Málaga, Spain, February 29, 2024 — Want to lower your blood pressure? Forget fad diets—a new study reveals that modified alternate-day fasting is significantly more effective than other popular eating plans. The research, a subanalysis of a randomized controlled trial, found this form of intermittent fasting led to an average drop of 11.6 mmHg in systolic blood pressure and 7.1 mmHg in diastolic blood pressure.
Intermittent Fasting Outperforms Keto, Mediterranean Diets in Blood Pressure Control
A new study shows modified alternate-day fasting is a standout nutritional strategy for managing hypertension, affecting over a billion people worldwide.
- Modified alternate-day fasting—alternating between normal eating days and days with 75% calorie reduction—showed the most significant blood pressure improvements.
- Participants following other diets, including time-restricted eating, ketogenic, and Mediterranean plans, experienced minimal changes in blood pressure.
- Weight loss was consistent across all diet groups, suggesting blood pressure benefits from fasting aren’t solely tied to weight reduction.
- Researchers suspect factors like sodium balance, circadian rhythms, and improved insulin sensitivity may play a role in fasting’s unique effect.
High blood pressure is a major contributor to cardiovascular disease, and lifestyle changes are often the first line of defense. While weight loss is known to help, determining the *best* nutritional approach has been a challenge. A team led by Ana María Gómez-Pérez from the Virgen de la Victoria University Hospital in Málaga set out to compare the effects of several calorie-restricted diets.
The Study Design
The researchers conducted a subanalysis of a randomized controlled trial involving 96 obese participants (BMI 30-45 kg/m²). For three months, participants followed one of five diets:
- Frühes Time-Restricted Eating (meal window 8 a.m. to 4 p.m.)
- Spätes Time-Restricted Eating (meal window 2 p.m. – 10 p.m.)
- Ketogenic diet
- Modified Alternate-Day-Fasting (Alternation of normal and fasting days with 75% calorie reduction)
- Mediterranean diet (control group)
All diets involved a daily energy deficit of approximately 600 kcal. Participants also received nutritional support, exercise recommendations—including daily whole-body training and aiming for 10,000 steps per day—and the primary endpoint was change in 24-hour blood pressure.
Similar Weight Loss, Different Results
Interestingly, all groups experienced comparable weight loss, ranging from 8.7 to 11.5 kg. Improvements in BMI (-3.1 to -4.3 kg/m²), waist circumference (-8.71 to -12.5 cm), and fat mass (-5.9 to -15.3 kg) were also similar across the board. A moderate loss of muscle mass (−1.2 to −3.1 kg) occurred in all groups as well.
What’s the best diet for lowering blood pressure? While all diets led to weight loss, only modified alternate-day fasting resulted in significant blood pressure reductions. The 24-hour systolic value fell by an average of -11.6 mmHg, and the diastolic value decreased by -7.1 mmHg. Late time-restricted eating showed modest improvements in mean arterial pressure, but the other diets had little effect.
Beyond Weight Loss: Unraveling the Mechanisms
The researchers are exploring why these diets impact blood pressure differently despite similar weight loss. They propose that additional mechanisms, independent of weight, are at play. These include potential changes in sodium balance during fasting days, the influence of meal timing on circadian rhythms, improved insulin sensitivity, and reduced systemic inflammation. Notably, they found no direct link between ketone bodies and blood pressure reduction, despite slightly elevated levels in the ketogenic diet group.
Did you know? Intermittent fasting isn’t just about *when* you eat, but also about giving your body periods of rest and repair, potentially impacting metabolic processes beyond calorie restriction.
