What Should I Eat Part 5

Well, this is part of our ongoing discussion of what should I eat? That big question. And I want to focus on one nutrient that's gaining a lot of attention recently, a nutrient that's been in the news for decades, but certainly now we're understanding more about it. And that nutrient is sodium, part of the salt molecule. So what do we know about salt? Well, we know that salt consumption has been purported to create an increasing risk to hypertension and an increasing risk therefore to cardiovascular disease. And, and in fact there is a very good review paper that appeared in the New England Journal of Medicine in 2014 entitled Global Sodium Consumption and Death from Cardiovascular Disease. This particular review, multiple authored from very highly acclaimed authors in the area of nutrition, and the Harvard School of Public Health and at the School of Biostatistics at the Imperial College London, have looked globally at the consumption of sodium as salt and in foods and found a very strong association between excessive salt consumption and increasing risk to heart disease. Now what is excessive? That's a really good question. In the past we've heard recommendations that our sodium salt consumption should be less than 2 grams a day, 2,000 milligrams a day. And as we go up from there above 2,000 milligrams a day, we get an increasing kind of linear relationship with the increasing incidence stroke and heart attack. And in fact, in this modeling study of global sodium consumption, it was found that 1.65 million deaths from cardiovascular disease that occurred between 2010 and 2011 were attributed to sodium consumption above the reference range of 2 grams a day. Now that's a fairly significant number. So we would say salt restriction should be very important in anyone's decision about how they're going to consume their diet. Then the question is, well, where do we get our salt? And of course that leads to the question of food processing because we get so much of our food as pre packaged or pre prepared food, either in store bought convenience foods or in restaurant convenience foods. So what do we know about sodium consumption and labeling? Well, that's another interesting paper that appeared in the New England Journal of Medicine front of packaged nutrition labeling, discussing nutrients, and one of which was, and it's interesting to note that in Britain there was a very significant change just recently in the labeling of foods to go to a green light, orange light, red light kind of food labeling program in which, for instance, salt restriction was implied if you got an orange label on the orange stoplight or traffic light or a red traffic light, that food would be providing excessive amounts of sodium. And in fact, even though There was a $1.5 billion lobbying effort against the European Union's adoption of this traffic light approach. It did get introduced and it had significant impact on reducing the incidence of both hypertension and cardiovascular disease over the subsequent years, even though nothing else was changed. Now, as we know, the mantra of the food industry has traditionally been there is no such thing as a bad food. You hear that all the time. But we can say on the basis of this type of data that certain foods certainly impart higher relative risk. And that would be that of high sodium containing foods generally coming as hidden salt, not that which people add to their foods from a salt shaker, but rather in the pre processing of foods to add increasing flavor sensation of salt. Now with all of that said, now we get into an area of controversy, right? Just to show that nothing is simple, we now go to 2016. The New England Journal of Medicine has already told us earlier from a global perspective that too much salt is very dangerous. Now we see a paper in the Lancet in 2016 entitled Associations of urinary Sodium excretion with Cardiovascular events in Individuals with and without a pooled analysis of the data from four studies. In this particular paper they raise the question as to whether this ingestion of salt is a linear relationship then to vascular disease or could be curvilinear. And in this study they suggest that it's a J shaped curve that at low sodium intake, meaning low sodium excretion levels, there's an increased incidence of heart disease. Therefore it's not just salt in and of itself, it's the amount of salt and it's the salt response that an individual has. And there may be some individuals that are more salt salt sensitive for which then sodium inclusion in their diet has a dramatic effect in weighting their risk towards hypertension and towards cardiovascular disease and stroke. So the editorial that followed this recent Lancet paper, Salt too much or too Little goes on to say that, and I want to quote because I think it's a very interesting type of theme about this whole nature of nutrition and diet and its relationship to disease. They go on to say when apparent dogma is challenged, we should speak not of controversy but rather exceed to the all encompassing expression of the so called scientific uncertainty so as to avoid unbecoming rhetoric. There is no argument other than excessive salt in the diet raises blood pressure and that strategies to reduce salt in individuals with hypertension do in fact prevent cardiovascular consequences of the disease. However, the corollary that reducing sodium intake across all populations will be beneficial to everyone has Also been challenged with the assertion that doing some might be harmful to others. Until relatively recently, there has been a tacit acceptance that governments across the world should be lobbied to lower salt in the diet for the betterment of health. The first serious challenge to this approach came from this European study that I just mentioned showing low salt excretion was associated with increased cardiovascular incidence. Oh boy, the gauntlet is thrown down. Now we have a controversy. Is there such thing as too little sodium intake in the general population? Well, countering that, there are two more recent articles that appeared right on the heels of the Lancet paper. This is the Journal of the American Medical association. This paper, sodium Saving lives by putting choice into consumer hands is a very, very powerful, I think, kind of exposition on this topic because they go on to say that there are 70 million people who have hypertension and only half of it is controlled. And a major component in many of these individuals is excessive sodium intake. 9 out of 10 adults and children consume too much sodium. And even modest reductions, as little as 400 milligrams a day of reduction of sodium could prevent 32,000 myocardial infarctions and 20,000 strokes annually. Goes on to say this article. So again, excessive salt, what is excessive and who is excessive for? How does it influence their blood pressure? Becomes an important part of the story. What we're really saying is trying to keep at or below 2000mg a day of sodium intake probably makes very good sense based on these statistics. So then we go on from the Journal of the American Medical association article on the August 9 to the now August 16 issue of the New England Journal of Medicine in which they talk about dietary sodium and cardiovascular disease, Measurement Matters goes on to say this article. They point out that in studies reporting a J shaped or U shaped curve of sodium intake, they forgot to mention that many of these people that are low sodium excreters are people that have diabetes or they have existing diseases for which they may be taking drugs. That then changes their whole principle towards relative risk to ultimate disease. So it's not just jumping to a cause and effect relationship because they're a low sodium excretor, that it's necessarily the fact that their cardiovascular higher incidence is caused by low sodium intake. I think it's a very interesting point. So they go on to show that for every 1% reduction in sodium intake, on average there's about a 4% reduction in cardiovascular disease risk. So the trials of hypertension prevention showed a linear 17% increase in cardiovascular disease risk per thousand milligrams of sodium per day and from levels starting at 1500 milligrams per day. This was among 2,275 participants that were studied. An analysis of more than 100 trials lasting at least seven days, including some in which the participants consumed less than 1,500 milligrams of sodium a day, showed that daily sodium reduction of 1000mg was associated with an average decrease in systolic blood pressure of about 1.7 milligrams. So for most people who are consuming on the average of three and a half grams, or 3500 milligrams of sodium a day, a 1500 milligram reduction, which would take them down to 2000 milligrams a day, will lower their blood pressure equivalent to or greater than that of most successful first stage antihypertensive drugs and lower their risk to stroke and heart attack by a significant margin. So I think you can see that we have kind of the thorns of a dilemma here. How much is too much for whom and what is a good target level? It would seem, first of all, that our food labeling laws are such that you can get away with a lot of problems relative to sodium confusion because we're not getting clarity on the label so that people can make intelligent choices about processed foods or packaged foods or convenience foods that may be slipping in higher percentages in their diets, which is where most of the sodium is coming from. Secondly, it would be very beneficial, I think, for all of us to recognize that sodium is a problem nutrient. It is in excess in most people's diets. It does contribute to an increasing risk of hormonal changes that are associated with cardiovascular disease and stroke, and that the closer we can eat to unprocessed whole foods, the lower the sodium, the higher the potassium, and the lower the risk of a simple take away from all of this. When we say what should we eat is eat fresh, unprocessed whole foods, fruits and vegetables, and stay away from highly processed foods, which is where most of your sodium resides. That may be one of the most significant determinants for the overall risk to cardiovascular disease and may trump many, many other variables that we would think about in changing diet. That alone can make an extraordinary change in our relative disease risk. And in fact, in this last article that just appeared in the New England Journal of Medicine, they give a statistic that I think is absolutely fascinating because one would not think of the magnitude of these effects on a public health population based being as great as they are. But I think that you would be amazed to say that, or amazed to learn that reduction in the average sodium intake by just 400 milligrams a day could potentially avert as many as 28,000 deaths annually and save $7 billion in health care costs in the United States alone. So news to use as it relates to this problem, nutrient sodium.