophagy is a natural waste removal process that eliminates intracellular pathogens, clears damaged organelles and balances sources of energy in response to nutrient stress. Not akin to its cousin Apoptosis, Autophagy is not programmed cell death but is the process in which cellular waste and dysfunctional proteins are recycled.
Autophagy is typically upregulated when the body is in a state of fasting for between 24 – 48 hours (Alirezaei et al., 2010) or in a state of ketosis. Research suggests that autophagy can be beneficial in supporting overall positive health outcomes, as well as regulating energy levels, enhancing the immune system and protecting the stability of DNA. Furthermore, diminished autophagic activity has been shown to play a major role in age-related manifestations such as a decrease in the turnover of cellular components and oxidative damage accumulation (Cuervo et al., 2005). Defective autophagy is associated with pathological conditions such as cancer, autoimmune disease, neurodegenerative disease and senescence (Netea-Maier et al., 2015).
However, whilst these claims are emboldened and, on the surface, seem to support the therapeutic utilisation of autophagy, we must be cognisant of conflicting research that leads to caution when practicing therapies that may not be suitable for everyone. Indeed, more recent research suggests that autophagy suppresses degenerative diseases but has a context-dependent role in cancer. In some models, cancer initiation is suppressed by autophagy (White, Mehnert and Chan, 2015) whilst in other studies, autophagy has been reported to either inhibit or promote cancer cell proliferation or tumorigenesis, suggesting that the role of autophagy in cancer is context dependent (White, 2012). Furthermore, fasting is not typically recommended for those who or pregnant or experience diabetes – so achieving upregulating autophagy can be an unrealistic challenge for some.
From this brief investigation of autophagy, we can arrive at the traditional conclusions when discussing nutritional trends:
- There are benefits and drawbacks to upregulating this biological process
- Peer reviewed research must be explored
- Vulnerable groups must be properly advised based on the studies and their individual circumstances.
This article may act as a reminder to look deeper, into all corners of the research, to arrive at a balanced conclusion that we as nutrition professions need to continually strive towards to ensure that we provide optimal advice to each and every one of our clients.
Alirezaei, M., Kemball, C., Flynn, C., Wood, M., Whitton, J. and Kiosses, W. (2010). Short-term fasting induces profound neuronal autophagy. Autophagy, 6(6), pp.702-710.
Cuervo, A., Bergamini, E., Brunk, U., Dröge, W., Ffrench, M. and Terman, A. (2005). Autophagy and Aging: The Importance of Maintaining “Clean” Cells. Autophagy, 1(3), pp.131-140.
Netea-Maier, R., Plantinga, T., van de Veerdonk, F., Smit, J. and Netea, M. (2015). Modulation of inflammation by autophagy: Consequences for human disease. Autophagy, 12(2), pp.245-260.
White, E. (2012). Deconvoluting the context-dependent role for autophagy in cancer. Nature Reviews Cancer, 12(6), pp.401-410.
White, E., Mehnert, J. and Chan, C. (2015). Autophagy, Metabolism, and Cancer. Clinical Cancer Research, 21(22), pp.5037-5046.