Blood pressure of omnivorous and semi-vegetarian postmenopausal women and their relationship with dietary and hair concentrations of essential and toxic metals

OBJECTIVE

This study aims to ascertain the relationships between mineral consumption, hair mineral content, and blood pressure.

METHODS

The study involved 26 postmenopausal women from enclosed religious communities, 14 were semi-vegetarians and 12 were omnivores. Mineral dietary assessment was performed using a 14-d precise weight method and Food tables. Hair mineral levels were measured by means Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-OES). Multivariable stepwise linear regression analyses were performed to find out the variables that affected most blood pressure.

RESULTS

In general terms, the omnivorous diet contained a significantly higher mineral content than the semi-vegetarian one. The mineral intake from both diets implied no health risk to the women studied, as their estimated daily intake (EDI) of toxic elements such as Cd and Pb was lower than their respective provisional tolerable weekly intake (PTWI) of these minerals. Hair of the semi-vegetarians contained higher amounts of Al (p < 0.01), Ba (p < 0.01), K (p < 0.001), Na (p < 0.001), Pb (p < 0.001) and Mn (p < 0.01) but lower levels of Ca (p < 0.05) and Zn (p < 0.05) than that of their omnivorous counterparts. The omnivores presented significantly higher systolic (p < 0.01) and diastolic (p < 0.05) pressures than the semi-vegetarians. Levels of hair Co (R² = 0.328; p = 0.032) and hair K (R² = 0.409; p = 0.014)) were explicative for systolic and diastolic blood pressure, respectively.

CONCLUSION

Several dietary mineral and hair contents were higher in semi-vegetarian women suggesting that the hair is an important mineral excretion via contributing to maintain blood pressure at low levels.