MCT for Health

I enjoy studies investigating how light affects metabolism. Its effects are very similar to those of a diet rich in fat and sugar. In experiments, mice continue eating exactly the same food, yet their metabolism changes significantly. Are we just as sensitive? Perhaps somewhat less so, meaning it takes us a little longer to damage important organs, but the changes will certainly become apparent over time. I would not assume that we are fundamentally different. This time, we will look at a study investigating what happens when the standard 12-hour light / 12-hour dark (LD) cycle is eliminated in mice and replaced with continuous artificial light (LL). Their diet remains unchanged. In a third group of mice, the researchers added a substance (Cpn) to their drinking water, and, lo and behold, this substance suppressed almost all the changes. But we will get to that later. Looking at the graphical results, continuous light suppressed the ability to obtain energy from fats. Specifically, thi...

For quite some time, one idea has been recurring throughout my posts: slowing down certain specific processes could be the solution to metabolic problems and could increase the overall metabolic rate.  This idea is supported by a number of clues.  If the main problem is an excess of the aldehyde HNE , produced after linoleic acid is released from cardiolipin by the enzyme iPLA2γ in response to oxidative stress, then the solution is to reduce oxidative stress, simply by limiting the processes that generate it. Fat burning under unfavorable conditions could be one such process.  There is absolutely nothing wrong with using stored fat to obtain energy, but under certain conditions the system becomes overloaded, generating oxidative stress. This can happen, for example, due to an overall lack of oxygen, insufficient reduced glutathione (GSH), insufficient NADPH molecules to recycle oxidized glutathione (GSSG), inadequate function of the ALDH2 enzyme , which removes the aldehy...

In one of the previous posts , we saw how the omega-6 vegetable fat stored in adipose tissue, specifically linoleic acid (LA), causes weight gain even with reduced food intake when blue light induces increased lipolysis. Eventually, it is probably depleted and replaced by oleic acid, a much more stable fat. At least, this is how I explain the rather incomprehensible recovery of metabolism at the end of the experiment. It did take somewhat longer than the approximately 20 days that might be expected based on the results of the study of LA kinetics in mice , but the change was induced solely by ambient light, not by zero fat intake. The 1959 study of LA kinetics in mouse adipose tissue is interesting because it shows how, after just three weeks on a diet providing 30% of calories from vegetable oil, the fat composition of fat cells changes to become very similar to the composition of the oils being consumed. It is as if the composition of dietary fats were copied directly into the compos...

Let's continue exploring the effects of light on the eyes and metabolism. My interest focuses mainly on effects associated with the photoreceptors OPN3, OPN4, and OPN5. The first two are sensitive to blue light, while OPN5 is sensitive to near-ultraviolet light, that is, UV-A. It appears that OPN5 is an important component of the mechanisms involved in healing mechanical tissue injuries. Here, we'll look at an interesting study investigating the healing of corneal injuries. Genetic suppression of OPN5 (Opn5-/-) leads to impaired healing of corneal injuries and a loss of light sensitivity in the healing process. Perhaps we can quote a few paragraphs here. The non-visual opsins, OPN3, OPN4, and OPN5, are opsinfamily receptors that are activated by light but that subserve non-visual functions. We have previously shown that the local molecular circadian clocks in cells of the murine retina and skin display an Opn5-dependent violet-light-induced photo-entrainment, which is independe...

The literature usually states that blue light is harmful because it damages DNA. This damaged DNA activates the mechanism of cellular senescence or directly triggers cell removal through apoptosis/ferroptosis. Something about this doesn't add up to me.  DNA damage occurs constantly in our bodies, and at the same time, DNA is constantly being repaired . Why should blue light in particular be so extremely harmful, much more so than other destructive environmental factors, such as cosmic radiation? It doesn't make much sense to me. Don't you think? First of all, if blue and UV-A light directly damage DNA, how is it possible that there are methods that protect cells? Yes, you might argue that activating pigment production can protect cells by safely absorbing blue radiation. But pigment production is only triggered by UV-B. So how is it that there are methods to protect cells from blue light even in the absence of UV-B? Perhaps I'm being too bold, but I believe that DNA dam...

If you haven't read the previous post on this topic, here it is: Can Mobile Phone and Computer Screens Cause Obesity? What Is the Difference Between Blue Light and a High-Fat Diet? I have to return once again to the issue of modern light sources and the filtering of daylight by windows and glasses. It seems that inadequate research before the widespread adoption of new LED light sources may be responsible for a number of health problems. We could already observe changes when fluorescent computer screens were introduced, when it became apparent that their light could cause vision problems. Our ancestors were fairly lucky when fluorescent tubes were introduced into schools and workplaces. Fluorescent lights were developed in such a way that they are still used today as control sources of white light in animal studies . That does not mean they have no effect; it only means that the effect was sufficiently small that it went unnoticed. LED light sources are different. I really like thi...