Salt in Fast Food: No Great Shakes for Your Health
LAURA CUNNINGHAM
St Thomas Aquinas
Floor Location : J 211 H

Sodium, primarily in the form of salt, is often used as a preservative and to enhance the texture and flavour of most prepared and restaurant foods. In excess, research has linked high dietary sodium intake to hypertension, a major risk factor for many diseases. I wondered whether the sodium in even just one fast food meal was enough to raise a healthy adult’s blood pressure.

I asked whether the average sodium content of one fast food meal (3000mg) would increase the mean systolic and diastolic blood pressure of a healthy adult shortly after consumption.

For each of 18 healthy adult participants, I first recorded a baseline blood pressure, then administered 250ml of plain water (my control), and after 30 minutes, recorded his/her blood pressure. I then administered a 250ml ‘sodium beverage’ (3000mg sodium), and after 30 minutes, recorded his/her blood pressure.

The 3000mg ‘sodium beverage’, equivalent to the sodium content of a fast food meal, raised the mean systolic blood pressure by 7.7 mmHg and the mean diastolic blood pressure by 3.6 mmHg. Both of these results were significant. By comparison, an equal volume of water did not change the mean systolic or diastolic blood pressure significantly.

In conclusion, I found that the average salt content of a fast food meal is sufficient to raise the systolic and diastolic blood pressure of a healthy adult by a significant amount.