Chia seeds may help the brain regulate appetite and inflammation

Recent research suggests that components derived from chia seeds may help mitigate some of the harmful effects that a poor diet inflicts on the brain. The study indicates that chia flour and chia oil can alter how the brain regulates appetite and manages inflammation. These findings were published in the journal Nutrition.

Diets rich in saturated fats and sugars have become increasingly common worldwide. This eating pattern is often referred to as the Western diet. It is strongly linked to a rise in metabolic conditions such as obesity and type 2 diabetes. However, the consequences of such a diet extend beyond the rest of the body to the central nervous system. Consuming high amounts of fat and fructose can disrupt the delicate balance of hormones that signal fullness.

This disruption often leads to a cycle of overeating. In addition to confusing appetite signals, unhealthy diets can trigger inflammation within brain tissue. They also cause oxidative stress, which is a form of cellular damage. Scientists are currently searching for functional foods that might reverse or prevent these neurological changes.

Researchers from the Federal University of Viçosa in Brazil investigated whether chia seeds could offer a solution. Chia seeds are known for their nutritional density. They contain high levels of dietary fiber, vitamins, and healthy fatty acids. The research team wanted to see if processing the seeds into flour or oil would affect their biological activity.

The study was led by Bárbara Pereira da Silva from the Department of Nutrition and Health. The paper’s first author is Patrícia Nayara Estevam. They focused on how these chia products influenced gene expression in the brains of rats.

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The scientists conducted their experiment using male Wistar rats. They divided the animals into groups to test different dietary conditions. For the first eight weeks, a majority of the rats consumed a diet designed to mimic unhealthy human habits. This feed was high in lard and fructose.

This initial phase was intended to induce metabolic alterations in the animals. A control group received a standard, healthy diet during this time. After the eight weeks concluded, the researchers redistributed the animals into new groups for a ten-week treatment phase.

One group continued on the high-fat, high-fructose diet without any changes. Another group received this unhealthy diet but with soybean oil replaced by chia oil. A third group had their high-fat feed supplemented with chia flour. The researchers then collected brain tissue samples for analysis.

The team looked for specific genetic markers associated with satiety. Satiety is the feeling of being full after eating. They also measured levels of hormones that control appetite. Finally, they assessed biological markers related to inflammation and antioxidant activity.

The results revealed distinct differences between the effects of chia flour and chia oil. The animals that consumed chia oil showed increased activity in specific genes that suppress hunger. These genes produce proteins known as POMC and CART.

These proteins are essential for signaling to the body that it has consumed enough energy. The activation of this pathway typically leads to a reduction in food intake. The researchers did not observe this specific genetic increase in the group fed chia flour.

However, both the flour and oil treatments appeared to improve how the brain handles leptin. Leptin is a hormone produced by fat cells that inhibits hunger. In a healthy brain, leptin binds to specific receptors to stop the urge to eat.

Diets high in fat often cause the brain to ignore leptin signals. This condition is known as leptin resistance. The rats fed chia products showed a reduction in the genetic expression of the leptin receptor. This suggests a restoration of normal sensitivity to the hormone.

The study also examined a neurotransmitter called Neuropeptide Y. This chemical is a potent stimulator of appetite. The high-fat diet caused levels of Neuropeptide Y genetic expression to rise. Both chia flour and chia oil succeeded in lowering the expression of this hunger-inducing marker.

Beyond appetite control, the researchers investigated inflammation. The unhealthy diet increased the expression of a protein complex called nuclear factor kappa B. This molecule acts as a switch that turns on inflammation in cells.

Both chia treatments were effective in lowering the activity of this inflammatory switch. This indicates that components in chia seeds may protect brain cells from inflammatory damage. The researchers attribute this to the bioactive compounds found in the seeds.

Chia flour provided an additional benefit regarding antioxidant defense. The group fed flour showed increased expression of a gene called Nrf2. This gene serves as a master regulator for the body’s antioxidant response.

It helps cells produce enzymes that neutralize harmful free radicals. The researchers believe the phenolic compounds in the flour are responsible for this effect. These compounds act as antioxidants and help maintain cellular health.

To understand these molecular interactions better, the team used computer simulations. This method is often called molecular docking. It allows scientists to predict how different molecules might fit together physically.

They analyzed specific phenolic acids found in chia flour, such as rosmarinic acid and caffeic acid. The simulation tested how these compounds interact with appetite receptors in the brain. The analysis showed that these compounds can bind directly to the receptors.

Rosmarinic acid showed the strongest potential interaction. This suggests that the compounds in chia might physically attach to brain receptors to help regulate satiety. This direct interaction could explain some of the observed changes in gene expression.

Despite these promising changes in brain chemistry, the study reported a notable caveat. The animals consuming chia did not lose body weight compared to the untreated group. The researchers suggest that the extremely high calorie count of the diet might have masked the benefits.

It is possible that the molecular changes were a first step. Behavioral changes in eating and subsequent weight loss might require a longer period to manifest. The intense energy density of the feed was likely sufficient to maintain weight gain despite better appetite signals.

Another limitation is that this research was conducted on rats. Animal models provide essential insights but do not perfectly replicate human metabolism. The human brain and digestive system are influenced by a wider variety of environmental factors.

Future research is needed to determine if these effects translate to humans. Clinical trials would need to establish the correct dosage of chia flour or oil for people. Scientists also need to investigate if these changes can lead to actual weight loss in a human population.

The study highlights the potential of functional foods to modulate brain health. It reinforces the idea that what we eat directly influences the molecular machinery of our brains. Chia seeds may offer a dietary strategy to help unwanted metabolic changes.

The study, “Chia flour and chia oil (Salvia hispanica L.) modulate the satiety and inflammation in brain of rats fed a high-fat high-fructose diet,” was authored by Patrícia Nayara Estevam, Renata Celi Lopes Toledo, Vinícius Parzanini Brilhante de São José, Luiza de Paula Dias Moreira, Bárbara Nery Enes, Mariana Grancieri, Neuza Maria Brunoro Costa, Hércia Stampini Duarte Martino, and Bárbara Pereira da Silva.