When eaten in moderation, bread can be part of a healthy, balanced diet. This is especially true of breads that are enriched with extra nutrients (such as folic acid and iron), breads that are whole-grain, and sprouted breads.

However, eating too much bread, especially white, refined bread, can lead to negative health outcomes. This is due to six main reasons:

1. Bread is high in carbs, which break down into glucose, leading to an increase in blood sugar levels. Excess carbs also increase risk of Alzheimer’s disease. 
2. Bread is typically low in essential nutrients (including protein, fat, fiber, vitamins and minerals)
3. Bread contains gluten, which can be hard for some people to process,
4. Breads can have refined sugar, which is generally harmful for health, including brain health, and can promote inflammation
5. Breads contain antinutrients, which are compounds that block your body from taking in certain minerals
6. Bread has the potential to promote bad bacteria in the gut. Because about 95% of the body’s serotonin is produced in the gastrointestinal tract, an imbalance in the gut can cause negative effects on a person’s emotions. 

One of the potential health consequences of consuming too much bread, especially white and/or processed bread, is negative impacts on the brain such as impaired brain functioning and a worsening of mood disorders like depression and schizophrenia. 

Multiple studies have found a correlation between a diet high in refined sugars and impaired brain function due to the reasons listed above. 

Other research has also suggested that bread might impair brain function because of how it impacts the gut and the types of compounds it releases in the body. 

Regarding impacts on the gut, this research suggests that bread makes the gut more permeable and as a result can encourage food particles to move to places they shouldn’t be, which causes the body’s immune system to attack both those particles and other substances from the brain that look like those particles to the brian. 

Regarding the compounds released, the research suggests that bread causes the release of opioid-like compounds that can cause mental problems if they make it to the brain. 

While specific meals can have immediate impacts on your physical or mental health depending on preexisting conditions and the type of food being eaten, most potential serious health impacts from diet take place over time, not instantaneously. This is true with bread. More research is needed to better understand the connection between bread, gluten, and brain health in the short and long-term.

It’s common for claims to circulate online making blanket statements about certain foods or drinks being very good or very bad for you. The reality is that there is typically more nuance in existing research about the risks and benefits of foods and drinks than these claims make clear. That is the case with bread, which has the potential to be harmful in the long-term – especially when it comes to white or refined bread – but which can also be a healthy part of a balanced diet – especially when it comes to whole wheat or sprouted breads.