Medical cost savings in Sakado City and worldwide achieved by preventing disease by folic acid fortification

Abstract

The introduction of mandatory fortification of grains with folate in 1998 in the United States resulted in 767 fewer spina bifida cases annually and a cost saving of $603 million per year. However, far more significant medical cost savings result from preventing common diseases, including myocardial infarction, stroke, dementia and osteoporosis. A cost-effectiveness analysis showed a gain of 266 649 quality-adjusted life-years and $3.6 billion saved annually, mainly due to the reduction of cardiac infarction. The recommended folate intake in Japan is 240 μg/day whereas it is 400 μg/day internationally. Our Sakado Folate Project targeted individuals with genetic polymorphism of methylenetetrahydrofolate reductase or with hyperhomocysteinemia. Using, for example, folate-fortified rice, resulted in an increase in serum folate and a decrease in serum homocysteine in the participants, and reduced medical costs were achieved by decreasing myocardial infarction, stroke, dementia and fracture. Due to the small population of Sakado City (approximately 101 000) and small number of births (693) in 2015, a decrease in spina bifida could not be confirmed but there was a significant decrease in the number of very low birthweight infants. The genome notification of subjects was effective in motivating intake of folate, but the increase in serum folate (from 17.4 to 22.5 nmol/L, 129%) was less than that observed following compulsory folic acid fortification of cereals in the USA (from 12.1 to 30.2 nmol/L, 149.6%). Mandatory folic acid fortification is cheap in decreasing medical costs and is thus recommended in Japan.

Keywords: folate; fortification; genetic polymorphism; medical cost.

Figure 1

Steps comprising the Sakado Folate Project.

Figure 2

Effects of the Sakado Folate Project on serum folate and homocysteine, and the intake of dietary folate and green‐yellow vegetables, on individuals carrying three genotypes of MTHFR. (A) Serum folate concentration (ng/mL, y‐axis); the horizontal line indicates the standard (7 ng/mL). (B) Serum homocysteine (μmol/mL, y‐axis), and the horizontal line indicates the standard (6 μg/mL). (C) Intake of dietary folate (μg/day, y‐axis), and the horizontal line indicates the standard (300 μg/day). (D) Intake of dietary green‐yellow vegetables (μg/day, y‐axis), and the horizontal line indicates the standard (200 μg/day).

Figure 3

Effects of genome notification on changes in serum folate and serum homocysteine in individuals carrying three different genotypes of MTHFR (CC, CT and TT). Bars represent the means ± SD.

Figure 4

Prevalence of obesity, hypertension, diabetes and dyslipidemia among the population in Sakado City and three other cities in Saitama Prefecture (Saitama Prefecture Local Government 2011). The ordinate indicates prevalence in percentage. The prevalence in Sakado City was significantly fewer than that in other three cities in men (P = 0.04).

Figure 5

Trend in relative medical costs in Sakado City compared with four cities in Saitama Prefecture. The abscissa shows the year and the ordinate indicates the medical costs incurred by each city relative to the average total medical costs in Japan (=1.00) taken from the home page of the Ministry of Health, Labor and Welfare (http://www.mhlw.go.jp/topics/bukyoku/hoken/iryomap/). The relative decrease of medical costs from 2003–2005 to 2006–2008 in Sakado City plotted in Figure 5 is statistically significant (P = 0.0459, using Wilcoxon rank sum test). Black thick line: Sakado City, black broken line: average for Saitama Prefecture. Black dotted line: city A, gray line: city B, gray broken line: city C, and gray dotted line: city D.

Figure 6

Expected medical costs and actual medical costs of subjects participating in the Sakado Folate Project. The abscissa shows the year and the ordinate indicates the medical costs per person per month in yen. Black line: expected costs of citizens in Sakado City, Gray line: average of actual costs of the subjects participating in the Project, Light gray line: median of the actual costs of the subjects participating in the Project.