Dr. Uma Naidoo, a psychiatrist, brain expert, and faculty member of the B School of Medicine, reviewedHarvard university, in an article about the effect of foods on the brain and poor memory, concentration and ability to learn.
The author of the best-selling book This Is Your Brain According to What You Eat identified five types of foods to avoid due to their negative impact on the brain.
No matter your age, Uma wrote, it’s never too late to start eating in a way that gives you the best possible chance of staving off dementia as you age and making sure you feel focused and energized every day.
She pointed to a study she did, on “how our gut bacteria can stimulate metabolic processes and reduce brain inflammation that affects memory.” Current studies suggest the ability to reduce the likelihood of developing dementia by avoiding foods that can compromise our gut bacteria and impair our memory and focus.
Uma categorized foods into 5 main groups that should be avoided or reduced to fight inflammation, promote brain health, sharp thinking, and make good decisions:
1. Added sugars
The brain uses energy in the form of glucose, a form of sugar, to fuel cellular activities. However, a high-sugar diet can lead to increased glucose in the brain, which studies have linked to poor memory and decreased plasticity in the hippocampus – the part of the brain that controls memory.
She noted that consuming unhealthy processed foods like baked goods and soda, which are often loaded with refined and added sugars, floods the brain with a lot of glucose.
Although every body has different needs, the American Heart Association recommends that women consume no more than 25 grams of added sugar per day, and men keep less than 36 grams of added sugar per day.
2. Fried foods
It’s helpful to reduce the amount of fried foods you eat, as one study of 18,080 people found that a diet rich in fried foods was associated with lower scores in learning and memory.
Another study looked at 715 people and measured their levels of depression and mental flexibility. It also documented their level of consumption of fried foods, and the researchers found that those who ate more fried foods were more likely to have depression in their lifetime.
3. Carbohydrates that are high in blood sugar
Even foods high in carbohydrates, or starches, like bread, pasta, and anything else made with refined flour, the body handles them the same way it handles sugar.
This means that they can also increase the risk of depression. Uma said there is no need to panic, or eliminate carbohydrates from your diet completely! But the quality of the carbohydrates you eat is important.
In 2018, researchers sought to assess which, if any, carbohydrates were associated with depression. They administered a questionnaire called the “Carbohydrate Quality Index” to 15,546 participants.
“Best quality” carbohydrates were defined as whole grains, foods high in fiber and those that rank low on the glycemic index, or GI, which is a measure of how quickly foods turn into glucose when they are broken down during digestion; The faster a food turns into glucose in the body, the higher the GI rating.
The researchers found that people with the highest scores on the Carbohydrate Quality Index, meaning they ate better quality carbohydrates, were 30% less likely to develop depression than those who ate carbohydrates that were high in sugar.
Carbohydrates that are high in sugars include potatoes, white bread, and white rice. Honey, orange juice, and whole-meal bread were moderately sugary foods. Foods with a low GI include green vegetables, most fruits, raw carrots, beans, chickpeas, and lentils.
Uma stressed that drinking alcohol may make some people who resort to it after hard work to a temporary sense of comfort, but it increases stress and brain fog more.
Used as a preservative and to enhance color in steaks and cured meats such as bacon, salami, and sausages, nitrates may be linked to depression.
One recent study suggests that nitrates can alter gut bacteria in a way that tip the scales toward bipolar disorder.