Although the mechanisms involved are not yet well understood, studies have already shown that eat whole grains regularly would reduce the risk of chronic diseases such as type 2 diabetes or cardiovascular disease, as well as the risk of cancer. Researchers from the University of Eastern Finland and the International Agency for Research on Cancer (IARC) believe they have taken a step forward in understanding the benefits of whole grains. In a new study, published in theAmerican Journal of Clinical Nutrition on April 26, they explain how whole grains help regulate serotonin levels in the gutthe second brain.
There serotonin, nicknamed the “happiness hormone”, is a neurotransmitter in the brain that helps the body manage moods. When produced at balanced levels, primarily in the intestines, it prevents one from feeling stressed, anxious or depressed. Its effects are actually opposite to those of dopamine, which encourage risk taking and trigger the reward system. Serotonin is also involved in circadian cycle regulation or the digestive mobility. Its increase in the blood is also associated with high blood sugar levels.
Decreased serotonin in the blood and colon
For the purposes of the experiment, the scientists made 15 participants eat six to ten slices of white bread a day for four weeks. The volunteers then, during the same time, eat the same quantity of wholemeal rye bread. Fasting plasma samples were taken at the end of each period for comparison. The consumption of whole rye eventually led to a significant drop in serotonin concentrations, compared to consumption of low-fiber bread.
The researchers also tested whether the addition of whole grains in the diet modified this production in the intestine in mice. For nine weeks, the rodents’ diet was supplemented with rye bran, wheat bran or cellulose flour. Finally, those who consumed rye bran and wheat bran had significantly lower serotonin levels in their colon.
“Whole grains are known to reduce the risk of diabetes, and based on these new findings, the effect may at least in part be due to a decrease in blood levels of serotonin”says study co-author Kati Hanhineva in a press release. His team focuses particularly on theassociation of the hormone with colorectal cancer. “Some recent studies have shown that blood serotonin levels are higher in cancer patients than in healthy controls”adds Pekka Keski-Rahkonen of IARC.
Read also :
- Foods that make you happy!
- Whole grains for weight loss
