Researchers investigating cardiac autonomic function via 24-hour electrocardiogram recordings of over 7,000 adults in the Maastricht Study have found that higher adherence to the Dietary Approaches to Stop Hypertension (DASH) and Dutch Healthy Diet (DHD) patterns correlates with increased very-low-frequency heart rate variability, though researchers note that self-reported dietary data and observational designs prevent causal claims.
The cross-sectional study, published in the journal Scientific Reports, examined baseline data gathered from participants aged 40 to 75 in the southern Netherlands. Investigators sought to understand whether consuming specific diets influences the subtle regulatory rhythms of the heart, measured through heart rate variability (HRV), which serves as an indicator of cardiovascular regulation and is associated with cardiovascular mortality risk.
In Plain English: The Clinical Takeaway
- Heart Rate Variability (HRV): This reflects cardiac autonomic function and serves as a marker of cardiovascular regulation.
- Very-Low-Frequency (VLF) Power: A specific frequency domain derived from 24-hour heart monitoring that measures slow fluctuations in the intervals between heartbeats. While the DASH and DHD diets showed positive linear associations with VLF power, researchers emphasize that the physiological meaning of VLF power in 24-hour recordings remains debated.
- Beta-Blocker Interplay: The study uncovered a significant interaction between DASH diet adherence and the use of beta-blockers, indicating that medication use should be considered when examining associations between diet and HRV.
The Maastricht Cohort and 24-Hour Heart Monitoring Protocols
Cardiovascular diseases remain the leading cause of death worldwide, driving the medical community to identify underlying risk factors early. Reduced HRV is associated with higher cardiovascular mortality, and factors such as age, hypertension, type 2 diabetes mellitus, and smoking habits can affect HRV. To test whether diet can affect these, the research team analyzed data from 7,256 qualified adults out of 9,187 initially recruited between November 2010 and October 2020.
A low HRV score is linked to an increased risk of sudden cardiac death. This single metric reveals the hidden state of your autonomic balance and heart health.Heart rate variability measures the tiny fluctuations in time between consecutive heartbeats. A healthy heart does not… pic.twitter.com/RsLPImmuGh
Dietary intake was evaluated using a validated, self-administered food frequency questionnaire spanning 253 food items across 23 groups, yielding adherence scores for four primary patterns: the Mediterranean diet, the DASH diet, the DHD diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. Cardiac autonomic function was captured using a 12-lead Holter monitoring system for 24-hour electrocardiogram (ECG) recordings. The team calculated time-domain and frequency-domain parameters—including SDNN, RMSSD, total power, and very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) power—while adjusting for demographic, lifestyle, clinical, and medication variables.
| Dietary Pattern | Key Favorable Cardiometabolic Associations | Observed HRV Frequency Association |
|---|---|---|
| DASH Diet | Lower systolic/diastolic blood pressure, reduced BMI and triglycerides, higher physical activity | Significant positive linear association with VLF power ($P le 0.001$) |
| Dutch Healthy Diet (DHD) | Lower blood pressure, reduced triglycerides, higher fiber and calcium intake | Significant positive linear association with VLF power ($P le 0.001$) |
| Mediterranean Diet | Favorable cardiometabolic characteristics | No significant associations identified after full covariate adjustment |
| MIND Diet | Higher BMI and lower levels of total, HDL, and LDL cholesterol | No significant associations identified after full covariate adjustment |
Cardiometabolic Characteristics Across Dietary Adherence Quartiles
Higher adherence scores for the Mediterranean, DASH, and DHD diets mapped to several favorable cardiometabolic profiles, though lipid outcomes were not uniformly better. Participants scoring higher on these three diets typically demonstrated lower smoking rates, reduced systolic and diastolic blood pressure, lower body mass index (BMI), and decreased serum triglyceride levels alongside higher physical activity. Conversely, those adhering more closely to the MIND diet tended to show a higher BMI and lower levels of total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol.
When researchers evaluated the frequency-domain parameters after applying a Bonferroni-adjusted significance threshold of $P < 0.00125$ to account for 40 primary comparisons, distinct patterns emerged. Greater adherence to the DASH and DHD diets correlated with higher VLF power, with regression coefficients per adherence scale point of 11.81 ± 3.58 for DASH and 4.66 ± 1.20 for DHD. However, time-domain measures—which assess variations in the intervals between successive heartbeats—showed no significant associations with any of the four dietary patterns.
Subgroup analyses further revealed that medication usage altered these dietary associations. A notable interaction surfaced between DASH adherence and beta-blocker therapy in relation to VLF power. Among individuals not using beta-blockers, greater adherence to both DASH and DHD regimens tracked alongside higher VLF power. Exploratory stratifications also pointed toward specific links among women and non-obese adults, though formal interaction tests found no significant differences by sex, obesity, smoking, diabetes, or age.
Study Limitations
The observational, cross-sectional design of the Maastricht Study prevents investigators from drawing definitive causal conclusions, while potential limits to the interpretation and broader application of the results stem from participant dietary reports, unmeasured variables, and an overrepresentation of adults diagnosed with type 2 diabetes mellitus. Prospective research, including randomized controlled trials, is needed to determine the clinical significance of these findings.
References
- Haeri, F., Eussen, S. J. P. M., Schram, M., Yu, E. Y.-W., Seyedhosseini, S. M., Sarebanhassanabadi, M., Soltani, S., Salehi-Abargouei, A., Zeegers, M. Nutritional habits and cardiac rhythm variation: an observational evaluation involving more than seven thousand participants from the Maastricht investigation. Scientific Reports. DOI: 10.1038/s41598-026-74731-w
