Fasting, Fast-Food and Aging: Are they related? is it Hope or Hype?


posted by Yasir Hashim

Today is the 20th day of the holy month of Ramadan. Upwards of billions of Muslims all around the world are observing the practice of fasting from sunrise to sunset. In addition to Islam, Christianity, Judaism, Buddhism, and even some North and South American first peoples traditions observe some form of fasting for better heath, sacrifice, mourning and purification. 

Thinking back across the history of man, it seems that fasting has always been a part of our existence. Paracelsus, one of the three fathers of Western medicine is quoted as saying, “Fasting is the greatest remedy, the physician within”.

Fasting has also made somewhat of a resurgence in western culture with the recent excitement around intermittent fasting and its endorsements from celebrities like Hugh Jackman, Terry Crews, Jimmy Kimmell and Benedict Cumberbatch. 


I've fasted for the month of Ramadan since my childhood, and I've also experimented with intermittent fasting. Being completely honest, I don’t remember feeling “healthier”, just plenty of vivid memories being hungry and tired. This blog, I decided to take a deep dive into the phenomenon of fasting and see if there’s more to it.

So, fasting has been around for a long time... I’ve had plenty of experience with the practice... but does it really play a role in our health and wellbeing, is it just a spiritual practice, or could it just be another short-term fad? I was recently reading a paper that suggested fasting may play a fascinating role in our health and even more specifically on how we age.

The researchers in this study wanted to look at the genes that were affected by fasting and whether they played a role in the regulation of genes that were related to aging. They looked at brains of mice that had been fasting from 12 to 72 hours. Their findings were fascinating. There was an overlap between the specific genes that were “turned on” (upregulated) during fasting and the genes that are turned on during aging (example a and b below). The relationship between these genes was even more interesting. Fasting has the ability to turn on (up regulate) genes that are normally turned off (downregulated) during aging, especially after 72 hours of fasting.


“During the fasting period, the mouse brain responded reducing all processes connected to cell death...”.

So, researchers believe short periods of abstaining from food could potentially fight against the effects of aging. One explanation could be that it has been an evolutionary advantage to have a brain that is better adapted to food scarcity. 

Grocery stores as we know them today didn't come about until the early 20th century. We live in a day and age where you can have whatever you want, whenever you want it. In the past, this wasn't the case. Before the age of the grocery store, humans had to grow and harvest their own food or hunt for it. If our brains began to degrade and our judgement became clouded every time we were short on food, that would have been a huge disadvantage. 

I can’t help but think of how our diets then play a role on this aging. Living in the age of processed foods is also very different from historical diets of the past. If we chose to fast, how are we then supplementing the practice? How is our shift in diet affecting our health?

I do my best to eat a healthy diet, but I'm on a startup founder's budget and occasionally cave for the cheap and easy carryout deal. I can see how it is an advantage to practice fasting, but if I break my fast with some fast-food, am I just running in circles?

This same study shed light on this question because the researchers fed a different group of mice a variation of either food pellets or McDonalds. You weren't expecting that, huh? I’m surprised this didn’t raise any flags with the ASPCA, those poor mice! They found that the brains of the mice eating a McDonalds diet were similar to those of mice that were much older in age (brain of 5-month-old mouse on a high fat diet was similar to the brain of a 30-month-old mouse).

This supports the growing movement that the foods we eat play a larger role on our health and wellbeing than we may think. The connection between food and health has been a hot topic in the past couple years as we’ve started to see a push for food transparency and food justice. Keeping in mind what happened to the brains of mice on a McDonalds diet, it has been pretty well understood that a high fat diet (saturated fat and trans-unsaturated fat) can lead to obesity and to cognitive decline.

It is important to keep in mind that these studies were conducted on mice, and that they may not directly superimpose on the human brain. However, as we’ve seen with many studies in the past, our findings in mice tend to be a good analogue for humans.

I’m intrigued by the concept of fasting and I now know that it may even play an integral role in maintaining our health and cognitive abilities as we age. While some of us may adopt fasting as a practice, I still think that it is also important to keep in mind what we are eating to break our fast and, in an even broader context, what our diets are on a regular basis.

I’m not a nutritionist, nor am I advocating for any diet in particular. I know that different diets work well for different people. I do, however, believe that avoiding fast-food (processed foods) as often as possible is a fair and easy way to jump-start a healthier lifestyle. We are learning more and more about our bodies every day and it’s important to always approach health and wellness holistically.