It's not just in the genes: the foods that can help and harm your brain

Guardian Design Team

"Lisa Mosconi

Mon 12 Feb 2018

Our diet has a huge effect on our brain and our mental wellbeing, even protecting against dementia. So, what should be on the menu?

As a society, we are used to the idea that we feed our bodies, and that our diet shapes our waistlines. But many of us forget that the same diet also feeds our brains, and that the food we give our brains shapes our thoughts and actions. I invested many years formally studying neuroscience and neurology, and have spent many more years as a scientist in those fields. Back when I started, most of my time was spent with medical journals. But 15 years into my research, much of my time is spent with cookbooks.

These books are essential to contemporary brain science. The recipes become food, and that food shapes our brains just as surely as it builds our bodies. Day after day, the foods we eat are broken down into nutrients, taken into the bloodstream and carried up into the brain. Once there, they replenish depleted storage, activate cellular reactions and become the very fabric of our brains.

The brain is the hungriest organ in the body, consuming more than 20% of your body’s total energy haul. At the same time, our brain cells are irreplaceable. Unlike the rest of the body, where cells are continuously replaced, the vast majority of brain cells stay with us for our entire lives – which means they are in need of extra care and nourishment.

Next-generation medical imaging and genomic sequencing studies, including work from my lab at the Alzheimer’s Prevention Clinic at Weill Cornell Medical College, New York, have helped us understand that some foods play a neuro-protective role, shielding the brain from harm. It’s no surprise that, conversely, other foods are harmful for the brain, slowing us down and increasing the risk of cognitive decline. So, what does this mean for your daily menu in terms of optimising for brain health? It means lots of the following:

Fatty acids

A specific kind of fats called polyunsaturated long-chain fatty acids, such as the famous omega-3s. Fatty fish, such as salmon, mackerel, anchovies and sardines, is the best natural source of the only kind of fat the brain needs throughout a lifetime. Where fish isn’t an option, flax and chia seeds are good alternatives.

Glucose

A specific kind of carbohydrate called glucose. Glucose is the only energy source for the brain, so it’s crucial that the brain gets enough of it. Foods that are naturally rich in glucose and that at the same time contain enough fibre to stabilise your blood-sugar levels are beetroot, kiwi fruit, whole grains, sweet potatoes, onions and spring onions. Raw honey, maple syrup and coconut sugar are also good sources.

Vitamins and minerals

All sorts of vitamins and minerals, especially those with antioxidant effects such as vitamin A, vitamin C, vitamin E and selenium – but also iron, copper and zinc. Fruit and vegetables are the best natural source of these: go for berries, oranges, grapefruit and apples, which are sweet but have a low glycemic index. Leafy green or cruciferous vegetables (broccoli, cabbage, spinach, kale, dandelion greens), as well as other vegetables such as onions, carrots, tomatoes or squash are also full of vitamins, minerals, fibre and disease-fighting nutrients that are needed for a healthy nervous system. Make every meal a rainbow.

Extra-virgin olive oil

Last but not least, extra-virgin olive oil is a brain-must, as it is loaded with anti-ageing nutrients such as omega-3s and vitamin E. Vitamin E is particularly important to protect ourselves against dementia. Large studies in the US and Europe have found that elderly people who consumed more than 16mg a day of vitamin E had a 67% lower risk of developing dementia compared with those who consumed little to none. Dementia risk was further reduced by taking vitamin E in combination with vitamin C. Both these vitamins protect brain cells from the harmful effects of toxins and free radicals, while vitamin E has the added benefit of increasing oxygen delivery to the brain.

Now for the no-nos

At the same time, some foods are a big no-no. These include fast food, fried food such as fish and chips, fatty foods such as red meat, pork and high-fat dairy, and, most of all, processed foods: baked goods loaded with trans fats and refined sugar such as cakes, biscuits, crisps, ready meals and frozen pizza, as well as many snacks. Then there are all of the margarines and commercial cheeses, along with other spreadable or “creamy” products. Ditto for processed meats such as salami, bologna and frankfurters. The more of these processed foods you consume on a regular basis, the higher your risk of cognitive decline and dementia. Across multiple studies, people who consumed as little as 2g a day of trans fats had twice the risk of those who ate less than 2g. It’s disheartening to discover that most people in those studies ate at least 2g a day, with the majority of participants eating more than double that dose on a regular basis.

Genes aren’t destiny

Beyond thoughts, moods and memory, diet plays a clear and determinant role in brain ageing and the risk of developing Alzheimer’s, the most common form of dementia, which affects 46 million people worldwide (and is projected to affect 130 million by the year 2050). When I started working in the field, most people understood Alzheimer’s as the inevitable outcome of bad genes, ageing or both. In 2018, it is clear that genes aren’t destiny, and ageing isn’t a linear path to unavoidable dementia.

Most people don’t realise that less than 1% of the Alzheimer’s population develops the disease due to a genetic mutation. These mutations are very rare and so is their outcome: an early-onset and particularly aggressive form of Alzheimer’s that develops when people are in their 30s, 40s and 50s. But the majority of the population doesn’t carry those mutations, and so the real risk for the rest of us is simply not determined by our genes.

While the blueprints for an individual brain do depend in part on DNA, recent discoveries have led neuroscientists to understand that genes load the gun, but lifestyle pulls the trigger. In fact, there is consensus among scientists that at least one third of all Alzheimer’s cases could be prevented by improving our lifestyle, from ameliorating cardiovascular fitness, to keeping our brains intellectually stimulated and, of course, eating better.

The human brain has evolved over millions of years to absorb specific nutrients and to function on a relatively specific diet. Now our society must also evolve, to attend to what our brains need to be fed. On a personal level, that’s for anyone pursuing a long life and a youthful brain to enjoy it. On a global level, that is millions of people who will have a chance to age gracefully with their mental capacities intact".

Fonte e imagem: https://www.theguardian.com/lifeandstyle/2018/feb/12/its-not-just-in-the-genes-the-foods-that-can-help-and-harm-your-brain

We Can’t Keep Eating Like This

This is the question everyone should be attending to – where is the food going to come from?

By George Monbiot, published in the Guardian 11th December 2017

"Brexit; the crushing of democracy by billionaires; the next financial crash; a rogue US president: none of them keeps me awake at night. This is not because I don’t care – I care very much. It’s only because I have a bigger question on my mind. Where is the food going to come from?

By mid-century there will be two or three billion more people on Earth. Any one of the issues I am about to list could help precipitate mass starvation. And this is before you consider how they might interact.

The trouble begins where everything begins: with soil. The UN’s famous projection that, at current rates of soil loss, the world has 60 years of harvests left, appears to be supported by a new set of figures. Partly as a result of soil degradation, yields are already declining on 20% of the world’s croplands.

Now consider water loss. In places such as the North China Plain, the central United States, California and north-western India – among the world’s critical growing regions – levels of the groundwater used to irrigate crops are already reaching crisis point. Water in the Upper Ganges aquifer, for example, is being withdrawn at 50 times its recharge rate. But, to keep pace with food demand, farmers in South Asia expect to use between 80 and 200% more water by 2050. Where will it come from?

The next constraint is temperature. One study suggests that, all else being equal, with each degree Celsius of warming the global yield of rice drops by 3%, wheat by 6% and maize by 7%. This could be optimistic. Research published in the journal Agricultural & Environmental Letters finds that 4°C of warming in the US Corn Belt could reduce maize yields by between 84 and 100%.

The reason is that high temperatures at night disrupt the pollination process. But this describes just one component of the likely pollination crisis. Insectageddon, caused by the global deployment of scarcely-tested pesticides, will account for the rest. Already, in some parts of the world, workers are now pollinating plants by hand. But that’s viable only for the most expensive crops.

Then there are the structural factors. Because they tend to use more labour, grow a wider range of crops and work the land more carefully, small farmers, as a rule, grow more food per hectare than large ones. In the poorer regions of the world, people with less than 5 hectares own 30% of the farmland but produce 70% of the food. Since 2000, an area of fertile ground roughly twice the size of the United Kingdom has been seized by land grabbers and consolidated into large farms, generally growing crops for export rather than the food needed by the poor.

While these multiple disasters unfold on land, the seas are being sieved of everything but plastic. Despite a massive increase in effort (bigger boats, bigger engines, more gear), the worldwide fish catch is declining by roughly 1% a year, as populations collapse. The global land grab is mirrored by a global seagrab: small fishers are displaced by big corporations, exporting fish to those who need it less but pay more. Around 3 billion people depend to a large extent on fish and shellfish protein. Where will it come from?

All this would be hard enough. But as people’s incomes increase, their diet tends to shift from plant protein to animal protein. World meat production has quadrupled in 50 years, but global average consumption is still only half that of the UK – where we eat roughly our bodyweight in meat every year – and just over a third of the US level. Because of the way we eat, the UK’s farmland footprint (the land required to meet our demand) is 2.4 times the size of its agricultural area. If everyone aspires to this diet, how do we accommodate it?

The profligacy of livestock farming is astonishing. Already, 36% of the calories grown in the form of grain and pulses – and 53% of the protein – are used to feed farm animals. Two-thirds of this food is lost in conversion from plant to animal. A graph produced last week by Our World in Data suggests that, on average, you need 0.01m2 of land to produce a gram of protein from beans or peas, but 1m2 to produce it from beef cattle or sheep: a difference of 100-fold.

It’s true that much of the grazing land occupied by cattle and sheep cannot be used to grow crops. But it would otherwise have sustained wildlife and ecosystems. Instead, marshes are drained, trees are felled and their seedlings grazed out, predators are exterminated, wild herbivores fenced out and other lifeforms gradually erased as grazing systems intensify. Astonishing places – such as the rainforests of Madagascar and Brazil – are laid waste to make room for yet more cattle.

Because there is not enough land to meet both need and greed, a global transition to eating animals means snatching food from the mouths of the poor. It also means the ecological cleansing of almost every corner of the planet.

The shift in diets would be impossible to sustain even if there were no growth in the human population. But the greater the number of people, the greater the hunger meat eating will cause. From a baseline of 2010, the UN expects meat consumption to rise by 70% by 2030 (this is three times the rate of human population growth). Partly as a result, the global demand for crops could double (from the 2005 baseline) by 2050. The land required to grow them does not exist.

When I say this keeps me up at night, I mean it. I am plagued by visions of starving people seeking to escape from grey wastes, being beaten back by armed police. I see the last rich ecosystems snuffed out, the last of the global megafauna – lions, elephants, whales and tuna – vanishing. And when I wake, I cannot assure myself that it was just a nightmare.

Other people have different dreams: the fantasy of a feeding frenzy that need never end, the fairytale of reconciling continued economic growth with a living world. If humankind spirals into societal collapse, these dreams will be the cause.

There are no easy answers, but the crucial change is a shift from an animal to a plant-based diet. All else being equal, stopping both meat production and the use of farmland to grow biofuels could provide enough calories for another 4 billion people and double the protein available for human consumption. Artificial meat will help: one paper suggests it reduces water use by at least 82% and land use by 99%.

The next Green Revolution will not be like the last one. It will rely not on flogging the land to death, but on reconsidering how we use it and why. Can we do this, or do we – the richer people now consuming the living planet – find mass death easier to contemplate than changing our diet?"

Fonte e imagem: http://www.monbiot.com/2017/12/13/we-cant-keep-eating-like-this/

The Messy Facts about Diet and Inflammation

Celia Krampien

"Can certain foods really help you fight heart disease, arthritis and dementia?

By Claudia Wallis | Scientific American January 2018 Issue

In health, as with so many things, our greatest strength can be our greatest weakness. Take our astonishingly sophisticated response to injury and infection. Our bodies unleash armies of cellular troops to slaughter invaders and clear out traitors. Their movements are marshaled by signaling chemicals, such as the interleukins, which tell cells where and when to fight and when to stand down. We experience this as the swelling, redness and soreness of inflammation—an essential part of healing.

But when the wars fail to wind down, when inflammation becomes chronic or systemic, there's hell to pay. I'm looking at you, arthritis, colitis and bursitis, and at you, diabetes, colon cancer, Alzheimer's and cardiovascular disease.

Cardiovascular disease is the world's biggest killer, and we've known for 20 years that inflammation (along with too much cholesterol) ignites the buildup of plaque in our arteries. Still, no one knew if runaway inflammation could actually pull the trigger on heart attacks and strokes—until this summer. Results from a large, well-designed trial showed that certain high-risk patients suffered fewer of these “events” (as doctors so mildly call them) when given a drug that precisely targets inflammation (aiming at interleukin 1). It was sweet vindication for cardiologist and principal investigator Paul Ridker of Harvard University, who had long contended that inflammation was as vital a target as cholesterol.

The patients in Ridker's study had already suffered a heart attack and had persistent inflammation (as measured by blood levels of C-reactive protein). But it is tempting to extrapolate lessons for all of us. Given that chronic inflammation plays a nefarious role in heart disease and many other disorders, shouldn't we all do what we can to keep it in check? And I'm not talking about taking drugs like ibuprofen, which ease short-term inflammation. I mean something we can do every day of our lives: eat right.

Hop on the Internet or visit a bookstore, and you will see “anti-inflammatory” diets galore, dishing out recipes and hope. Many aim at specific ailments—arthritis, breast cancer, heart disease, various autoimmune disorders. Health guru Andrew Weil goes so far as to offer an “Anti-Inflammatory Food Pyramid.”

The underlying science, however, is somewhat shaky. Sure, plenty of foods have been found to reduce inflammation—many of them in laboratory experiments as opposed to in people: turmeric, blueberries, ginger, tea, various vegetables, dark chocolate, fish. University of South Carolina epidemiologists James Hébert and Nitin Shivappa valiantly surveyed 1,943 such studies and published in 2014 a Dietary Inflammatory Index, with 45 food elements. They created it as a research tool for evaluating diets but concede it's built from studies that varied widely in methodology.

When I asked Ridker his views on anti-inflammatory diets, he grew uneasy. “This has caught on like wildfire,” he says, “but I have seen extremely little data that say this piece of food is ‘anti-inflammatory’ and this piece is ‘pro-inflammatory.’” He advises his own patients to eat a Mediterranean-type diet, heavy on vegetables, whole grains and fish and light on red meat and processed foods.

That diet, long endorsed by cardiologists, has been shown in well-designed studies to reduce key markers of inflammation and the risk of heart disease. Would it be even more effective if it incorporated more blueberries and turmeric? No one knows for sure.

Diet research is tricky. Turmeric may work anti-inflammatory wonders for mice, but “that's in the context of rodent chow with a whole different set of macro and micro nutrients,” explains Martha Clare Morris, a nutritional epidemiologist at Chicago's Rush University. And context matters. The typical Mediterranean diet calls for loads of seafood a week, and yet studies of people taking fish oils as a supplement have not found much benefit. The virtues of fish may lie elsewhere or have more to do with displacing meat.

That's why researchers such as Morris prefer to study overall dietary patterns rather than particular ingredients. Her current project examines whether cognitive decline can be slowed with a regimen called the MIND diet, which combines elements of the Mediterranean diet with another well-studied diet called DASH. It will look at inflammation, but results won't be out before 2021.

Until then, there is no harm in adding more so-called anti-inflammatory ingredients to your diet. Hébert suggests a spicy chai (loaded with ginger, turmeric and pepper). But remember, context! So don't drink it with cookies and chips.

This article was originally published with the title "The Messy Facts about Diet and Inflammation""

Fonte e imagem: https://www.scientificamerican.com/article/the-messy-facts-about-diet-and-inflammation/?utm_source=facebook&utm_medium=social&utm_campaign=sa-editorial-social&utm_content&utm_term=health_feature_text_free