11/17/19
Recently, there has been a huge increase in attention on fasting, a dietary regimen that has been around as long as life has. Since I started implementing it myself, I've found that no one I tell about it understands what it is or why someone would do this to themselves. After all, we need at least three meals, breakfast being the most important of the day... right? Wrong. In this post, I'll try to demystify some of the vague, general claims that have been made about fasting.
Before I get started, I want to say that to understand some of these processes, a basic understanding of biochemistry can go a long way. For any term that may be new or unclear, I'll define it at the end of the page in a glossary. Also, I'd like to point out that a lot of these benefits are still hardly understood. Limits of today's science cause problems in distinguishing cause and effect; there are an inconceivable amount of processes in our bodies that could be confounding variables and therefore barriers to clearly proving the positive effects of things like fasting. However, this knowledge is still valuable because of the risk (or lack thereof) inherent to fasting. More on that later.
So many of the current diseases that harm the human population can all be classified under the same umbrella: hyperinsulinemia. Diseases in this category include heart disease, cancer, stroke, obesity, Alzheimer's, and diabetes. These are all the biggest killers today. Intuitively, the best way to avoid hyperinsulinemia is to be on the low end of the healthy insulin range and lower insulin resistance. This is where fasting can come into play. Fasting empties the cells of glucose, because the body needs that glucose for energy to keep you moving. Due to lack of food, blood glucose isn't rising, leading to the body needing less insulin and responding more efficiently to it. The pancreas picks up on this, and dials back on the production of it. The way I see it, this is huge news. Why would I wait to get one of these awful diseases to start treating it? Instead I'd like to lower my chances of getting it in the first place. A study was done on worms, and they manipulated their DAF-2 gene, which controls insulin levels. The worms that had regulated insulin levels doubled their lifespan. That's exciting stuff. Metformin is a popular diabetes drug that has been suggested to lengthen lifespan and it regulates insulin, too. And as for that DAF-2 gene, humans don't have it, but the equivalent lies in pathways of proteins like mTOR, AMPK, and the sirtuins. I'll explore these, as well as promising life-extenders like rapamycin in another longevity post sometime in the future. As it relates to fasting, though, mTOR is inhibited in the absence of food in a way that could extend life.
In ways that could be tied to these same processes more than we know, fasting also brings good products in other areas of health. It reduces blood pressure and inflammation, lowers LDL, and raises HDL. Also, it helps the body clear out damaged cells that secrete pro-inflammatory signals and create more problems. This is known as autophagy, and is a process essential to keeping our cells healthy. Energy levels can be more steady, too. I do find that I'm much less likely to crash while fasting than after eating a carbo-load meal on a normal day.
Not to mention, fasting is the tried and true way to lose weight. Nowadays, there are so many diets to choose from, and it can get confusing. It can be hard to tell the difference between low-carb and low-fat, Atkins and Paleo. At the end of the day, if you want to lose weight, you need to eat less food. Sounds simple, but diets can make people think that eating the right kinds of food allows limitless volume, and that's just not true. If you're eating, say, a Mediterranean diet, that may be a better choice than eating pizza for breakfast, lunch, and dinner. But, if you eat bigger portions than you would otherwise, it may not be any better for you. On the other hand, if you simply don't eat food for seven days, you will lose weight in a healthy way.
Now that's a lot of good. With all these possible benefits, you must be wondering, "OK, where's the catch? What's the downside?" That's the best part. Despite popular belief, there aren't any known downsides to intermittent fasting. If our bodies weren't capable of surviving these conditions, and doing it well, we never would've survived the caveman years. Those guys and gals sometimes needed days to hunt or forage successfully. So, while all of these benefits might not be completely backed up or true, even one of them would be enough for me to be interested. Health is also more interconnected within our bodies than we may think. For example lowered cortisol lowers inflammation, but we know that lower inflammation translates to health in many other, seemingly unrelated ways.
That brings me to risk assessment. When deciding whether or not to do something, I like to use an analogy. Imagine you're crossing the street, and you spot a flashy coin out of the corner of your eye. You don't know what kind of coin it is, but you first look down the road to see what's coming. Of course, if you see a double-decker bus, you're going to run like hell. Not worth it. But maybe it's not a bus, and instead it's a toddler on a skateboard. Now, there's little downside to seeing what's there. How I look at fasting is picking up a coin in the latter situation. There is little to no downside, so I'll give it a shot. Fasting could end up being a flowing-hair dollar worth millions, or a dime.
The most efficient way of implementing fasting is not clear for the same problems with clinical trials that I highlighted earlier; the science just isn't there. Some time in the near future more studies will surface that inch us closer to knowing the exact effects, but for now, we can give it our best guess. My regimen includes daily time restricted feeding including around 16-17 hours of fasting (after dinner, until lunch) with the rest of the time being my feeding period, and I'll do a quarterly extended fast of about 5 days. Ideally, you'll break a fast with a smaller, low-carb meal and work your way back up to normal, keeping blood glucose levels from spiking. Another good idea is working out just before breaking it, as working out forces your body to create glucose, which can help you get steadily back on track. Supplementation can be helpful along the way too, as long as no calories are provided.
At the end of the day, another reason I do it is because I just don't love breakfast. Don't get me wrong, the food is some of my favorite, but I'm just never that hungry in the morning. So if that works for you too, then it might be enough to take a gamble on using potentially one of the most potent medicines. It's already in your back pocket.
All of this material is science that I have learned through clinical trials brought to light by people like Peter Attia, David Sinclair, Satchin Panda, and David Sabatini. Peter is a doctor with focus in longevity, and he goes through a lot of this in further detail than I can comprehend sometimes, so if you are interested check out his site at www.PeterAttiaMD.com. Satchin Panda is another great reference, and he gave a really interesting TED talk on the possible implications of harnessing the power in our circadian rythms: https://www.youtube.com/watch?v=erBJuxVR7IE
Disclaimer: I'm not a doctor, and I can't recommend anything to you. You should ask your doctor about this stuff if you want to know more about how anything would work in your body. Everyone's different. I'm not trying to take credit for this science either, just want to talk about it in an easy-to-understand way.
Glossary:
Hyperinsulinemia: This is when there is too much insulin being created by the pancreas and circulating in our blood. It's all telling cells to take up glucose, but there isn't a proportionate amount of glucose. This can lead to hyperglycemia and Type 2 diabetes, because it damages the pancreas through beta cell failure--the pancreas is clogged with fat. In turn, the pancreas can't make enough insulin, flipping the script because now there is too much glucose in the blood, but your cells may already be full of it. You can see how this spirals into a bad cycle.
Insulin Resistance: When cells stop responding well to insulin. There is too much glucose in the blood, and the insulin doesn't have much power anymore, because the body's cells already have too much glucose. Insulin resistance makes the body think it needs more insulin, leading to hyperinsulinemia. In the past, we have treated this problem by giving patients more insulin. Clearly, this doesn't help much because you're trying to get the glucose out of the blood and into cells, but the cells are full. So what was happening was we were trying to stuff cells with glucose. Instead, if we focus on emptying the cells of this overflowing glucose, the cells can start responding to the insulin that's already in the blood.
LDL: "Bad", small particle cholesterol that causes blood clots.
HDL: High density lipoproteins."Good" cholesterol that transport cholesterol from around your body back to the liver, where it is removed.
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