Stem Cells Help Fight Ageing. Here's How You Can Increase Your Stem Cell Stock.

While each cell has some specific function, not all cells begin their journey that way. A stem cell’s journey is a lot like careers for us humans, we all go to school and later on specialise and work in different fields. Similarly, stem cells can turn into any cell type. They pick up different functions just the same way we pick up different careers.?

Cells in our body are replaced all the time: while growing up, recovering from an injury or making up for the cells that died for some reason. There is constant cell replacement happening at different rates for different tissues. When the need for a new cell arises, existing ones split into two virtually identical copies. However, this ability to replicate has some limitations. This is because most cells can only perform their specific functions, for example a muscle cell can't divide into brain cells. Also, they can only divide a limited number of times before they retire. This is where stem cells come into the picture. In their most basic form, stem cells are extremely generic and can become any type of cell. When they divide, they can not only make more of the generic stem cells but also make more specialised copies, and these can go on to divide into more specific types of cells, eventually getting to cells that can only divide into cells of their exact same type (like our other cells that have one specific function).

DNA inside all cells have protective caps at their ends, called telomeres. Telomeres shorten with each copy the cell makes. When the telomeres become dangerously short, the cell stops making copies. Stem cells try to solve this problem by producing a chemical called telomerase, which can make telomeres longer. While this is helpful, it doesn't prevent stem cell populations from slowly sinking over time. The shortening of telomeres is itself a cause for stem cell exhaustion. This is because they wear out faster than they rebuild.?

A decline in a variety of stem cells has been observed as we age. This decline results in a decline in cells involved in the brain, blood and muscles - which leads to a variety of diseases and conditions, including frailty, muscle loss, osteoporosis, anaemia, poor immune function, and the general ability to maintain our organs and tissues. While these changes happen slowly and we can't instantly spot them, one apparent sign of stem cell depletion is grey hair!?

Hair colour comes from melanin, a pigment produced by cells in the hair follicles. Over time, our cells suffer damage and become depleted, losing their ability to make melanin. When all your melanocyte stem cells disappear, so does your hair pigment. Thus – grey hair. This is one known factor responsible for grey hair. There are however more factors involved (specifically the causal factors for premature greying) that are yet to be uncovered.

Stem cell exhaustion does not mean we completely run out of stem cells, but the numbers decline massively as we age and also a lot of existing ones stop performing as efficiently over time.??

Another cause for stem cell exhaustion is a blocker protein which can block the cells’ ability to duplicate. This protein is overproduced in older ages, which makes it even harder to sustain stem cell populations.?

Also, removing senescent cells and their secreted SASP senescence-associated secretory phenotypes as discussed in the previous edition) may potentially have a positive impact on stem cell function; the removal of some inflammatory sources would likely reduce the overall burden of inflammation and could plausibly reduce stem cell inhibition.

Not just these, there are various other causal factors for stem cell exhaustion: epigenetic modifications, altered microRNAs, defective RNA splicing, loss of proteostasis, change in cell polarity, mitochondrial dysfunction, deregulated nutrient sensing, niche deterioration, altered circulating factors, defective intercellular communications, and inflammations.

Molecules involved in these pathways serve as biological markers to assess stem cell ageing. Some of the key biomarkers are:

• Altered antioxidant status?
• DNA strand breaks and mutations?
• Telomere shortening?
• Altered levels of sirtuins?
• Changes in chaperones and protein synthetic mechanisms?
• Modification in intracellular signaling of IGF-I/insulin, Wnt, mTOR, FoxO, and AMP-K?

What does the research say??

In the early days of stem cell research, the most versatile stem cells were collected from early-stage embryos. However, a lot has changed in the last decade. We have now found ways to turn adult cells back into stem cells and re-inject them back into the body. We call these reprogrammed adult stem cells induced pluripotent stem cells (iPSCs).

What can you do?

1. Reduce Triglycerides?

Triglycerides (TGs) are storage systems for unwanted carbohydrates. Consuming more carbohydrates than we burn results in high TGs. People with high TGs are more likely to gain weight, resulting in metabolic syndrome (a cluster of conditions that increase the risk of heart disease, stroke and diabetes). Additionally, stem cells don’t grow as well in bodies that have high TGs.?

2. Avoid excess calories and eat smart!

Studies have shown that the number of circulating stem cells in the blood increases with caloric restriction. Additionally, the lifespan of the organs is lengthened. Intermittent fasting is a good way to induce stem cell production and increase the overall functioning of cells.

3. Take Omega-3 Fatty Acids

Taking omega-3 fatty acids can balance out TGs and help stem cell growth. Omega-3 fatty acids will also support healthy inflammatory pathways, a marker for stem cell activity.

This newsletter is a part of our ongoing series The Longevity Hack. Our aim is to help you understand the science, learn to recognise the markers of ageing and to develop biohacks for each of these. Next week, we will look at the last hallmark of ageing, altered intercellular communication. You can read the previous editions here.?

Curious to know more about longevity, ageing and how you can cultivate a lifestyle that will help you live longer, healthier and happier???

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See you next week!