Cruciferous vegetables can lower your blood pressure

Cruciferous vegetables, including broccoli, cabbage, kale and cauliflower, have been found to lower blood pressure in middle-aged and older Australian adults with elevated blood pressure, according to research conducted by Edith Cowan University (ECU) and published in the journal BMC Medicine.

As noted by ECU PhD student Emma Connolly, “Hypertension, or high blood pressure, is the leading risk factor for heart disease, with its prevalence increasing with age. Increasing vegetable intake is widely recommended to reduce heart disease risk, and previous observational studies have shown cruciferous vegetables like broccoli, cabbage and Brussels sprouts have stronger relationships with lower heart disease risk than other vegetables.”

Connolly explained that compounds called glucosinolates, which are found almost exclusively in cruciferous vegetables, have been shown to lower blood pressure in animals, but evidence in humans has thus far been limited. Cruciferous vegetables also contain several other components that likely provide additional benefits in lowering blood pressure, such as nitrate and vitamin K.

ECU researchers conducted a randomised, controlled, crossover trial over a six-week period, with participants completing two dietary interventions separated by a ‘washout’ period where they followed their normal diet. During one intervention period participants consumed four serves of cruciferous vegetables per day as soups with lunch and dinner, while during the other intervention period they consumed a root and squash vegetable soup.

The blood pressure of participants was measured continuously for 24 hours before and after both two-week intervention periods, and showed a 2.5 mmHg difference in blood pressure reduction for eating cruciferous vegetables compared to root and squash vegetables, which translates to roughly 5% lower risk of experiencing a heart attack or stroke. Background diet and lifestyle remained consistent throughout the study, indicating the reduction in blood pressure seen was not influenced by these factors.

ECU NHMRC Emerging Leader and Heart Foundation Postdoctoral Fellow Dr Lauren Blekkenhorst noted that less than one in 15 Australian adults currently meets recommendations for vegetable intake, with cruciferous vegetables the lowest consumed group of vegetables. If people want to lower their blood pressure and reduce their risk of developing heart disease later in life, they should ideally consume these vegetables most days of the week, she said.

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