
For decades, researchers have searched for ways to slow down biological aging — not just look younger, but keep our cells and organs functioning as though they belong to a younger body.

Now, a groundbreaking 3-year clinical trial suggests that two simple nutrients — [<span className="text-emerald-400 hover:text-emerald-300">omega-3 fatty acids</span>](/nutrients/omega-3-fatty-acids) and [<span className="text-emerald-400 hover:text-emerald-300">vitamin D</span>](/nutrients/vitamin-d) — may help do just that.

## The Study: DO-HEALTH

The DO-HEALTH trial, led by Prof. Heike Bischoff-Ferrari at the University of Zurich, is one of Europe's largest and longest-running aging studies.

It followed 777 older adults (aged 70+) over three years, testing how vitamin D (2,000 IU daily), omega-3 fatty acids (1 gram daily from algae oil), and strength training (30 minutes, three times per week) affected participants' health and biological aging.

The study's results were published in *Nature Aging* (2025) and mark the first time researchers have measured biological aging changes in humans using DNA-based "epigenetic clocks."

## How Biological Age Was Measured

Biological age reflects how quickly your body is aging at a cellular level — which can differ significantly from your chronological age.

To measure it, researchers used epigenetic clocks, a cutting-edge method developed by Dr. Steve Horvath (Altos Labs, Cambridge, UK).

These clocks analyze DNA methylation, small chemical tags that accumulate on our DNA over time and can be used to estimate how fast the body is aging.

By comparing DNA methylation patterns before and after the interventions, the researchers were able to see how each lifestyle factor affected the pace of aging.

## The Results: Slower Aging Across Multiple DNA Clocks

After 3 years, the team found that:

**Omega-3 fatty acids slowed biological aging by up to 4 months** compared to the control group — across several epigenetic clocks.

**The combination of omega-3 + vitamin D + strength training** produced the strongest effect, showing the greatest slowing of biological aging.

These effects were consistent regardless of age, gender, or body mass index.

In other words, the simple combination of nutrient supplementation and light exercise measurably slowed the molecular signatures of aging — something previously only seen in animal or calorie-restriction studies.

## Why This Combination Works

Each intervention appears to work through a distinct, complementary pathway:

**Omega-3 fatty acids (EPA and DHA)** reduce inflammation and protect DNA from oxidative stress.

They're essential for maintaining healthy cell membranes and modulating immune and metabolic function.

**Vitamin D** supports cellular repair, strengthens bones and muscles, and helps regulate immune responses.

Adequate levels are linked to lower infection risk and improved mitochondrial health.

**Strength training** increases muscle mass, activates genes associated with longevity, and improves insulin sensitivity.

Exercise also enhances DNA repair and reduces chronic inflammation.

Together, these three interventions reinforce one another — improving resilience at the cellular and whole-body level.

## Beyond Aging: Broader Health Benefits

Earlier results from DO-HEALTH showed that the same trio — vitamin D, omega-3, and home-based exercise — led to:

- Fewer infections
- Lower risk of cancer
- Reduced incidence of falls and frailty

Now, researchers believe these benefits may stem from their shared impact on slowing biological aging itself.

> "Each of these measures works through different mechanisms that complement each other and, when combined, result in a heightened overall effect."
> 
> — Prof. Heike Bischoff-Ferrari, University of Zurich

## What It Means for You

You can't stop time — but you can slow your biological clock.

The DO-HEALTH findings suggest that small, consistent habits — sunlight exposure, omega-3-rich foods, and moderate strength training — can make a measurable difference.

Here's what the study protocol used:

**Vitamin D:** 2,000 IU per day (from sunlight, salmon, or supplements)

**Omega-3 fatty acids:** 1 gram daily of combined EPA + DHA (from algae oil, fish oil, or fatty fish like salmon, sardines, or mackerel)

**Exercise:** 30 minutes of strength training, three times per week

⚠️ **Note:** Always consult your healthcare provider before starting new supplements, especially if you have existing medical conditions or take prescription medications.

## The Future of Measuring Aging

While the results are compelling, researchers emphasize that there's still no single "gold standard" for measuring biological age.

However, the epigenetic clocks used in this study are among the best-validated tools available today — and the findings pave the way for using molecular biomarkers to track aging interventions in real time.

The research team now plans to expand analyses to include DO-HEALTH participants from Germany, France, Austria, and Portugal, to better understand how genetics, nutrition, and lifestyle interact to shape healthy aging across populations.

## Track Your Nutrient Intake Effortlessly

Not sure if you're getting enough omega-3 or vitamin D from food?

**Microgram** lets you track all your vitamins, minerals, and macros with just a photo of your meal — helping you ensure your diet supports long-term cellular health and longevity.

## References

- Bischoff-Ferrari HA, Gängler S, Wieczorek M, et al. Individual and additive effects of vitamin D, omega-3 and exercise on DNA methylation clocks of biological aging in older adults from the DO-HEALTH trial. *Nature Aging*. 2025;5(3):376–385. [https://pubmed.ncbi.nlm.nih.gov/39900648/](https://pubmed.ncbi.nlm.nih.gov/39900648/)
- Bischoff-Ferrari HA, de Godoi Rezende Costa Molino C, Rival S, et al. DO-HEALTH: Vitamin D3–Omega-3–Home exercise—Healthy aging and longevity trial—Design of a multinational clinical trial on healthy aging among European seniors. *Contemporary Clinical Trials*. 2021;100:106124. [https://www.sciencedirect.com/science/article/pii/S1551714420302020](https://www.sciencedirect.com/science/article/pii/S1551714420302020)


Could fish oil turn back your biological clock?

Related Articles

Why Protein is the Key Nutrient for Healthy Aging

Why Balancing Omega-6 and Omega-3 Fats Matters

5 Proven Tips to Actually Heal Your Gut

Track your nutrition with Microgram