Why is it healthy to eat whole grains?

Original title: Why whole grains are healthy
A new study by the University of Eastern Finland and the International Agency for Research on Cancer (IARC) shows that adults who eat
whole wheat
ryl wheat
loaf
have lower plasma serotonin levels than those who eat low-fiber
wheat
white bread. At the same time, taking cereal fiber from rye or wheat can also reduce serotonin levels in the colon of mice.
, also known as serotonin, is the most famous neurotransmitter in the brain. Serotonin, produced by the intestines, is still isolated from the brain, but it is the source of most serotonin in the body and has a variety of peripheral functions, including regulating intestinal movement.
according to the study, published in the American Journal of Clinical Nutrition, the health benefits of whole
grains
foods may be at least partially related to changes in intestinal serotonin production.
whole grain intake is associated with a lower risk of type 2 diabetes, cardiovascular disease and some cancers, and despite its potential health benefits, the mechanism of action remains unclear. It may have an effect on bioactive compounds found in whole grains, phytochemicals and fibers, from which gut bacteria produce different metabolites.
new study explores how whole wheat rye intake regulates the concentration of different metabolites in the blood. The study used non-targeted metabolite analysis, also known as metabolomics, to detect many metabolites simultaneously, including previously unknown ones.
recent years, metabolomics has increasingly been used in dietary intervention studies to identify new dietary biomarkers and to explore metabolic changes associated with specific foods, nutrients and dietary patterns. For example, previous studies have found that whole wheat rye intake can reduce insulin response after meals or improve weight maintenance by inducing satiety.
the first four weeks of the dietary intervention study, participants ate 6 to 10 slices of low-fiber wheat white bread per day, and then ate the same amount of whole wheat rye bread or wheat white bread supplemented with rye fiber for the next 4 weeks. At the end of each cycle, the researchers collected samples of the participants' fasting plasma and analyzed them using liquid chromatography-mass spectrometry to compare the distribution of plasma metabolites in different dietary cycles.
results showed that the intake of whole wheat rye bread led to a significant decrease in serotonin concentrations compared to low-fiber wheat white bread.
researchers also tested in mice whether adding cereal fiber to the diet altered the production of serotonin in the intestines. They supplemented the mice's nine-week diet with rye bran, wheat bran, or cellulose powder, and found a significant reduction in serotonin in the colon of mice receiving rye bran or wheat bran.
serotonin is associated with high blood sugar levels. "Whole grains are thought to reduce the risk of diabetes, and according to these new findings, this effect is at least partly due to lower serotonin levels." Kati Hanhineva, a researcher at the University of Eastern Finland, said.
researchers are also interested in the link between serotonin and colorectal cancer. Pakka Keski Rahkonen, a scientist at IARC, added: "Recent studies have found that cancer patients have higher levels of plasma serotonin than in the healthy control group. The
intake of whole wheat rye bread was also associated with lower plasma taurine, glycerin choline and two endolytic glycerin phospholipid concentrations. In addition to this endogenous metabolite, the researchers also found 15 rye phytoseric chemicals associated with whole wheat rye bread intake, which have also been shown to inhibit the growth of colon cancer or prostate cancer cells outside the body.
authors say the study found a dose-response relationship between whole grain intake and a reduced risk of these diseases, supporting the current increase in whole grain intake in dietary guidelines.
related paper information: DOI: 10.1093/ajcn/nqy394.