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  • It's impossible to avoid them!

  • For decades we have been surrounded by sweet and fatty foods.

  • And the body has not been dealing well with these eating habits.

  • But what about the brain?

  • Do our mental health, our moods, and our brain abilities

  • suffer from the wrong kind of nutrition?

  • We know that junk food is making us fat,

  • but science is telling us now that it might also be shrinking our brains.

  • Brain researchers have joined the dining table?

  • to study the effects of our eating habits.

  • Diets that are high in fat and sugar, in the long term,

  • lead to changes in part of the brain involved in memory.

  • This is a recent field of research,

  • a developing science that spotlights a new facet of nutrition.

  • Habitual intake of foods high in fat and sugar

  • results in a reprogramming of the brain.

  • In short, our brain is affected by what's on our plates.

  • It all starts with our very first meals, even before birth.

  • The brain is built up during pregnancy.

  • How it functions later on depends on how it has been nourished by

  • the expectant mother's diet over nine months.

  • A number of consequences of poor nutrition during gestation

  • have been known for a long time.

  • Today, scientists in Australia

  • are looking at the repercussions of nutrition on brain function.

  • Felice Jacka, a professor at the University of Melbourne,

  • examined the behavior of babies

  • after following the eating habits of 23,000 pregnant women.

  • We measured their intake of junk and processed foods,

  • we measured their intake of the healthful foods,

  • foods with lots of fiber and nutrients, etc.

  • And then we looked at the emotional health of their children

  • over the first few years of life from 18 months to 5 years.

  • Of course, taking into account things such as education, income,

  • the mother's mental health, parenting practices, these sorts of things.

  • And what we saw very clearly was that mothers who ate

  • more junk and processed foods, so sweet drinks, and salty snacks, you know,

  • cakes, biscuits, during their pregnancy,

  • their children had more of these behaviors such as aggression,

  • and anger, and tantrums.

  • This disquieting correlation suggests that the mother's diet

  • impacts the mental development of the baby,

  • though the link remains to be demonstrated on the biological level.

  • In any case, Felice Jacka is convinced.

  • So what we also saw in this large Norwegian study

  • is that the children's diet seemed to be important as well,

  • independent of what mum ate.

  • If children were eating too much junk and processed foods,

  • and/or not enough of the healthful foods,

  • they had more of these anger and aggressive-type behaviors,

  • but also sadness, anxiety, worry, nightmares.

  • Since then, Professor Jacka's conclusions have been confirmed by studies in Spain,

  • the Netherlands, and Canada.

  • Excess fat and sugar are now in the sights of scientists working on the brain.

  • Excesses and deficiencies.

  • Junk food is often low on essential nutrients, so it leaves the body,

  • and especially the nerve cells, lacking.

  • In this laboratory at the University of Bordeaux,

  • scientists are studying the consequences of dietary deficiencies on mouse brains.

  • This experiment is used to measure anxiety.

  • The animal has the choice between exploring the lighted area or hiding in the shade.

  • A normal mouse takes the time to examine the lighted area.

  • But this animal was deprived of omega-3 fatty acids during its development.

  • Omega-3s are called 'good' fats due to their benefits to the heart and arteries.

  • Instead of exploring the environment, the mouse takes refuge in a dark corner.

  • It is stressed, anxious.

  • The experiment has been reproduced many times on dozens of mice.

  • For researchers, this strange behavior can simply explained:

  • without omega-3 fatty acids, the brain does not develop and function normally.

  • They are needed because the brain's 'gray matter'

  • is 90% fat which it cannot produce itself.

  • The brain is the organ, after adipose tissue,

  • that is the richest in polyunsaturated fatty acid?

  • or omega-3.

  • So omega-3 is indispensable because the body can not make it.

  • We have to ingest it.

  • It has to come from the diet.

  • Oily fish, organ meat, vegetable oils, and seeds and nuts

  • such as almonds have long been the main sources of omega-3 for humans.

  • But these foods have become scarce in the cuisine of industrialized countries.

  • The amount of omega-3 that enters the brain is crucial for

  • making brain cells more efficient.

  • Because when these fatty acids are incorporated into

  • the membranes of nerve cells,

  • they improve their electrical properties.

  • In omega 3-rich neurons, the signals propagate faster.

  • The network is more efficient.

  • Depriving the brain of omega-3 is linked to a risk that it will function less well.

  • The general population is deficient in omega-3.

  • We have insufficient intake of omega-3,

  • so it's important to pay attention to it.

  • especially in the pre-natal developmental period,

  • when omega-3 is incorporated in large quantities into the brain.

  • Also, in adolescence, since adolescence is a particular time of change of diet.

  • And, during aging where the incorporation of

  • omega-3 into the brain tends to be less effective,

  • so we must increase its intake.

  • The first rule for a brain to run at full speed is:

  • avoid deficiencies.

  • But good nutrients and a varied diet should be available.

  • What happens to neurons when meals are poor and, above all, always the same?

  • That is a problem that is now affecting the wild-living European hamster,

  • which thrived for a long time in the plains of France's Alsace region.

  • Since the 1960s, there has been a decline in the hamster population,

  • which is on the verge of extinction today.

  • And, at the same time, what we have seen is

  • an increase in the agricultural area where corn is cultivated.

  • Caroline Habold wondered whether the collapse

  • of the population was linked to the sudden glut of corn.

  • So she did a laboratory experiment, feeding hamsters exclusively corn.

  • During breeding, we observed behavioral disturbances in females,

  • which resulted in hyper-aggression and hypersensitivity

  • as soon as there was noise in the room.

  • And above all, what we did not expect is that

  • these females would devour their young the first day after birth.

  • This behavior was observed in more than 80% of females.

  • A dietary deficiency was enough to make a hamster devour its children.

  • The cause?

  • A simple vitamin.

  • A lack of vitamin B3 is at the origin of this abnormal behavior.

  • When we supplemented them with vitamin B3

  • in addition to their corn-based diet,

  • they exhibited quite normal behavior.

  • They began to nurse their young, to raise them in the same way

  • as the females that were fed a diversified diet.

  • The case of the cannibalistic hamsters is disturbing.

  • Could a unbalanced diet also trigger aggressive, violent behavior in humans?

  • Ap Zaalberg is a clinical psychologist and political advisor

  • to the Dutch Ministry of Justice.

  • His specialty: nutrition and crime.

  • He is convinced that enriching food with vitamins, fatty acids, and minerals

  • can reduce aggression.

  • It's a hypothesis that is difficult to test in normal life because

  • so many factors and circumstances can influence our behavior and our impulses.

  • In order to study nutrition without the influence of the many parameters,

  • he chose prisons as a nearly ideal setting.

  • Here in the Netherlands,

  • we conducted a study of young prisoners in eight different prisons.

  • For three months, we gave them vitamins, minerals,

  • and fatty-acid supplements.

  • And then we looked at the effect on their behavior.

  • We measured it in two different ways.

  • First, we asked the detainees how aggressive they were

  • and we asked the supervisors for their views on the issue.

  • Above all, we looked at the incident log.

  • The number of times detainees were punished.

  • And we saw that solitary confinement had fallen dramatically.

  • In the group of inmates whose meals were improved,

  • the number of incidents was reduced by one-third.

  • What we eat may have the power to change our moods,

  • to stimulate certain impulses.

  • But could the food on our plate also influence our decisions?

  • the ones we believe we make using our free will?

  • When people are asked if they think that the food they eat

  • has an impact on health, most of them answeryes."

  • But when asked if diet can also influence tthoughts and decisions,

  • very few people are willing to believe this is the case.

  • However, at the Institute of Psychology of the University ofbeck in Germany,

  • Professor Soyoung Park has, for the first time, proven it.

  • Her work reveals the mechanism by which food could influence our thoughts.

  • And for that, the researcher has developed a rather original experiment.

  • Imagine that you face the following dilemma.

  • The money on the table is to be divided into two sums.

  • But it's your partner, a stranger, who decides how it is to be distributed.

  • I'll give you two euros and keep eight for me.

  • If you accept the unfair offer,

  • you leave with a little money but much less than your partner's.

  • If you refuse, no one wins anything. So what would you do?

  • Do you accept the offer and take the two euros, even if you feel cheated?

  • Or, do you refuse, and leave with empty pockets but your head held high?

  • Well, it turns out, surprisingly,

  • that whether you'll take the money or not depends on what you've just eaten.

  • As part of this study, we follow 24 people who came to the laboratory

  • twice to have two different breakfasts.

  • We found that the same person made completely different decisions

  • based on what they ate in the morning.

  • To the test person, the two breakfasts look the same.

  • In reality, one is far more protein-rich than the other.

  • The ratio of protein to sugar is the only parameter that changes.

  • A few hours after the meal, the subject takes several tests on a computer.

  • Today he tends to accept the offer.

  • His self-interest outweighs his anger at the unfairness,

  • and he will leave with a little money in his pocket.

  • Last week he mainly refused and won almost nothing.

  • When the subjects consumed a higher-protein breakfast in the morning,

  • they were more tolerant towards unfair offers.

  • Conversely, when the subject had consumed a high-carbohydrate breakfast,

  • he was less tolerant in the face of unfair offers.

  • On average the subjects who had little protein

  • rejected unfair offers twice as often.

  • But how can this surprising result be explained?

  • In their search for biological evidence for this observation,

  • the scientists carried out blood tests.

  • We will send the blood to the lab right away and they will analyse

  • the level of hormones and amino acids in the blood,

  • especially the hormones insulin, cortisol, adrenaline, and A-C-T-H.

  • And for the amino acids tryptophan and tyrosine.

  • Of these substances, the most important is tyrosine.

  • The amino acid is one building-block of a protein that is key to brain function:

  • dopamine.

  • This molecule ensures communication between

  • neurons involved in motivation and risk-taking.

  • The results of the blood analysis show that

  • subjects with higher levels of tyrosine

  • in their blood are more willing to accept the unfair offer.

  • In other words, what we eat can within hours

  • subtly alter the chemistry of the brain,

  • and thus the communication between the neurons.

  • Enough to guide some of our decisions.

  • Experiments are continuing inbeck to confirm this result.

  • The implications are wide-ranging.

  • Since we eat three times a day, every day,

  • we realize that food has enormous power, modifying and shaping us.

  • So it's important to think about how we can use food to

  • promote our well-being and optimize our mental state.

  • Not only does an unbalanced diet affect our brain functions and behavior,

  • and our meal plan interfere with everyday decisions,

  • it is also becoming increasingly clear that diet plays a decisive role in our mood?

  • and, possibly mental health.

  • But what about junk food, dripping with sugar and bad fats?

  • What would happen if we ate more of that?

  • This is the focus of research here in Australia at the University of Sydney.

  • Margaret Morris runs a laboratory where rats are fed the kind of junk food

  • that you find in supermarkets or cheap, fast-food restaurants.

  • Our experiments use a range of Western foods, of the type eaten by all of us.

  • So we feed ouf rats meat pies, chips, cakes, and biscuits.

  • The sort of foods that are readily available and cheap.

  • So we are modelling the Western world.

  • The first consequence of this diet:

  • the rat doubles its food rations.

  • The animal seems never satiated.

  • But that is not the most surprising outcome.

  • One of our chief interests is the impact of this diet on the animal's memory.

  • And we can measure this easily in the rat by using

  • a task known as the novel object and novel place task.

  • In this test, the researcher places objects in the rat's cage.

  • The animal comes over immediately to examine them.

  • Rodents are very curious by nature.

  • Once it has completed its examination and memorized its surroundings,

  • it is temporarily removed.

  • We then place the animal in the arena with one object that has been shifted.

  • On its return, the rat spends more time examining the object that has changed

  • places because it already knows the other objects.

  • They are engraved in its memory.

  • The rats