New epidemiological research1 published in the journal Circulation suggests that fortifying foods with folic acid could help reduce stroke deaths - resulting in almost 16,000 fewer annual deaths in some countries.

The findings add to the growing body of evidence supporting the theory that folic acid, commonly added to cereals, breads and some spreads, contributes towards a reduction in stroke death by reducing the homocysteine level - an emerging risk factor for cardiovascular disease (CVD).

Stroke is major public health burden and each year more than 12 million people die of a heart attack or a stroke . Therefore, the results of this study could have implications for public health strategies to prevent heart disease and stroke.

The researchers analysed stroke-related deaths over a 12-year period; between 1990 - 1997 (before compulsory folic acid fortification was introduced in the USA and Canada) and between 1998 - 2002. The data was then compared with the same periods in England and Wales where fortification is not mandatory.

The researchers found that:

-- The average decline in stroke deaths in the USA accelerated from 0.3% per year between 1990 and 1997 to nearly 3% per year between 1998-2002 resulting in 12,900 fewer deaths*

-- The average decline in stroke deaths in Canada accelerated from 1.0% per year between 1990-1997 to 5.4% per year in 1998-2002, resulting in 2,800 fewer deaths*

-- The decline in stroke mortality in England and Wales did not change significantly.

The accelerating decline in stroke deaths could not be explained by changes in other major risk factors, such as cigarette smoking, hypertension, diabetes and total serum cholesterol levels, many of which did not improve or even worsened during the period studied.

Lead researcher Dr Quanhe Yang observed: "Stroke and cardiovascular disease cause an extraordinary societal burden, and all effective prevention and treatment strategies ought to be implemented."

"If folic acid fortification is responsible for even a fraction of the accelerated improvement we observed, this public health benefit is an important bonus to the reduction in neural tube defect rates. Moreover, these benefits accrue to all members of the population, regardless of ethnic, social, and economic barriers"

-- Fortifying foods with folic acid is currently only compulsory in the USA, Canada and in South American countries such as Chile with many EU countries preferring not to impose mandatory regulations.

-- Fortification of grain products (140 ug folic acid per 100g of flour in the USA and 150 ug in Canada) was introduced by the Food and Drug Administration and Health Canada in 1998 as a preventative measure to reduce the number of birth defects.

Reference:
1. Improvement in Stroke Mortality in Canada and United States, 1990-2002. Quanhe Yang et al. Circulation March 2006.

CIRCULATION