The Study
Impact of Ramadan Intermittent Fasting on the Heart Rate Variability and Cardiovascular Parameters of Patients with Controlled Hypertension
This study watched a group of people with high blood pressure during and after Ramadan to see what changed in their hearts. It found that their heart rhythms looked a little calmer in the afternoon while fasting — but that doesn’t mean fasting made it happen. Something else, like sleeping more or eating differently, could’ve caused it.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
People with high blood pressure who fasted during Ramadan had their hearts show signs of less stress in the afternoon — like a calm-down signal — but their blood pressure and cholesterol didn’t change.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 547 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — improved heart rate variability suggests the heart is under less stress, which is good, but higher blood sugar could be a concern, especially for people with diabetes risk.
- 2Afternoon heart rate variability (a stress marker) improved significantly; blood glucose rose by 6.65 mg/dL; men lost about 1 kg and had smaller hips; women showed no changes.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Nutrition and Metabolism
Year
2021
Authors
Sabah Hammoud, Iman Saad, R. Karam, F. Abou Jaoude, B. V. D. van den Bemt, M. Kurdi
Related Content
Claims (6)
Fasting for 12 to 16 hours is associated with higher heart rate variability and lower resting heart rate, while fasting for more than 48 hours is associated with lower heart rate variability.
Adults with controlled hypertension who fast during Ramadan experience higher fasting blood glucose levels, while their lipid levels remain unchanged.
Among adults with controlled high blood pressure, men who fast during Ramadan lose a small but measurable amount of weight and reduce their hip size, while women do not experience these changes.
In adults with controlled high blood pressure, fasting during Ramadan is associated with increased heart rate variability in the afternoon, reflecting higher parasympathetic nervous system activity, but this change does not occur in the morning or evening and is not linked to changes in blood pressure or cholesterol levels.
In adults with controlled high blood pressure, fasting during Ramadan does not change levels of triglycerides, total cholesterol, LDL, HDL, or non-HDL cholesterol, even when these levels are initially high.
In adults with controlled high blood pressure who take their blood pressure medications, fasting during Ramadan does not change their systolic or diastolic blood pressure readings, even though their eating and sleeping patterns change.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.