Australian researchers have shown that individuals with hypertension can substantially decrease their blood pressure by increasing dietary fibre and protein.
In this small study, 41 adults receiving no more than two antihypertensive drugs were initially assigned to a diet providing 12.5 per cent of energy from protein and 15 g of fibre/day.
After four weeks on this diet, the participants were randomly assigned to either continue with the low-fibre diet, switch to one supplemented with 66 g of soy protein (providing 25 per cent of their total energy) or an additional 12 g of soluble fibre in the form of psyllium, or both, for a further eight weeks.
Those who consumed the high-fibre, high-protein diet achieved the largest decreases in blood pressure, with their systolic blood pressure dropping by an average of 10.5 mmHg compared with the control subjects.
The investigators documented 'significant independent effects of fibre and protein on 24-hour systolic blood pressure and awake systolic blood pressure, and a significant effect of protein on asleep systolic blood pressure'.
As long as a patient does not have an impaired kidney function, concluded the researchers, an increased intake of protein and fibre, particularly with fruits and vegetables as sources of soluble fibre, should be considered as a means of controlling hypertension (Hypertension, 2001; 38: 821-6).