More orthodox doctors are incorporate fasting into their prescriptions. Picture: KOSTIANTYN ZAPYLAIEV/123RF
More orthodox doctors are incorporate fasting into their prescriptions. Picture: KOSTIANTYN ZAPYLAIEV/123RF

Fasting is as old as the hills of ancient Greece and still shrouded in the myth and mystery of time. Now, it is finding a home in modern, mainstream medicine due to the growing popularity of intermittent fasting.

Intermittent fasting has a robust scientific evidence-base and growing celebrity endorsers. The latest are US Hollywood stars Jennifer Aniston and Reese Witherspoon.

In media reports and YouTube videos, both say that they fast for 16 hours daily. Both also “never eat in the mornings”. With their glowing skin, wrinkle-free, ageless faces and super-slender figures, both are the best advertisements for what they preach on intermittent fasting. (Botox benefits notwithstanding.)

Yet many modern medicine men — and women — still dismiss fasting as dangerous. These orthodox medical doctors say that classic, extended fasting and shorter intermittent fasting are “fringe” and “passing fads”.

How something that has proved its worth over centuries, if not millennia, can be considered a fad is anyone’s guess. These days, more orthodox doctors incorporate fasting into their prescriptions.

Canadian nephrologist (kidney specialist) Dr Jason Fung is author of The Complete Guide to Fasting (Victory Belt, 2016) and a pioneer of fasting in Canadian conventional medical settings.

How something that has proved its worth over centuries, if not millennia, can be considered a fad is anyone's guess.
Marika Sboros

One of fasting’s biggest benefits, he says, is reduction of the hormone, insulin. This fights diseases of too much insulin, such as obesity and type 2 diabetes that doctors now call “diabesity” because of the linked, twin occurrences, and all their related problems.

Fung is a big fan of intermittent fasting. It’s “much simpler than all other diets”, he says. It’s not about what but rather when you eat. It simply means “eating nothing for a certain period”.

Other diets are full of “eat this but not that, and maybe a little bit of the other”, Fung says. This confuses the layperson, especially since the “science” seems to change daily.

More evidence for intermittent fasting comes from a US study on the Muslim spiritual fasting tradition of Ramadan, presented at the annual Digestive Diseases Week in California in May 2019.

The study authors say that Ramadan fasting from dawn to sunset for 30 days increases levels of proteins that improve insulin resistance and protect against other risks from bad diets.

Ramadan fasting offers “a potential new treatment approach for obesity-related conditions, including diabesity, metabolic syndrome and nonalcoholic fatty liver disease (NAFLD)", they say.

Of course, fasting does not come easily to many. And the lure of instant gratification and quick fixes is strong.

Modern medical science has an answer for those who lack the discipline and willpower required to fast. It lies in what is called caloric restriction mimetics (CMRs).

Caloric restriction has been a buzzword on the anti-ageing scientific scene for decades.

CMRs are natural substances that can simulate the health-promoting effects of fasting without any need for discipline and willpower, say researchers. CMRs’ main claim to health fame is that they induce autophagy, the scientific term for the body’s way of cleaning out dead or damaged cells to regenerate newer, healthier cells.

Scientists call autophagy an “evolutionary self-preservation method”, a path not just to a longer but healthier life.

If you’re a red wine lover, you’ve probably heard of the most well-known CMR, resveratrol. Your favourite tipple is full of it — if you buy the right red wine. “Right”, in this case, is a synonym for expensive.

Another CMR you may not yet have heard of is spermidine. Good dietary sources are aged cheeses, mushrooms and other fungi, soya products (GMO-free, of course), legumes and whole grains.

[Do the] real thing rather than look for short cuts or easier routes to longevity.
Dr Jacques Jooste

A new French study in the journal EMBO Molecular Medicine earlier in October reported on an agent in these CMRs called 3,4-dimethoxy chalcone (3,4-DC). The authors say that 3,4-DC may induce autophagy through different, more effective pathways than spermidine and resveratrol.

They acknowledge the study limitation: it’s in mice and thus, too early to suggest help for humans.

Critics of CMRs and 3,4-DC say these are targets of the pharmaceutical industry’s desire to reap the benefits of fasting. After all, drug companies need something they can patent in pill form.

Randburg GP Dr Jacques Jooste says CMRs are not proven alternatives to fasting. And the new French research is just another sign that the pharmaceutical industry has not found its “magic, blockbuster pill”.

Jooste advises patients to do the “real thing rather than look for short cuts or easier routes to longevity”.

Intermittent fasting’s health benefits are proven “beyond a shadow of doubt”, Jooste says. For proof, he cites Japanese cell biology professor Yoshinori Ohsumi, 2016 Nobel prize winner in physiology or medicine. Ohsumi’s groundbreaking research includes autophagy and intermittent fasting benefits.

For patients, Jooste mostly advises fasting for periods ranging from 22 to 36 hours once or twice weekly. In between, he recommends a 16-hour fast every 24 hours. Including sleeping hours in the fast makes it “more tolerable”.

A ketogenic (low-carb, high-healthy fat) diet with intermittent fasting can further extend life and boost health, Jooste says.

Fung sees “no reason” for 30-consecutive-day fasts “just for the sake of argument”. Four separate seven-day fasts would have “roughly the same beneficial health effects with far less risk”.

In his intensive dietary management programme, Fung sometimes prescribes extended fasts of between seven and 14 days. But only in appropriate patients and only under supervision. He mostly recommends 24- to 36-hour fasts two to three times weekly, under medical supervision for patients.

When used appropriately, in the right hands, fasting can be “more powerful than any drug”, Fung says. Used inappropriately, in the wrong hands, it can be “dangerous and destructive”.

In essence, CMRs are in their infancy when it comes to evidence. And intermittent fasting is simply a safer route.

“Longer fasts have more power but more risk,” Fung says.