Beetroot juice can reduce blood pressure in pregnancy: can we predict which women will respond?

By looking at the bacteria present in women’s mouths, our researchers want to find out why drinking beetroot juice reduces blood pressure in some pregnant women with hypertension, while others do not respond to this treatment.
  • Author's list

    Dr Elizabeth Cottrell, Thomas Willmott, Dr Gavin Humphreys, Professor Andrew McBain, Professor Jenny Myers

    Start: September 2018
    End: March 2022

  • Research centre

  • Research status

    Ongoing projects

Why do we need this research?

Around 1 in 10 pregnant women have chronic hypertension – high blood pressure before or early in pregnancy. These women are more likely to suffer from pre-eclampsia, and their babies may be born too small or too soon because there isn’t enough blood flowing across the placenta for the baby to get the food and oxygen it needs. There are very few treatments available for pregnant women with high blood pressure. We believe this needs to change.

Beetroot juice can reduce blood pressure in some women

Our scientists have recently shown that drinking beetroot juice can reduce high blood pressure in pregnant women. This works because beetroot juice is a source of nitrate, which our bodies convert into nitric oxide – a small molecule that makes our blood vessels get wider and allows blood to flow more easily. However, they found that some women were not able to make use of the nitrate in beetroot juice, meaning that they did not benefit from this treatment.

Bacteria living in our mouths and gut can affect how we digest certain foods. Previous research has shown that people may only benefit from dietary nitrate if they have a particular mixture of bacteria in their mouths. Researchers funded by Tommy’s now want to find out if this is also the case for pregnant women with high blood pressure, so that we can predict who will respond to beetroot juice and who won’t.

What’s happening in this project?

Our researchers are investigating whether there are any differences between the bacteria present in the mouths of pregnant women with normal blood pressure and those with high blood pressure. So far, nearly 50 women have agreed to take part in the study. The team will find out whether women with different mixtures of bacteria in their mouths have different responses to beetroot juice. They are also working in the lab to see if it is possible to use nitrate supplements to encourage the growth of beneficial bacteria.

What difference will this project make?

This study should show why some women with high blood pressure benefit from drinking beetroot juice while others don’t. The results will help researchers to assess whether this treatment can be used to manage high blood pressure in pregnancy, therefore reducing the risks for mother and baby.