In part I of this series of posts we introduced the concept of poison, in order to understand the damage that a substance may cause.
We also analyzed in depth the milk, to see if it is as harmful as some argue and whether or not it influences certain diseases.
If you haven’t read that article yet, I recommend you to start there, it will make it easier for you to understand this one.
This time we are going to analyze two other suspects, white rice and salt. Should we cut on sushi and paella?
Let the analysis begin …
Rice is the most consumed crop in the world and is the basic food in many developing countries (source).
It is a type of grass. The grains we consume are the seeds of the plant.
According to the archaeological evidence, the domestication of rice began in the Neolithic Revolution Era about 7,800 years ago in Northeast China, more precisely in the Yangtze and Huang He River Basin (source) (source).
Domestication consisted essentially of choosing those plants that did not disperse their seeds once maturity of the panicle (the structure that contains the rice grains) has been reached.
The rice grain that grows on the plant has an inedible outer layer (chaff). Beneath that layer are the bran layers and in turn below these is the endosperm next to the germ (embryo) from which the new plant will be born.
The brown rice has only the outermost layer is removed, preserving the bran which contains various nutrients such as flavonoids, fiber and several minerals such as magnesium, phosphorous, manganese, iron and zinc (source) (source) (source) (source).
In white rice, the bran layer and germ have also been removed, so it loses nutritional value. What is consumed in this case is the endosperm, basically starch.
Those who criticize white rice argue that it sharply increases blood glucose levels, generating excessive insulin secretion, which increases the risk of Diabetes and overweight/obesity.
While this may be true, the problem comes when brown rice is recommended as a replacement.
When the medicine is worse than the disease…
Beyond all the nutrients present in the bran layers and germ, brown rice also has a higher concentration of arsenic and phytic acid.
Arsenic is a heavy metal that exists naturally in the environment. However, due to human activity, its concentrations are usually above natural levels.
Rice is a crop that needs a lot of water to grow. If the irrigation comes from groundwater layers with very high levels of arsenic, it goes into the grains of the plant. The bran layers of brown rice are especially prone to accumulate arsenic (source).
Even the exposure during pregnancy and the first years of life can increase the likelihood of suffering from any of the aforementioned diseases (source).
Recommendations about rice
As discussed in the previous post, the issue is the ingested dose.
The level of arsenic in the grain varies depending on how contaminated was the land where it was grown.
If you eat rice 1-2 times a week there shouldn’t be any problems, choose the one you like the most. However, if you consume 3 or more times (which I do not recommend), it would be better to opt for white to prevent potential effects of arsenic and phytic acid (unless you know the levels of arsenic of the place where the rice is coming from).
Another argument is that eating brown rice instead of white avoids undesirable spikes in insulin and some even go beyond recommending it for Diabetic people.
However, a study comparing the effects of eating white and brown rice in two groups of 101 people each for 16 weeks found no significant differences in different indicators such as body mass index, waist circumference, blood pressure, levels glucose and insulin, etc (source)
Finally, like all cereals, rice does not provide nutrients that you couldn’t obtain from other better sources and should not be the basis of your diet.
But eating a stew once a week won’t harm you.
Who said that stones can’t be eaten?
It can be said that salt is a type of edible rock (obviously not the type that this lady ingests).
In the past, salt was used to preserve food since it has properties that hinder the growth of bacteria.
Over time, it became so important that it was used as an exchange currency and was even the cause of wars.
Chemically, it is composed of sodium (40%) and chlorine (60%). Both are important in the balance of body fluids, muscle contractions and in the transmission of nervous system’s impulses.
Some types of salt have also little amount of other minerals such as calcium, iron, potassium, zinc or iodine (the latter artificially added).
It should be noted that salt is naturally present in most foods.
Where does the salt come from?
Most of the salt we consume is extracted from mines or by evaporation of salt water (from the sea or from saline springs).
Types of salt
- Fine salt (refined or table salt): it is the most common and the cheapest. It presents the highest degree of grinding. It has the problem that sometimes, due to humidity, it hardens and forms lumps. So what companies do is add anti-caking agents. Iodine is also often added (in many countries by law) as a policy to prevent thyroid gland problems.
- Coarse salt: like fine, but less ground. It usually has fewer additives since it is more difficult to cake.
- Sea salt: obtained by evaporation of seawater from the sea or springs. It is usually less milled and has fewer additives than the previous ones, but in turn, due to the pollution of the seas, it may have small amounts of heavy metals or plastic microparticles. However this wouldn’t affect health (source).
- Himalayan salt (pink): obtained from the Khewra mine in Pakistan. The color is due to trace amounts of iron (natives of Misiones know this well). It contains little amounts of other minerals like calcium, potassium, magnesium but they are not relevant from a nutritional point of view. The good news about this salt is that it has no additives.
- Low sodium salt: it is not actually salt, it is a substitute. In this case, sodium has been replaced by potassium. The flavor it provides to meals is different, some describe it as bitter.
Those who question salt, specifically sodium, state that it is responsible for producing hypertension, which in turn increases the risk of suffering a stroke or heart disease.
What does the scientific evidence say?
There is an interesting review of 34 studies (more than 3000 people) that shows that a reduction in salt intake from 9-12 g to 6 g per day significantly reduces blood pressure (source).
There is also evidence that a reduction in salt intake could increase insulin resistance (source).
In short, both eating everything without salt and an excess in its intake can be problematic for your health.
So, what to do?
Like almost everything in Biology, we have a gray area. Not everyone has the same sensitivity to sodium.
This is due in part to each one’s genetic background and to the current situation of the person.
It is also known that the balance with potassium is important to lower blood pressure and reduce the risk of a stroke (source).
Who should limit the intake?
Older adults, the African American population, people with chronic kidney disease, women who have had pre-eclampsia (increased blood pressure during pregnancy), and people with low birth weight are especially sensitive (source) (source).
Who could add a little more of salt?
Healthy adults, who practice a lot of physical activity, will lose several minerals like sodium, magnesium and potassium through sweat (especially in hot weather). In those cases it may be recommended to ingest a little more of salt to recover some sodium as well as foods that provide potassium and magnesium such as fish, avocados, pumpkins, carrots, bananas, potatoes, parsley, celery (leafy vegetables in general), nuts and dark chocolate (with high percentage of cocoa).
How much to ingest?
Official health authorities recommend a daily dose of 2.3 g of sodium (about 6 g of salt, this is approximately one teaspoon) (source).
This value comes from several studies where it was observed that both a daily intake greater than 7 gr and lower than 3 gr were associated with cardiovascular events and mortality (source) (source). In this way it was established that the ideal would be to be in an intermediate range such as 5-6 gr.
Our ancestors did not add salt to their food. Therefore today it is not essential to do so either.
However, scientific evidence shows us that, in normal conditions, a moderate amount of salt (one teaspoon) distributed between the meals of the day, balanced with appropriate sources of potassium, is totally safe and will give a better flavor to your meals. If you are part of the most sensitive population (e.g. older adults), better stay near the lower limit of 3-4 grams per day.
If your diet is based on the four fundamental foods salt will not provide you with any important nutrients. However, a salt-free diet is tasteless and, even though you might get used to it, it is difficult to cope with.
If you also sweat a lot during the day, salt can be a quick and cheap option to recover some of the lost sodium. Of course, do not forget to also incorporate potassium and other minerals through food.
As for the type of salt, the less additives the better, so if you can get some Himalayan pink salt or sea salt, do it. But if you eat correctly and just add salt in the recommended doses (5-7 gr daily), I would simply go for the common table iodized salt.
Regarding low sodium salt, it could be used from time to time as a source of potassium, but I always recommend to incorporate nutrients from food rather than from an artificial compound.
The salt whose consumption you must reduce is the one that is not seen, that is, the one that is hidden in ultra-processed foods (snacks, instant broths, sausages, industrial breads, etc.) since you could easily exceed the 7-8 gr per day and generate some problems.
And do not trust what the front label says, look at the nutritional information and/or the ingredients.
Again science gives us a bit more insight into what these two supposed White Poisons really are.
Although rice and salt are not essential foods to improve your health and there are some risks when ingested in excess, they are totally safe in the right doses and there is no reason to completely eliminate them from your diet. So you can continue enjoying every once in a while a good Paella seasoned with a little bit of salt.
In the next article we will discuss the last two “white poisons”: sugar and wheat flour.