What About the Sodium in Miso?

According to the second World Cancer Research Fund/American Institute for Cancer Research expert report, “[s]alt is a probable cause of stomach cancer,” one of the world’s leading cancer killers. If the report’s estimate of an 8 percent increase in risk for every extra gram of salt a day is correct, then in a country like the United Kingdom, nearly 1,700 cases of stomach cancer happen every year just because of excess salt intake, as you can see at 0:27 in my video Is Miso Healthy?, and, in a country like the United States, it would be thousands more annually.

The risk of stomach cancer associated with salt intake appears on par with smoking or heavy alcohol use, but may only be half as bad as opium use or increased total meat consumption, as you can see at 0:43 in my video. These findings were based on a study of more than a half million people, which may explain why those eating meatless diets appear to have nearly two-thirds lower risk.

We know dietary salt intake is directly associated with the risk of stomach cancer, and the higher the intake, the higher the risk. A meta-analysis went one step further and looked at specific salt-rich foods: pickled foods, salted fish, processed meat, and miso soup. Habitual consumption of pickled foods, salted fish, and processed meat were each associated with about a 25 percent greater risk of stomach cancer. The pickled foods may explain why Korea, where the pickled cabbage dish kimchi is a staple, appears to have the highest stomach cancer rates in the world, as you can see at 1:39 in my video. But researchers found there was no significant association with the consumption of miso soup. This may be because the carcinogenic effects of the salt in miso soup are counteracted by the anti-carcinogenic effects of the soy, effectively canceling out the risk. And, if we made garlicky soup with some scallions thrown in, our cancer risk may drop even lower, as you can see at 2:06 in my video.

Cancer isn’t the primary reason people are told to avoid salt, though. What about miso soup and high blood pressure? Similar to the relationship between miso and cancer, the salt in miso pushes up our blood pressures, but miso’s soy protein may be relaxing them down. If we compare the effects of soy milk to cow’s milk, for example, and, to make it even more fair, compare soy milk to skim cow’s milk to avoid the saturated butter fat, soy milk can much more dramatically improve blood pressure among women with hypertension, as you can see at 2:43 in my video. But would the effect be dramatic enough to counter all the salt in miso? Japanese researchers decided to put it to the test.

For four years, they followed men and women in their 60s, who, at the start of the study, had normal blood pressure, to see who was more likely to be diagnosed with hypertension in that time: those who had two or more bowls of miso soup a day or those who had one or less. Two bowls a day may add a half teaspoon of salt to one’s daily diet, yet those who had two or more bowls of miso soup every day appeared to have five times lower risk of becoming hypertensive. So, maybe the anti-hypertensive effects of the soy in the miso exceed the hypertensive effects of the salt.


Indeed, miso paste, a whole soy food, can be used as a “green light” source of saltiness when cooking. That’s why I used it in my pesto recipe in How Not to Die and in my How Not to Die Cookbook. It can help you in Shaking the Salt Habit.

Not convinced that salt is bad for you? Check out these videos:

Not convinced that soy is good for you? See:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Is Milk Lowering Uric Acid a Good Thing or a Bad Thing?

Parkinson’s disease, the second most common neurodegenerative disorder after Alzheimer’s, is characterized by a slowness of movement, rigidity, tremor, and stooping posture, all of which worsen over time. Non-movement symptoms such as cognitive impairment and sleep, smell, and mood disturbances occur as the disease spreads to other areas of the brain. The cause of Parkinson’s is perhaps “one of the important questions posed by the neurobiology [science] of aging.” For example, why is the consumption of dairy products associated with increased risk of Parkinson’s? Perhaps because they contribute to our exposure to pesticides and other neurotoxins like dieldrin, which continues to be found in the autopsied brains of Parkinson’s victims. Even though dieldrin was banned decades ago, it lingers in the environment and we “continue to be exposed to the pesticide through contaminated dairy and meats…”

The cause of Parkinson’s “is unlikely to be due to milk compounds such as calcium, vitamin D, total fat, or total protein as these compounds are not associated with [the disease] when derived from other sources.” However, it could be lactose, the milk sugar, perhaps accounting for the increased associated risk of death and bone fractures, as well as Parkinson’s. Earlier onset of Huntington’s disease has also been identified. There is, however, a third possibility.

As I discuss in my video Parkinson’s Disease and the Uric Acid Sweet Spot, milk lowers uric acid levels, and uric acid may be protective against Huntington’s and also slow the decline caused by Parkinson’s. More importantly, it may lower the risk of getting Parkinson’s in the first place. Why? Perhaps because uric acid is an important antioxidant in the brain, something we’ve known for more than 30 years. We can demonstrate uric acid’s importance directly on human nerve cells in a petri dish. When the pesticide rotenone is added, oxidative stress goes up. Add the pro-oxidant homocysteine, and it goes up even more. But, when uric acid is added, it completely suppresses the oxidative stress caused by the pesticide.

Drinking milk, however, has a uric acid-lowering effect. In the paper making this assertion, a study they cited was “A cute effect of milk on serum urate concentrations,” but that was just a cute typothey meant Acute effect. Indeed, drink cow’s milk, and, within hours, uric acid levels drop 10 percent. Drink soymilk, and, within hours, they go up 10 percent. Now, for gout, a painful arthritic disease caused by too much uric acid, the uric acid-lowering effect of dairy is a good thing—but uric acid is “a double-edged sword.”

If our uric acid levels are too high, we can get gout, but, if they’re too low, it may increase our risk of neurodegenerative diseases, such as Alzheimer’s, Huntington’s, Parkinson’s, and multiple sclerosis.

Incidence rates of gouty arthritis over five years indicate that if our uric acid is over 10.0 mg/dl, we have a 30 percent chance of suffering an attack of gout within the next 5 years. However, at levels under 7.0 mg/dl, our risk is less than 1 percent, so it might make sense to have levels as high as possible without going over 7.0 to protect the brain without risking our joints. But having excessive uric acid in the blood puts more than just our joints in jeopardy. Yes, having levels that are too low may increase our risk of MS, Parkinson’s, Alzheimer’s, and even cancer, but having levels that are too high may increase our risk of gout, kidney disease, and heart disease.

In fact, having a uric acid level over 7.0 mg/dl isn’t only associated with an increased risk of gout, but also an increased risk of dying from all causes. However, having a low uric acid level may also shorten our lifespan by increasing mortality. High uric acid levels are associated with increased risk of death from heart disease, but low uric acid levels are associated with increased risk of fatal stroke. So, keeping uric acid at optimum levels, the sweet spot between 5.0 and 7.0 mg/dl, may protect the brain in more ways than one.

If we measure the uric acid levels in patients with Parkinson’s, they come in around 4.6 mg/dl, which may help explain why dairy consumption may increase risk for Parkinson’s since milk pushes down uric acid levels. Dairy intake may also explain the differences in uric acid levels among meat-eaters, vegetarians, and vegans. In the graph in my video, you can see that vegan men have significantly higher uric acid levels at 5.7 mg/dl than vegetarians, presumably because vegans don’t drink milk, and those who both eat meat and consume milk fall between the vegans and vegetarians.


For more on Parkinson’s see:

Uric acid as an antioxidant? I’ve touched on that before in Miocene Meteorites and Uric Acid.

If uric acid levels are too high consider cutting down on Flesh and Fructose and eating cherries. (See Gout Treatment with a Cherry on Top and Treating Gout with Cherry Juice for more information.) Also, check out Preventing Gout Attacks with Diet.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Healthier Salt Substitutes

As I discuss in my video Shaking the Salt Habit, the two most prominent dietary risks for death and disability in the world are not eating enough fruit and eating too much salt. Eating too little fruit kills nearly five million people every year, and eating too much salt kills four million.

There are three things we can do to lower our salt intake. First, don’t add salt at the table. One third of us add salt to our food before even tasting it! Second, stop adding salt while you’re cooking. At first, the food may taste bland, but within two to four weeks, “as the sensitivity of the salt taste receptors in the mouth become more sensitive to the taste of salt in the usual concentrations”—believe it or not—you may actually prefer the taste of food with less salt. Some of the flavorings you can use in the meanwhile instead of salt include “pepper, onion, garlic, tomato, sweet pepper, basil, parsley, thyme, celery, lime, chilli, nettle, rosemary, smoke flavoring, curry, coriander and lemon.” Even if you did add salt while cooking, though, it’s probably better than eating out, where even at non-fast food restaurants, they tend to pile it on. And, finally, avoid processed foods that have salt added.

In most countries, only about half of sodium intake comes from processed foods, so there’s more personal responsibility. In the United States, however, even if we completely stopped adding salt in the kitchen and dining room, it would only bring down salt intake a small fraction. This has led public health commentators to note how challenging it is for everyone to reduce their salt intake, since so much of our sodium intake is out of our control. But is it? We don’t have to buy all those processed foods. We can choose not to turn over our family’s health to food corporations that may not have our best interests at heart.

If we do buy processed foods, there are two tricks we can use. First, try to only buy foods with fewer milligrams of sodium listed on the label than there are grams in the serving size. So, if it’s a 100-gram serving size, it should have less than 100 mg of sodium. Or, second, shoot for fewer milligrams of sodium than there are calories. For example, if the sodium is listed as 720 and calories are 260, since 720 is greater than 260, the product has too much sodium.

That’s a trick I learned from Jeff Novick, one of my favorite dieticians of all time. The reason it works is that most people get about 2,200 calories a day. So, if everything you ate had more calories than sodium, you’d at least get under 2,300 milligrams of sodium, which is the upper limit for healthy people under age 50. Of course, the healthiest foods have no labels at all. We should try to buy as much fresh food as possible because it is almost impossible to come up with a diet consisting of unprocessed natural foodstuffs that exceeds the strict American Heart Association guidelines for sodium reduction.


Not eating enough fruit as a leading killer? For more, see my video Inhibiting Platelet Aggregation with Berries.

In my latest sodium series, I lay out the evidence and dive into the manufactured controversy to expose salt industry shenanigans. See:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: