What Is the MIND Diet

The MIND diet, as the name implies, is designed to promote a healthy mind and lower the risk of Alzheimer's disease. It is a mash-up of the Mediterranean diet and the DASH diet — two diets that have been found to have several health benefits.

Diet information

MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. It was developed by a nutritional epidemiologist, Martha Clare Morris, at Rush University Medical Center through a study that was funded by the National Institute on Aging. Her goal was to lower the risk of Alzheimer's disease by promoting a diet consisting of brain-healthy foods.

The Mediterranean diet focuses on eating foods that are as natural as possible, while limiting unhealthy fats and red meat. The DASH (Dietary Approaches to Stop Hypertension) diet, as its name suggests, is aimed at helping to ease hypertension. It focuses on helping people to eat foods that can lower their sodium intake and blood pressure. 

Morris told Live Science in a 2015 article that the researchers focused on this mix of two-well-known, healthy diets because it would be easy for Americans to follow. The MIND diet recommends eating 10 foods daily and avoiding five types of foods. The healthy-food group contains:

1. Vegetables 
2. Green leafy vegetables in particular
3. Berries, especially blueberries
4. Nuts
5. Beans
6. Wine
7. Whole grains
8. Fish
9. Poultry
10. Olive oil 

The five unhealthy foods are: 

1. Fried or fast food
2. Red meats
3. Cheeses
4. Butter and stick margarine
5. Pastries and sweets

The rules of the diet are:

• Get at least three servings of whole grains per day 
• Eat a salad each day
• Eat one other vegetable every day 
• Drink a glass of wine each day 
• Snack almost every day on nuts 
• Eat beans every other day 
• Consume poultry and berries at least twice a week 
• Consume fish at least once a week
• Unhealthy foods are allowed, but less than one serving per week, with the exception of butter  
• Less than 1 tablespoon a day of butter is allowed per day 

Benefits

The researchers' main goal in creating the MIND diet was to reduce the risk of Alzheimer's disease (AD). According the Alzheimer's Foundation of America, it is estimated that about a half-million Americans younger than age 65 have some form of dementia, including Alzheimer's disease.

Morris and her team conducted studies of the MIND diet for nearly a decade, working with a group of 923 seniors. The results showed that the diet lowered the risk of Alzheimer's by as much as 53 percent in participants who meticulously adhered to the diet. It also helped 35 percent of the seniors who followed the diet moderately well, according to Rush University Medical Center.

The study also found that the longer a person followed the MIND diet, the better protected the individual was from developing Alzheimer's. The results of the study were published in March 2015, in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

In another study, Morris' team conducted a head-to-head comparison of the MIND diet with the DASH and Mediterranean diets. The results that they obtained with the other two diets were similar to those they found with the MIND diet alone. A high adherence to the diets reduced the risk of Alzheimer's by 39 percent among those who followed the DASH diet and 54 percent among those who followed the Mediterranean diet, according to Rush University Medical Center. However, the participants obtained very little benefit from the two other diets if their adherence to them could be termed moderate rather than strict.

"One of the more exciting things about this is that people who adhered even moderately to the MIND diet had a reduction in their risk for AD," Morris said in a Rush University press release. "I think that will motivate people."

In various studies, the Mediterranean diet and the DASH diet have each been found to have health benefits in other areas as well. For example, people in one study who followed the DASH diet experienced a decrease in their blood sugar levels over a three-month period. Researchers in that study thought that the decrease was due to the higher consumption of probiotics than the diet prescribed. According to the Mayo Clinic, the DASH diet may also help reduce blood pressure by a few points in just two weeks, and systolic blood pressure could be reduced eight to 14 points, over time. 

Another study, which was published in April 2010, found that the Mediterranean diet helped dieters lose weight and lower cholesterol, triglycerides and blood pressure. And a study of 780 male firefighters that was conducted by the Harvard School of Public Health and Cambridge Health Alliance also found that a Mediterranean-style diet was associated with lower risk factors for cardiovascular disease.

Risks

Live Science asked Dana Hunnes, senior dietitian at Ronald Reagan UCLA Medical Center and an adjunct assistant professor at the UCLA Fielding School of Public Health, to weigh in on the risks that may be associated with the MIND diet. "The Mediterranean and DASH diets are very healthy diets in general," said Hunnes. "They are extremely high in plant-based foods: fruits, vegetables, plant-based proteins (nuts, seeds, legumes). They are also very high in potassium and magnesium, two electrolytes/minerals we don't typically get enough of through diet.

"When it comes to eating fish and fish products, which the Mediterranean diet recommends more of, we need to be careful about some of the potential pollutants and toxins that end up in fish, including mercury and plastic residues. More and more, plastic residues, BPA — other persistent pollutants including DDT — and mercury are found in fish, Hunnes said. "So, if you eat fish, it's a good idea to aim low in the food chain and look for sustainably fished (line and pole caught) products."

"In general though, these are healthy eating patterns that are high in produce, low in saturated fat and good for human health and even the environment."

As with any diet, consult with a doctor before starting any new diet plan.

Unfrozen: Greenland Was Once Ice-Free for 280,000 Years

More than a million years ago, frosty Greenland was ice-free, its bare bedrock exposed for 280,000 years, researchers have found.

During this exposed stint, the island's overall ice cover could have dropped by more than 90 percent, the scientists reported today (Dec. 7) in the journal Nature.

Previous studies have reported that Greenland's ice shrank in the distant past, but this study is the first to explain how long a span Greenland may have endured without its usual frozen cover. This discovery hints that its surface ice was more variable than once thought — which does not bode well for its future stability in a warming world, the researchers said.

As valuable as moon rocks

The study authors gathered their data from isotopes — atoms of the same element but with a different number of neutrons — extracted from bedrock minerals. The isotopes, beryllium 10 and aluminum 26, are produced only by cosmic rays, which means that they only occur when the rock that holds them is exposed; as such they can offer clues about when rocks were bare of ice, and for how long.

These isotopes originated in the only rocky core ever extracted from land underneath Greenland ice, drilled at the Greenland Ice Sheet (GIS) summit in 1993.

Minerals from this solitary core are second only to moon rocks in their rarity and importance, as they are the only existing evidence of Greenland's ice-covered extant bedrock, according to lead author Joerg Schaeffer, a paleoclimatologist with the Lamont-Doherty Earth Observatory, and a professor with the Department of Earth and Environmental Sciences at Columbia University.

When this core was first examined decades ago, researchers were able to detect isotopes in the sediment produced by cosmic rays, but their equipment wasn't sensitive enough to gather precise climate data, Schaeffer told Live Science. In order to get to the isotopes, "we literally digested those rocks," he said, describing how he and his colleagues dissolved minerals with acid so they could observe the atoms.

The atomic isotope beryllium 10 told the scientists that the rock had at one point been ice-free. To gauge how long that period lasted, they compared the amount of beryllium to quantities of aluminium 26. It appears at a 7 to 1 ratio to beryllium 10, but decays twice as fast. The quantity of aluminium atoms relative to beryllium told the scientists that once the ice cover melted away, the rock was exposed for more than 280,000 years, until about 1.1 million years ago.

The extent to which Greenland's ice may have waxed and waned over time was the subject of another new study, also published today (Dec. 7) in Nature. Lead author Paul Bierman, a professor of geology at the University of Vermont, told Live Science that the study found evidence of ice covering the island for a period of 7.5 million years, a much longer period than described in any prior study.

A patchwork history

Though many scientists have investigated Greenland's ice for clues about its behavior over time, a comprehensive picture long remained elusive. And Greenland itself is to blame for this incomplete view, as recurring changes in ice cover scrub away geologic evidence over and over again, Bierman said.

"Whenever the ice expands, it wipes away what it did last time," Bierman told Live Science. "It's like looking at a chalkboard that's been erased, and you have to figure out what happened three classes ago."

Bierman and his colleagues analyzed deep-sea samples from a core of weathered bedrock that originated in East Greenland, but was carried into the ocean off the coast.

Their examination revealed that during the past 7.5 million years, Greenland ice was "persistent" but also "dynamic," the scientists wrote in the study, allowing that there were likely periods when the ice cover dwindled due to global temperature changes.

Addressing uncertainties

While Bierman's study suggests that ice consistently blanketed Greenland, that doesn't necessarily rule out that some parts of the island were ice-free at times. High-altitude regions in the east could have stayed frozen even during warm conditions, while other parts of Greenland lost their ice, according to Ginny Catania, an associate professor with the Jackson School of Geosciences at the University of Texas at Austin.

Catania, who was not involved in the new studies, told Live Science in an email that both investigations support reduced ice in Greenland's past, but more data would be required to understand the processes that contributed to massive and rapid ice loss, and how they might drive future melt. [5 Places Already Feeling the Effects of Climate Change]

"These uncertainties limit our ability to accurately predict the future of the ice sheet," Catania said. "We are in for a lot of change in Greenland in the future. The question remains — how quickly will it happen?"

Techniques used in both studies introduce novel methods for looking at how Greenland's ice changed, but there is still more work to be done. Determining more precisely when and why historical ice loss happened could greatly improve computer models that would find a threshold for instability in Greenland's ice today, according to Anders Carlson, an associate professor of geology and geophysics with the College of Earth, Ocean and Atmospheric Sciences at Oregon State University.

"Regardless of when Greenland had ice-free conditions, the ice sheet has been unstable and collapsed in the past," Carlson told Live Science. "And that probably occurred when CO2 [carbon dioxide] levels were below what they are now — which bodes ill for future," he said.

And time may be running short. Seasonal melt for Greenland in 2016 was above average, with the third highest surface mass loss of ice in 38 years of satellite observations, according to the National Snow and Ice Data Center. Were Greenland to lose the majority of its ice, as it did in the past, the water released into the world's oceans could produce around 23 feet (7 meters) of sea level rise, Schaeffer added.

"We have never seen the planet warming as fast as it is now, and we have to prepare as best we can," Schaeffer told Live Science. "We need to get organized quickly, and, hopefully, this helps to make the case."

The Universe Is Flat — Now What

Spoiler alert: The universe is flat. But there's a lot of subtlety packed into that innocent-looking statement. What does it mean for a 3D object to be "flat"? How do we measure the shape of the universe anyway? Since the universe is flat, is that…it? Is there anything else interesting to say?

Oh yes, there is.

Walk the line

First, we need to define what we mean by flat. The screen you're reading this on is obviously flat (I hope), and you know that the Earth is curved (I hope). But how can we quantify that mathematically? Such an exercise might be useful if we want to go around measuring the shape of the whole entire universe. [The History & Structure of the Universe (Infographic)]

One answer lies in parallel lines. If you start drawing two parallel lines on your paper and let them continue on, they'll stay perfectly parallel forever (or at least until you run out of paper). That was essentially the definition of a parallel line for a couple thousand years, so we should be good.

Let's repeat the exercise on the surface of the Earth. Start at the equator and draw a couple parallel lines, each pointing directly north. As the lines continue, they never turn left or right but still end up intersecting at the North Pole. The curvature of the Earth itself caused these initially parallel lines to end up not-so-parallel. Ergo, the Earth is curved.

The opposite of the Earth's curved shape is a saddle: on that surface, lines that start out parallel end up spreading apart from each other (in swanky mathematical circles this is known as "ultraparallel").

So there you have it: You can measure the "flatness" of a structure just by watching how parallel lines behave. In our 3D universe, we could watch beams of light: If, say, two lasers started out perfectly parallel, then their long-term behavior would tell us important things.

Flat as a (big) pancake

Remember that measuring the shape of the universe is a question for cosmology, the study of the entire universe. And in cosmology, nobody cares about you. Or me. Or solar systems. Or black holes. Or galaxies. In cosmology we care about the universe only at the very largest scales; small-scale bumps and wiggles are not important for this question.

The universe has all sorts of deformations in space-time where it varies from the perfectly flat. Any place where there's mass or energy, there's a corresponding bending of space-time — that's General Relativity 101. So a couple light beams would naturally collide inside a wandering black hole, or bend along weird angles after encountering a galaxy or two.

But average all those small-scale effects out and look at the big picture. When we examine very old light — say, the cosmic microwave background — that has been traveling the universe for more than 13.8 billion years, we get a true sense of the universe's shape. And the answer, as far as we can tell, to within an incredibly small margin of uncertainty, is that the universe is flat.

There is no spoon

Well, that settles that. But this article isn't over yet, which means there's more to the story.

Have you ever asked yourself if there's a difference between a cylinder and a sphere? More than likely not, but it's never too late to try new things.

Take out your piece of paper with two parallel lines on it. Go ahead, dig it out of the trash. Wrap one end around to meet the other, making a cylinder. Carefully observe the parallel lines — they remain parallel, don't they? That's because cylinders are flat.

You heard it here first: Cylinders are flat.

There's an important distinction between geometry, the behavior of parallel lines, and topology, the way a space can get all twisted up. While the geometry of the universe is very well measured (again, it's flat), the topology is not. And here's a bonus fact: not only can we not determine the topology of the universe from observations, but there are also no laws of physics that predict or restrict the topology.

With your 2D piece of paper, you can connect the ends a few different ways. Connect one of the dimensions normally and you have a cylinder. Flip one edge over before connecting and you've made a Mobius strip. Connect two dimensions, the top to the bottom and one side to the other, and you have a torus (aka a donut).

In our 3D universe, there are lots of options — 18 known ones, to be precise. Mobius strips, Klein bottles and Hantzsche-Wendt space manifolds are all non-trivial topologies that share something in common: if you travel far enough in one direction, you come back to where you started. In the case of flipped dimensions, when you come back to your starting point, you'll find yourself upside down without having tried to do so at all. [Watch: Explaining the Shape of the Universe.]

Of course we've looked to see if our universe is connected like this; we don't see any copies of galaxies, and we don't see the cosmic microwave background intersecting itself. If the universe is pretzeled-up, it's on scales far, far larger than what we can observe.

So don't get too excited by possibility of living in a real-life version of the "Asteroids" game — which, as you now know, is played on the surface of a donut.

Learn more by listening to the episode "What's the shape of the universe?" on the Ask A Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to Greg S. and Michael W. for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul