For thousands of years, as far back as the writing of Herodotus, humans have been searching for what we know as the "Fountain of Youth." In legends this has been described as a tangible spring with the ability to restore the youth of all who come in contact with it. Herodotus referred to this spring in reference to an ancient civilization known as the Macrobians who reportedly lived to upwards of 120 years long.I don't know about you but I figure if Ponce De Leon and Indiana Jones couldn't find it....then maybe it just doesn't exist..........
Dr. Cynthia Kenyon, however, would tend to disagree.
Over the past 20 years Kenyon's research has been based on and progressed the concept that genes regulate the process of aging. This may not seem novel to some as many of us understand and believe that our genetics play an important role in health, disease, life expectancy, etc. What follows is some potential scientific basis for a number of "diets" and "fads" we are currently seeing in the health and fitness industry. If you don't feel like getting nerdy (shame on you) then feel free to skip to the good stuff and how you may apply this research to your lifestyle and nutrition further down.
Dr. Kenyon's most ground breaking research was a series of gene isolations done on a species of worm known as C. elegans, to investigate which genes may play a role in the onset of aging and senescence. Through what seemed to be absolute luck of the draw, one of Kenyon's lab rotation students stumbled across a mutant gene, dubbed daf-2 that made the worms live twice as long. In addition to the discovery that daf-2 may regulate aging it also plays a role in reproductive development, resistance to oxidative stress, thermotolerance, and resistance to bacteria. From this initial research Kenyon has also uncovered the integrative role that this daf-2 gene has on the insulin/IGF-1 pathway and rate of aging. In these studies, changes in IGF-1 activity caused IGF-1 receptors to initiate a cascade of events that deactivate the FOXO transcription factor, daf-16. This gene, which plays a nearly identical role in humans, is responsible for upregulating transcription of genes responsible for cellular protection such as heat shock proteins and antioxidants. This means that when daf-2 or resultant daf-16 activity is lower, then the C. elegans (and potentially humans) are less equipped to deal with environmental stressors and more likely to age, develop health conditions or diseases, and die.
So how do carbohydrates and insulin tie into this topic of conversation? Check out this comprehensive explanation of both the triggers and effects of insulin for more background information. The short version is that high carbohydrate diets and more specifically high sugar and processed carbohydrate diets lead to chronically higher insulin levels (and obesity). Insulin is a powerful storage hormone that works antagonistically to many other hormones in our body. ALL hormones play an important role in the body so I will include that no hormone, not even cortisol, is inherently bad. Kenyon's research however suggests that chronically higher insulin levels may lower protective mechanisms and immunity to make us age faster.
In most eukaryotes, increased insulin levels activate this beneficial daf-2 signalling but research has shown that insulin actually inhibits daf-2 receptors in these C. elegans as well as humans. Connecting the dots has led many researchers and followers to conclude that decreasing carbohydrates in the diet to lower insulin levels will lead to a longer and healthier lifespan. Kenyon's further studies also support this theory as wild C. elegans fed a glucose free diet lived 20% longer than those fed a diet made up of 2% glucose.
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| It's fine bro, I'm bulking |
There is plenty of research left to be done on the topic but that is the nature of the beast because there WILL ALWAYS be more research that needs to be done. Maybe the Macrobians did have a fountain of youth....... or maybe they just knew how to eat? I am just as interested as you to see how all of this actually plays out in the human body. For now you can take what you like or hopefully what you have learned and choose to do what you wish. That is the basis of critical thinking.
I have had a number of conversations recently about ketogenic, low carbohydrate, and "paleo" dietary interventions and all of this research may be applied very differently based on your health and fitness goals, but hopefully it leads to more conversation or if I am lucky........maybe a good debate. Check out the video below for a solid TED Talk given by Dr. Kenyon and decide for yourself. Interesting stuff!!








