Many people are concerned about their high blood pressure, but they often do not know why it is so high. Often they think that only when it is too high does bad things happen to them, but this is not the case. It is possible to have high blood pressure and be relatively healthy at the same time. New research has addressed both of these problems and involved further examination of the relationship of a Mediterranean fish diet to lowered blood pressure readings with statistical adjustment to multiple risk factors associated with both lowering and increase of blood pressure. The conclusion of the study concluded that individuals who ate a Med fish diet were not at an increased risk for hypertension and actually had a lower risk than a control group.
The researchers studied 5 groups of men and women from ages forty to eighty-four, who were free of any documented health conditions and who ate a Mediterranean or non-Mediterranean dietary pattern on a daily basis. They found that there was no significant difference in the blood pressure of the three groups when comparing at baseline characteristics, despite the fact that the subjects adhered to a high sodium diet. This finding suggested to the researchers that the high sodium diet was unrelated to the blood pressure and could therefore not be the cause of hypertension. However, since no known lifestyle factors were related to either elevation or decrease of blood pressure, the researchers concluded that other factors, most likely diet, were more important in determining the association of blood pressure and diet.
In addition to examining the possible effects of diet on blood pressure, researchers examined several other factors that were known to affect hypertension. They examined psychosocial variables, such as sociability and self-esteem, and found that these factors were not related to blood pressure at all. They also looked at several factors that were related to several types of diseases and found that none of these factors was related to either hypertension or any other cardiovascular condition. The results seemed to indicate that hypertension is influenced by many factors that are psychosocial in nature, rather than by known physiological causes.
In one study that examined high blood pressure and diet, an international group of researchers investigated the role of sex, race, and educational level in relation to hypertension. They examined many different sets of variables and came up with the following conclusions: men were not significantly more or less likely to be hypertensive than women, and race did not moderate the effect of diet on hypertension. The one exception was that white men were found to have a slightly higher tendency to smoke than other races. The lack of association between race and hypertension was puzzling to many researchers, because it is often assumed that African Americans are more hypertensive than Caucasians.
Subsequently, other researchers followed up on the original investigation, using data from 3 nationally representative surveys of adults. Again, they found no significant relationship between diet and hypertension. However, they did find that people who tended to eat more plant-based diets (such as nuts and seeds) were less likely to be hypertensive than others. This evidence suggests that dietary patterns may play a role in the development of hypertension.
A study conducted by the U.S. Department of Agriculture sought to determine whether dietary factors were associated with hypertension. The analysis focused on changes in dietary sodium, potassium, and fiber levels over a period of time, rather than assessing hypertension per se. The result was a suggestion that lowering dietary salt and increasing dietary fiber might be able to reduce blood pressure. Subsequent research has not borne this out, however, and there is no clear indication that any dietary factors related to hypertension help reduce it.
Finally, there is considerable debate among researchers about whether exercise affects blood pressure, and how much exercise is necessary. Some researchers find that too little physical activity is linked to increased blood pressure; others believe that too much physical activity results in decreased blood pressure. It seems that exercise helps to increase the body’s metabolic rate, which increases the heart’s efficiency in pumping blood. The beneficial effect of exercise on blood pressure can only be guessed, since there are so many studies of the matter that have been unable to reach a consensus. In some cases, the results seem to be better for people who are sedentary, as they tend to be older and have more health problems. Another factor that may affect the relationship between exercise and hypertension is the amount of time people spend in sedentary lifestyles; those who are constantly in active occupations may have more trouble dealing with the consequences of their lifestyle.
Overall, the data are too scattered and inconclusive to allow any firm conclusions to be drawn from the studies. More research is needed to establish that there is a significant relationship between blood pressure and diet, and whether or not diet can lower levels after a diagnosis of hypertension. The best advice for patients at risk is to speak with their doctor and take action to lower levels when necessary.