By Kelley Herring
What doesn’t kill us makes us stronger…
This is not only an old adage with a lot of inherent wisdom. It also summarizes a biological process – called hormesis – where certain forms of stress stimulate beneficial improvements in strength, resilience, immune function and other important health markers.
And while the consumption of food is a pillar on which life depends, the “hormetic stress” caused by temporarily abstaining from food can result in benefits that are not only profound, but also very long lasting.
In fact, it is safe to say that fasting could be considered the world’s safest and most effective medicine!
Dozens of controlled studies show that occasional fasting can slow the aging process and lead to increased healthy longevity. It can arrest the development of cancer, protect the brain1, improve blood sugar2, reverse insulin resistance3, reduce risk of Alzheimer’s and Parkinson’s4, reduce inflammation5,6, and calm digestive distress.
And in today’s article, we delve into new research that shows how fasting can supercharge your dieting efforts and produce long-lasting changes in your metabolism and health.
Remodel Your Microbiome, Remodel Your Metabolism
Researchers at the Max Delbruck Center for Molecular Medicine in Germany set out to discover how a fast before a diet might improve health outcomes.
The researchers selected 71 participants with metabolic syndrome and high blood pressure and divided the subjects into two groups. Both groups followed a Mediterranean-style diet. However, one of the groups started the diet with a 5-day fast.
The researchers used a technique called immunophenotyping to show how the immune cells of the volunteers changed depending on what they ate.
What they discovered is that the innate immune system remained stable during the fast, but the adaptive immune system shuts down. They also found that the number of pro-inflammatory T cells dropped, while regulatory T cells (which are critical for preventing autoimmunity) multiplied.
The researchers also compared the composition of the volunteers’ gut bacteria. They discovered stark contrasts in the microbiomes of the two groups. The fasting group experienced a dramatic shift in bacteria that beneficially impact blood pressure. And these beneficial changes remained… even when food intake was resumed!7
Lead researcher, Dominik Müller, states:
“Body mass index, blood pressure and the need for antihypertensive medication remained lower in the long term among volunteers who started the healthy diet with a five-day fast.”
This is especially impressive, considering that blood pressure can be quite volatile in those with metabolic syndrome and typically rises rapidly when just one anti-hypertensive tablet is forgotten!
Short-Term Fast Yields Long-Term Benefits
So, how does a short period of food restriction make such a profound impact on blood pressure and the immune system?
It is well known that gut bacteria work in close harmony with the immune system. And fasting acts as a catalyst for protective microorganisms in the gut.
Not only does fasting modify the genes and proteins that comprise your immune system, it can also modify your metabolism.
That’s because an unhealthy imbalance in the gut (called dysbiosis) promotes numerous inflammatory, cardiovascular and metabolic disorders, including hypertension.8,9,10 And fasting is known to remodel the microbiome and increase healthy biodiversity – therefore reducing dysbiosis and its associated health risks.11,12,13
Fasting is arguably the most powerful – and underutilized – tool we have in our arsenal against the most devastating chronic diseases. Not only is it “free” – it will actually save you money and only requires your personal commitment to reap the astounding benefits. And unlike pharmaceuticals that claim to do the same thing, fasting does not come with a laundry list of harmful “side effects”.
If you’ve never tried a fast, start slowly and work your way up. Begin with intermittent fasting by eating during a compressed eating window each day. Once you’re accustomed to going 16-20 hours without food – and there are many benefits to these shorter fasts too – then consider doing two to five day fast.
In addition to focusing your attention on the amount of grazing and “mindless eating” we all engage in, the health benefits are remarkable. And as this study – and many others – demonstrates, these benefits continue long after the fast itself has concluded.
And when it’s time to refeed after a fast – replenish your body with the nutrient-dense ancestral superfoods you are designed to enjoy, including grass-fed beef, farm-fresh-eggs and wild seafood!
Read more of Kelley Herring’s health and wellness articles on our Discover Blog.
Ed Note: Need some kitchen inspiration? Grab Kelley’s free guide – Instant Pot Keto Dinners – made exclusively with Paleo-and-Keto ingredients, for quick and delicious meals that taste just as good – of not better – than your restaurant favorites. Get your free guide here.
References
1 Anson, RM, Guo, Z, de Cabo, R, Iyun, T, Rios, M, Hagepanos, A, Ingram, DK, Lane, MA, Mattson, MP. Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. PNAS May 13, 2003 100 (10) 6216-6220.
2 Varady KA, Hellerstein MK. Alternate-day fasting and chronic disease prevention: a review of human and animal trials. Am J Clin Nutr. 2007;86:7–13.
3 Halberg N, Henriksen M, Soderhamn N, et al. Effect of intermittent fasting and refeeding on insulin action in healthy men. J Appl Physiol. 2005;99:2128–2136.
4 Mattson MP. Energy intake and exercise as determinants of brain health and vulnerability to injury and disease. Cell Metab. 2012;16(6):706–722.
5 Mattson, MP, Longo, VD, Harvie, M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017 Oct;39:46-58. PMID: 27810402
6 Longo, VD, Mattson, MP. Fasting: molecular mechanisms and clinical applications. Cell Metab. 2014 Feb 4;19(2):181-92. PMID: 24440038
7 András Maifeld, Hendrik Bartolomaeus, Ulrike Löber, Ellen G. Avery, Nico Steckhan, Lajos Markó, Nicola Wilck, Ibrahim Hamad, Urša Šušnjar, Anja Mähler, Christoph Hohmann, Chia-Yu Chen, Holger Cramer, Gustav Dobos, Till Robin Lesker, Till Strowig, Ralf Dechend, Danilo Bzdok, Markus Kleinewietfeld, Andreas Michalsen, Dominik N. Müller, Sofia K. Forslund. Fasting alters the gut microbiome reducing blood pressure and body weight in metabolic syndrome patients. Nature Communications, 2021; 12 (1) DOI: 10.1038/s41467-021-22097-0
8 Lynch, S. V. & Pedersen, O. The human intestinal microbiome in health and
disease. N. Engl. J. Med. 375, 2369–2379 (2016).
9 Yan, Q. et al. Alterations of the gut microbiome in hypertension. Front Cell
Infect. Microbiol. 7, 381 (2017).
10 Li, J. et al. Gut microbiota dysbiosis contributes to the development of
hypertension. Microbiome 5, 14 (2017).
11 Frost, F. et al. A structured weight loss program increases gut microbiota
phylogenetic diversity and reduces levels of Collinsella in obese type 2
diabetics: a pilot study. PLoS ONE 14, e0219489 (2019)
12 Ozkul, C., Yalinay, M. & Karakan, T. Structural changes in gut microbiome
after Ramadan fasting: a pilot study. Beneficial Microbes 11, 227–233
(2020).
13 Louis, S., Tappu, R. M., Damms-Machado, A., Huson, D. H. & Bischoff, S. C.
Characterization of the gut microbial community of obese patients following a
weight-loss intervention using whole metagenome shotgun sequencing. PLoS
ONE 11, e0149564 (2016).
