Because of reported associations of Mg with cardiovascular diseases (CVD), we assessed changes in soil Mg and Mg/Ca ratio with human CHD in order to clarify, whether these soil parameters could be associated with the human CHD epidemic in Finland. Human CHD and soil statistics are based on old data. Soil Mg and Mg/Ca ratio values are assessed by six successive 5 year periods from 1961 to 1990 (1961-1965, 1966-1970, etc). Mg has been included in basic samples (including Ca and K) since 1986, before it the number of Mg samples was lower and its distribution differed from basic samples. Soil-type-specific data are available from periods 1966-1970, 1976-1980 and 1986-1990. By benefiting the soil-type-distribution data from 1986-1990 and soiltype specific Mg and Ca values from these three periods we calculated adjusted Mg and Mg/Ca values for periods 1966-1970 and 1976-1980 (respective values for 1986-1990 were readily given).
In original data soil Mg and Mg/Ca were decreasing in the 1960’s and increasing after that. Human CHD associated inversely with these soil values. In original data soil Mg explained 98 % (p < 0.001) of male CHD (M.CHD) and 80 % (p = 0.017) of female (F.CHD) during 1961-1990. Soil Mg/Ca explained 93 % (p = 0.002) variation in M.CHD and 70 % (p = 0.039) in F.CHD. By soil-type adjusted soil Mg and Mg/Ca confirm their increase in 1966-1990 during CHD reduction.
Magnesium status of Finnish agricultural soils associated inversely with human CHD in 1961-1990 and could be one causative factor of the Finnish CHD epidemic.
Veterinary surgeon Nuoranne found trend-like associations between Mg deficiency in soil and fodder values with pig cardiac and other symptoms. Through his suggestions, Mg supplementation of fodder was increased since 1972. He wrote that “serious attention should be paid to the possibility of the respective existence of Mg-deficiency in humans” . Annual Mg-supplementation of Finnish agricultural soils before 1972 has been estimated to be about 15 kg/ha, lower than the estimated losses via yields and leaching (25-30 kg/ha) . 1972-1980 liming agents were mainly changed to dolomites, which increased annual Mg supplementation via liming agents from 4 to 25 kg/ha and put the Mg-balance on the positive side . The fatal CVD risk of human populations has been generally predicted by parameters like gender, age, smoking, systolic BP, cholesterol and total cholesterol: HDL cholesterol ratio . Several associations of Mg with CVD events have been reported: Decreased tissue magnesium in sublingual epithelial cells  and femoral muscles  have been reported in connection with vascular pathology. Mg has been directly or non-directly known to be associated with CVD risk factors : Mg supplementation has been reported to decrease systolic and diastolic blood pressure in humans . Proper tissue Mg can work as an “on-demand-antioxidant” against oxidative stress and a protector against lipid peroxidation and ATP deficiency . Because oxidized LDL can increase tissue LDL/HDL ratio , total cholesterol/HDL-cholesterol could to some extend indicate tissue Mg level. Additionally, Mg can reduce mortality from acute myocardial infarction by reducing serious arrhythmias and left ventricular heart failure, as well as give some protec Female CHD was about 1/5 of male CHD. M.CHD and F.CHD were first increasing. Both begun to decline coincidentally since 1967. The decline of F.CHD was faster until 1983.