The Claim

Among adults with controlled hypertension, intermittent fasting during Ramadan is associated with a statistically significant increase in heart rate variability during the afternoon, as measured by elevated SDNN and SD2 and reduced stress index, indicating a shift toward greater parasympathetic tone, with no significant effect observed in the morning or evening and no correlation with changes in blood pressure or lipid profiles.

Source: Impact of Ramadan Intermittent Fasting on the Heart Rate Variability and Cardiovascular Parameters of Patients with Controlled Hypertension

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
47score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

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.

See the scientific wording

Among adults with controlled hypertension, intermittent fasting during Ramadan is associated with a statistically significant increase in heart rate variability during the afternoon, as measured by elevated SDNN and SD2 and reduced stress index, suggesting a shift toward greater parasympathetic tone, though this effect was not observed in the morning or evening and did not correlate with changes in blood pressure or lipid profiles.

Why this might work

When a person goes without food for many hours, the body slows down its metabolic activity and stops sending stress signals to the heart. This lets the calming part of the nervous system take over, especially in the afternoon, making the heart beat more steadily and with greater variation. This effect does not happen in the morning or evening because the body's internal clock shifts when fasting changes when food is consumed.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Impact of Ramadan Intermittent Fasting on the Heart Rate Variability and Cardiovascular Parameters of Patients with Controlled Hypertension

    In people with well-controlled high blood pressure, fasting during Ramadan made their hearts more relaxed and less stressed in the afternoon, but not in the morning or evening—and this didn’t change their blood pressure or cholesterol levels.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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