Improvement in Stroke Mortality in Canada and the United States, 1990 to 2002

Abstract

Background— In the United States and Canada, folic acid fortification of enriched grain products was fully implemented by 1998. The resulting population-wide reduction in blood homocysteine concentrations might be expected to reduce stroke mortality if high homocysteine levels are an independent risk factor for stroke. Methods and Results— In this population-based cohort study with quasi-experimental intervention, we used segmented log-linear regression to evaluate trends in stroke-related mortality before and after folic acid fortification in the United States and Canada and, as a comparison, during the same period in England and Wales, where fortification is not required. Average blood folate concentrations increased and homocysteine concentrations decreased in the United States after fortification. The ongoing decline in stroke mortality observed in the United States between 1990 and 1997 accelerated in 1998 to 2002 in nearly all population strata, with an overall change from −0.3% (95% CI, −0.7 to 0.08) to −2.9 (95% CI, −3.5 to −2.3) per year ( P =0.0005). Sensitivity analyses indicate that changes in other major recognized risk factors are unlikely to account for the reduced number of stroke-related deaths in the United States. The fall in stroke mortality in Canada averaged −1.0% (95% CI, −1.4 to −0.6) per year from 1990 to 1997 and accelerated to −5.4% (95% CI, −6.0 to −4.7) per year in 1998 to 2002 ( P ≤0.0001). In contrast, the decline in stroke mortality in England and Wales did not change significantly between 1990 and 2002. Conclusions— The improvement in stroke mortality observed after folic acid fortification in the United States and Canada but not in England and Wales is consistent with the hypothesis that folic acid fortification helps to reduce deaths from stroke.

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

“…Following the implementation of mandated folic acid fortification, a decline in stroke mortality was observed in the US between 1990 and 1997, and this decline accelerated in 1998 to 2002 in nearly all population strata, with an overall change from −0.3% (95%CI, −0.7 to 0.08) to −2.9 (95%CI, −3.5 to −2.3) per year ( P  = 0.0005) (Yang et al 2006). The fall in stroke mortality in Canada averaged −1.0% (95%CI, −1.4 to −0.6) per year from 1990 to 1997 and accelerated to −5.4% (95%CI, −6.0 to −4.7) per year in 1998 to 2002 ( P  ≤ 0.0001).…”

“…The fall in stroke mortality in Canada averaged −1.0% (95%CI, −1.4 to −0.6) per year from 1990 to 1997 and accelerated to −5.4% (95%CI, −6.0 to −4.7) per year in 1998 to 2002 ( P  ≤ 0.0001). In contrast, the decline in stroke mortality in England and Wales did not change significantly between 1990 and 2002 (Yang et al 2006). After the implementation of compulsory folic acid fortification, trends in serum folate, red blood cell (RBC) folate, and circulating total homocysteine concentrations in the United States were analyzed in 17 144 participants in the National Health and Nutrition Examination Surveys (Ganji and Kafai 2006).…”

“…A few years may be necessary for this Project to expect a reduction in the significant amount of the medical expenditure. However, in the large population of Sakado city, similar to United States as soon as the serum folate elevation, rapid decrease in stroke took place within a year (Yang et al 2006), because the increase of serum folate and decrease of serum homocysteine takes place only within a few weeks (Hiraoka et al 2004, 2014). Moreover, rapid preventive effects of folate on cardiac infarction was reported in detail (Moens et al 2008).…”

“…For example, moderate hyperhomocysteinemia induced by low folate status is an independent risk factor for cardiovascular disease (CVD) (Ishihara et al 2008; Bentley et al 2009), stroke (Yang et al 2006; Huo et al 2015; Li et al 2016b), colon cancer (Bentley et al 2009), dementia (Jernerén et al 2015), fracture (Gjesdal et al 2007), kidney diseases (Massy 2003) and depression (Bottiglieri 2005; Hiraoka et al 2014). These diseases can be prevented or alleviated by increased folate intake, as shown by many epidemiological and interventional studies.…”

Use of FAO food balance sheets to estimate the potential ability of novel folate-enriched eggs to increase the folate supply in European Union countries

“…Unfortunately, compliance with this advice has been poor (8)(9)(10)(11)(12)(13)(14) , and this fact, plus the recognition that as many as 50 % of all pregnancies are unplanned (15) and unlikely to be protected, has led governments in the USA, Canada, Chile and other countries to introduce mandatory folic acid fortification of grain products (16)(17)(18)(19) . These policies have succeeded in reducing NTD occurrence by approximately 20-50 % (20)(21)(22)(23)(24) and may also have reduced stroke-related mortality in the general population (25,26) , as well as having had some benefit against CHD through their effect on lowering homocysteine (27) .…”