56 | Noncommunicable Diseases in Saudi Arabia
Population-level sodium reduction intervention In 2003, the UK government developed a national program aimed at reducing salt intake. These measures involved clear labeling of the salt content in food, public awareness campaigns, and partnerships with the food industry (He, Brinsden, and MacGregor 2014). Since 75 percent of salt intake came from the food industry in the form of processed food (of which bread was the largest contributor, at 18 percent of total salt intake), it was expected that working with the food industry—in particular, the bread industry—would contribute the most to reducing population-level salt intake (Brinsden et al. 2013). From 2001 and 2011, salt levels in supermarket bread were reduced by 20 percent (Brinsden et al. 2013). During this time, population-level salt intake decreased by 15 percent (1.4 grams per day) (He, Brinsden, and MacGregor 2014). Average sodium consumption in Saudi Arabia is 10.8 grams per day for men and 9.3 grams per day for women (Saeedi et al. 2017; table 3A.2), with an estimated 20.9 percent of daily salt intake coming from bread (Al Jawaldeh and Al-Khamaiseh 2018). Since bread intake is higher on average in the Middle East than in the United Kingdom (20.9 percent and 18.0 percent of the diet for the Middle East and the United Kingdom, respectively), the 15 percent reduction in population-level salt intake is adjusted upward (17.4 percent) to account for higher average bread consumption and the increased likelihood that changing bread-manufacturing processes would exert a higher proportionate change in the population level of sodium consumption:
Adjusted salt intake decrease = 15.0% ×
.209 = 17.4%. (3A.1) .180
If a 17.4 percent reduction in salt consumption could be achieved within 10 years, then this would yield a reduction of 1.9 grams of salt per day for men and 1.3 grams of salt per day for women. Based on the estimated impact of this reduction on isolated blood pressure, reducing salt intake by 1.74 grams per day would reduce systolic blood pressure by 3.44 mmHG. Therefore, reducing salt consumption by this amount would result in a 4.2 mmHg reduction in systolic blood pressure for men and a 3.0 mmHg reduction for women (He, Markandu, and MacGregor 2005). This corresponds to a 9.2 percent decrease in systolic blood pressure. The calculation for men is as follows: 3.44 = 11.3%. (3A.2) 10.8 × 17.4% × 1.74
TABLE 3A.2 Adjusted decrease in salt intake and changes to systolic blood pressure in Saudi Arabia, by gender
% change INDICATORS
Salt consumption (grams per day)
WOMEN
MEN
9.3
10.8
−1.3
−1.9
121.6
124.6
Reduction in mean SBP (mmHg)
−3.0
−4.2
Standard deviation (mmHg)
12.6
11.3
% reduction in population-level SBP
−7.0
−11.3
Reduction in salt consumption from interventions (grams per day) Mean blood pressure (mmHg)
Sources: Calculations for decrease in systolic blood pressure a using the estimates of relative risk (IHME 2018a) and calculations of the population-attributable risk fractions. Note: mmHg = millimeters of mercury. SBP = systolic blood pressure.
