Saturday, November 28, 2020

Smog-infested Delhi slum that may show link between pollution and Covid-19 levels

It's an obvious conclusion to blame the illness on pollution but it may not be so.  The polluted areas are also ones where poor people live and we already know that poor people have worse health.  

But a distinction could be drawn between low levels of pollution and the extraordinary levels in Delhi.  The body can cope with low level polution but very high levels may overwhelm its coping measures.

So the point is that the respiratory illness noted below may be specific to levels of polution found in the Third world only.  Extrapolating it to the developed world would be adventurous

During the winter months, it’s hard to tell whether the sun rises at all in the New Delhi neighbourhood of Sukhdev Vihar.

Enveloped in a thick layer of impenetrable smog, the natural light is blocked out and a gloomy shadow hangs over the hundreds of high-rise residential flats.

Breathing the air outside triggers waves of nausea and a throbbing headache, while walking up a flight of stairs leaves people breathless.

The sprawling megacity of New Delhi, home to approximately 30 million people, is the most polluted capital in the world.

Earlier this month, the Air Quality Index (AQI) - which measures the level of pollutants - exceeded 1,300 in Sukhdev Vihar, over thirty times the safe level set by the World Health Organization.

The level of pollution in New Delhi is hazardous all year, thanks to largely unregulated industrial and vehicular emissions, but it peaks during the winter months when thousands of farmers in surrounding states burn crop stubble to fertilise their soil.

As the pollution levels soared in the city in November the number of daily Covid-19 cases also rose, doubling to more than 7,000.

This bucked the national trend, with India as a whole seeing half the number of new daily infections halving from its September peak.

Public health experts are still exploring the link between Covid-19 and air pollution but initial reports indicate a strong correlation.

A Harvard University study of 3,000 districts in the United States found that areas witnessing small increases in pollutants also had a large uptick in Covid-19 fatalities.

In late October, a second study by a group of German researchers found 15 percent of global deaths from the virus could be attributed to long-term exposure to air pollution.

There has been both a 70 percent increase in the number of Covid-19 patients and also far more cases where patients have severe symptoms since pollution began to surge in New Delhi, according to Dr Sumit Ray, a critical care doctor at Holy Family Hospital in Sukhdev Vihar.

“The direct effect is on the lungs, prolonged exposure to pollutants makes your airwaves hyper-reactive and they go into constriction, then reacting badly to any infection,” explains Dr Ray.

“Long-term exposure to air pollution causes damages to the air sacs themselves and if someone gets a respiratory infection it becomes much more difficult to fight it off because they already have lung damage.”

The Covid-19 fatality rate in Holy Family Hospital has increased from 3.3 per cent between June and September to 5.05 percent since October 1.

Air pollution can also cause underlying health problems such as heart disease, which in turn can cause the fatality rate from Covid-19 to soar.

A three-month study from the virus epicentre in Wuhan found Covid-19 patients with heart disease had a fatality rate of 16.7 percent, compared to four percent for those without.

The record-breaking pollution levels in Sukhdev Vihar are exacerbated by a waste-to-energy plant that pumps out toxic gasses every evening.

“I receive a lot of patients with breathing difficulties, especially in October and November” explains Dr M. Rehman, who runs a clinic in the neighbourhood.

“Many inhabitants are asthmatics and are forced to use inhalers, even the younger generation, and I have seen many people die of pulmonary disorders.”

Despite growing public outrage the Delhi Government has failed to make any dent in lowering pollution levels.

Politicians are cautious to limit industrial growth and attempts to curb stubble burning have failed in surrounding states, with the practice so entrenched.

Saturday, November 21, 2020

The Corn Oil Controversy: Are Polyunsaturated Fats Bad For Us?

Rummage around the fringes of nutrition “science” for a while and you’ll soon bump into a strongly held belief that the vegetable oils most of us consider a healthier option—like canola, soy, corn, safflower, peanut and soy oils—will actually lead to your grizzly (drizzly?) demise, usually via the route of obesity, heart disease and diabetes.

Detractors lump these vegetable oils into the bracket “industrial seed oils,” with hashtags such as #vegoilsucks or #fakefats, and emotionally charged narrative around the “chemicals” used to extract and refine them (in fact, refining to remove free fatty acids, gums and other impurities makes vegetable oils less likely to smoke and oxidize and thereby potentially safer for human health).

For the most part, it’s proponents of the paleo and other “ancestral” diets who promote the theory that seed oils are bad for us. The paleo diet postulates that the only healthy foods are those that were around during the Paleolithic era—which obviously doesn’t extend to a bottle of vegetable oil for your stir fry or salad. But the half-baked theory completely overlooks that subsequent evolutionary changes have allowed us to adapt to a more industrialized diet.

There’s another reason the seed-oils-are-death brigade give for ditching vegetable oils that is more cited than any: their high content of polyunsaturated fats. The irrational hatred runs alongside a conspiracy theory that the American Heart Association, who have always promoted vegetable oils over animal fat, grew their profile based on funding from Proctor and Gamble, makers of the first 100% vegetable oil brand, Crisco.

So, what does science actually say about polyunsaturates, and their effect on health?

The Sydney Diet Heart Study

Much of the backlash against polyunsaturated fats centers around a retrospective data dredge of a study conducted in Sydney, Australia. The original 1970s study involved men aged 30-59 with coronary heart disease who ate either a safflower oil-supplemented diet where 9.8% of calories came from saturated fatty acids and 15.1% from polyunsaturated fatty acids (mostly linoleic acid), or one where saturates contributed 13.5% and polyunsaturates 8.9% of total calories. Survival, measured at the time only in terms of all-cause mortality, was slightly better in the group that ate more saturated fats (typically found in meat and dairy), though multivariate analysis showed that none of the dietary factors were significantly related to survival.

The 2013 re-analysis showed that men with a high intake of safflower oil had a statistically higher risk of dying from a second cardiac event, even though their cholesterol levels fell.

However, in the context of now, these results are of little concern, given nobody recommends linoleic acid intake being as high as in the treatment arm of this decades-old study anymore. The current US recommendations are for 5-10% of energy to be provided by linoleic acid, while actual intake comes in at around  6-7% according to dietary surveys.

For the men in the Sydney study, 70% of whom were smokers with already damaged arteries, piling excessive quantities of linoleic acid into them wasn’t a sensible thing to do in retrospect: we now know that when linoleic acid oxidizes, which it’s chemistry means it has a tendency to do, it creates potentially atherogenic metabolites. Perhaps even more relevant, is that the safflower oil was consumed in the form of margarine, which in the 1970s, was almost certainly likely to have been partially hydrogenated and therefore to contain trans fats, which have since been found to increase risk of heart disease.

The Minnesota Coronary Experiment

The Minnesota Coronary Experiment is also regularly used as evidence for rejecting vegetable oils and embracing animal fats.

The original randomized controlled trial tried but failed to show that replacing saturated fatty acids in the diet with linoleic acid from corn oil reduced coronary heart disease (CHD).

A 2016 reinvestigation, which unearthed and used new raw data, focused on a subgroup of 2355 of the original 9570 participants on whom blood cholesterol measurements were available. It confirmed no overall difference in all-cause mortality between groups, but also found that the greater the fall in blood cholesterol, the greater the risk of death.

However, despite the brouhaha that surrounded this study and the new data, it still didn’t uniquely incriminate polyunsaturates, as the noted association between a fall in blood cholesterol and a greater risk of death occurred both in the group eating a lot of corn oil and the control group. There’s also the confounding complication that illness can result in a fall in blood cholesterol.

More recent analysis lets linoleic acid off the hook

A big multinational review published last year in Circulation gives reason to be fairly relaxed about polyunsaturated fats. The individual-level pooled analysis of 30 cohort studies involved 15,198 cardiovascular events occurring among 68, 659 participants, with medians of follow-up ranging from 2 to nearly 32 years. The analysis showed higher levels of linoleic acid to be significantly associated with lower risks of total CVD, cardiovascular mortality, and ischemic stroke. Arachidonic acid levels—arachidonic acid is a metabolite of linoleic acid that has also come in for some stick as a potential driver of inflammation in arteries —were also not associated with a higher risk of cardiovascular events.

As you were — seed oils won’t kill you!

As unexciting as it is, current dietary advice— including from the American Heart Association—probably has it about right. That advice doesn’t promote large amounts of polyunsaturates anymore, but recommends a balance of monounsaturates and polyunsaturates, with the additional recommendation that polyunsaturates consumed should not be just the omega-6 variety (linoleic acid) but should also include omega-3s.

In terms of an everyday diet, that means consuming a mix of vegetable and olive oils—or if you were to just pick one, canola oil, as it has a good balance of monounsaturates, omega-6 polyunsaturates and some omega-3 polyunsaturates—as well as having 1–2 oily fish meals weekly. Other foods to include as a part of a heart-healthy portfolio of foods include more dietary fiber, less salt, more fruit and vegetables, along with modest alcohol.

The bottom line? “Seed oils” aren’t poison, nor are they the sole dietary answer to heart disease either. It’s 40 years since scientists flirted with this notion, and now it’s time to move on.

Saturday, November 14, 2020

Vegans have TWICE as much sex as meat-eaters and are more adventurous in the bedroom, survey reveals

It should be noted that this finding is based on the statements of married people using a dating site to start affairs.  So the generalizability of the findings to the population at large is unknown.  

The findings are in any case probably the result of "faking good".  As very deviant people, vegans have a strong incentive to promote themselves as being superior people.  They would appear to have done that in their responses to this survey.

The findings are therefore unlikely to represent real-life even within the group concerned

Vegans have twice as much sex as meat-eaters and are more willing to experiment in the bedroom, according to a new survey.

Dating website found over half of the vegans asked claimed they have sex four times a week, while only half of meat-eaters reported having sex twice in the same time period.

The research found two thirds of vegans were prepared to experiment in the bedroom, while over half of the meat-eaters surveyed admitted they were less adventurous between the sheets, reports the Mirror.

The survey also suggested that vegans have a better time in the bedroom with 84 per cent saying they're satisfied with their sex life compared with a measly 59 per cent of those with a meat-based diet.

Meanwhile 35 per cent of those on a meat-based diet describe themselves as 'givers', compared to 58 per cent of vegans.     

Spokeswoman Jessica Leoni said: 'Vegans are masters of seduction it would appear. Our statistics don't lie and vegans eat foods known for their aphrodisiac qualities such as ginseng and aniseed.'

Saturday, November 07, 2020

'Super pea' could reduce risk of Type 2 diabetes, researchers find

A "super pea" should be added to flour to stave off diabetes, Imperial College London researchers have said, with a study finding that it helps prevent blood sugar spikes.

A type of wrinkled pea may help control blood sugar levels and could reduce the risk of Type 2 diabetes, a study published in the journal Nature Food suggests.

Scientists have said incorporating "super peas" into foods in the form of whole pea seeds or flour may help tackle the global Type 2 diabetes epidemic.

The research focused on a naturally occurring wrinkled pea which, while genetically identical to the regular smooth peas often found in supermarket frozen food aisles, contains higher amounts of so-called resistant starch due to a natural mutation.

"If peas were not harvested fresh for freezing, but allowed to mature on the plants, it is likely that many would develop into wrinkled seeds," said Dr Katerina Petropoulou, of the Centre for Translational and Nutrition Food Research at Imperial College London and first author of the research.

The body breaks down starch to release sugar but resistant starch is broken down more slowly, meaning sugar is released more slowly into the bloodstream. This results in a more stable increase rather than a "sugar spike" in which blood sugar levels rise sharply after a meal, researchers say.

The same effect was seen when consuming flour made from wrinkled peas incorporated in a mixed meal. Researchers suggested this could be important because frequent, large sugar spikes are thought to increase the risk of diabetes.

They added that flour from these peas could potentially be used in commonly consumed processed foods which, if eaten over the long term, could prevent these sugar spikes.

In the experiments, researchers at Imperial College London, the John Innes Centre, Quadram Institute Bioscience and the University of Glasgow compared the larger, mature wrinkled peas, which produced a lower overall carbohydrate content, with normal peas.

The team gave healthy volunteers a mixed meal including 50 grams of wrinkled peas, and in a series of control experiments gave them regular peas. They also added a tracer molecule to the peas, so they could track how they were absorbed and digested by the human gastrointestinal tract.

The experiments were repeated using flour made from wrinkled peas or regular peas.

To further investigate the impact of long-term consumption, they recruited 25 volunteers and asked them to consume pea hummus and mushy peas made from wrinkled or regular peas for a period of four weeks.

Previous research from the same group suggested that, as these bacteria ferment the starch, they produce compounds called short chain fatty acids. These compounds help boost the function of cells that produce insulin, which helps control blood sugar.

Further tests using a mimic of the human gut showed that the way in which the peas were prepared and cooked affected how quickly they were digested.

Dr Petropoulou said: "There is much evidence that diets rich in a type of carbohydrate called resistant starch have a positive impact on controlling blood glucose levels, and hence reduce susceptibility to Type 2 diabetes."

Professor Pete Wilde, of the Quadram Institute, said: "This study has shown us that, by preparing these peas in certain ways, we can further reduce blood sugar spikes, opening up new possibilities for making healthier foods using controlled food processing techniques."

The researchers are now planning further trials involving volunteers with early stage Type 2 diabetes.

Sunday, November 01, 2020

Diet Coke could be just as bad for you as sugared one: Artificially sweetened drinks and sugary beverages BOTH increase the risk of heart disease by up to 20%

They were probably looking just at poverty.  Poor people drink a lot of fizz and are generally unhealthy.  So the health outcomes that they  found were probably a poverty effect rather than a sweetner effect.  They had no data on income so could not control for poverty

The study was "Sugary drink consumption and risk of cancer: results from NutriNet-Santé prospective cohort by Chazelas et al.

An additional concern about the study is that it was an internet study only -- with all the biases consequent on that.  Less sophisticated people would have been much under-represented in the study sample

French researchers tracked more than 104,000 people over ten years, looking at how many sugary or sugar-free soft drinks they consumed.

They found the consumers of both sugary and artificially sweetened drinks are up to  20 per cent more likely to suffer heart disease, stroke or heart attacks than those who avoid soft drinks.

The scientists, at Sorbonne University in Paris, split people into three groups based on their consumption of sweetened beverages.

These categories were labelled as non-consumers, low consumers and high consumers and drinks split into either artificially sweetened or sugary.

A sugar content equalling or exceeding five per cent meant it was considered sugary whereas a sub-five percentage and the presence of 'non-nutritive sweeteners' was enough to be classified as an artificially-sweetened beverage.  

The study required participants to fill in three daily diet diaries every six months.

A decade of records from 2009 to 2019 looked for any relationship between intake and heart-related issues, such as stroke, transient ischemic attack (TIA), myocardial infarction, acute coronary syndrome and angioplasty.

A study of more than 5,000 US-based couples found that in 79 per cent of relationships, both people fall into the 'non-ideal' category for heart health. On average, couples also share the same risk factors which can make events such as a stroke or heart attack more likely.  This is due to both people falling into an unhealthy routine with poor diet and inadequate levels of exercise.

It revealed people who drank lots of low-sugar diet drinks had the same elevated heart disease risk as those who drank the full-sugar versions.

People who are considered to be high consumers of either artificially sweetened or sugary drinks were 20 per cent as likely to suffer heart problems than people who avoided both types of soft drinks, sticking to other options such as water, tea or coffee.

There was no difference between the two types of drink.  

Diet drinks such as Diet Coke, and the artificial sweeteners they contain, are often marketed as a way of reducing calorie and sugar intake.

But experts are concerned at growing evidence that artificial sweeteners alter the body's metabolism, increasing the speed at which sugar is absorbed.

Lead author Eloi Chazelas concluded: 'Higher intakes of sugary drinks and artificially sweetened beverages were associated with a higher risk of cardiovascular diseases, suggesting that artificial sweeteners might not be a healthy substitute for sugary drinks.'

'These data provide additional arguments to fuel the current debate on taxes, labeling, and regulation of sugary drinks and artificially sweetened beverages.'

'To establish a causal link, replication in other large-scale prospective cohorts and mechanistic investigations are needed.'