Wonders of Intermittent Fasting
Short or long - it all works.
Mardis Gras, aka ‘Fat Tuesday’, has just marched past us … like the jazz bands of New Orleans. A final burst of feasting leading into Lenten’s fasting and delayed gratification.
During the 40 days of Lent, Catholics are expected to abstain from meat on all Fridays and Ash Wednesday, in addition to other fasting and reflection practices. [Hence, why Friday Fish Fries are so popular in the parish.] But, this St. Patrick’s Day falls on a mid-Lent Friday; thus Catholics would be forbidden to ingest any meat consumption then. So Cardinal Sean O’Malley granted a dispensation that allowed Boston Catholics to enjoy a traditional Corned Beef and cabbage meal on St. Patrick’s Day.
My Muslim friends lord it over me that their fasting for Ramadan is serious. No fluids or food during daylight for a whole month. Come sundown, the feasting begins; Iftar, the fast-breaking meal just after sunset and a morning meal called Sahur, usually eaten just before dawn.
These long standing religious traditions, do they do more than strengthen spirituality and faith? Are they based on good health practices?
Intermittent Fasting
The term intermittent fasting covers several approaches. Unlike Ramadan, the restrictions only affect food – never water intake.
The Eat Stop Eat method Alternate days of normal eating and fasting, including two non-consecutive fasting days in a week.
The 5:2 method This alternates between five days of normal eating and two days (which can be consecutive) of 70-75% calorie reduction during the week.
Time-restricted eating Narrowing the food intake window to between 6 - 10 hours daily, and therefore fasting between 14- 18 hours.
Intermittent fasting appears to effectively boost metabolic health if you ensure that the periods of fasting and food intake are consistent with your biological clock. In response to light cycles, our body adapts our food intake to the body’s energy needs: the optimal period for eating is therefore from sun rise to sun set.
Time restricted eating can also help those who are sick with NAFLD:
Innovative non-pharmacological lifestyle strategies to treat non-alcoholic fatty liver disease (NAFLD) are critically needed. This study compared the effects of alternate day fasting (ADF) combined with exercise to fasting alone, or exercise alone, on intrahepatic triglyceride (IHTG) content. Adults with obesity and NAFLD (n = 80, 81% female, age: 23–65 years) were randomized to 1 of 4 groups for 3 months: combination of ADF (600 kcal/2,500 kJ “fast day” alternated with an ad libitum intake “feast day”) and moderate-intensity aerobic exercise (5 session per week, 60 min/session); ADF alone; exercise alone; or a no-intervention control group. By month 3, IHTG content was significantly reduced in the combination group (−5.48%; 95% CI, −7.77% to −3.18%), compared with the exercise group (−1.30%; 95% CI, −3.80% to 1.20%; p = 0.02) and the control group (−0.17%; 95% CI, −2.17% to 1.83%; p < 0.01) but was not significantly different versus the ADF group (−2.25%; 95% CI, −4.46% to −0.04%; p = 0.05). Body weight, fat mass, waist circumference, and alanine transaminase (ALT) levels significantly decreased, while insulin sensitivity significantly increased in the combination group compared with the control group. Lean mass, aspartate transaminase (AST), HbA1c, blood pressure, plasma lipids, liver fibrosis score, and hepatokines (fetuin-A, FGF-21, and selenoprotein P) did not differ between groups. Combining intermittent fasting with exercise is effective for reducing hepatic steatosis in patients with NAFLD but may offer no additional benefit versus fasting alone. - M Ezpeleta et al
In animal experiments, time restricted feeding improved outcomes in obese mice. [Half maintained continuous access to food while the other half had access restricted to the 12 hours they were most active—7 p.m. to 7 a.m.] Research in a mouse model of diet-induced obesity showed that time restricted feeding improves markers of kidney and vascular health. They excreted less of a key marker of kidney damage. They showed less damage to two different parts of renal tissue and reversed the intercellular damage. The small blood vessels in their kidneys increased their metabolic coenzyme, NAD+, and activation of the key metabolic enzyme, AMPK, was comparable to that of normal-diet mice.
Intermittent fasting can also be beneficial in terms of reducing hypertension by reshaping the composition of gut microbiota in the animal models. This provides evidence that gut dysbiosis contributes to hypertension by altering bile acid signaling.
Intermittent fasting may help heal nerve damage. Intermittent fasting changes the gut bacteria activity of mice, such that they increase production of a metabolite known as 3-Indolepropionic acid (IPA), that can regenerate nerve fibers. This novel mechanism was discovered in mice. The bacteria that produces IPA, Clostridium sporogenesis, is found naturally in the guts of humans as well as mice and IPA is also present in human bloodstreams.
The study assessed nerve regeneration of mice with crushed sciatic nerve. Half of the mice underwent alternate days intermittent fasting for 10 or 30 days, half ate freely. Recovery was monitored 24 - 72 hrs; length of the regrown axons was 50% greater in the fasting mice.
When IPA cannot be produced by these bacteria and it was almost absent in the serum, regeneration was impaired. When IPA was administered p.o. to mice after nerve injury, regeneration and recovery increased.
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So with these bon mots, relish those bon bons nestled in your time tested traditions for holiday feasting!
REFERENCES
Yes, intermittent fasting can boost your health, but how and when to restrict food consumption is crucial. January 5, 2023 https://theconversation.com/yes-intermittent-fasting-can-boost-your-health-but-how-and-when-to-restrict-food-consumption-is-crucial-197170
M Ezpeleta et al. Effect of alternate day fasting combined with aerobic exercise on non-alcoholic fatty liver disease: A randomized controlled trial, Cell Metabolism (2022). DOI: 10.1016/j.cmet.2022.12.001
Intermittent fasting protects kidneys of obese mice (2022, June 27) retrieved 15 March 2023, https://medicalxpress.com/news/2022-06-intermittent-fasting-kidneys-obese-mice.html
H Shi et al Restructuring the Gut Microbiota by Intermittent Fasting Lowers Blood Pressure, Circulation Research (2021). DOI:10.1161/CIRCRESAHA.120.318155
E Serger et al. The gut metabolite indole-3 propionate promotes nerve regeneration and repair, Nature (2022). DOI: 10.1038/s41586-022-04884-x
Jayanta Kumar Das et al,
Calorie restriction modulates the transcription of genes related to stress response and longevity in human muscle: The CALERIE study, Aging Cell (2023).
DOI: 10.1111/acel.13963