A Neuroscientist Explains How Diet Can Influence Mood, Behavior and More

Vitamin C Happy Fruit Citrus                                                                               

Our total health is impacted by what we eat, and getting the correct balance of nutrients is vital.

The Age of Discovery, which spans the 15th and 16th centuries, is noted for its long maritime trips during which time mariners saw visions of exquisite cuisines and lush landscapes. After months at sea, it was agonizing to learn that these were merely hallucinations. Some seamen cried bitter tears of longing, while others plunged themselves overboard.

It was believed that a mixture of sophisticated chemicals would be the solution to these terrifying mirages. Lemon juice, it turns out, was a really straightforward remedy. These sailors had scurvy, a condition brought on by a lack of vitamin C. Fruits and vegetables are good sources of vitamin C, which is an important micronutrient.

The synthesis and release of neurotransmitters, the chemical messengers employed by the brain, depend on vitamin C. Without it, communication between brain cells is impaired, which can cause hallucinations.

There is a close relationship between food and the brain, as this well-known instance of early explorers demonstrates, and scientists like myself are trying to understand it. I am primarily interested in how food ingredients and the breakdown products of those ingredients can alter the genetic instructions that regulate our physiology as a scientist studying the neuroscience of nutrition at the University of Michigan.

Understanding how food can affect our thoughts, moods, and behaviors is another objective of my research. Even though we can't yet prevent or treat brain disorders with diet, researchers like myself are learning a lot about how nutrition affects the regular brain functions that shape who we are.

Unsurprisingly, maintaining a precise nutritional balance is important for brain health. Vitamin, sugar, fat, and amino acid deficiencies or excesses can have positive or negative effects on the brain and behavior.

For the health of the brain, it's crucial to consume a balanced diet that contains all the necessary vitamins and minerals.

Similar to vitamin C, deficiencies in other vitamins and minerals can cause nutritional illnesses that have a negative impact on a person's brain. For instance, pellagra, a disease that results in dementia, is brought on by low dietary amounts of vitamin B3/niacin, which is normally found in meat and fish.

Niacin is necessary for the body to convert food into energy and building blocks, safeguard the genetic code against deterioration, and regulate the production of specific gene products. Neurons, which are brain cells, malfunction and die too soon in the absence of certain vital processes. Dementia may result from this.

Niacin synthesis in the brain is decreased or blocked in animal models, which encourages neuronal damage and cell death. However, it has been demonstrated that raising niacin levels can lessen the consequences of neurodegenerative conditions like Parkinson's, Huntington's, and Alzheimer's. Observational studies in people suggest that adequate doses of niacin may offer protection against several diseases, while the results are still preliminary.

Interestingly, pellagra-like symptoms can result from a niacin shortage brought on by excessive alcohol intake.

Iodine is another nutrient that, like niacin, must be obtained from diet and has been shown to have an impact on brain function. Seafood and seaweed naturally contain it, and iodized salt also contains it. Iodine is a crucial component of thyroid hormones, signaling molecules that are crucial for many biological processes in humans, including as growth, metabolism, appetite, and sleep. Low iodine levels interfere with several crucial physiological functions by preventing the generation of enough thyroid hormones.

Iodine is particularly crucial for the human brain's development. In fact, iodine deficiency was a significant global contributor to cognitive dysfunction before this mineral was added to table salt in the 1920s. The progressive increase in IQ scores over the past century is supposed to have been facilitated by the introduction of iodized salt.

The ketogenic diet may be beneficial for those with drug-resistant epilepsy.

Not all nutritional shortages harm the brain. In reality, studies show that individuals with drug-resistant epilepsy, a disorder in which brain cells fire inexplicably, can lessen the frequency of seizures by using a ketogenic diet regimen, in which 80% to 90% of calories are derived from fat.

The body prefers to get its energy from carbohydrates. Cells utilise the ketones created by the breakdown of fats as fuel when other sources are not available, such as during fasting or a ketogenic diet. When ketones are used as fuel, significant changes are made to the body's metabolism and physiology, which affect things like hormone levels, brain neurotransmitter production, and the kinds of bacteria that reside in the gut.

The enhanced production of brain chemicals that can calm neurons and lower levels of inflammatory molecules are two diet-dependent alterations that researchers believe may contribute to the ketogenic diet's capacity to reduce the frequency of seizures. These modifications may also account for the advantages of a ketogenic state on mood and cognitive function, whether achieved through diet or fasting.

Your memory and mood may be significantly impacted by certain foods.

The brain might suffer from excessive amounts of specific nutrients. Increased consumption of refined sugars and saturated fats, which are frequently present together in ultra-processed meals, encourages eating in both humans and animal models by making the brain less sensitive to the hormonal signals that control feelings of fullness and satisfaction.

It's interesting to note that consuming a lot of these meals also dulls the sense of taste, causing both humans and animals to find food to be less sweet. These sensory changes may have an impact on both the food we choose and the pleasure we derive from it. For instance, studies have shown that eating ice cream every day for two weeks causes a dulling of people's responses to it in reward- and taste-related brain regions of the brain. According to some experts, this reduction in food reward signals may increase desires for even more fatty and sugary foods, much as how smokers experience cravings for cigarettes.

In humans and animal models, high-fat and processed-food diets are also linked to worse memory and cognitive performance as well as a higher prevalence of neurodegenerative illnesses. Scientists are still unsure as to whether these effects are brought on by these meals specifically or by the weight gain and insulin resistance that come with consuming these diets over an extended period of time.

This brings up time, a crucial factor in how nutrition affects the brain. Some foods have a rapid impact on how the brain and behavior work, such as over a period of hours or days, but other foods take weeks, months, or even years to have an impact.

For instance, eating a piece of cake quickly converts a person with drug-resistant epilepsy's fat-burning, ketogenic metabolism into a carbohydrate-burning metabolism, raising the risk of seizures. On the other hand, it takes weeks of sugar consumption for taste and the reward circuits in the brain to change, and it takes months of vitamin C deprivation to develop scurvy. Last but not least, risk is influenced by years of food exposures combined with other hereditary or lifestyle factors like smoking when it comes to diseases like Alzheimer's and Parkinson's.

In the end, the connection between food and the brain is somewhat like the delicate Goldilocks: We require the right amount of each nutrient—not too little, not too much, but just right.

Authored by University of Michigan Associate Professor of Molecular, Cellular, and Developmental Biology Monica Dus.

The Conversation originally published this article.

By MONICA DUS, UNIVERSITY OF MICHIGAN