Such preservatives in steamed bread and bread may cause diabetes?

*It is only for medical professionals to read for reference.
Propionic acid is considered to be a very safe food preservative.
Is it going to collapse this time? Most people may not be very familiar with propionic acid, but if the editor tells you, it is used as a preservative in the steamed bread, noodles, bread, pastry, vinegar, soy sauce, soy products and other foods bought in daily life.
, Did you suddenly start to feel a little bit of substitution
?
Propionic acid is the product of the oxidation of amino acids and fatty acids in the human body.
It is converted into succinic acid in the body to increase the circulation of pyruvate in the liver, thereby increasing gluconeogenesis
.

Because propionic acid is a naturally occurring short-chain fatty acid, and people have not fully understood the adverse consequences of consuming propionic acid so far, it is considered very safe by the U.
S.
Food and Drug Administration (FDA)
.

 Figure 1 The molecular structure of propionic acid.
Previous mouse studies have found that propionic acid can induce acute glycogen decomposition.
With the increase of glucose production and insulin secretion, the administration of propionic acid stimulates glucagon and fatty acid binding protein 4 (FABP4).
) And the release of norepinephrine, which may mediate the hyperglycemia caused by propionic acid
.

In addition, long-term oral propionic acid was compared with placebo.
After a few weeks, mice gradually increased body weight, insulin resistance, fat mass and EGP [1]
.

 A recent study published in the British Medical Journal found that after oral administration of propionic acid in healthy people, it will cause inappropriate activation of the insulin counter-regulatory hormone network, and this inappropriate stimulation indicates that propionic acid may be latent Metabolic disruptors [2]
.

 Figure 2 The publication of the study.
Propionic acid can become a "metabolism disruptor" by taking 1500-2000mg in a short period of time.
The study used randomized, placebo-controlled, and crossover research methods and included 27 healthy men and women, of whom 15 People are women and 12 are men
.

The average age is 30±9 years old, and the average body mass index (BMI) is 26.
7±3.
8 kg/m2
.

 The subjects were given two study visits, and before each visit, they maintained a propionic acid-free diet for 1 week (a 7-day PA-free diet was prepared by the nutrition group of the BWH Clinical Investigation Center)
.

During each visit, subjects were divided into fasting resting group, normal blood glucose (85-90 mg/dL) hyperinsulinemic clamp group, and hypoglycemia (65-70 mg/dL) hyperinsulinemic clamp group
.

After 2 hours of oral administration of propionic acid or placebo, glucose, insulin, glucagon, norepinephrine, epinephrine, and EGP were evaluated
.

 In this study, participants took 4 or 3 calcium propionate capsules with a content of 500mg each (total amount is about 1500~2000mg)
.

Propionic acid is often present in processed foods at a concentration of 0.
15%-0.
30% w/w [3]
.

At this concentration, the amount of propionic acid contained in 270-530g foods containing PA (such as cheese sandwiches) is consistent with this study
.

 The results of the study found that in the resting state after 8 hours of fasting, compared with placebo, the glucagon in the propionic acid intake group increased significantly, and post-hoc analysis showed that the increase was significant at T=180 min and T=210 min
.

In addition, propionic acid also significantly increased norepinephrine (Norepinephrine) (T=150min)
.

Compared with placebo, no significant effects of propionic acid on glucose (Glucose), insulin (Insulin), epinephrine (Epinephrine) or EGP were observed
.

 Figure 3 Metabolism of propionic acid under fasting resting state.
Under the hyperinsulinemic clamp conditions of normal blood sugar and hypoglycemia, the glucose and insulin levels of individuals receiving propionic acid and placebo are similar, indicating the consistency of the test conditions
.

Among them: Under normal blood sugar conditions, compared with placebo, propionic acid significantly increases glucagon, norepinephrine and epinephrine, and has no significant effect on EGP
.

Under hypoglycemic conditions, compared with placebo, propionic acid again significantly increased norepinephrine and epinephrine, although EGP also increased, but there was no significant difference
.

Both the propionic acid group and the placebo group had a significant increase in glucagon (about 50%), but there was no significant difference between the two groups
.

Figure 4 During the euglycemia (left picture) and hypoglycemia (right picture) hyperinsulinemic clamp studies, propionic acid (PA) and placebo had an effect on glucose (A and B), insulin (C and D), and glucagon (E and F), norepinephrine (G and H), epinephrine (I and J), and endogenous glucose production (EGP) (K and L)
.

The gray bars indicate the time of taking PA or placebo
.

This study further proves that under the conditions of normal blood sugar and hypoglycemia and high insulin in humans, short-term intake of 1500~2000mg of exogenous propionic acid will increase adrenaline
.

In the case of normal fasting blood glucose, the consumption of propionic acid leads to a significant increase in insulin counter-regulatory hormone; and in mild hypoglycemia, the effect of propionic acid to increase EGP may be secondary to the increase of norepinephrine and epinephrine induced by it
.

The ability of propionic acid to reduce liver insulin sensitivity (ie, inhibit the decrease in insulin-induced EGP) under mild hypoglycemia conditions is consistent with the conclusions of previous studies [1]
.

 The results of this study suggest that exposure to exogenous PA in a diet based on processed foods may lead to inappropriate activation of the metabolism of the integrated insulin counter-regulatory hormone network
.

Although the chronic effects of repeated exposure to PA on humans are uncertain, it may lead to insulin resistance, impaired blood sugar control, and gradual weight gain
.

 How to avoid the harm caused by ingesting propionic acid in life? Seeing this seriously, some readers may question whether the amount of propionic acid used in this study is consistent with the amount of propionic acid consumed by our Chinese people in their daily diet
.

 The editor found the relevant regulations in China's "Sanitary Standards for the Use of Food Additives" (GB 2760-2011): The maximum use amount of propionic acid in bean products, bread, pastries, vinegar, and soy sauce is 2.
5g/kg, and the maximum use amount of raw grains is 1.
8g/kg, the maximum consumption of raw wet noodle products (such as noodles, dumpling wrappers, wonton wrappers, and siu mai pi) is 0.
25g/kg, and the maximum consumption of other (for canned bayberry processing) is 50.
0g/kg
.

 Figure 5 A screenshot of the use of sanitary standards for food additives.
A piece of bread usually eats is about 200g.
Estimated according to the maximum use of propionic acid, it contains up to 0.
5g of propionic acid
.

For the time being, let’s convert all the food for a day into bread, which is about 4 yuan, which means 2.
0g of propionic acid
.

In this study, each subject ingested 2.
4g or 3.
2g of propionic acid at a time.
The total amount is actually close to the daily consumption.
The difference is that we often take long-term small amounts of propionic acid in our daily lives
.

 Therefore, we also need to further study the chronic effects of this food preservative on humans, but chronic hyperinsulinemia and insulin resistance may be the cause of weight gain and obesity, not just the result.

.

Inappropriate activation of the sympathetic nervous system and the increase of counter-regulatory hormones may be particularly important for diabetic patients, because the reduction of EGP inhibition in the postprandial state is also a cause of diabetes [4]
.

Therefore, we should avoid taking large amounts of foods containing preservatives in our daily lives, so those supermarket packaged snacks.
.
.
eat less if you can! Seeing this, everyone must be scratching their heads again.
You are not allowed to eat this, and you are not allowed to eat.
How should you eat it? Don't panic, I just want to tell you that although legal food additives are not enough to kill you, they may still harm the health of consumers
.

Therefore, before the current science has not fully clarified food additives, it is always best not to eat too much
.

In order to avoid long-term excessive intake of preservatives, you must master these careful considerations when buying goods: 1.
When buying things in the supermarket, you must develop the habit of turning over and looking at the "back"
.

It is best not to buy foods that contain more additives
.

2.
Choose low-processed foods
.

When buying food, try to choose low-process foods
.

The higher the processing degree, the more additives
.

3.
Eat it later if you "know" it
.

I hope you can eat it after you know what kind of additives are contained in the food
.

4.
Don't go straight to bargains-there is a reason for being cheap, and "good quality and low price" is not suitable for the food field
.

5.
Think more about why
.

"Why is the color of this sausage so beautiful?" "Why is this steamed bun so white?" With the spirit of "simple doubt", when choosing processed foods, the truth will naturally appear
.

Sixth, the last and most important point, try to eat only fresh food! Fresh meat, fish, eggs, vegetables.
.
.
This kind of food that keeps its original form instead of being decomposed and packaged is the most direct and efficient way for us to avoid contact with foods with preservatives
.

References: [1] Sci Transl Med 2019;11.
[2] BMJ Open Diabetes Res Care.
2021 Jul;9(1):e002336.
[3] Eur J Clin Nutr 2012;66:789–94.
[4] Diabetes 2004;53:3048–56.
[5] Hao Liping, Xia Yanbin, Chen Yongquan, Liao Xiaojun.
Food additives.
Beijing: China Agricultural University Press, 2002.