By Kristina Harris Jackson, PhD, RD.
Aug 21st, 2025
A timeless, human question is, “How can we live longer?” Now, the main question might be, “How can I live healthier for longer?” As we learn more about the aging process, many different theories about how we can live longer and healthier have emerged. One such theory is to attempt to prolong life starting at the cellular level.
Could learning how to prolong the life of a cell potentially add healthy years to our own lives? Research is showing how nutrition can affect our lifespan through protecting the lifespan of our cells.
Cell Health and Telomeres
One of the most important components of a cell’s lifespan is the telomere. Telomeres are repeating, non-coding DNA sequences at the end of the DNA strand, or chromosome. These extra DNA sequences loop back on themselves and tuck back into the DNA strand to form a telomere cap. This cap helps protect the encoding part of DNA by providing extra nucleotides during the DNA replication process to finish off any incomplete DNA strands.This process accounts for only a small portion of telomere loss, however. Telomeres are usually lost to oxidative damage from outside forces, like exposure to heavy metals, air pollution, and UV rays, thus damaging the DNA. A way to remember the function of a telomere is to relate it to the protective covering at the end of a shoelace, i.e. an aglet. The aglet caps the shoelace protecting it from unraveling like a telomere caps the DNA protecting it from damage.
When the telomere becomes too short for the DNA to replicate safely, the cell can do one of two things:
- It can be marked for apoptosis (cell death)
- Or enter senescence. The latter is when a cell continues to function but doesn’t replicate anymore due to chronic stress.
As we age, senescent cells tend to build up causing damage to surrounding cells. Apoptosis, on the other hand, ensures the damaged cell is eliminated and is not allowed to build up causing damage to other cells.
So, there are two hypotheses that could increase a cell’s lifespan:
- Slow down telomere loss (preservation)
- Have the telomere sequence continue to replicate (repletion)
When telomere sequences are able to replicate, it is done with an enzyme called telomerase. The telomerase enzyme is mainly activated during the development of a fetus, when most cells are being created. Most tissue cells are not able to activate telomerase, except for parts of the body that have high cell turn-over like germline and stem cells and skin, immune, and intestinal cells. As the science of telomeres has progressed, researchers have been using different techniques to assess telomere health, such as:
- Comparing the length of telomeres to the rate at which telomeres are lost
- The potential for telomerase to be activated later in life
Having measurements of telomere health allows researchers to use them as biomarkers to predict health outcomes (Monaghan & Haussmann, 2006).
Can We Affect the Health of Our Telomeres?
Telomeres are affected by both non-modifiable and modifiable factors. For example, sex is a non-modifiable factor that affects telomeres in that women tend to have longer telomeres, and their telomeres shorten at a slower rate compared to men.
Modifiable factors like proper nutrition, exercise, and stress management are ways that can help decrease telomere loss, likely via a reduction in oxidative stress. Proven ways to prevent telomere shortening are not smoking, maintaining a healthy body weight and composition, and treating chronic diseases. Another possible way to positively affect telomere life and activate telomerase is by increasing omega-3 fatty acid levels in the body.
Omega-3s
Omega-3 fatty acids are a class of fats that are essential nutrients, meaning the body needs to get them from its environment to survive. Omega-3s are known for:
- Anti-inflammatory, pro-resolving properties
- Lowering blood triglyceride levels
- Lowering blood pressure
- Improving cardiac function
- Maintaining the skin barrier
The main omega-3 fatty acids in telomere research are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are found in seafood and fish.
The body can make EPA and DHA from another omega-3, alpha-linolenic acid, albeit very inefficiently. Eating pre-formed EPA and DHA in food is a more efficient way to increase levels in the body, primarily from:
- Fish and seafood like tuna, salmon, and sardines
- Fish oil or algal supplements
Before drastically changing your diet, it is good practice to obtain your O3I in order to know your baseline and talk to a healthcare provider. Then:
- Dietary changes
- Fish oil supplementation at the appropriate doses
…can help to increase the O3I to the desired goal. It takes 3 to 4 months to increase the O3I due to the lifespan of those cells, at which time repeating your O3I test can be done to see if further adjustments are needed.
How Does Omega-3 Status Affect Telomere Health?
Farzaneh-Far et al. compared telomere aging metrics and O3I levels in people with cardiovascular disease. The observational study took place over a 5-year period in 667 participants.
The researchers measured telomere length using qPCR in blood collected at baseline and after 5 years, whereas the O3I was measured in fasting whole blood collected at baseline only.
People with the lowest baseline O3I had a significant decrease in telomere length of 0.13 T/S units (telomere repeat sequence copy number/reference single-copy gene copy number) over the 5-year period, whereas those with a higher baseline O3I only had a slight, non-significant decrease in telomere length by 0.05 T/S units. This can be interpreted to mean that having a higher omega-3 level slowed telomere shortening in this study.
Another study by Kiecolt-Glase et al., from 2013, looked at the effect of omega-3 supplementation on telomere length in an intervention study. This was a trial conducted over 4 months with 3 different groups:
- Placebo (0 g/d fish oil)
- 1.25 g/day supplement of fish oil
- 2.5 g/day of fish oil
The fish oil product was high-EPA, with a ratio of 7:1 of EPA to DHA. There was not a significant difference in telomere length between the groups after the supplementation, but there was a significant difference when analyzed by fatty acid blood levels. A decrease of omega-6:omega-3 in the ratio, which is typically a proxy of increased omega-3 levels, was associated with an increase in telomere length.
While omega-3s may not show a dramatic increase in telomere length or increasing telomerase activity, they do appear to have a positive effect on slowing down cell replication. Preservation of healthy cells is one aspect of keeping our bodies healthy and functional for longer. Slowing down DNA replication by preserving telomere length can potentially prolong the life of a cell, allowing the DNA to replicate safely. More research needs to be done in this exciting area so we can learn more about the connections between our overall and cellular health.
