少吃盐 降血压
http://www.100md.com
2001年1月4日
BOSTON (Reuters) - Lowering salt intake appears to significantly reduce high blood pressure whether or not a person already eats a healthy diet, researchers reported in Thursday's New England Journal of Medicine (news - web sites).
The finding does more than reinforce the conventional wisdom that people with high blood pressure should cut their salt intake. It also suggests that even those without high blood pressure can benefit from a low-salt diet, according to the researchers at Boston's Brigham and Women's Hospital.
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Experts cautioned, however, that most U.S. consumers would have difficulty taking advantage of the results unless the makers of processed foods changed their practices.
The results were based on a comprehensive evaluation of 412 volunteers, half of whom ate a typical U.S. diet and half who consumed mostly fruits, vegetables and low-fat products -- a diet already found to lower blood pressure.
At the same time, researchers, led by Dr. Frank Sacks had volunteers consume one of three different levels of salt. The patients stuck with each diet for 30 days, then switched to a diet with a different salt content.
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The team found those who consumed three grams of salt a day instead of the nine grams in a typical diet were able to lower their systolic blood pressure -- the higher number in a blood pressure reading -- by nearly seven points if they were on a regular diet and by three points if they ate the healthier diet.
The diastolic pressure (the lower number) also declined -- by 3.5 points with the regular diet and 1.6 points on the low-fat diet. Consuming six grams of salt produced an intermediate benefit.
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A healthy diet and lower salt intake ``both lower blood pressure substantially, with greater effects in combination than singly,'' Sacks and his colleagues concluded.
Reducing blood pressure by three points may not seem like a lot, Dr. Philip Greenland of Northwestern University Medical School in Chicago said in an editorial in the Journal. But the population-wide impact could be significant.
A decrease in two diastolic points cuts the risk of high blood pressure by 17 percent, the risk of heart disease by 6 percent and the chance of a stroke or angina by 15 percent.
, 百拇医药
The researchers stressed that the health benefits of the diet would not be proven conclusively unless it was followed for a long period.
Low-salt products were also hard to find, they said.
``The attainment of a lower sodium level in the population as a whole presents challenges, since sodium is widely prevalent in the food supply'' and most of the salt in the U.S. diet comes from processed foods, the team noted.
, 百拇医药
``Hence, efforts to reduce sodium intake must ultimately rely both on consumers' selection of low-sodium foods and, perhaps more important, on the increased availability of low-sodium products.''
The study was part of the Dietary Approaches to Stop Hypertension (DASH) project, funded by the National Heart, Lung and Blood Institute.
In 1977, it demonstrated the blood pressure-reducing benefits of a diet rich in fruits, vegetables, grains and fat-free products. In that study, the researchers kept salt consumption steady at slightly less than 9 grams of salt per day., 百拇医药
The finding does more than reinforce the conventional wisdom that people with high blood pressure should cut their salt intake. It also suggests that even those without high blood pressure can benefit from a low-salt diet, according to the researchers at Boston's Brigham and Women's Hospital.
, http://www.100md.com
Experts cautioned, however, that most U.S. consumers would have difficulty taking advantage of the results unless the makers of processed foods changed their practices.
The results were based on a comprehensive evaluation of 412 volunteers, half of whom ate a typical U.S. diet and half who consumed mostly fruits, vegetables and low-fat products -- a diet already found to lower blood pressure.
At the same time, researchers, led by Dr. Frank Sacks had volunteers consume one of three different levels of salt. The patients stuck with each diet for 30 days, then switched to a diet with a different salt content.
, http://www.100md.com
The team found those who consumed three grams of salt a day instead of the nine grams in a typical diet were able to lower their systolic blood pressure -- the higher number in a blood pressure reading -- by nearly seven points if they were on a regular diet and by three points if they ate the healthier diet.
The diastolic pressure (the lower number) also declined -- by 3.5 points with the regular diet and 1.6 points on the low-fat diet. Consuming six grams of salt produced an intermediate benefit.
, http://www.100md.com
A healthy diet and lower salt intake ``both lower blood pressure substantially, with greater effects in combination than singly,'' Sacks and his colleagues concluded.
Reducing blood pressure by three points may not seem like a lot, Dr. Philip Greenland of Northwestern University Medical School in Chicago said in an editorial in the Journal. But the population-wide impact could be significant.
A decrease in two diastolic points cuts the risk of high blood pressure by 17 percent, the risk of heart disease by 6 percent and the chance of a stroke or angina by 15 percent.
, 百拇医药
The researchers stressed that the health benefits of the diet would not be proven conclusively unless it was followed for a long period.
Low-salt products were also hard to find, they said.
``The attainment of a lower sodium level in the population as a whole presents challenges, since sodium is widely prevalent in the food supply'' and most of the salt in the U.S. diet comes from processed foods, the team noted.
, 百拇医药
``Hence, efforts to reduce sodium intake must ultimately rely both on consumers' selection of low-sodium foods and, perhaps more important, on the increased availability of low-sodium products.''
The study was part of the Dietary Approaches to Stop Hypertension (DASH) project, funded by the National Heart, Lung and Blood Institute.
In 1977, it demonstrated the blood pressure-reducing benefits of a diet rich in fruits, vegetables, grains and fat-free products. In that study, the researchers kept salt consumption steady at slightly less than 9 grams of salt per day., 百拇医药