The relationship between cation intake and blood pressure (BP) in populations with specific dietary habits such as a low fat intake, remains unclear. A low fat intake has been prevalent during human evolution.The average of 6 BP readings and heart rate (HR) recordings has been calculated. Dietary intake was measured using the 24 h recall-method. A 24 h urine sample was collected.A highly significant correlation was found between the sodium/potassium ratio (Na/K), after adjustment for age, weight, height, heart rate, alcohol intake and sex and systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP). The same applies to the sodium/creatinine (Na/Cr) and potassium/creatinine (K/Cr) ratios, with a positive correlation for Na/Cr and a negative one for K/Cr. The partial regression coefficient was in absolute value about 4-5 times greater for K/Cr than for Na/Cr. Age correlates highly significantly and independently with both SBP and DBP.If a Na/K ratio of 1 is considered optimal, by achieving that goal mean SBP could be reduced by about 6 mm Hg and mean DBP by 3 mm Hg in this normotensive population.