The Connection Between Good Nutrition and Good Cognition

Alice G. Walton - Alice G. Walton is a health-and-science journalist who writes on medical issues, particularly those related to the brain and behavior. She holds a Ph.D. in biopsychology and is an editor at TheDoctorWillSeeYouNow.com.

Jan 13 2012
A study that looked at biomarkers in the blood to correlate vitamins and brain function found very clear links between nutrition and brain health.

A new study goes deeper in understanding the connection between good nutrition and a healthy brain. Previous studies have linked individual vitamin deficiencies to cognitive decline. But new research looks at a wider range of vitamins, and even better, it uses biomarkers in the blood to correlate vitamins with brain health, both good and bad.

Many studies exploring the relationship between nutrition and cognitive health rely on people's personal reports of their diets -- a notoriously unreliable way to gather personal nutritional information. For this reason, the researchers behind the current study decided to use a more objective means of studying the nutrition-brain link: they looked at biomarkers in the blood to measure the vitamin levels in 104 participants. They also had participants take tests to measure thinking and memory function, and 42 participants had MRI scans to measure their brain volume.

The researchers found some striking connections between nutrition and brain health. People who had higher levels of B family vitamins, as well as vitamins C, D, and E had higher scores on cognitive tests than people with lower levels. The same positive relationship was found for omega-3 fatty acids, which have previously been linked to better brain health.

On the flipside, people with higher levels of trans fats in their blood had poorer performance in thinking and memory tests. Their MRI scans also revealed more brain shrinkage than people who had lower trans fats levels. Trans fats are found in a variety of junk foods, like fried, packaged, and fast foods.
The researchers also determined the portion of the cognitive test scores the participants' nutrient statuses accounted for. They found that nutrient biomarkers accounted for 17 percent of the variation in the tests of thinking and memory function. Other variables, like age, education, and having high blood pressure accounted for more: 46 percent. But for brain volume, the role of nutrition was larger, accounting for 37 percent of the variation. 

Author Gene Bowman said that the team's findings "need to be confirmed, but obviously it is very exciting to think that people could potentially stop their brains from shrinking and keep them sharp by adjusting their diet." 

More and more research is showing that there's a lot of truth to the old adage you are what you eat -- and the same goes for the brain since, after all, it is an organ too. Genetic and environmental factors also play a role in the development of disease, but we can do our best to give our brains the nutrients they need for good cognitive health.

The study was carried out at the Oregon Health & Science University in Portland, and is published in Neurology

Image: Lightspring/Shutterstock."

Fonte e imagem:

How Does Meat in the Diet Take an Environmental Toll?

David Pimentel of Cornell University's College of Agriculture and Life Sciences says that the grain currently fed to some seven billion livestock in the United States could feed nearly 800 million people directly. Image: Digital Vision/Thinkstock

"Dear EarthTalk: I heard that the less meat one eats, the better it is for the environment. How so?
-- Jason K., Sarasota, FL

Our meat consumption habits take a serious toll on the environment. According to the Environmental Working Group (EWG), the production, processing and distribution of meat requires huge outlays of pesticides, fertilizer, fuel, feed and water while releasing greenhouse gases, manure and a range of toxic chemicals into our air and water. A lifecycle analysis conducted by EWG that took into account the production and distribution of 20 common agricultural products found that red meat such as beef and lamb is responsible for 10 to 40 times as many greenhouse gas emissions as common vegetables and grains.

Livestock are typically fed corn, soybean meal and other grains which have to first be grown using large amounts of fertilizer, fuel, pesticides, water and land. EWG estimates that growing livestock feed in the U.S. alone requires 167 million pounds of pesticides and 17 billion pounds of nitrogen fertilizer each year across some 149 million acres of cropland. The process generates copious amounts of nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide, while the output of methane—another potent greenhouse gas—from cattle is estimated to generate some 20 percent of overall U.S. methane emissions.

“If all the grain currently fed to livestock in the United States were consumed directly by people, the number of people who could be fed would be nearly 800 million,” reports ecologist David Pimentel of Cornell University’s College of Agriculture and Life Sciences. He adds that the seven billion livestock in the U.S. consume five times as much grain as is consumed directly by the entire U.S. population.

Our meat consumption habits also cause other environmental problems. A 2009 study found that four-fifths of the deforestation across the Amazon rainforest could be linked to cattle ranching. And the water pollution from factory farms (also called concentrated animal feeding operations or CAFOs)—whereby pigs and other livestock are contained in tight quarters—can produce as much sewage waste as a small city, according to the Natural Resources Defense Council (NRDC). Further, the widespread use of antibiotics to keep livestock healthy on those overcrowded CAFOs has led to the development of antibiotic-resistant strains of bacteria that threaten human health and the environment in their own right.

Eating too much meat is no good for our health, with overindulgence linked to increasing rates of heart disease, cancer and obesity. Worldwide, between 1971 and 2010, production of meat tripled to around 600 billion pounds while global population grew by 81 percent, meaning that we are eating a lot more meat than our grandparents. Researchers extrapolate that global meat production will double by 2050 to about 1.2 trillion pounds a year, putting further pressure on the environment and human health.

For those who can’t give up meat fully, cutting back goes a long way toward helping the environment, as does choosing meat and dairy products from organic, pasture-raised, grass-fed animals. “Ultimately, we need better policies and stronger regulations to reduce the environmental impacts of livestock production,” says EWG’s Kari Hammerschlag “But personal shifting of diets is an important step.”"

Fonte e imagem:

Investigadora portuguesa premiada por comprovar que comer devagar emagrece

Adriano Miranda
in Jornal Público,
01.01.2012 - 10:13 Por Lusa

"A velocidade com que ingerimos os alimentos tem influência no peso corporal e comer devagar tem resultados equiparáveis aos de uma cirurgia bariátrica, revela um estudo realizado por uma investigadora portuguesa que ganhou um prémio internacional.

A investigação premiada de Júlia Galhardo durou um ano e teve por base 500 jovens obesos que estavam a ser acompanhados no Hospital Pediátrico de Bristol, em Inglaterra, com o objectivo de estudar as hormonas que estão relacionadas com os hábitos alimentares. São duas hormonas do sistema digestivo que circulam no sangue: a grelina, segregada pelo estômago e que induz a sensação de fome e o peptídeo tirosina-tirosina (PYY), segregado pelo intestino e que dá a sensação de saciedade.

Os jovens foram divididos em dois grupos e a um foi dada uma balança computorizada na qual colocavam o prato com os alimentos do almoço e do jantar e que media a velocidade a que comiam, sendo que o ritmo pré-formatado era de cerca de 300-350 gramas em 12-15 minutos. Caso a velocidade fosse superior, o computador dizia para comerem mais devagar.

Ao segundo grupo (de controlo) foi apenas fornecido aconselhamento dietético e físico.

“Passados esses doze meses fomos ver o índice de massa corporal (IMC) do grupo de controlo e do grupo estudado e o grupo relacionado com a balança tinha uma diminuição do índice de massa corporal significativamente superior à do grupo de controlo. Isto deixou-nos muito contentes porque era uma forma barata e acessível de todos diminuírem o peso”, revelou à agência Lusa a investigadora.

Júlia Galhardo apontou que é do senso comum que comer devagar faz com que se fique saciado mais depressa e não se ganhe peso, mas que ninguém tinha antes estudado o que acontecia a nível hormonal.

“No fundo há uma comunicação entre o aparelho digestivo e o cérebro, em que o aparelho digestivo diz: ‘estamos com fome, venha daí comida’. Depois de estarmos a comer, ele diz: ‘já chega, já estamos saciados, não é preciso vir mais comida’”, explicou a investigadora.

De acordo com Júlia Galhardo, quando as crianças e os adolescentes comiam de forma lenta, as hormonas que regulam a fome e a saciedade, e que tinham estado totalmente alteradas pelos maus hábitos alimentares, ficaram novamente reguladas, regularizando também a comunicação entre o sistema digestivo e o cérebro.

Segundo Júlia Galhardo, nunca se deve perder menos de trinta minutos a comer, tendo em conta que cada uma das refeições deve incluir uma sopa de legumes e um prato principal.

A investigadora espera que esta descoberta seja divulgada nos centros de saúde, campanhas de esclarecimento ou mesmo nos estabelecimentos de ensino, lembrando que este é um caso de saúde pública.

Júlia Galhardo foi premiada este ano com o Henning Andersen da Sociedade Europeia de Endocrinologia Pediátrica."

Fonte e imagem:
http://www.publico.pt/Ci%C3%AAncias/investigadora-portuguesa-premiada-por-comprovar-que-comer-devagar-emagrece--1527140

Começa hoje programa para incentivar consumo de fruta nas escolas

Foto: João Henriques
in Jornal Público, 03.01.2012 - 07:35 Por Lusa

"A Associação Portuguesa Contra a Obesidade Infantil (APCOI) inicia hoje nas escolas um programa educativo para incentivar o consumo de fruta no lanche escolar nos jardins-de-infância e escolas do primeiro ciclo.


O programa “Heróis da fruta - lanche escolar saudável” começa num colégio do concelho da Amadora, um dos 516 jardins-de-infância e escolas do primeiro ciclo que adeririam à iniciativa de intervenção escolar de âmbito nacional.

O projecto, que vai decorrer ao longo de seis semanas, até 10 de Fevereiro, pretende incentivar as crianças até aos 10 anos a dar importância ao consumo diário de fruta e a adoptar definitivamente este hábito alimentar.

Segundo a Comissão Europeia, Portugal está entre os países da Europa com maior número de crianças com excesso de peso: 32% das crianças entre os 6 e os 8 anos têm excesso de peso e 14% são obesas. O sexo feminino apresenta valores superiores aos do sexo masculino.

O último estudo do Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA) sobre obesidade infantil revela também que mais de 90% das crianças portuguesas come fast-food, doces e bebe refrigerantes, pelo menos quatro vezes por semana. Isto ao mesmo tempo que menos de 1% das crianças bebe água todos os dias e só 2% consome fruta fresca diariamente."

Fonte e imagem:
http://www.publico.pt/Educa%C3%A7%C3%A3o/comeca-hoje-programa-para-incentivar-consumo-de-fruta-nas-escolas-1527362