Calcium-rich foods and blood pressure: findings from the Italian National Research Council Study (The Nine Communities Study)

The present report analyzes the relation between different categories of consumption of varied calcium-rich foods and blood pressure in a population sample of 5,049 Italian men and women aged 20-59, examined between November 1978 and May 1979. The consumption pattern of the various foods was estimated with the use of a food frequency questionnaire. The findings are consistent with an inverse association between whole milk consumption and systolic, but not diastolic, blood pressure. Daily consumption of cheese, on the other hand, is not associated with reduced blood pressure levels. The possibility of an adverse effect of the high saturated fats and sodium content on blood pressure that could counteract the beneficial effect of calcium is discussed. Daily skim milk consumption is surprisingly associated with higher systolic, but not diastolic, pressure, compared with infrequent consumption. The possibility of these findings being the result of pre-existing health problems leading to the selection of skim milk over whole milk is discussed. Daily consumption of legumes is associated with lower systolic pressure than infrequent consumption, but the differences do not reach statistical significance, probably because of limited statistical power. These associations are similar in both males and females.