Autophagy: the body’s spring cleaning

March 18, 2019
/ Aging

With aging, the body’s inbuilt mechanisms for sweeping out and recycling cellular metabolic waste products starts to wane.

Kick-starting this inbuilt cleaning up process, known as “autophagy”, could be a key anti-aging target to slow the degenerative impacts of growing older.

Housekeeping

First named in 1963 by Christian de Duve, Yoshinori Ohsumi identified autophagy mechanisms in the 1990s, earning him the 2016 Nobel Prize.

Autophagy literally refers to eating yourself (“auto” means self and “phagy” means eat).

For years it was thought to just be a form of programmed cell death. But researchers have now “shed important light on the true identity of autophagy – which is, in part, an adaptive cellular mechanism,” writes Beth Levine in the journal Cell Death and Differentiation.

By cleaning up waste products and damaged cells, autophagy stimulates cellular repair and regeneration. So rather than causing cell death, autophagy boosts cell survival.

“It is recycling and cleaning at the same time, just like hitting a reset button to your body,” Dr Luiza Petre told Healthline. “Plus, it promotes survival and adaptation as a response to various stressors and toxins accumulated in our cells.”

Anti-aging

When cells are stressed by disease, autophagy ramps up its spring cleaning. It has therefore gained much attention for its role in several conditions including obesity, diabetes, cancer, and infection.

The process decreases with aging, which may contribute to age-related pathologies including reduced muscle mass, neurodegeneration, heart malfunction, fat accumulation and increased insulin sensitivity.

Diminished autophagy has also been implicated in Parkinson’s and Alzheimer’s disease.

Increasing health span and longevity

Although more research is needed, Nuria Martinez-Lopez and co-authors suggest that “longevity and health-span can potentially be improved by activating [autophagy] pathways”.

The most well-established mechanism for triggering this process is caloric restriction – reduced food intake without malnutrition – and fasting, defined by Fernanda Antunes as “the complete deprivation of food but not water, with intervening periods of normal food intake”.

This can be intermittent fasting – alternate day fasting for over 16 hours or 48 hours of fasting per week – or periodic fasting (a minimum of 3 days of fasting every 2 or more weeks).

Restricted dietary intake has been shown to decrease the incidence of age-related diseases and to increase life span in many experimental models ranging from yeasts to mammals.

Autophagy might account for the benefits that caloric restriction has shown for reducing risk of diabetes, heart disease, cancer, and brain-related diseases.

There may be other ways to trigger cell cleaning and regeneration. A flowering Japanese plant called ashitaba (Angelica keiskei) has been traditionally used in Asian medicine for its longevity and health-promoting properties.

Recently, researchers discovered the plant contains a powerful flavonoid, DMC, that lengthened the lifespan of yeasts, fruit flies, worms and human cells – primarily through switching on the cells’ fasting response.

Older adults considering caloric restriction or intermittent fasting should consult their health care professional, being especially mindful of the high malnutrition risk with aging.