Throughout the prolonged seafaring voyages of the fifteenth and sixteenth centuries, a interval that is named the Age of Discovery, sailors skilled visions of chic meals and verdant fields. The invention that these had been nothing greater than hallucinations after months at sea was excruciating. Whereas some sailors wept in longing, others threw themselves overboard.
It was suspected that the treatment for these harrowing mirages can be a concoction of complicated chemical compounds. Nonetheless, it turned out that the antidote was fairly easy: lemon juice. These sailors suffered from scurvy, a illness attributable to vitamin C deficiency, Vitamin C is a necessary micronutrient that folks purchase from consuming vegatables and fruits.
Vitamin C is essential for the manufacturing and launch of neurotransmitters, the chemical messengers utilized by the mind. With out it, mind cells don’t talk successfully with each other, which may result in hallucinations.
As this well-known instance of early explorers illustrates, there’s a shut connection between meals and the mind, one which scientists like myself are working to unravel. As a scientist who research the neuroscience of diet on the College of Michigan, I’m primarily considering how elements of meals and their breakdown merchandise can modify the genetic directions that management our physiology.
Past that, one other aim of my analysis is knowing how meals can affect our ideas, moods, and behaviors. Whereas we will’t but stop or deal with mind situations with food regimen, scientists reminiscent of myself are studying an important deal concerning the position that diet performs within the on a regular basis mind processes that make us who we’re.
Maybe not surprisingly, a fragile steadiness of vitamins is vital for mind well being: Deficiencies or excesses in nutritional vitamins, sugars, fat, and amino acids can influence brain and behavior in either beneficial or detrimental ways.
Vitamins and mineral deficiencies
As with vitamin C, deficits in other vitamins and minerals can also lead to nutritional diseases that adversely impact the brain in humans. For instance, low dietary levels of vitamin B3/niacin – typically found in meat and fish – cause pellagra, a disease in which people develop dementia.
Niacin is essential for the body to turn food into energy and building blocks, protect the genetic blueprint from environmental damage, and control how much of certain gene products are made. In the absence of these critical processes, brain cells, also known as neurons, malfunction and die prematurely. This can lead to dementia.
In animal models, decreasing or blocking the production of niacin in the brain promotes neuronal damage and cell death. On the other hand, enhancing niacin levels has been shown to mitigate the effects of neurodegenerative diseases such as Alzheimer’s, Huntington’s, and Parkinson’s. Although the results are still inconclusive, observational studies in humans indicate that sufficient levels of niacin may protect against these diseases.
Interestingly, niacin deficiency caused by excessive consumption of alcohol can lead to similar effects as those found with pellagra.
Another example of how a nutrient deficiency affects brain function can be found in the element iodine, which, like niacin, must be acquired from one’s diet. It is present naturally in seafood and seaweed, and can also be obtained through iodized salt. Iodine is an essential building block for thyroid hormones – signaling molecules that are important for many aspects of human biology, including development, metabolism, appetite, and sleep. Low iodine levels prevent the production of adequate amounts of thyroid hormones, impairing these essential physiological processes.
Iodine is particularly important to the developing human brain. In fact, before table salt was supplemented with this mineral in the 1920s, iodine deficiency was a major cause of cognitive disability worldwide. The introduction of iodized salt is thought to have contributed to the gradual rise in IQ scores in the past century.
Ketogenic diet for epilepsy
Not all dietary deficiencies are detrimental to the brain. In fact, research shows that people with drug-resistant epilepsy – a condition in which brain cells fire uncontrollably – can reduce the number of seizures by adopting an ultralow-carbohydrate regimen, known as a ketogenic diet, in which 80% to 90% of calories are obtained from fat.
Carbohydrates are the preferred energy source for the body. When they are not available – either because of fasting or because of a ketogenic diet – cells obtain fuel by breaking down fats into compounds called ketones. The utilization of ketones for energy leads to profound shifts in metabolism and physiology, including the levels of hormones circulating in the body, the amount of neurotransmitters produced by the brain, and the types of bacteria living in the gut.
Researchers think that these diet-dependent changes, especially the higher production of brain chemicals that can quiet down neurons and decrease levels of inflammatory molecules, may play a role in the ketogenic diet’s ability to lower the number of seizures. These changes may also explain the benefits of a ketogenic state – either through diet or fasting – on cognitive function and mood.
Some meals can negatively have an effect on your reminiscence and temper.
Sugar, saturated fat, and ultra-processed meals
Extra ranges of some vitamins also can have detrimental results on the mind. In people and animal fashions, elevated consumption of refined sugars and saturated fat – a mix generally present in ultra-processed meals – promotes consuming by desensitizing the mind to the hormonal indicators recognized to manage emotions of fullness and satisfaction.
Curiously, a food regimen excessive in these meals additionally desensitizes the style system, making animals and people understand meals as much less candy. These sensory alterations might have an effect on meals alternative in addition to the reward we receive from meals. Analysis reveals, for instance, that folks’s responses to ice cream in mind areas essential for style and reward are dulled once they eat it day-after-day for 2 weeks. Some scientists imagine this lower in meals reward indicators might improve cravings for much more fatty and sugary meals, just like the way in which people who smoke crave cigarettes.
Excessive-fat and processed-food diets are additionally related to decrease cognitive operate and reminiscence in people and animal fashions in addition to the next incidence of neurodegenerative ailments. Nonetheless, scientists nonetheless don’t know if these results are as a result of these meals or to the load achieve and insulin resistance that develop with long-term consumption of those diets.
This brings us to a crucial side of the impact of food regimen on the mind: time. Some meals can affect mind operate and conduct acutely – reminiscent of over hours or days – whereas others take weeks, months, and even years to have an impact.
For instance, consuming a slice of cake quickly shifts the fat-burning, ketogenic metabolism of a person with drug-resistant epilepsy right into a carbohydrate-burning metabolism, rising the chance of seizures. Alternatively, it takes weeks of sugar consumption for style and the mind’s reward pathways to vary, and months of vitamin C deficiency to develop scurvy. Lastly, with regards to ailments like Alzheimer’s and Parkinson’s, risk is influenced by years of dietary exposures in combination with other genetic or lifestyle factors such as smoking.
In the end, the relationship between food and the brain is a bit like the delicate Goldilocks: We need not too little, not too much, but just enough of each nutrient.
Written by Monica Dus, Associate Professor of Molecular, Cellular, and Developmental Biology, University of Michigan.
This article was first published in The Conversation.