Harvard study sheds light on link between fasting and healthy aging

Intermittent fasting and remodeling cells’ mitochondrial networks may promote health and aging benefits.

A Harvard study published in Cell Metabolism indicates that remodeling the mitchondrial networks inside cells, through either dietary restriction (intermittent fasting) or genetic modifications that create similar effects, “may increase lifespan and promote health.”

Image source: Mind to Muscle Fitness

A cell's energy-processing capability deteriorates over time, which correlates with aging. Using nematodes, researchers highlighted a causal link between adjustments in the shapes of mitchondrial networks and lifespan:

"The researchers found that restricting the worms’ diet, or mimicking dietary restriction through genetic manipulation of an energy-sensing protein called AMP-activated protein kinase (AMPK), maintained the mitochondrial networks in a fused or “youthful” state. In addition, they found that these youthful networks increased lifespan by communicating with organelles called peroxisomes to modulate fat metabolism.”
source: The Harvard Gazette

What this study means therapeutically

Although this is not the first instance where dietary restriction and intermittent fasting have been shown to promote healthy aging, lead author of the study, Heather Weir, asserts that the findings constitute a vital step toward being able to employ the benefits therapeutically.

It essentially provides a biological explanation of why dietary restrictions have such a positive impact on the human body and its sub-components. William Mair, senior author of the study, concludes:

“Our work shows how crucial the plasticity of mitochondria networks is for the benefits of fasting. If we lock mitochondria in one state, we completely block the effects of fasting or dietary restriction on longevity.”
source: The Harvard Gazette

Researchers will now conduct similar studies on mammals in order to determine whether mitochondrial remodeling might shed light on a link between obesity and age-related diseases.

What is Intermittent Fasting (IF)?

Intermittent fasting is “a term for an eating pattern that cycles between periods of fasting and eating,” according to Healthline.

Back in 2011, Mark Sisson of Mark’s Daily Apple wrote an excellent article with medical references detailing the litany of health benefits associated with IF:

• Longevity
• Blood Lipids
• Dietary Compliance
• Cancer (i.e. ketogenic diets)
• Neurological Healthline
• Growth Hormone
• Autophagy (process by which cells recycle waste and repair themselves)
• Fitness
• Mental Well-being and Clarity

The multitude of benefits linked to IF lead Sisson to ultimately assert:

"It’s like a reset button for your entire body, presumably across a large spectrum of maladies and dysfunctions. It puts your body into repair mode – at the cellular level – and it can restore normal hormonal function in the obese or overweight. Now, you don’t have to fast, but it’s definitely something to consider.”

How to Fast Intermittently

Fasting intervals can involve daily 16-hour fasts or even occasional 24-hour fasts, but there isn’t necessarily a singular effective method for practicing IF. Some useful methods include:

1. Skipped Meals: let yourself skip a meal when you find your body isn’t hungry or even plan to skip a meal when convenient or forced (i.e. traveling)
2. Condensed Eating Window: daily food intake is condensed within four to seven hours
3. Early and Late: food intake is balanced between an early meal and a late meal
4. Single 24-Hour Fast: this can be done weekly, bi-weekly or monthly – some choose to eat dinner and fast until the follow evening while others elect to fast until the following morning
5. Alternating Day Fast for Week (or longer): this can be done seasonally or several times per year and one can choose to drink only water or tea and small amounts of juices or eat reduced calories on alternate days

Since intermittent fasting addresses when one should eat, rather than what one should it, it is more of an “eating pattern” than a “diet” or "eating regimen". Some, like Sisson, prefer to spontaneously fast based on circumstance – either when traveling, too busy to eat, or not hungry. Others suggest “eating in a condensed window” for those trying IF for the first time.

Have you tried intermittent fasting? What protocol did you follow and how did it work for you? Let me know in the comments below!

I prefer to follow the “condensed eating option” - usually I don’t get hungry until 2-3 in the afternoon and I eat until 8-9 at night. I find it helps me manage satiety and keeps me energized and enthusiastic.

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Further Reading on Intermittent Fasting

“My Intermittent Fasting Lifestyle: How I Dropped 50 Pounds” by Sumaya Kazi, Medium
“How To: Intermittent Fasting” by Worker Bee, Mark’s Daily Apple
“The Myriad Benefits of Intermittent Fasting” by Mark Sisson, Mark’s Daily Apple
“Intermittent Fasting 101 — The Ultimate Beginner's Guide by Kris Gunnars, BSc