Suggesting that there might be controversy in the link between salt intake and hypertension in itself might seem a little controversial, given the vast amount of media attention that our salt intake has received over recent years. But controversial it is.
Some 45 published papers on ‘salt and hypertension’ were uploaded onto the CAB Abstracts database in 2006 alone. Sticking to these, by way of example, it seems that the more sophisticated our analytical techniques become, the weaker the relationship between sodium intake and high blood pressure appears to be in the general population (Franco and Oparil, 2006). In fact, these authors report that the effects of reducing salt intake on blood pressure highly variable between individuals. Some people’s blood pressure responds quite dramatically even to small changes in salt intake – these individuals have been dubbed ‘salt sensitive’. It seems that salt sensitivity itself has a large number of determinants, including genetic factors, race/ethnicity, age, body mass and dietary factors in addition to sodium level.
Dickinson and colleagues (2006), on the other hand, conducted a ‘systematic review of randomised controlled trials’ and concluded that a number of factors were able to have a beneficial influence over blood pressure in hypertensive patients. These factors included improving diet, doing aerobic exercise, alcohol and sodium restriction and the use of fish oils supplements. Or, as Norman Hollenberg of Brigham and Women’s Hospital and
so eloquently put it: ‘At the level of the individual patient and that patient’s physician, it is important to recognize that salt intake can make a substantial contribution to hypertension. That contribution is more likely if the patient is old rather than young, obese rather than lean, black rather than white, has diabetes mellitus with hypertension, or has evidence of renal injury.’
Adding fuel to the fires of controversy, Yalcin Tekol of Erciyes University Medical Faculty in
recently argued that all this debate about how or how much link there is between sodium intake and high blood pressure was wasting time in combating the problem. His belief is that the minimum dietary level of salt that can produce hypertension is 1.76g/day. Far lower than the 6g per day we are all worrying about trying to reduce our intake too. Tekol thus recommends that salt be treated as a drug and as such really should not be permitted to be added to food in the first place. More on this later.
Tekol, Y (2006). Is systemic hypertension only a sign of chronic sodium chloride intoxication? Medical Hypotheses, Vol. 67, No. 3, pp. 630-638.
Hollenberg, N.K. (2006). The influence of dietary sodium on blood pressure. Journal of the American College of Nutrition, Vol. 25, No. 3(S), pp. 240S-246S.
Dickinson et al. (2006). Lifestyle interventions to reduce raised blood pressure: a systematic review of randomised controlled trials. Journal of Hypertension, Vol. 24, No. 2, pp. 215-233.
Franco, V. and Oparil, S. (2006). Salt sensitivity, a determinant of blood pressure, cardiovascular disease and survival. Journal of the American College
of Nutrition, Vol. 25, No. 3(S), pp. 247S-255S.