Does Omega-3 Slow Down Aging? A Three-Year Clinical Study Reveals Small but Significant Changes

"Taking 1 gram of Omega-3 daily can make your biological age 3 months younger"

Such a headline would likely catch the attention of many people interested in longevity and anti-aging. Omega-3 from fish oil or algae is easily available at drugstores or online. If simply taking a capsule daily could delay aging without special treatments or strict dietary restrictions, it sounds very appealing.

However, interpreting the study results as "the body became 3 months younger" or "lifespan extended by 3 months" is not accurate.

The study confirmed that in some elderly individuals who took Omega-3, the progression of aging indicators calculated from DNA methylation patterns in the blood was slightly slower than in those who did not take it.

In other words, it did not rewind the calendar age, but suggested that the "aging clock," which estimates changes in cells and internal environments, advanced about 3 to 4 months more slowly on average over three years.

While this may seem like a small change, the fact that a cheap and relatively easy intervention showed differences in aging-related indicators is noteworthy in health longevity research. However, it is still unclear how much health benefit this translates to in real life.

The Stage of the Study: "DO-HEALTH Trial"

The study in question is an additional analysis using stored blood samples from the large-scale clinical trial "DO-HEALTH" conducted in Europe.

The DO-HEALTH trial involved 2,157 men and women aged 70 and older living in five European countries. The participants were relatively healthy and active elderly individuals, and the effects of vitamin D, omega-3 fatty acids, and simple home exercises were examined, either alone or in combination.

Participants were randomly divided into eight groups combining the following three types of interventions.

Omega-3 was administered at 1 gram per day, consisting of 330 milligrams of EPA and 660 milligrams of DHA. The oil was derived from marine algae.

Vitamin D was given at 2,000 international units per day. The exercise program involved 30-minute strength training sessions conducted at home three times a week.

The analysis of biological age focused on 777 Swiss participants whose blood samples were available at the start of the study and three years later. The average age was about 75, with 59% being women.

It is important to note that this was not an analysis planned from the beginning with biological age as a primary evaluation item, but a "post-hoc analysis" conducted later using stored samples. This point is crucial when considering the reliability of the study results.

What Does "Biological Age" Measure?

A person's age can be calculated from their birthday as chronological age, or it can be reflected in the state of their body as biological age.

Even at the same age of 75, some people exercise regularly and have good metabolism and cardiopulmonary function, while others may experience significant physical decline due to chronic diseases or muscle weakness. The concept of biological age attempts to quantify such individual differences.

In this study, a measurement method called the "epigenetic clock" was used.

DNA has mechanisms that regulate gene function without changing the sequence of genetic information itself. A representative phenomenon is DNA methylation. By adding or removing chemical markers called methyl groups at specific locations on DNA, genes can become more or less active.

DNA methylation patterns change with age, living environment, inflammation, metabolic state, etc. The epigenetic clock estimates the degree and speed of aging by statistically combining numerous measurement points.

The research team focused on analyzing four relatively new indicators: PhenoAge, GrimAge, GrimAge2, and DunedinPACE.

These do not all measure the same thing. They differ in design philosophy, with some estimating the difference from chronological age, others related to mortality risk and blood proteins, and others evaluating the speed of aging.

Therefore, an intervention may show effects on one clock but not exhibit clear changes on another.

Omega-3 Showed Changes in Three of the Four Clocks

The analysis revealed that participants who took 1 gram of Omega-3 daily showed changes in the direction of slowing aging progression in three of the four main epigenetic indicators: PhenoAge, GrimAge2, and DunedinPACE.

When the research team converted the effect size into time, it was calculated that the progression of aging was suppressed by about 2.9 to 3.8 months over three years.

On the other hand, no clear effect was shown with GrimAge. Additionally, older generation epigenetic clocks did not confirm any significant changes.

The fact that "results in the same direction were obtained with multiple indicators" is a strength of the study, but it was not consistent across all indicators.

When only vitamin D was taken or only the exercise program was conducted, no clear changes were confirmed in the four main clocks.

However, with PhenoAge, there was a tendency for the effect to be additive when Omega-3 was combined with vitamin D and exercise. The group that implemented all three showed greater changes in aging indicators than the Omega-3 only group.

However, this additive effect was mainly confirmed with one clock and was not reproduced in all analysis results. It cannot be concluded that "combining the three will certainly rejuvenate."

Why Did Omega-3 Affect Aging Indicators?

Omega-3 fatty acids include several types, such as EPA, DHA, and ALA.

EPA and DHA are abundant in fatty fish like mackerel, sardines, and salmon, as well as in marine algae. ALA is found in plant-based foods such as flaxseed oil, perilla oil, and walnuts.

In the body, some ALA is converted to EPA and DHA, but the conversion efficiency is not high. Therefore, consuming 1 gram of plant oil is not the same as consuming a total of about 1 gram of EPA and DHA used in this study.

The mechanism by which Omega-3 affects biological age is not confirmed by this study alone.

One possible pathway is its action on chronic inflammation. A state of low-grade inflammation persisting over a long period with aging is called "inflammaging," and its association with cardiovascular diseases, glucose metabolism disorders, muscle weakness, etc., is being studied.

EPA and DHA are involved in the composition of cell membranes and lipid metabolism, in addition to being materials for substances related to inflammatory responses. As a result, changes in the cellular environment, including DNA methylation, may have occurred.

In the study, changes in DNA methylation indicators related to PAI-1, leptin, TIMP-1, etc., were observed in the group that took Omega-3. These are related to metabolism, adipose tissue, inflammation, tissue repair, etc.

However, it has not been proven that these changes directly lead to lifespan extension or disease reduction. There is still a research gap to be filled between the improvement of aging clock numbers and actually living longer and healthier.

Consider Results Separately from Infections, Falls, and Cancer

In the DO-HEALTH trial, additional analyses previously reported that those who took Omega-3 had a 13% lower incidence of infections and a 10% lower incidence of falls.

Moreover, in the group that combined Omega-3, vitamin D, and exercise, the risk of transitioning to pre-frailty was 39% lower, and the incidence of invasive cancer was 61% lower.

Pre-frailty refers to a state between being healthy and full-fledged frailty, where some signs such as fatigue, muscle weakness, decreased walking speed, and reduced activity levels begin to appear.

These are intriguing results, but they were not newly discovered by the current analysis of biological age. They are separate analysis results previously reported from the same DO-HEALTH trial.

Furthermore, in the primary evaluation items initially set by the DO-HEALTH trial, such as blood pressure, physical ability, cognitive function, fractures, and infections, no clear benefits meeting strict statistical criteria were confirmed.

Analyzing various items afterward increases the possibility of finding favorable results by chance. Therefore, it is prudent to express that "the effects of Omega-3 have been proven" based only on individual positive results.

On Social Media, "Want to Take It Immediately" and "Isn't It Exaggerated?" Intersect

The study results were widely reported in overseas media and actively discussed on the bulletin board-style social network Reddit, which handles science news.

A prominent reaction was the welcome of the fact that Omega-3 is relatively inexpensive and easily accessible.

Comments included, "It's interesting that a nutrient that can be taken daily, rather than a large-scale treatment, can change aging," and "It gives a reason to increase the habit of eating fish." There were also voices showing interest in algae-derived Omega-3 products, similar to the study, from those who want to avoid fish-derived products.

On the other hand, there was also confusion about the magnitude of the effect.

Questions were posted such as, "Is the result of 3 to 4 months over 3 years significant enough in real life?" and "Will it become a year if continued for 9 years?"

However, there is no guarantee that this effect will accumulate proportionally over time. It has not been investigated whether the same difference will continue to widen beyond three years, stop at a certain point, or return to the original state if intake is interrupted.

Comments from users familiar with research methods pointed out that this analysis was a post-hoc analysis and that the original clinical trial did not produce significant results in the primary evaluation items it set.

This is a concern about so-called multiple comparisons or p-hacking, where favorable results are picked up by examining many indicators afterward.

The research paper is peer-reviewed and has the strength of using data from a randomized trial. However, since it is a post-hoc analysis, it is desirable that a new clinical trial with biological age as the primary purpose from the beginning be reproduced.

Questions about the ingredients also followed.

Questions included, "Does flaxseed oil have the same effect?" "Is there a difference between fish oil and algae oil?" and "Is the ratio of EPA to DHA important?"

The product used this time was algae-derived oil containing 330 milligrams of EPA and 660 milligrams of DHA, not general plant oil centered on ALA. Therefore, not all products or foods labeled "Omega-3" will necessarily yield the same results.

Concerns about safety were also observed. Some posts linked their own arrhythmia experiences and showed a cautious attitude towards fish oil supplements.

While causal relationships cannot be determined from personal experiences on social media, the issue raised that Omega-3 supplements are not unconditionally suitable for everyone is meaningful.

Note that these reactions were confirmed from some Reddit posts in the English-speaking world and are not a survey representing the entire public opinion. It is also important to note that posts with strong expectations or critical posts tend to stand out on social media.

What This Study Does Not Clarify

There are several important limitations to the current results.

First, there is no globally standardized method for measuring biological age.

Multiple epigenetic clocks are made using different data. Even if the value of one clock improves by 3 months, it is not clear to what extent those 3 months correspond to the risk of myocardial infarction, dementia, need for care, death, etc.

Second, the analysis subjects are limited.

The subjects were Swiss residents aged 70 and older, many of whom were relatively healthy and active. The same results may not apply to younger people, middle-aged individuals, those with severe chronic illnesses, or groups with different races, ethnicities, and diets.

Third, the blood measurement points were limited to two times: at the start of the study and three years later.

Since detailed tracking of changes in between is not possible, it is unknown when the difference began to occur or whether it changed at a constant rate.

Fourth, lifespan extension has not been proven.

What was shown this time is a change in proxy indicators, not direct evidence that participants actually lived longer, became less prone to illness, or rejuvenated their physical abilities.

Fifth, the effect is an average value.

Not everyone who took Omega-3 gained the same 3-month benefit. There is considerable individual variation, and those with lower blood levels of EPA or DHA at the start of the study may have shown a larger response.

For those who already frequently eat fish and have sufficient blood Omega-3 levels, adding supplements may result in smaller benefits.

It's Not a Conclusion That You Should Just Take Supplements

The current results alone do not necessitate that everyone start taking 1 gram of Omega-3 supplements daily.

Supplement ingredients vary greatly by product. Even if labeled "1,000 milligrams of fish oil," the total amount of EPA and DHA may not be 1,000 milligrams. It is necessary to separately confirm the total weight of the fish oil and the amount of EPA and DHA included as active ingredients.

The product used in this study was an algae-derived product containing a total of 990 milligrams of EPA and DHA. Even commercial products labeled "1 gram" may not have identical contents.

According to materials from the U.S. National Institutes of Health, side effects reported with Omega-3 supplements within the normal range are mostly mild, such as stomach discomfort, heartburn, nausea, diarrhea, bad breath, and fishy aftertaste.

On the other hand, high doses of EPA and DHA may affect bleeding time and blood coagulation. People using anticoagulants or antiplatelet drugs should not add them on their own and should consult a doctor or pharmacist.

In some trials targeting people with cardiovascular diseases or at high risk, a slight increase in atrial fibrillation was observed with high doses of Omega-3, around 4 grams per day. While the 1 gram per day used in this study should not be equated with high-dose prescription drugs, especially cautious judgment is required for those with a history of arrhythmia.

For those who can obtain it from their diet, incorporating fish