Mg/Ca ratio in fertilization and agricultural soils, Mg percent of liming agents and human mortality in Finland during 1961-90

Abstract

Background: Mg is a cofactor in more than 300 enzymatic reactions and its deficiency has been reported to be associated with cardiovascular diseases. Human Mg balance depends on food composition, food processing and Mg variation in foodstuffs, which can be roughly prognostigated by Mg proportion in fertilization and soil. Strong increase of NPK (nitrogen, phosphorus and potassium) in mineral fertilization (fm) included relative delay in Mg supplementation and dilution in plant available silicon (Si) via recycled nutrients (rcl). (Silicon is not included in essential fertilizers in Finland.) Methods: We have assessed old data on Ca and Mg in agricultural soils and approximate data on fm, rcl, as well as Mg % of liming agents (Mg-%.lim) and total (TOT), CHD and non-CHD (nCHD) death-rates of humans by R squares and graphics, in order to clarify their associations and possible causality. Results: Mg/Ca ratio in total fertilization (ft =fm + rcl) was decreasing in 1951-64 and after that mainly increasing. Soil (Mg/Ca) in 1961- 2000 responded on (Mg/Ca).ft with delay of ca 5 years. During 1961-90 (Mg/Ca).fm "explained" CHD by 74-89 %, non-CHD by 87 - 96 % and TOT by 90 - 94 %. (Mg/Ca) fertilization ratios "explained" better female than male CHD, but TOT and non-CHD more similarly. Soil (Mg/Ca) "explained" male CHD by 94 %, but all other death-rates weaker than (Mg/Ca).fm. Different smoking habits could explain this sex difference. All given associations were highly significant (p < 0.001). Conclusion: Mg/Ca changes in fertilization preceded respective changes in soil Ca by five years. They explained in general better than the soil value changes in death-rates, except M.CHD with obvious “tobacco delay”. Effects of silicon and its association with rcl/ft ratio are discussed.