Longevity, Fasting, and Fast-mimicking Diets (FMD’s)
Nutrition science has long been a controversial subject matter. Some would argue whether the body of evidence collected over the past century even constitutes science at all. There are precious few topics researchers agree upon, preferring rather to act like politicians and disagree violently in their interpretation of the same set of basic facts. One idea that has surprisingly widespread agreement is that caloric restriction (CR) promotes longevity.
The data in mice are incontrovertible: feed them less and they live longer. In fact, it would seem that the relationship is rather linear; the less they eat, the longer they live (its linear only up until a point that you don’t feed the enough and they die). These caloric restriction studies have been replicated many times in rodents and more recently in other animals, including non-human primates.
Eat Less, Live Longer?
It is unclear, however, if this phenomenon holds true in humans, where long-term CR studies are challenging and fraught with practical and ethical concerns. But these hurdles haven’t stopped some intrepid researchers from testing this theory. In fact, our good friend Ancel Keys set out to see what effects long term CR would have on health some 75 years ago. In the infamous Minnesota Experiment, Keys “recruited” (or shall we say compelled) otherwise healthy men (most of whom were conscientious objectors) to enroll in this war-time study where they would be deprived of calories in order to maintain a 25% body weight reduction. While some bio-markers actually improved (cholesterol, blood pressure, etc), overall mental and physical health of participants was dangerously compromised as the subjects lapsed into full-fledged malnutrition. In the modern era such studies are almost inconceivable owing to IRB’s, ethics committees, and a little thing called free will. In the end, these studies were unnecessary. Simply ask anyone who’s ever tried a long-term CR diet and they’ll tell you how freaking hard–if not impossible–it is to maintain and how poorly it works in the long run (that’s why Weight Watchers is so successful: they have a business model that virtually guarantees return customers).
Eat Nothing?
But the question remains: can we harness the longevity and anti-aging benefits of prolonged CR without the risk of malnutrition and the impossibly low compliance rates? Some think that fasting or intermittent fasting (IF) is the solution. While we’ve written extensively about IF on this blog and are big believers in its benefits for weight management, metabolic health, and productivity, the best clinical evidence suggests that fasting periods 3-5 days are needed for autophagy and the cellular regenerative effects (anti-aging properties) to truly work. Although this is compelling, fasts of longer than 24-36 hours are mentally and physically challenging, and potentially unsafe for the average person.
Fast-mimicking Diets (FMD’s)
Enter Valter Longo, Italian-born scientist (and amateur rock musician) who’s made a name for himself as the most accomplished researcher in fasting and related subjects. He’s an interesting fella, and you get a good idea of what he’s like by listening to his STEM-talk podcast or by reading his book, The Longevity Diet. I highly recommend both, but don’t agree with everything he promotes.
In short, Dr Longo hypothesized that a diet could physiologically replicate the fasted state. Over many years of study and development, he and his team created just that: a dietary program that he has dubbed a “fast-mimicking diet” or FMD, which replicates the fasted state on the cellular level. In subsequent published studies, he has demonstrated that FMD’s can induce many of the beneficial elements of water-only fasting, but with much better compliance, tolerability, and safety profile. As he lays out in The Longevity Diet, there appears to be broad clinical applications–from metabolic disorders (type 2 diabetes, obesity) to cancer (both prevention and adjunct to chemotherapy) and longevity. Last, but certainly not least, his FMD kits appear to be surprisingly profitable, fetching $250 per kit!
He suggests that a 5-day long “cycle” of the FMD can be done as often as once per month for the appropriate patient, while it would be recommended less often (quarterly or biannually) for otherwise healthy individuals. Sounds great, right? Let’s take a look at what goes into these FMDs
Day 1
1,100 calories
* 500 calories from complex carbohydrates (vegetables such as broccoli, tomatoes, carrots, pumpkin, mushrooms, etc.)
* 500 calories from healthy fats (nuts, olive oil)
* 1 multivitamin and mineral supplement
* 1 omega-3/omega-6 supplement
* Sugarless teas (up to 3 to 4 cups per day)
* 25 grams of plant-based protein, mainly from nuts
* Unlimited water
Days 2-5
800 calories
* 400 calories from complex carbohydrates (vegetables such as broccoli, tomatoes, carrots, pumpkin, mushrooms, etc.)
* 400 calories from healthy fats (nuts, olive oil)
* 1 multivitamin and mineral supplement
* 1 omega-3/omega-6 supplement
* Sugarless teas (up to 3 to 4 cups per day)
*25 grams of plant-based protein, mainly from nuts
* Unlimited water
Conclusions?
Long term results are unknown at this point, but the short/medium term results from his lab studies and clinical trials in humans are impressive, with improvements in weight, glucose control and blood pressure. There’s even a suggestion that FMDs in coordination with cancer therapy may help protect normal tissues, while increasing cellular toxicity to cancer cells, but this is still preliminary. In mice, the longevity data are clear: FMDs replicate the extended survival seen with traditional prolonged CR. In other words, suffering with little for 5 days a few times a year may actually extend your life. Pretty compelling stuff.
So what do you think? have you tried fasting or a fast-mimicking diet? We’ve tried both and will share with you in upcoming posts…stay tuned!
~Brendan