Intermittent Fasting Increases Telomere Length in Young Women: What the Research Shows

Medical disclaimer: This article summarises published research for informational purposes only. It is not medical advice and is not a substitute for guidance from a qualified health professional. Always consult your doctor before starting any fasting protocol, especially if you have an existing health condition or take medication.

Study at a Glance

What This Study Looked At

Telomeres are the protective caps at the ends of chromosomes — and their length is one of the most widely studied biomarkers of biological aging. As telomeres shorten over time, cells lose the ability to divide and repair, accelerating the aging process. The question this study addressed was whether intermittent fasting — specifically Ramadan fasting, a form of daily time-restricted eating practiced over four weeks — could influence telomere length when combined with structured exercise.

Ramadan fasting involves complete food and water abstinence from dawn to sunset, typically creating a 13–16 hour daily fast. This makes it functionally equivalent to an aggressive intermittent fasting protocol applied daily for a month. The researchers wanted to understand whether adding this fasting layer to an exercise program produced any different cellular aging outcomes compared to exercise alone. This connects directly to ongoing research on how intermittent fasting promotes autophagy and intermittent fasting's effects on longevity.

Who Was Studied

Participant profile: Young women aged 20–30 years, non-obese (BMI 20–30 kg/m²), non-smoking, healthy, and free of chronic disease or medication. All participants were Muslim and voluntarily observing Ramadan.

How Ramadan fasting worked in this study: Participants in the fasting group abstained from all food and water from the pre-dawn meal (suhoor) to sunset (iftar) each day for the four weeks of Ramadan. No specific dietary composition requirements were imposed during the eating window. The fasting period in Qatar during Ramadan 2024 lasted approximately 13–15 hours per day.

The exercise protocol: Both groups completed the same structured 4-week exercise training program (aerobic and resistance components, performed during the fasting period for the Ramadan group and during the day for the control group).

What the Researchers Found

Telomere Length

The central finding of the study was clear: telomere length increased significantly from baseline in the group combining Ramadan fasting with exercise, while those exercising without fasting showed no meaningful change in telomere length over the same four-week period.

This is notable because telomere lengthening — or even preservation — in adult humans over a short intervention period is uncommon. Most interventional studies find that telomeres either stay stable or decline. An active increase in telomere length over four weeks is a striking result.

Inflammatory Markers

• TNF-α: Significantly reduced in the fasting + exercise group. TNF-alpha is a key driver of chronic inflammation and is associated with accelerated cellular aging.
• The reduction in TNF-α accompanied the telomere lengthening, suggesting an anti-inflammatory mechanism may link fasting to telomere protection.

Lipid Profile Correlation

• A significant positive correlation was observed between the change in telomere length and HDL cholesterol levels in the fasting + exercise group only.
• Higher HDL — associated with cardiovascular protection — correlated with greater telomere length gains in the fasting group, but this relationship was absent in the exercise-only group.

What Did Not Change

• Exercise alone produced no significant telomere length change, despite being the same program as the fasting group. This isolates the fasting component as the driver of the telomere effect.
• The researchers did not report significant differences in body weight or BMI between groups, suggesting the telomere effect was not simply a function of fat loss.

What the Researchers Concluded

The researchers described their study as "the first to report an increase in telomere length after combining Ramadan fasting with training," and concluded that "exercising while fasting may be an effective tool for slowing down the aging rate." They proposed that the anti-inflammatory effect of fasting — evidenced by reduced TNF-α — may be a key mechanism through which fasting protects and potentially lengthens telomeres.

What This Means If You Fast

• Fasting may slow cellular aging beyond what exercise alone achieves. Both groups did the same exercise program, but only the fasting group showed telomere lengthening — which suggests fasting adds a distinct anti-aging layer that exercise does not replicate on its own.
• The inflammation connection matters. Chronic low-grade inflammation (sometimes called "inflammaging") is one of the leading drivers of telomere shortening. Fasting's ability to reduce TNF-alpha provides a plausible explanation for why fasting may protect telomere length. This aligns with evidence on how intermittent fasting reduces inflammation.
• Four weeks may be enough to move the needle. This study lasted only one Ramadan month — four weeks. That telomere changes were measurable in such a short window suggests fasting has a relatively rapid effect on cellular aging biomarkers.
• The HDL connection suggests cardiovascular benefit too. The positive correlation between telomere gains and HDL in the fasting group points to a broader metabolic benefit — not just a single biomarker effect. HDL improvement and telomere preservation may share common inflammatory pathways that fasting activates.
• Combining fasting with exercise may be more powerful than either alone. The exercise-only group served as the control, and they did not move telomere length. Adding fasting to the same exercise program produced a different outcome — suggesting the combination is greater than the sum of its parts.
• Women specifically may benefit. This study was conducted exclusively in young women, so results apply most directly to this population. Whether similar effects appear in men, older women, or those with chronic conditions remains to be studied.

Study Limitations

• Small sample size (n=29). With approximately 14–15 participants per group, the study is underpowered to detect small effects with statistical confidence. Larger trials are needed to confirm findings.
• All-female cohort. Results cannot be extrapolated to men or older women without additional research.
• Short duration (4 weeks). While the telomere changes were significant, it is unknown whether these gains persist long-term, or whether they reflect transient cellular adaptation.
• Exercise confound. Both groups exercised, but the timing and physiological context differed — the fasting group exercised while fasted, which itself has independent effects on cellular metabolism and inflammation. The study cannot fully separate fasting from the effects of exercising in a fasted state.
• No dietary control during eating window. The composition of the food consumed during iftar (the breaking of the fast) was not controlled, which could have influenced inflammatory markers and telomere-related outcomes.
• Ramadan-specific context. Ramadan involves social, spiritual, and sleep pattern changes beyond the fasting itself. These contextual factors could have influenced results.
• Self-reported dietary adherence during Ramadan. Participants' food intake during the eating window was not rigorously monitored.
• No conflict of interest statement found in the available summary.

Source

Almuraikhy, S., Sellami, M., Naja, K., Al-Amri, H. S., Anwardeen, N., Aden, A., Dömling, A., & Elrayess, M. A. (2024). Joint effects of exercise and Ramadan fasting on telomere length: Implications for cellular aging. Biomedicines, 12(6), 1182. PMID: 38927389

Frequently Asked Questions

What are telomeres and why do they matter for aging?

Telomeres are the protective end-caps on chromosomes, similar to the plastic tips on shoelaces. Each time a cell divides, telomeres shorten slightly. When they become too short, the cell can no longer divide — it either enters a dormant state or dies. Shorter average telomere length in blood cells is associated with greater biological age, higher disease risk, and shorter lifespan.

Does intermittent fasting actually lengthen telomeres?

This 2024 study found that Ramadan fasting combined with exercise produced a significant increase in telomere length over four weeks. Exercise alone did not. This is one of the first RCTs to show telomere lengthening with a fasting intervention in humans, though the sample size is small and more research is needed to confirm the finding.

Why would fasting affect telomere length?

The most likely mechanism is inflammation reduction. TNF-alpha, a key inflammatory cytokine, was significantly reduced in the fasting group — and chronic inflammation is a known driver of telomere shortening. Fasting also activates autophagy (cellular clean-up) and reduces oxidative stress, both of which are thought to protect telomere integrity.

Is Ramadan fasting the same as intermittent fasting?

Functionally, yes — Ramadan fasting creates a daily time-restricted eating window (typically 8–10 hours for eating, 13–16 hours of fasting), which is very similar to the 16:8 or 18:6 protocols practiced in intermittent fasting. The key difference is that during Ramadan, water is also restricted during the fasting hours, whereas most IF protocols allow water, black coffee, and herbal tea.

How long do you need to fast to see changes in biological aging markers?

This study showed measurable telomere changes in just four weeks of daily Ramadan fasting. Other fasting studies measuring different aging biomarkers (like autophagy markers and IGF-1) have shown effects over similar timeframes. Four weeks appears to be a meaningful minimum window for cellular-level adaptation.

Related Research and Articles

• Intermittent fasting and longevity: what the science says
• How intermittent fasting promotes autophagy
• Does intermittent fasting slow aging?
• Intermittent fasting and inflammation: the research explained
• What is autophagy and when does it start during fasting?
• Intermittent fasting benefits: the complete science-backed guide
• Does fasting boost human growth hormone (HGH)?

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