What is autophagy? Why is fasting related?

One of the side benefits of fasting is that it's possible to initiate autophagy with a long enough fast.  But what does that mean?  After researching for a while, the simple way I view the idea is that the body has a natural means of dealing with damaged cells that goes into action when fasting.  How long a fast depends on a variety of factors, but for many people 24-48 hours is sufficient.  In some situations, 12 hours may be enough.

The benefits of autophagy include decreased risk of some cancers as well as improved brain function.  There is ongoing research in animals and humans related to Alzheimer's.

Below are descriptions of autophagy by a sample of people who believe in the value of fasting and/or a ketogenic diet.  The viewpoints and styles vary.  As with any medical topic, getting more than one opinion is valuable as you decide what may work best for your unique situation.

Autophagy & Intermittent Fasting: Activate Garbage Recycling and Cell Remodeling, 4 min, 2017

https://youtu.be/10jNZleNH9w

Dr. Eric Berg, chiropractor with an interest in nutrition

Autophagy and Fasting: The Mystery Explained, 13 min, 2018

https://youtu.be/rDzIbkyr5QQ

Dr. Annette Bozworth, internal medicine, promotes a keto diet

Top Fasting Benefits: Autophagy Explained - Thomas DeLauer, 8 min, 2018

https://youtu.be/FGoLcJxApCA

Thomas DeLauer, fitness and health guru

Intermittent Fasting and the Aging Woman | Autophagy, Cancer, Anti Aging and Fasting, 21 min, 2017
https://youtu.be/aQXjKgKEe2A
Dy Ann Parham, 50-something woman interested in helping older women be fit

Intermittent Fasting BBC Documentary 2012 by Dr. Michael Moseley

Dr. Michael Moseley discovered the potential benefits of fasting back 2012 when he was a BBC science journalist and executive producer.  Dr. Moseley studied to be a psychiatrist at the Royal Free Hospital Medical School in London, but his first job was as a banker.  He changed direction professionally again in 1985 and joined a BBC trainee program as an assistant producer.  He is married to a physician and is a father of four.

In 2012, Moseley was asked to research fasting for a BBC documentary, including trying the idea himself.  He was in his fifties.  Researchers he met with included Prof. Luigi Fontana of Washington University School of Medicine, Dr. Krista Varady of the Univ. of Illinois, and Prof. Mark Matteson.    He was not particularly looking forward to the idea of fasting for 3 days and 4 nights.  However, the changes were significant enough (at 33 minute mark in the BBC documentary) that after going home he experimented with the fasting for five weeks based on the 5-2 approach.  The results were similar to the 4-day fast (52 min mark).  His first book about the "Fast Diet" came out in 2013 and became a NY Times best seller; it was updated in 2015.

The BBC documentary is an hour and well worth watching.  For a shorter introduction, check out report below by an Australian journalist who traveled to meet Moseley in 2014.

5 2 Diet, 16 min - 2014

https://youtu.be/VWtaLLjJzn4

Eat, Fast & Live Longer BBC Documentary, 1 hr, created 2012, posted 2015

https://youtu.be/Ihhj_VSKiTs

Delay Don't Deny about IF by Gin Stephens

I've been experimenting with intermittent fasting (IF) for about a year.  Based on how things went during the summer and fall when I was being more organized about when I was or wasn't eating, I plan to continue IF in assorted ways.  The most consistent change is that I don't eat breakfast when I'm home.  When traveling, if breakfast is available then it's still my favorite meal of the day.

The second book I read about was Delay, Don't Deny by Gin Stephens.  Her style is quite different from Dr. Fung, who she references often.  Stephens holds a Doctorate in Education for Gifted and Talented Education and a Master of Arts in Natural Sciences.  She's a teacher who recently retired after almost 30 years teaching in Georgia.  What I like about this small book is that the ideas are presented simply, but there are plenty of references including URLs for online sources.  There are stories from several people in an appendix that are from her Facebook support group.

After experimenting with different IF approaches, Stephens settled on One Meal A Day (OMAD) as the best fit for her.

Her second book was Feast Without Fear, which also includes links to supporting info.  Another place to find the links is on this book's website.  The links for Chapter 2 are about medical journal articles about autophagy.

http://www.feastwithoutfear.com/book-links.html

NBC 26 Women Today - Gin Stevens Story, May 2018

https://youtu.be/wq1YVm3v5ks

Gin Stephens Interview/Delay Don't Deny and Feast Without Fear - Oct 2017

https://youtu.be/W0bET6TSNxw

Intermittent Fasting Interview with Gin Stephens and Dvorah Lansky

https://youtu.be/Aqjjz4K52CI

(audio interview)

https://youtu.be/Aqjjz4K52CI

Bone biology basics, skiing is good for hip bones

How bones grow and shrink is not something I remember from my high school biology class.  Found a website by a physician and professor that is designed to teach kids about the different types of bone cells.  Much easier to understand than descriptions written for adults.  More fun too.

Bone Biology for Kids

One of the webpages is good news for older skiers, at least when it comes to the likelihood of breaking a hip.  The bone density for top athletes in various olympic sports differs quite a bit.  Gymnasts, volleyball players, and weight lifters tend to have pretty dense bones all over.  Cyclists and swimmers need to do other stuff to encourage bone growth in certain parts of their body, in particular the spine.  Cross-country skiers tend to have dense arm bones, as well as leg and hip bones.  Probably true of alpine skiers as well.  But skiers should think about what they can do off the slopes to increase bone density in their spine.

Comparison of bone density in spine, arms, hips, legs for a few common sports
http://depts.washington.edu/bonebio/bonStrength/exercise/sports.html

Based on this blog article by a physician in 2013 (includes a few references), it's easy to understand why skiers who do ski conditioning exercises in the off-season generally don't have to worry that much about breaking a hip.  The basic exercises he recommends are squats, lunges, and step ups.  Those are pretty standard for ski conditioning.  Of course, to build bone it's better to do them with weights of some sort.

Can Weight Lifting Increase Bone Density?

Ways to improve bone density, not just for people with osteopenia/osteoporosis

Breaking a hip was something my mother worried about, especially in her 80s and 90s.  She worked hard to avoid bone loss after age 60 or so.  She took calcium and Vitamin D supplements, made good nutrition choices, and did basic exercises to keep her bones as healthy as possible.  In her 90s, she walked for exercise a few times a week or used a small hydraulic stepper in her apartment (independent retirement community) if she did not feel like going out.  She was quite successful at avoiding any fractures, even after a couple hard falls at age 95.

I did not do a bone density screening until close to age 60.  Turned out that my legs and hips were in great shape.  The ski conditioning I started doing after knee rehab at age 57 probably was helpful.  However, my T-score for my spine was classified as osteopenia.  After a little research, I learned that it's possible not only decrease bone loss, it's even possible to improve bone density with appropriate exercise.  There are several relevant studies that include women over 70.

Found a video made by two physical therapists that is a good introduction to why bone loss in the spine can cause problems.  It's done in serious but light-hearted way.  Their focus is on people who probably are not out hiking, skiing, or even walking very much.  They mention four elements that should be addressed by specific exercises:

• weight bearing
• resistance
• posture
• balance

After showing what can happen with a model of a spine, they demonstrate three basic exercises: modified dead lift, lunge, push up.

The key point is that bones are not static.  Bone is constantly being re-modeled by osteoblasts and osteoclasts in response to the needs of the body.  The goal of exercises based on weight and/or resistance is to provide appropriate levels of stress to stimulate osteoblasts and build more bone.  Aerobic exercise from swimming or cycling is good for cardio but do not help build bone in the spine.  For more details, check out this webpage about weight bearing exercise as a way to prevent fractures in older people.

Working with heavy kettle bells is a straightforward way to to improve bone density.  Must be using enough weight.  8-10 pounds is not nearly enough.

The 66yo woman in this video is using 26 pounds.  Of course, her trainer had her work up to that weight.  Good form is especially important for anyone with osteoporosis in the spine already.

I found working with my trainer that 20 pounds was okay for the kettle bell swing and chest-hold squat when she started adding bone building exercises to my sessions.  The ideal is to do the exercises 3 times a week, possibly alternating between heavier and slightly lighter weights.

Here are a couple other examples of exercises with weights.  The first is a lunge and press, the second is a single leg deadlift with weights.  I started with 12 pound dumbbells.  Fewer reps with more weight at slow speed is better.

Benefits of fasting for active people goes beyond weight loss

Although intermittent fasting starting making news in 2016 and really became popular in 2017, researchers began considering the effectiveness of fasting a decade earlier.  Dr. Mark Mattson has studied in the connection between nutrition and diseases such as Alzheimers for quite a while.  He is the chief of the Laboratory of Neurosciences at the National Institute of Aging and Professor at Johns Hopkins.  His research influenced Dr. Michael Moseley, who did a BBC documentary in 2012 about the benefits of intermittent fasting.

I became more curious about Mattson after reading Kyle Boelte's May 2017 article in Outside Online entitled "What I Learned from a Year of Intermittent Fasting."  Boelte is an active man in his 30s who does not need to worry about losing weight.  However, he tried fasting to address issues that were compromising the quality of his life.  The subtitle for the article is "It won't solve all your health problems, but it might make your life a bit better."  In Nov 2017, he wrote a followup article entitled "How to Start Fasting: A beginner's guide to the burgeoning nutrition trend" that is also a good read.  It's the best introduction I've found so far for active people willing to experiment with fasting.

"I settled on the 16-hour fast, where I’d limit eating to an eight-hour window every day. As Mattson explains, the liver stores glucose (the body’s main energy source when you are regularly eating carbohydrates) for about ten to 12 hours after a meal. When you fast for more than 12 hours, your body switches from glucose metabolism to fat metabolism, which leads to a bunch of positive adaptive cellular stress responses. So, if you fast for 16 hours each day, you’re receiving the benefits of those adaptive responses without limiting your total caloric intake." 

https://www.outsideonline.com/2181151/what-i-learned-year-intermittent-fasting 
https://www.outsideonline.com/2258396/how-start-fasting

The 2014 medical journal article by Dr. Mattson referenced in Outside Online is entitled "Meal frequency and timing in health and disease."  There is a long list of references for those interested in learning more.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4250148/
Proc Natl Acad Sci U S A. 2014 Nov 25; 111(47): 16647–16653. 
Published online 2014 Nov 17. doi:  10.1073/pnas.1413965111

Reasons to avoid diet soda

The idea that diet soda is "healthy" seems to be more a function of good marketing since the 1960s than any scientific research.  The same could be said of sugar substitutes in general, but those who drink diet soda regularly probably consume far more soda than other food with the same amount of sugar substitutes.  The negative impact of drinking 1+ diet sodas per day in the U.S. is not new information.  However, the long term impact from an epidemiological standpoint is probably more obvious in 2018 than it was fifty years ago when diet drinks were still relatively new.  Coca-Cola and Pepsi were selling diet sodas by 1963.

A search on "reasons not to drink diet soda" will bring up lots of articles.  Here are a few to think about.

10 Reasons to Give Up Diet Soda - 2013

11 Reasons You Should Never Drink Diet Soda, Like Ever - 2017

Diet Soda: Good or Bad?

includes links to references - 2018

Looking for clinical trials related to diet soda can get pretty complicated.  Here's an example.  This 2015 study from the American Journal of Clinical Nutrition compared diet soda to water over a 24-week period.  It's a small study considering obese women with about 30 subjects in each group.  The soda group drank 1 soda at lunch 5 days a week.  The results was that the group drinking water at lunch lost more weight and the difference was statistically significant.  The level of insulin resistance was also measured and the water group did better.

Effects on weight loss in adults of replacing diet beverages with water during a hypoenergetic diet: a randomized, 24-wk clinical trial

It's clear that a diet soda causes just as much of an insulin spike as a regular soda.  Higher insulin levels means less chance the body switches over to burn stored fat.  That can be a key reason people who drink diet soda all day long have big waistlines and trouble staying at a healthy weight, no matter how much they restrict calorie intake and/or exercise.

The development of diabetes, kidney failure, heart failure, or osteoporosis takes years and there are many risk factors.  The research in the last 10-20 years generally supports the idea that finding an alternative to diet soda that does not include sugar substitutes is worthwhile for people interested in long term health.

When I was growing up, my family never drank soda of any kind.  Now that I am over sixty, I am rather glad I do not like soda or the taste of any sugar substitute in any type of drinks.

Science behind fasting, hunger, and daily eating habits

As I looked around for information about fasting, I came across a series of well researched videos by an American living in Tokyo in a blog called What I've Learned.  Some of the videos go together with a blog entry of the complete text.  My interest in learning more about fasting is in longevity with a high quality of life, as opposed to any need to lose more than a few pounds.

The 2018 video below is a good summary of about why someone who is fasting does not feel hungry all the time.  There are several hormones involved with eating and how the body finds fuel from food or stored fat that have only been measured relatively recently as part of medical research.  An example of of Ghrelin (hunger hormone) levels during fasting begins at the 5 min. mark.  Note that 2017 book The Obesity Code by Dr. Jason Fung is referenced.

The 2016 video about eating one meal per day includes references that demonstrate that the idea of fasting as beneficial are not particularly new.  What's actually new in the history of human beings is the concept that three meals a day are necessary for a healthy lifestyle.

Intermittent Fasting & Hunger - What the Science says, 11 min - 2018

https://www.patreon.com/posts/16239257

https://youtu.be/dFT2IKmwyfg

Longevity & Why I eat once a day, 16 min - 2016

https://lifeforbusypeople.com/2016/07/23/longevity-why-i-eat-once-a-day/

https://youtu.be/PKfR6bAXr-c