Designer plants have vital fish oils in their seeds

MOVE over, cod liver oil. A biofuel crop related to cabbages, called camelina, has been genetically modified to produce components of fish oils beneficial for cardiovascular health. The approach could relieve some of the pressure on the oceans.

The flesh of oily fish such as mackerel and salmon, plus the livers of white fish such as cod, are good sources of omega-3 fatty acids. The most important ones are eicosapentaenoic acid (EPA) – known to reduce the risk of heart disease – and docosahexaenoic acid (DHA) – a lack of which has been linked to visual and cognitive problems.

Breast milk is a good source of both, and our bodies can make small amounts of EPA from another omega-3 called alpha-linolenic acid (ALA) found in nuts and vegetable oil, which is then converted into DHA.

The richest source of these fatty acids is fish. However, they do not produce the acids themselves. In the wild, they get them from eating smaller fish that have eaten algae, the only organisms that can make appreciable amounts of EPA and DHA. Farmed fish are fed fishmeal enriched with fish oil containing these fatty acids.

Every year, around a million tonnes of oil is extracted from ground-up fish. A tenth of this goes to make fish-oil capsules and the rest is given to farmed fish. But supplies are limited and unsustainable, says Douglas Tocher of the Institute of Aquaculture at the University of Stirling, UK.

Now Johnathan Napier and colleagues at Rothamsted Research in Harpenden, UK, have created an alternative, sustainable source of EPA and DHA. They took seven genes that algae use to produce these fatty acids and inserted them into the genome of Camelina sativa, a plant chosen because its seeds are already rich in ALA. The seeds of the modified plant yielded oil that, when purified, contained around 12 per cent EPA and 14 per cent DHA – the same proportions as in fish oil (The Plant Journal, doi.org/qn8).

Napier says that if all goes to plan, the plant oil could be available commercially within 10 years. It could then help replace the fish oil used in capsules or fed to farmed fish. "We're never going to replace that 1 million tonnes a year from the sea, but if we could supply even 10 per cent, we would significantly take the pressure off fish stocks," he says.

Tocher says that modified camelina should make it possible for people to consume the World Health Organization's recommended daily intake of 400 to 1000 milligrams of EPA and DHA. Without the plants, "if everyone ate that much, there would only be enough to supply about half the population, through capsules, fish or both", he says.

This article appeared in print under the headline "Designer plant oozes vital fish oils"

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GPS satellites suggest Earth is heavy with dark matter

GPS is handy for finding a route, but it might be able to solve fundamental questions in physics too. An analysis of GPS satellite orbits hints that Earth is heavier than thought, perhaps due to a halo of dark matter.

Dark matter is thought to make up about 80 per cent of the universe's matter, but little else is known about it, including its distribution in the solar system. Hints that the stuff might surround Earth come from observations of space probes, several of which changed their speeds in unexpected ways as they flew past Earth. In 2009, Steve Adler of the Institute of Advanced Studies in Princeton, New Jersey, showed how dark matter bound by Earth's gravity could explain these anomalies.

Ben Harris at the University of Texas at Arlington wondered if dark matter might also affect satellites. "The nice thing about GPS satellites is that we know their orbits really, really well," he says. From nine months of data on the satellites in the GLONASS, GPS and Galileo groups, he calculated Earth's mass as "felt" by each one.

At a meeting of the American Geophysical Union in San Francisco in December, he reported an average figure that was between 0.005 and 0.008 per cent greater than the value for Earth's mass established by the International Astronomical Union. A disc of dark matter around the equator 191 kilometres thick and 70,000 km across can explain this, he says.

Harris has yet to account for perturbations to the satellites' orbits due to relativity, and the gravitational pull of the sun and moon. What's more, preliminary data from NASA's Juno probe, also presented at the AGU meeting, suggests its speed was as expected as it flew by Earth, casting doubt on the earlier anomalies.

But if Harris's explanation is correct, satellites could reveal properties of dark matter, such as whether its particles interact with each other.

This article appeared in print under the headline "GPS satellites hint at Earthly dark matter"

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Spray bacteria on the desert to halt its spread

AN ODD ally could stall the encroachment of deserts – bacteria. In northern China, the eastern edge of the Qubqi desert is a shifting wasteland of sand dunes. Most of the land is dusty and barren, but bacteria are giving some of it a new lease of life.

Desertification is a big problem for China. Overgrazing by livestock has destroyed much of the fragile layer of lichen, algae and mosses – the cryptobiotic crust – that binds the sand and soil to the ground. If left unchecked, creeping sands can slowly engulf vital infrastructure such as roads and railways. Farmland and even major cities can be swamped by dust storms that began in the desert.

Planting hardy grasses helps keep sand in place, but the wind can still whip away particles between the grasses. So Chunxiang Hu of the Chinese Academy of Sciences's Institute of Hydrobiology in Wuhan has developed an alternative approach. She coats planted dunes with a mixture of photosynthesising cyanobacteria that can thrive in the semi-arid environment.

Grown in nearby ponds, the cyanobacteria are trucked into the desert every few days and sprayed over the dunes, where they form sticky filaments that hold soil particles in place and prevent them from being blown away. Cyanobacteria get their energy from sunlight via photosynthesis, and as part of the chemical reactions involved, they absorb carbon from the atmosphere and provide the organic matter the soil needs to be productive.

Hu's long-running trial shows that after eight years, dunes treated with cyanobacteria developed a biological crust nearly 1 centimetre thick when on the shady side of dunes. On the sunny side, the crust was about half as thick. The topsoil improved where the crust developed, spurring plant growth.

The method is vital if semi-arid regions are going to rebound on a reasonable timescale, says Brian Whitton, an ecologist at Durham University, UK. "Unless you do something to help, you're probably talking centuries for it to recover naturally," he says.

Hu says the cyanobacteria are now being used to shore up the verges of roads and railways in northern China as well as the margins of oases and farmland. Her team plans to seed 133 square kilometres over the next five years (Environmental Science and Technology, doi.org/qn9).

People have been trying to use bacteria in this way since the 1980s, says Matthew Bowker, a soil ecologist at Northern Arizona University in Flagstaff. His group is working on a similar method, but hasn't yet used it on a large scale.

Desertification is also a problem in the US, says Bowker, but the issue isn't yet big enough to prompt the country to pour money into projects like Hu's. That might change soon, though. "The western US is getting dusty. With dust come automobile accidents and health issues," he says. "These biological soil crusts are like the living skin of the soil," Bowker says, and they need protecting.

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A break from booze, a break from bad habits

Quitting alcohol for short periods seems to bring health benefits – but it also changes your mindset about drinking, and that could be a bigger gain

GIVING up alcohol for January? For many people, in the UK at least, it has become a ritual in recent years. The assumption is that taking a break will help your liver to recover from the seasonal onslaught of alcohol and rich food.

Does it work? Upon investigation, we found little research on the effects of such "dryathlons". We thought that was surprising. So a group of New Scientist volunteers took part in a ground-breaking study organised by medical researchers at University College London.

The preliminary results are striking, suggesting that abstinence significantly reduces levels of liver fat, cholesterol and blood glucose (see "Our liver vacation: Is a dry January really worth it?"). Intriguing, but we'll have to wait for larger studies before we can be confident of how large or enduring those benefits really are.

But a period of abstinence may have consequences beyond the physiological. The health benefits of a one-month break may prove to be inconsequential when set against the detriments of drinking for the rest of the year – certainly if people take the break as licence to increase their alcohol intake at other times.

But a dry period may help with that, too. Alcohol is a drug: one that kills 2.5 million people each year globally and which the World Health Organization ranks as the third largest risk factor for premature death. When, how and why we drink is strongly affected by personal and social factors.

Habitual drinkers can find it difficult to negotiate social events without alcohol. But get over the initial discomfort of drying out, and healthier habits may follow. Several New Scientist participants reported they found it easier to decline alcohol after the study had ended, or to start an evening off with low-alcohol drinks. But the lack of palatable, non-sugary choices proved frustrating: perhaps drinks manufacturers could make more effort to cater to the month-off market.

This is, of course, just the anecdotal experience of a handful of people. But the potential for people to rewrite their contract with alcohol may prove a stronger argument for dialling back on booze for a while every year than any health benefits. Worth considering as you decide whether to open another bottle of wine.

This article appeared in print under the headline "New year, new habits?"

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Forgotten aliens: We should hunt for viruses in space

IMAGINE you are from an alien civilisation, tasked with collecting a sample from Earth to take back to your planet to look for signs of life. You will only be able to return a small representative sample, which means you will be collecting a small amount of seawater from your visit to this "pale blue dot".

In a thimbleful of Earth seawater there will be perhaps 10 million viruses, up to a million microbes and certainly no humans. So it's only a small leap to imagine that, if we ever found life on another planet, viruses would be present too. Why, then, don't space agencies such as NASA and the European Space Agency look for viruses on other planets?

Before we can begin to think about extraterrestrial viruses, however, we need a good understanding of the viruses on our own planet. This is where things get complicated. Although flu and ...

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Pacific coral happy as acidity of the ocean rises

COULD corals survive ocean acidification against the odds? That's the hope raised by reefs found to be thriving in naturally acidified waters.

Corals use the carbonate ions in water to build their skeletons from calcium carbonate. But ocean acidification caused by climate change reduces the available carbonate ions. Lab studies suggest that this leaves corals unable to grow and survive. The few known reefs living in naturally acidified water also tend to be unhealthy.

So Kathryn Shamberger of the Woods Hole Oceanographic Institution in Massachusetts and her colleagues were surprised to find that coral reefs around the Palau archipelago in the west Pacific were dense and diverse – even though the pH of the water and the amount of carbonate were unusually low (Geophysical Research Letters, doi.org/qnj).

This suggests that the corals have a way to calcify in more acidic waters, says Philip Munday at James Cook University in Brisbane, Australia, or that they have adapted to low carbonate levels.

Working out just how they do this will be important in understanding the likely impacts of ocean acidification on coral communities elsewhere, he says.

This article appeared in print under the headline "Pacific coral happy as water acidity rises"

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Mix of hepatitis and pollen blows hay fever away

HERE'S something not to be sneezed at. A vaccine against grass pollen, which can cause hay fever, has been shown as safe and effective in a trial of 180 patients. If larger trials are a success, a vaccine could be available within four years.

Hay fever is caused by the immune system's immunoglobulin E (IgE) antibodies reacting excessively to pollen. Therapy to prevent this reaction typically builds up immunity by injecting regular small doses of pollen over several years.

To offer faster relief, Biomay, a firm in Vienna, Austria, has developed a shot that combines part of a pollen molecule with a hepatitis B protein. The IgE antibodies still get activated, but the protein mobilises other antibodies, which block the IgE ones. This prevents an excessive immune response. Just four injections over a few months should be required, says Angela Neubauer of Biomay.

Another hay fever vaccine, made by Allergy Therapeutics in Worthing, UK, is about to re-enter trials after research was put on hold for five years while severe side effects in one patient were investigated.

This article appeared in print under the headline "Quick injections blow hay fever away"

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Armpit cheese: The sweeter side of bacteria

Would you eat cheese cultivated from your armpit sweat or toe jam? No? Then you should rethink your prejudices about bacteria

CHRISTINA AGAPAKIS stood in her kitchen trying to decide whether she had the nerve to eat what was in front of her. On the worktop sat four blobs of cheese – but not just any stinky fromage. Agapakis, who is a synthetic biologist at the University of California, Los Angeles, had made the stuff with bacteria from her armpit, nose and toes.

"Each one had a very different smell," she says. "Some were dry and brittle and yellow, others were more yogurty". Surely she wouldn't dare taste it. Would she?

Agapakis picked up a chunk and popped it in her mouth. If you're wondering why anybody would do such a thing, well, she has her reasons. Agapakis is on a mission to change our ideas about the role of ...

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Our liver vacation: Is a dry January really worth it?

Continue reading page |1|2

Less liver fat, cholesterol and weight – just some of the benefits that New Scientist staff enjoyed in a pioneering study into a month's alcohol abstinence

Editorial: "A break from booze, a break from bad habits"

"DRY January", for many a welcome period of abstinence after the excesses of the holiday season, could be more than a rest for body and soul. New Scientist staff have generated the first evidence that giving up alcohol for a month might actually be good for you, at least in the short term.

Many people who drink alcohol choose to give up for short periods, but there is no scientific evidence that this has any health benefits. So we teamed up with Rajiv Jalan at the Institute for Liver and Digestive Health at University College London Medical School (UCLMS) to investigate.

The liver plays a role in over 500 processes vital for functions as diverse as digesting food, detoxification and hormone balance. In 2009, of the 11,575 people who died of liver disease in the UK, more than a third were attributed to alcohol consumption. Most of what we know about liver health comes from studies of people with chronic disease, many of whom are alcoholics. Very few studies have focused on liver function in apparently healthy people.

Our project was on a small scale, but Jalan felt it could yield clues as to the effects of short-term abstinence. On 5 October, 14 members of the New Scientist staff – all of whom consider themselves to be "normal" drinkers – went to the Royal Free Hospital in London. We answered questionnaires about our health and drinking habits, then had ultrasound scans to measure the amount of fat on the liver. Finally, we gave blood samples, used to analyse levels of metabolic chemicals linked with the liver and overall health.

For the next five weeks, 10 of us drank no alcohol while four continued as normal. On 9 November, we returned to the hospital to repeat the tests.

"You're going to be very excited," said Jalan, when the results were in.

First off, he revealed that there had been no significant changes in any of the parameters measured for the four people who didn't give up alcohol.

But the changes were dramatic and consistent across all 10 abstainers (see charts).

Liver fat fell on average by 15 per cent, and by almost 20 per cent in some individuals. Jalan says this is highly significant, because fat accumulation on the liver is a known prelude to liver damage. It can cause inflammation, resulting in liver disease. "This transition is the harbinger first for temporary scarring called fibrosis and ultimately a non-reversible type of scarring that destroys liver structure, called cirrhosis," says Jalan. Although our livers were all judged to be generally healthy, the fat reductions would almost certainly help to retard liver deterioration, he says.

Then came another surprise. The blood glucose levels of the abstainers dropped by 23 per cent on average, from 5.1 to 4.3 millimoles per litre. The normal range for blood glucose is between 3.9 and 5.6 mmol/l. "I was staggered," says Kevin Moore, consultant in liver health services at UCLMS. "I don't think anyone has ever observed that before."

Glucose was measured using a fasting blood glucose test taken after participants had refrained from eating or drinking anything but water for 8 hours. This stimulates production of the hormone glucagon, which releases glucose from body stores into the blood. In a healthy person, a rise in glucose triggers the production of insulin, which tells certain cells to take up glucose from the blood to maintain a safe blood sugar level.

Type 2 diabetes results when cells no longer respond to insulin, leading to high blood sugar. A drop in circulating glucose in our tests could mean that our bodies had become more sensitive to insulin, removing more glucose from the blood – a sign of improved blood sugar control. We also lost weight, by 1.5 kilograms on average.

Total blood cholesterol, a risk factor for heart disease, dropped by almost 5 per cent, from 4.6 to 4.4 mmol/l. A healthy amount is considered anything below 5.2 mmol/l. "Basically, you're getting improved glucose and cholesterol management," says Moore.

The benefits weren't just physical. Ratings of sleep quality on a scale from 1 to 5 rose by just over 10 per cent, improving from 3.9 to 4.3. Ratings of how well we could concentrate soared 18 per cent from 3.8 to 4.5. "It represents a significant effect on quality of life and work performance," says Jalan, although he acknowledges that self-reported experiences are open to bias.

The only negative was that people reported less social contact.

Our experiment gives no indication of how long the improvements persist. "Whether it's 15 days or six months, we don't know," says Jalan. However, it lays the ground for larger studies, he says.

"What you have is a pretty average group of British people who would not consider themselves heavy drinkers, yet stopping drinking for a month alters liver fat, cholesterol and blood sugar, and helps them lose weight," says Moore. "If someone had a health product that did all that in one month, they would be raking it in."

Continue reading page |1|2

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We don't need to land to find life on Europa

"All these worlds are yours. Except Europa. Attempt no landing there." So warned the protectors of life on Jupiter's icy moon in 2010: Odyssey Two, by Arthur C. Clarke.

The novel's omnipotent aliens are adamant that the life forms inhabiting Europa's oceans should be left to evolve without interference.

The prospect of finding extraterrestrial life on Europa has inspired real scientists to plan ambitious – and expensive – missions. But they, too, are cautious about landing. The risk of contamination is very real: no one wants to introduce earthly bugs to a pristine environment.

Now the discovery that Europa is emitting plumes that could be checked for biomarkers offers a tantalising alternative (see "Water plumes spark a race to Jupiter moon Europa"). Perhaps we can detect life without attempting a landing at all.

This article appeared in print under the headline "ET: off limits but within reach"

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