It is often said that animal protein is a high quality protein, and its amino acid ratio is more similar to that of human, so the utilization ratio is higher. Plant protein is not a high quality protein. Some amino acids, such as methionine, are low.
Methionine is one of the twenty amino acids that make up proteins and one of the nine essential amino acids. When our cells synthesize every protein molecule, methionine is always the first “starting amino acid” to be added to a new protein.
In addition, methionine is also involved in other important physiological processes, such as DNA methylation and polyamine synthesis.
However, there is growing scientific evidence that methionine has a very subtle relationship with cancer. The growth of some cancer cells is dependent on methionine.
In one experiment, the scientists co-cultured cancer cells with normal cells and then removed each essential amino acid from the nutrient base.
When these cells were cultured in a medium devoid of methionine, an interesting phenomenon occurred that the cancer cells were clearly unable to adapt to the environment. Their morphology began to change, the cell surface began to bubble, the nucleus gradually turned to pieces, and finally the cell died. Scientists call this process “apoptosis.”
In contrast, normal cells that grew in the same medium continued to live.
Cancer cells and Amino acids
What causes cancer cells to rely on methionine? Under an ultra-high power microscope, we can see that, unlike ordinary cells, the chromosomes of cancer cells are often mutated by means of fluorescent labeling. Sometimes, a segment of the chromosome is inexplicably missing. All the genes that existed on that chromosome were, of course, lost.
Chromosome mutation is an important step in the development of cancer cells. Scientists have found that many cancer cells lose a section of their chromosome that contains the p16 gene. The abnormal expression of P16 gene is an important cause of cell carcinogenesis. So p16 is also called tumor suppressor gene.
Interestingly, another gene, MTAP, happens to live next door to the p16 gene. The protein encoded by MTAP plays a key role in the synthesis of methionine.
So the consensus among scientists is that the deletion of chromosomes causes p16 and MTAP to be lost at the same time. The loss of P16 leads to cell carcinogenesis, while the loss of MTAP causes cancerous cells to fail to synthesize their own methionine.
Therefore, it is very important to limit the intake of methionine in diet for the prevention and control of cancer. So how to limit methionine intake?
Did you hear about treating cancer with hunger? It is true that some people have witnessed the successful cure of cancer in this way.
As a direct result of cutting back on food intake and even fasting, caloric and protein intake is significantly reduced, and so is methionine intake. This may be one of the reasons for the effectiveness of this method.
But the extreme approach is for normal cells to starve with the cancer cells, depending on who dies quickly.
We don’t deny that short cuts may bring other benefits, but it is more logical and safe to limit methionine intake through food choices.
So what foods are high in methionine? Eggs, fish, meat, milk.
When ranked by the amount of methionine in the food, the top 300 were all animal products. In fact, the fishy odour of animal products is the result of the decomposition of methionine, which contains sulfur.
A plant-only diet is a natural low-methionine diet that may be beneficial to cancer prevention and control.
Other studies have found a link between a low-methionine diet and increased longevity.
It is true that methionine is an essential amino acid that humans cannot synthesize on their own, but we eat too much of it, and the methionine in vegetables, fruits and cereals is sufficient as long as we have enough to eat.
The rare is the most expensive.