Is MSG Bad for Your Heart?

Is MSG Bad for Your Heart?

Not in any way that singles out MSG. The largest study, which followed 108,932 adults, tied each extra 200 mg a day of added MSG to about 5% higher risk of heart artery disease. Glutamate that occurs naturally in food showed the same kind of link. The link was small, the study was observational, and it cannot prove that MSG causes heart disease.

MSG stands for monosodium glutamate. Glutamate is an amino acid, one of the building blocks of protein. Your body makes it, and it is found naturally in cheese, tomatoes, mushrooms, meat and soy sauce. MSG is a purified form that food makers add for savory flavor. Ajinomoto is a common brand.

Regulators classify MSG as safe to eat. A review of its safety record notes that the US Food and Drug Administration lists MSG as Generally Recognized as Safe, and that the joint expert committee of the UN food and health agencies set no upper limit on its daily intake.

What the Data Show

The main study is the French NutriNet-Santé cohort of 108,932 adults. Participants kept repeated 24-hour food diaries that recorded the brands they bought. The researchers also tested real food samples in the lab to measure how much added glutamate they held. Over a median of 7.92 years, 1,284 people developed ischemic heart disease, meaning narrowed or blocked heart arteries, and 1,113 had a stroke or other brain blood vessel event.

Here is how each type of glutamate tracked with ischemic heart disease in that study:

For cardiovascular disease overall, the links were weaker: about 9% higher for natural glutamic acid and 10% for total glutamate, while the 3% figure for added glutamate was not statistically clear. Stroke showed no link to any type of glutamate. The authors state that leftover confounding cannot be ruled out and that causality cannot be established from this single observational study.

Confounding matters a lot here. People who eat more added MSG tend to eat more packaged and processed food, which also carries extra salt, refined starch and calories. A food diary study cannot fully separate those things.

Does MSG Raise Blood Pressure?

The evidence points in both directions.

In the INTERMAP study of 4,680 adults from China, Japan, the United Kingdom and the United States, people who got more of their protein as glutamic acid had slightly lower blood pressure: about 1.5 to 3.0 points lower systolic (the top number) and 1.0 to 1.6 points lower diastolic (the bottom number). That study measured glutamate from the whole diet, mostly from protein, rather than MSG itself.

In a Chinese study of 1,227 adults followed for 5 years, higher MSG intake was linked to a larger rise in both systolic and diastolic blood pressure. The link was strongest in women and in people already taking blood pressure medicine.

Large single doses can push blood pressure up for a short time. In a blinded trial of 14 healthy men, systolic pressure rose after a drink containing 150 mg of MSG per kilogram of body weight, compared with a lower dose and a salt-water placebo. A similar trial in 14 healthy people gave the same high dose for 5 days and found a short-lasting rise in blood pressure that did not fade with repeated doses.

That dose is far more than a seasoned meal. For a 150-pound adult it works out to about 10 grams of pure MSG, taken in a drink.

On the other side, a trial in veterans with Gulf War Illness found no immediate effect on blood pressure when people were given MSG or a placebo without knowing which. In that trial, a month on a low glutamate diet did lower blood pressure. The authors concluded the drop came from eating more unprocessed food, not from cutting glutamate.

Does MSG Make Your Heart Race or Cause Palpitations?

Many people blame MSG for a racing heart after a restaurant meal. Blinded tests do not support that well.

In a multicenter blinded study of 130 people who believed they reacted to MSG, large doses taken without food caused more symptoms than placebo. But the reactions were uncommon, inconsistent, and did not repeat when people were retested. When MSG was given with food, the reactions did not appear.

A randomized blinded trial of 61 self-described MSG-sensitive people found that 36.1% reacted to 5 grams of MSG and 24.6% reacted to the placebo, a difference that was not statistically clear. On retesting, symptoms appeared from about 2.5 grams upward. The symptoms more common after MSG than placebo were headache, muscle tightness, numbness or tingling, weakness and flushing.

Palpitations were not among the symptoms either trial tied to MSG. If your heart races after a salty, heavy restaurant meal, a large dose of salt, alcohol, caffeine or simply a big meal are more common triggers worth considering.

Does MSG Raise Cholesterol?

No human study I found has tested MSG against LDL cholesterol or total cholesterol directly.

The closest evidence is mixed. In a study of 349 adults in rural Thailand, each extra gram of MSG a day was tied to about 14% higher odds of metabolic syndrome, a cluster of high blood pressure, high blood sugar, belly fat and abnormal blood fats, and about 16% higher odds of being overweight. That was a snapshot in time, so it cannot show which came first.

A Chinese cohort of 1,056 healthy adults found the opposite direction for blood sugar. People in the highest quarter of MSG intake had about 70% lower odds of developing high fasting blood sugar over 5 years than those in the lowest quarter.

Is MSG Bad for Heart Patients?

For people with heart disease or high blood pressure, sodium is the bigger concern, and MSG can work in either direction. MSG contains sodium, but much less than table salt, which is why food scientists use it to cut salt.

A US modeling study of 4,139 adults estimated that replacing some salt with umami seasonings such as glutamate could lower salt intake by about 7% to 14%, or 0.61 to 1.13 grams a day, without hurting taste.

The catch is where most added MSG shows up: instant noodles, bouillon cubes, chips, frozen meals and packaged sauces. Those foods are often loaded with salt as well. The MSG itself is unlikely to be the problem. The rest of the package often is.

Is Natural Glutamate Different From MSG?

Not to your body. Once digested, glutamate from a tomato and glutamate from a shaker are the same molecule.

The NutriNet-Santé study found that naturally occurring glutamic acid and added glutamate were both linked to higher heart artery disease risk. That makes it hard to argue that MSG on a label is the special danger.

Dr. Kumar’s Take

MSG has carried a bad reputation since the 1960s, and the heart data do not justify singling it out. The best study found small links for every source of glutamate, natural ones included, and no link at all to stroke. A 5% relative change per 200 mg a day is a weak signal from one observational study, and it is the kind that processed food alone could explain.

Where I would put attention is the food that carries MSG. Packaged savory foods bring salt, refined starch and extra calories, and those have far stronger evidence against them. Cooking with a pinch of MSG in place of some salt may even help someone trying to eat less sodium.

Practical Takeaways

• Do not hunt for MSG on labels as a heart risk. Natural glutamate showed the same link.
• Eat fewer heavily processed savory foods such as instant noodles, bouillon cubes, chips and packaged sauces.
• Keep cheese, tomatoes and mushrooms. A small observational link is no reason to drop whole foods.
• Use MSG to replace some salt when cooking if you are cutting sodium.
• Skip large doses on an empty stomach if you notice headaches or flushing after MSG.
• Focus on blood pressure, LDL cholesterol, smoking and activity if you have heart disease. Those matter far more.

Related Studies and Research

• Ultra-Processed Foods Linked to 47% Higher Heart Disease Risk
• Does Replacing Saturated Fat with Linoleic Acid Reduce Heart Disease Risk?
• A plant-based diet is linked to lower heart disease risk over 20 years
• Do food preservatives raise blood pressure and heart risk?
• Are artificial sweeteners bad for your blood sugar and heart?
• Too much salt may speed up memory loss in older men

FAQs

Is MSG bad for your heart?

The evidence does not single it out. One large study tied added MSG to slightly higher heart artery disease risk, but natural glutamate showed the same link, and the study could not prove cause.

Does MSG raise blood pressure?

Results are mixed. Glutamate from the diet tracked with slightly lower blood pressure in a large four-country study, while MSG intake tracked with rising blood pressure in a Chinese study. Very large single doses raised blood pressure briefly in small trials.

Can MSG cause heart palpitations?

Blinded trials have not tied palpitations to MSG. The symptoms that appeared more often after large doses were headache, flushing, tingling, muscle tightness and weakness, and they were inconsistent when people were retested.

Is MSG worse than salt?

MSG contains much less sodium than table salt, and food scientists use it to cut salt. Swapping some salt for umami seasonings could lower salt intake by roughly 7% to 14% without hurting taste, according to one US modeling study.

Is Ajinomoto bad for your heart?

Ajinomoto is a brand of MSG, so the same evidence applies. Used as seasoning, it has not been shown to harm the heart, and regulators classify MSG as safe.

Bottom Line

MSG is not a proven heart hazard. In 108,932 adults, added MSG tracked with about 5% higher heart artery disease risk per 200 mg a day, but natural glutamate showed the same pattern and stroke showed none. Blood pressure studies point both ways, and no blinded trial has tied MSG to palpitations. The processed foods that carry most MSG are worth eating less of. The seasoning itself is not the main problem.