Holiday brunches, buffets, dinners, and parties are often laden with salty food. For some people, a high-salt diet leads to high blood pressure, which makes the heart work harder and increases the risk of having a heart attack or stroke, or of developing heart failure or kidney disease. Other people are blessed with genes or physiology that lets them eat foods high in sodium without ever seeing a bump in their blood pressure. If you’re in the latter camp, is it OK to blithely eat ham, cheese logs, and other salty holiday foods?
No. As my colleagues David Edwards, Claudine Jurkovitz, William Weintraub, and I wrote in the Journal of the American College of Cardiology, too much sodium in the diet can damage health even when blood pressure stays normal.
By weight, salt is about 40 percent sodium. The human body needs some sodium to transmit nerve impulses, contract and relax muscles, and balance fluids throughout the body. The average person needs less than 500 milligrams of sodium a day to survive, but gets about 3,400 milligrams, nearly seven times what’s needed.
Very high dietary sodium appears to be especially harmful to blood vessels. It damages their innermost layer, called the endothelial layer. This thin sheet of cells helps blood vessels dilate to increase blood flow when the need arises. Damage to the endothelial layer sets the stage for atherosclerosis, the main artery-clogging disease process underlying nearly all cardiovascular problems, including heart attacks and poor blood flow to the legs and brain. Atherosclerosis can also cause kidney problems and vascular dementia.
Even when sodium doesn’t boost blood pressure, too much of it in the diet can:
- Harm the heart. Too much sodium can increase the size and the thickness of the left ventricle, the heart’s main pumping chamber. This makes it harder for the heart to efficiently circulate blood around the body.
- Damage the kidneys. In lab animals, diets high in sodium make it more difficult for the kidneys to filter blood. Lots of sodium also increases the level of blood markers of kidney damage.
- Affect the brain. A diet high in sodium can “sensitize” cells in the brain that are part of the sympathetic nervous system, which controls the body’s so-called fight or flight response. This sensitization creates a greater-than-usual blood pressure response to stress.
How much sodium is too much?
The average American consumes about 1 ½ teaspoons of salt (3,400 milligrams of sodium) a day. Most of this comes from the highly processed foods that we routinely eat. For example, a slice of pizza has approximately 600 milligrams of sodium. A serving of canned chicken noodle soup delivers more than 800 milligrams.
The current Dietary Guidelines for Americans recommend that younger, relatively healthy individuals get no more than 2,300 milligrams of sodium (1 teaspoon of salt) a day, while everyone over age 51 and those with high blood pressure, diabetes, or kidney disease should take in 1,500 milligrams a day. One element of the American Heart Association‘s definition of ideal cardiovascular health is a diet that contains less than 1,500 milligrams of sodium a day. While there is some inconsistency in what the upper daily limit should be, what’s important right now is that most Americans should cut back on the amount of sodium they take in.
Earlier this month, New York City started requiring large chain restaurants to label salty dishes that contain more than 2,300 milligrams of sodium — the upper limit of what you should get over the course of a whole day. The salt-shaker-in-a-black-triangle “sodium bomb” warning is intended to nudge diners toward less salty and presumably healthier dishes.
Avoiding sodium bombs is one way to optimize long-term cardiovascular health. Recent evidence suggests that a single high-sodium meal can temporarily impair blood vessel function. So staying away from high-sodium meals is important for everyone, even for those who don’t have salt-sensitive blood pressure. Cutting down on daily sodium intake requires eating less processed foods and more fresh foods. Food items that contain a lot of sodium include cold cuts, many soups, and condiments such as ketchup and soy sauce.
It will be interesting to see if sodium labels in New York City restaurants will nudge New Yorkers toward healthier choices. Whether or not they do, it’s a good idea for almost everyone to cut back on sodium during the holidays and beyond.
William B. Farquhar, PhD, is professor and chair in the department of kinesiology and applied physiology at the University of Delaware. He studies the role of diet and exercise on human health.
Iam RhB Neg, salt make me angry. iam white, I have very little salt I drink lots of water, to get rid of the salt, in my body. Not sure if it connected with being RhB Negative
I have lower leg vascular damage in both legs, nerve damage to both feet ( no feeling in either feet therefore difficult to walk, tend to stagger and weave while walking. Must use a cane to prevent falling constantly. Both feet or alarmingly swollen due to water retention, Because of past high intake of salt. Born without sense of smell and therefore tongue is the only limited taste I have and therefore I use(d) a lot of salt, pepper, and sugar As that was the only form of taste I had/have.
No olfactory taste sensation at all. Any articles related to this, treatment of this , Or looming dangers ahead would be greatly appreciated. Any references you might have for further knowledge/help for myself are much-needed. The Veterans Administration are doing the best they can but I feel I need more information
Much thanks, MWC
I must say, after years of this MYTH being debunked, you still want to throw out there that salt intake is bad? Come on really? Advise no more than 500mg a day? That is a very cruel lie to tell the public, they’ll believe it and you’ll end up getting people sick and die from you spreading lies. There is not one shred of evidence that supports your claim with salt being linked to high blood pressure. Your AHA and FDA who all stand by the big corporation that is the US government to make it’s entire populous sick to spend unending amounts of money to “cure diseases.” Salt is essential, unrefined salt is even better! You want to know the true culprit?? It’s sugar, simple carbohydrates. Eating too much carbs retain water that gives you high blood pressure. Guess what happens when you eat 5grams of salt? Excrete it through the kidneys as urine, no damage done. These carbs are the same stuff that get stored as fat, leading you to obesity along with high blood pressure and insulin resistance. Seriously, cut back off your sugar, and I mean as much as possible, and use sea salt or Himalayan pink salt. It’s better too have more than not enough. If no one is buying my claim, then do some legitimate research into it, or practice a two week diet on high carbs low salt, to a two week diet on low carbs and high salt.
everybody is different. Salt does constrict blood vessels and effect the sympathic nervous system like stimulants do which also constrict blood vessels.
I am very iterested in the salt articles, do you have any info on sodium intake with Meniere’s disease?
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