Saturday, January 30, 2021

Being fat can PROTECT you from certain diseases: People who eat foods high in saturated fats including bacon and cheese are less likely to develop acute pancreatitis

We're regularly told to minimise the amount of saturated fats we consume, but a new study suggests that eating foods rich in these fats could actually offer some protection against certain diseases.

Researchers have revealed that eating foods rich in saturated fats, including cakes, bacon and cheese, may reduce your risk of acute pancreatitis.

The US team analysed data from people in 11 countries on how different fats consumed by different nations – either unsaturated or saturated – are linked with the serious condition, where the pancreas becomes inflamed.  

Saturated fat is found in butter, lard, fatty meats and cheese – foods heavily consumed in western societies – while unsaturated fats are mostly found in oils from plants and fish and are prevalent in Asian and some South American diets.

The scientists found that high levels of unsaturated fat stored around the abdominal organs generates more of a certain type of molecule that triggers cell injury, inflammation and even organ failure.   

Official advice from the NHS is to swap saturated fats for unsaturated fats in our diet to reduce the risk of heart disease.

While this study does not challenge this advice, it does suggest obesity can sometimes protect patients during certain types of acute illnesses.

This 'obesity paradox' has already been controversially suggested in previous studies, but not without backlash from other experts.

Foods high in saturated fat include:

Fatty red meats like pork and beef
Butter and products made of butter, including pastries and pies
Cakes and biscuits
Cheese, cream and ice cream

Unsaturated fats are those found in:

Nuts and seeds
Fish such as salmon and mackerel
Vegetable oils, including olive oil
Peanut butter

'Here, we find that a higher proportion of dietary unsaturated fat can worsen AP [acute pancreatitis] outcomes at a lower adiposity than seen in individuals with a higher proportion of saturated fats in their diet,' say the researchers in their paper, published today in Science Advances.

Draft guidelines from the World Health Organisation recommend people get fewer than 10 per cent of their daily calories (150kcal-250kcal) from saturated fat and instead try to replace them with unsaturated.

Previous reports have observed that obesity appears to protect patients with acute medical issues such as burns, trauma and cardiovascular surgery.  

'Obesity sometimes seems protective in disease,' say the study authors, who are from the Mayo Clinic in Arizona and the Washington University School of Medicine in Missouri.

'This obesity paradox is predominantly described in reports from the Western Hemisphere during acute illnesses.'

However, the impact of fat composition on disease severity has remained unclear.

To better understand 'the obesity paradox', researchers assessed how the type of fats populations consume influence body fat composition and correlate with acute pancreatitis severity.

The team used 20 clinical reports from 11 countries that associated pancreatitis severity with a cutoff body mass index (BMI) of 30 – the point at which someone is officially classified as obese.

They also used seven clinical reports with a cutoff BMI of 25, and dietary fat data from the Food and Agriculture Organisation.

The researchers found a moderate correlation between the percentage of patients with severe acute pancreatitis and their unsaturated fat intake.

But they also observed that a severe form of this disease occurred in individuals with lower BMIs in countries that consumed food with fewer saturated fatty acids.

According to the team, visceral fat (stored around the abdominal organs) with a high unsaturated fat content leads to the generation of more non-esterified fatty acids (NEFAs).

These NEFAs trigger cell injury, systemic inflammation, and organ failure even in individuals with comparatively low body mass indexes (BMIs).

In contrast, visceral fat with a higher saturated fat content interferes with the production of these fatty acids, resulting in milder pancreatitis.

Researchers then conducted further experiments with mice in the lab.  

To test how fat composition affects pancreatitis outcomes, researchers fed mice either a diet enriched with linoleic acid (an unsaturated fatty acid) or palmitic acid (a saturated fatty acid).

When the researchers induced pancreatitis in the mice, only 10 per cent of those on the linoleic acid diet survived after three days.

This compared with 90 per cent of those on the palmitic acid diet.

By comparing the mice’s fat pads and fatty acid serum levels, the researchers found that saturated fats do not interact favourably with the enzyme pancreatic triglyceride lipase.

This leads to lower production of damaging long-chain NEFAs.  

'Therefore, visceral triglyceride saturation reduces the ensuing lipotoxicity despite higher adiposity, thus explaining the obesity paradox,' the researchers say.

The authors note that other factors they did not study, such as sex, genetic background, and the presence of other diseases, may also contribute to severe acute pancreatitis rates in humans.

In 2019, a team of scientists challenged the World Health Organisation's recommendation for people to cut down on saturated fats.

In their article published in the British Medical Journal, they argued that avoiding saturated fats entirely instead of considering the more general health impact of foods may mean important nutrients are missed.

Eggs, dark chocolate, meat and cheese, for example, are high in saturated but also contain a lot of vital nutrients and vitamins.

Researchers criticised the World Health Organisation for recommending that people cut down on saturated fats instead of being more specific.

In their report they said: 'Scientific and policy missteps may have led to many unnecessary deaths globally, and lessons should be learned.'

Saturday, January 23, 2021

Effect of Vitamin B12 Injection on the Vocal Performance of Professional Singers

Hagit Shoffel-Havakuk et al.


Importance  One-third of singers and vocal professionals report experiencing a benefit from empirical vitamin B12 injections for improvement of mild singing-related symptoms (eg, reduced stamina, vocal fatigue, and effort). However, there is no objective evidence to support or refute these claims.

Objective  To assess the presence and magnitude of the effect of empirical vitamin B12 injection on the vocal performance of singers.

Design, Setting, and Participants  A randomized, double-blind, placebo-controlled, crossover trial was conducted from November 7, 2017, to November 30, 2018, at an academic voice center among 20 active adult singers without dysphonia but with mild vocal symptoms. Individuals with known or suspected vitamin B12 deficiency or active or recent vitamin B12 treatment were excluded. Analysis was on a per-protocol basis.

Interventions  Participants were randomized to receive an intramuscular (deltoid) injection of either vitamin B12 (1000 μg of cyanocobalmin) or placebo (0.9% sodium chloride). After a washout period of at least 4 weeks, participants were crossed over to receive the opposite injection. Both the investigators and participants were blinded to the order of injections.

Main Outcomes and Measures  The participants completed the Singing Voice Handicap Index–10 (SVHI-10), the Voice Fatigue Index (VFI), and the Evaluation of the Ability to Sing Easily (EASE) before each injection and at intervals of 1 hour, 3 hours, 24 hours, 72 hours, and 1 week after the injection. The primary time point assessment was 72 hours after injection, and the SVHI-10 score was the primary outcome measure.

Results  Twenty singers (10 men; median age, 22 years [range, 19-42 years]) were enrolled. The improvements after either placebo or vitamin B12 injections were comparable to each other. At 72 hours after the vitamin B12 injection, the median difference in the SVHI-10 score was 1 (95% CI, –1 to 2) compared with 3 (95% CI, 0-4) after placebo. The median difference between differences at 72 hours between placebo and vitamin B12 injections were 1.5 (95% CI, –2 to 5) for the SVHI-10, 1 (95% CI, –9 to 9) for the VFI, and –1 (95% CI, –3 to 2) for the EASE. The improvements after both injections failed to reach the estimated minimal clinically important difference. Of the 20 participants, 4 (20%) reached the estimated minimal clinically important difference in their SVHI-10 score after 72 hours for both vitamin B12 and placebo injections.

Conclusions and Relevance  This randomized, double-blind, placebo-controlled, crossover trial found that after empirical vitamin B12 injection to improve mild voice-related symptoms, the improvement in self-reported voice measures in singers shows no meaningful difference compared with placebo.

Saturday, January 16, 2021

This'll shake you... too LITTLE salt can be bad for us

Health chiefs constantly tell us to slash our salt intake, but new research suggests that having too little also carries health risks.

Doctors at the Royal Free Hospital in London found that too little salt in the body, over a long period of time, weakens the immune system, increasing the risk of infections.

Patients with Gitelman syndrome and Bartter syndrome, which cause an excessive loss of salt through the kidneys, were more likely than others to suffer from recurrent fungal and urinary infections.

The authors of the study, published in the medical journal Nature Communications, explain that a lack of salt halts the production of a type of white blood cell called interleukin 17, which detects and destroys infections.

Sunday, January 10, 2021

Is eating fish healthy?

We know of fish as a healthy food, but pregnant women are told to limit consumption. Do the health benefits of eating fish outweigh the risks, particularly as stocks grow more depleted?

In recent decades, one of the biggest concerns about fish has been its potentially harmful levels of pollutants and metals.

One concern is polychlorinated biphenyls (PCBs). Although they were banned by the 1980s, these industrial chemicals were used worldwide in huge quantities and still linger in our soil and our water. They’ve been associated with a range of negative health effects on everything from the immune system to the brain. While PCBs are present in everything from dairy products to drinking water, the highest levels tend to be found in fish.

The solution for limiting your intake of PCBs from fish may be counterintuitive, says Johnathan Napier, science director at Rothamsted Research in Hertfordshire, England.

“The possible problem of the accumulation of toxic compounds is likely to be more of concern for wild species that are caught for direct human consumption,” he says. Because the marine-derived ingredients that farmed fish are fed are cleaned or scrubbed to remove toxins, farmed fish is often safer than wild.

That isn't always the case, however, and PCB content also fluctuates seasonally.

While they are generally viewed as better for our health and the environment, large-scale aquaculture has its own problems, such as polluting the oceans with waste and becoming breeding grounds for diseases that can spill over into the wild.

Another worry is mercury, a neurotoxin that could pass through the placenta and affect child development. There are numerous links between mercury ingestion and cancer, diabetes and heart disease. While mercury can be found in other foods, such as vegetables, one study found that 78% of participants' mercury intake came from fish and seafood.

In fish, mercury levels are high enough for the US Food and Drug Administration (FDA) to recommend that pregnant people limit their intake of some popular fish, including halibut and tuna, to one serving a week.

But concerns around the accumulation of heavy metals in fish has been overexaggerated, says Napier. He says it’s only a problem when it comes to species that live a particularly long time – like swordfish, which can live for 15 to 20 years. Swordfish has a mercury concentration of 0.995 PPM, while salmon, which lives on average for four to five years, has around 0.014. While research is still ongoing, the US's Environmental Protection Agency currently states that for pregnant women, the highest allowable average mercury concentration per serving, if eating one serving a week, is 0.46 PPM.

But the issue is set to worsen, as there’s evidence to suggest that levels of mercury found in the ocean may rise as the planet warms. Research has found that as Arctic permafrost melts, it releases mercury that was trapped in frozen ground into waterways.

While mercury poses a small risk, Napier says there stands to be much more to gain from fish – particularly marine omega 3.

Consumption of oily fish, including salmon, tuna, sardines and mackerel, has been linked to a lower risk of cardiovascular disease, thanks to its marine omega 3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

“Both EPA and DHA play a plethora of important roles in human metabolism, but we can’t make them very effectively in our bodies, so it’s really important to have them as part of our diet,” Napier says.

“Population data looking at the effects of marine omega 3 on health is consistent and strong, and shows that people with a higher intake of EPA and DHA have a lower risk of developing common diseases, particularly heart disease, and dying from them,” says Philip Calder, head of human development and health at England’s University of Southampton.

One way to avoid potential damage from mercury exposure while still getting omega 3 is to take fish oil supplements. However, research recently carried out on behalf of the World Health Organization (WHO) looking at omega-3 supplements across range of health outcomes found they don’t have the same effect as eating oily fish.

“Our findings suggest a very small beneficial effect [in terms of lowering the risk] of dying of coronary heart disease,” adds Lee Hooper, a reader at the University East Anglia and one of the WHO study’s researchers.  

Around 334 people would have to take omega-3 supplements for four or five years for one person not to die from coronary heart disease, she says.

But there’s an issue with population studies like Hooper’s. While some oily fish, such as sardines, aren’t relatively expensive, fish is generally associated with a more expensive diet. It’s widely accepted that socioeconomic status affects health outcomes – so it’s possible that families who eat more fish also have higher incomes and healthier lifestyles in general.

Normally, researchers will take into account such confounding factors, Calder says, but they might not think of everything that could skew a study’s results. The WHO report was a review of 79 studies, which each will have differed in how they controlled for participants' socioeconomic status.

But intervention trials, where people are randomly assigned to a group and an intervention such as taking omega-3 supplements is measured, have problems, too. Analysing potential health impacts of EPA and DHA deficiency, for example, is difficult, Calder says, because people start trials with varying levels of omega-3 in their systems.

In addition, research shows that fish might impact everyone’s health to varying degrees, depending on how well they can convert precursor forms of EPA and DHA. This difference could come down to a person’s overall diet and lifestyle, Calder says, but genetic differences could also play a role.

Another reason the health benefits of fish may vary is because of how fish are raised.

Marine ecosystems are full of omega-3: little fish eat marine plankton, and get eaten by bigger fish, and the whole food chain passes on omega-3 to humans. But the system is different for farmed fish, which is what most of us eat. “In a fish farm, it’s just thousands of fish in a cage. They eat what they’re given by the fish farmer,” Napier says.

As they would in the wild, farmed fish normally are fed smaller fish species. In the wild, however, fish would eat a variety of smaller fish. In farms, fish are often fed fish meal made from Peruvian anchovies.

But these anchovies are already being fished at the maximum level at which the industry can be sustained, Napier says – even as global aquaculture is expected to keep growing. According to the UN’s Food and Agricultural Organization, growing demand for fish oil supplements means that the fish oil contained in the fish meal fed to farmed fish is diminishing. That means the amount of omega-3 in the fish we consume is declining, too.

“There are finite levels of omega fish oils that come out of the ocean each year – that’s all we’ve got,” he says. “If aquaculture is expanding but the most important input you need to put into people’s diets, the fish oil, is completely static, you’re diluting how much is fed to the fish.”

Research from 2016 found that levels of EPA and DHA in farmed salmon decreased by half over a decade. Even so farmed salmon still has more omega-3 than wild salmon, Napier says.

“Wild salmon swims back forth across the Atlantic; it’s a lean animal. It’s not laying down fat because it’s burning everything it consumes,” he says.

Still, because there isn’t robust research suggesting major health inadequacies for people who don’t eat fish, Calder says it’s difficult to definitively say that fish is essential to overall human health. However, he adds, it is clear that omega-3 promotes health and reduces the risk of disease.

But getting to the bottom of how healthy fish really is may be a moot point after long. “Since fish isn’t a sustainable food source, research now will probably focus on solutions to that – such as how to grow algae and harvest omega-3 oil, instead of more studies into fish,” Calder says.

Individuals can help by choosing the most sustainable fish species available. Guides like the one by the Marine Conservation Society show which fish are the best, with 50 of the 133 species listed coming up as mostly sustainable, “good” choices – including, fortunately, popular favourites like farmed salmon, prawns, cod, mackerel, mussels, oysters and farmed halibut.