Tuesday, July 30, 2024


Fizzy drinks are the new tobacco for young people... that's why I believe that Coca-Cola should be banned from sponsoring the Olympics

The evidence for this claim is very poor. The Results section for the academic study they cite is below:

Results During an average of 18.5 years of follow-up, 3447 (22.3%) participants with incident CVD and 7638 (49.3%) deaths were documented. After multivariable adjustment, when comparing the categories of lowest intake of beverages with the highest intake, the pooled hazard ratios for all cause mortality were 1.20 (95% confidence interval 1.04 to 1.37) for sugar sweetened beverages (SSBs), 0.96 (0.86 to 1.07) for artificially sweetened beverages (ASBs), 0.98 (0.90 to 1.06) for fruit juice, 0.74 (0.63 to 0.86) for coffee, 0.79 (0.71 to 0.89) for tea, 0.77 (0.70 to 0.85) for plain water, 0.88 (0.80 to 0.96) for low fat milk, and 1.20 (0.99 to 1.44) for full fat milk. Similar associations were observed between the individual beverages and CVD incidence and mortality. In particular, SSB intake was associated with a higher risk of incident CVD (hazard ratio 1.25, 95% confidence interval 1.03 to 1.51) and CVD mortality (1.29, 1.02 to 1.63), whereas significant inverse associations were observed between intake of coffee and low fat milk and CVD incidence. Additionally, compared with those who did not change their consumption of coffee in the period after a diabetes diagnosis, a lower all cause mortality was observed in those who increased their consumption of coffee. A similar pattern of association with all cause mortality was also observed for tea, and low fat milk. Replacing SSBs with ABSs was significantly associated with lower all cause mortality and CVD mortality, and replacing SSBs, ASBs, fruit juice, or full fat milk with coffee, tea, or plain water was consistently associated with lower all cause mortality.

For start, it was a study of DIABETICS so may not generalize beyond that. And it can be seen that all the HRs were very low and were achieved only by discarding the middle ranges of their data. And there appears to have been no control for the big confounder in such studies: income. Nothing firm can be conluded from this study but the safest conclusion seems to be that Coke causes you no harm

Link for thestudy:
Because Coke is so popular, the superior people WANT it to be bad for you, but the evidence is not very co-operative



If you were watching the Paris Olympics and saw a winning athlete cross the finish line, light a cigarette and boast about the health-boosting benefits of their favourite tobacco brand, you'd be as surprised as you were disgusted.

Yet it's startlingly true that tobacco companies were major Olympic sponsors right up until 1988, when cigarette brands were finally banned from advertising at the Games.

For the previous 60 years, tobacco-funded Olympic medal-winners had lined up to extol the virtues of smoking and push the now bizarre claim that it enabled athletes to lead healthy lives — among them, the iconic Jesse Owens, who won four gold medals for sprinting, relay and long jump at the 1936 Berlin Olympic Games, but who died from lung cancer aged 66 in 1980, after decades of heavy smoking.

The biggest earner of tobacco funding, though, was the International Olympic Committee (IOC), which took millions of pounds every four years from cigarette-brand sponsorship, from 1920 until it was banned.

But you may be shocked to learn that today the IOC still takes similarly vast sums from another major industry — one that, I believe, when it comes to damaging the health of young people may now have overtaken cigarettes.

That industry is soft drinks — and that money comes from the global beverage giant Coca-Cola, which has sponsored the Olympics Games since 1928.

Sources estimate that Coca-Cola nowadays pays the Olympics around £70 million a year in sponsorship. In exchange, Coca-Cola can use the Olympic Games' five rings on all its products.

As an investigation in the French newspaper Le Monde said in May, this huge money deal enables Coca-Cola to 'promote the world's most talked-about sporting event, all over the world, while generating priceless advertising opportunities for itself'.

Indeed, Le Monde said of Coca-Cola's tie-up with the Olympics: 'The partnership has become so close that it's hard to say who runs the Games.'

Across the Olympics, wherever you look, Coca-Cola branding is ubiquitous. Even before the Games began, the drinks giant had sponsored the Olympic torch relay, so that a Coca-Cola van constantly flanked the torch's two-month tour.

It is time that all this Coca-Cola sponsorship stopped. For good. Because, beyond tobacco, as a doctor who advocates for public health, I fear the health-destroying power of fizzy drinks more than anything else. Soft drinks damage people's bodies, and the bodies of children in particular.

And what's more frightening is that these products are so friendly-looking, so familiar and so pervasive that we've become accustomed to them and have forgotten the damage they wreak.

The harms of soft drinks are extremely well documented over hundreds of scientific papers.

As a 2022 report by the University of North Carolina's Global Food Research Programme warned, they are 'a key driver of modern surges in nutrition-related diseases worldwide, including obesity, type 2 diabetes, high blood pressure and heart disease — the leading causes of disability and death in the world'.

Furthermore, fizzy drinks have no real nutritional benefit. In fact, they contribute to under-nutrition when consumed in place of foods containing essential nutrients. A major review by Yale University of 88 studies showed that consumption of soft drinks meant lower intakes of milk, calcium and other nutrients.

In a large multinational European study published in the BMJ last year, higher levels of consumption of sugar-sweetened and artificially sweetened soft drinks was associated with increased risk of death from all causes. And in the shorter term, there's tooth decay — a national catastrophe in the UK that causes unbelievable suffering.

The link with soda was demonstrated last year when researchers at the universities of Cambridge and Glasgow reported how the sugar tax on soft drinks, introduced in 2018, has helped prevent more than 5,600 hospital admissions for children having to have their teeth pulled out under general anaesthetic.

Part of the problem is a chronic shortage of dentists, but this study underlined how closely sugary drinks also play a key role.

Nor is it just sodas with sugar: low or no-sugar 'diet' versions often contain the enamel-rotting likes of phosphoric, citric and tartaric acids. There is concerning evidence that these acids don't just rot teeth: the phosphoric acid may also dissolve your bones from the inside.

Beyond the sugar tax, these harmful products remain basically unregulated. My seven-year-old can use the money from the Tooth Fairy to go into any corner shop and buy a fizzy drink without it carrying any health warning either for her or her parents.

The idea that the Olympics would partner with brands that market such products is appalling. The Games are effectively the strongest health brand in the world — and sponsorship by the likes of Coca-Cola cements in the minds of children and adults that soft drinks are deeply associated with healthiness, athleticism and building strong bodies.

Indeed, Australian researchers reported in the journal Public Health Nutrition in 2011 that parents perceive food products as healthier when endorsed by a professional athlete, making them more likely to buy them for their children.

(It's not just Coca-Cola: while it's the most active soft drink sponsor in global sports worldwide, other drinks companies have contracts with sporting events, such as PepsiCo's sponsorship of the National Football League in the U.S.)

Big-brand soda sponsorship of sport also effectively undermines the wealth of scientific evidence of the dangers of soft drinks. Consumers look at the Olympic branding and ask themselves: 'Well, how bad can these products be if they're linked with the most elite physical competition in the world?'

The reach of this kind of marketing is titanic. The 2020 Tokyo Olympics had a broadcast audience of more than three billion worldwide, with online videos of the event being watched more than 28 billion times. Such marketing power demolishes anything a doctor can tell their patients.

These brands don't even position themselves as 'health-neutral'. Coca-Cola and the rest trade on the idea that their products can provide 'sports nutrition' — supplying energy for people to do sports and live super-active fun lives.

These companies even fund medical studies. A team from Oxford and the London School of Hygiene and Tropical Medicine mapped the universe of Coca-Cola's research funding, which involves almost 1,500 different researchers (probably not all direct grant recipients), corresponding to 461 publications funded by the brand. Many of these promoted the idea that exercise and activities could help offset the excess calories from products such as Coca-Cola.

But we know from the research evidence that this isn't what happens. We know that physical inactivity is not actually a significant part of the obesity epidemic: it's down to calorie over-consumption from soft drinks and other junk foods.

Yet, as it stands, Coca-Cola will continue to peddle this 'health' message for the next two Olympics at least, as they have locked the Games' organisers into a contract that lasts until 2032.

*********************************************

Monday, July 22, 2024


What, Exactly, Is so Great About the Mediterranean Diet?

The journal article referred to below is "Primary prevention of cardiovascular disease in women with a Mediterranean diet: systematic review and meta-analysis"

At: https://heart.bmj.com/content/109/16/1208

Meta analyses are very susceptible to finding what you want to find and the hazard ratios reported were very low, indicating very marginal effects. And it appears that the authors did not even begin to look at confounders such as ethnicity and social class.

So this study is a very poor recommendation for a Mediterranean diet indeed. The diet is essentially a fad and nothing more


Healthful eating is important at any age to lower the risk of obesity and keep the heart and everything else inside the body functioning well. This becomes especially crucial later in life, because good nutrition helps reduce the risk of chronic conditions like hypertension, high cholesterol and cardiovascular disease.

Being smart about what you eat also can affect your mood no matter your age—ultra-processed foods that include hydrogenated oils and high-fructose corn syrup, for instance, can increase the risk of depression—and some studies even suggest that healthy eating patterns can help delay or prevent developing dementia as we get older.

One way to improve your health while also eating some really wonderful foods, says Natalie Bruner, a registered dietitian and nutritionist with St. Clair Health, is to follow the Mediterranean style of eating.

Often referred to as the Mediterranean diet, it’s not so much a “diet” in the traditional sense, which is often defined by a bunch of hard-and-fast rules such as calorie counting and macro-tracking what you put in your mouth each day. Eating Mediterranean style is more of a lifestyle.

Patterned around the foods eaten by people who live in countries bordering the Mediterranean Sea—think Italy, Greece, Spain and Northern Africa—it puts a daily emphasis on plant-based dishes and heart-healthy, unsaturated fats such as olive oil instead the refined or hydrogenated oils that are so common in fast food meals and snack foods.

Half a Tablespoon of Olive Oil Daily May Protect Brain Health
The diet also emphasizes whole, minimally processed foods such as beans, seeds and legumes, antioxidant-rich fresh fruits and vegetables, and moderate portions of lean protein like chicken and seafood, with only the occasional serving of red meat.

Fish that is high in omega-3 fatty acids, such as salmon, is especially key since it can help reduce inflammation and pain caused by arthritis, which is common in seniors, as well as improve cholesterol levels.

“It’s not a diet that’s restrictive,” says Bruner. “You’re eating everything that’s good for you, which is great.”

Dietitians and nutritionists generally don’t like to characterize food as “good” or “bad” because that can lead to restrictive behaviors, she says. Yet multiple studies have shown that those who follow the Mediterranean diet have better cognitive function and brain health in old age, she says.

Because of its anti-inflammatory and antioxidant properties and its effectiveness at preventing obesity, there also are a lot of heart health benefits, along with the prevention and progression of diseases such as Type 2 diabetes, which is associated with lifestyle and diet.

For instance, according to a 2023 study in the medical journal Heart, women who follow a Mediterranean diet more closely than others had a 24 percent lower risk of cardiovascular disease. They also had a 23 percent lower risk of mortality.

**************************************************

Wednesday, July 17, 2024


WFH could be WRECKING your health, study suggests... as experts find that 'active commuters' have a 47 per cent reduced risk of death

I thought that some of the claims below sounded a bit fishy so I looked up the underlying journal article. Its full citation is below:

Health benefits of pedestrian and cyclist commuting: evidence from the Scottish Longitudinal Study, BMJ Public Health (2024). DOI: 10.1136/bmjph-2024-001295

But it appears to have been withdrawn. It is offline. It no longer exists anwhere on the net. So there must have been something REALLY fishy about it!


Working from home really is unhealthier, it seems, as a new study reveals 'active commuters' have up to a 47 per cent reduced risk of death.

People who cycle or walk to and from work have lower risks of mental and physical ill health compared to those who don't rely on these options, a large, long-term study suggests.

Active travel is considered to be one of the easiest ways to increase the amount of daily physical activity we do, and there is mounting evidence in favour of its health benefits.

Researchers from the Glasgow Centre for Population Health analysed data from 82,000 people in Scotland aged between 16 and 74.

Participants were asked questions including which mode of travel they used for the longest part, by distance, of their journey to work.

Nearly all people who walked to work had a commuting distance of less than 5km.

Four-fifths of cyclists also travelled less than 5km, while 14 per cent travelled 5-9.9km to work.

Meanwhile, 58 per cent of inactive commuters travelled further than 5km to get to work.

Over the 18-year study period, participants' health data was also collected.

The researchers found that compared with inactive commuters who drove or took public transport to work, those who walked or cycled had lower risks of death and mental and physical ill health.

Commuting by bike was linked with a 47 per cent lower risk of death and a 10 per cent lower risk of any hospital admission.

It was also associated with a 30 per cent lower risk of being prescribed a drug to treat cardiovascular disease, a 51 per cent lower risk of dying from cancer, and a 20 per cent lower risk of being prescribed drugs for mental health problems.

Meanwhile, walking to work was linked with an 11 per cent lower risk of hospital admission for any cause, a 10 per cent lower risk of being prescribed drugs to treat cardiovascular disease and a 7 per cent lower risk of being prescribed drugs for mental health issues.

The authors said active commuting has clear health benefits and can be an effective way to accommodate physical activity into everyday working life.

While the study did not directly compare the health of those working from home and active commuters, previous research has shown that working from home is linked with more sedentary behaviour and less physical activity.

Writing in the journal BMJ Public Health the researchers said: 'This study strengthens the evidence that active commuting has population-level health benefits and can contribute to reduced morbidity and mortality.

'That cyclist and pedestrian commuting is associated with lower risks of being prescribed medication for poor mental health is an important finding.

'This study has wider global relevance to efforts to reduce carbon emissions and to shift to more active and sustainable travel modes.'

While the study did not determine the ideal commuting distance, the researchers pointed out that national guidelines suggests adults should spend 30 minutes a day being moderately physically active.

Cycling and walking briskly would both count. Therefore, someone cycling at 14km/h would reach this with a 3.5km return journey to work.

Meanwhile, a pedestrian walking at 4.8km/h would achieve this guideline level after 2.4km.

************************************************



Monday, July 15, 2024


Study finds women who regularly eat ultra-processed foods are more likely to develop lupus

The journal article:

Ultra-Processed Food Intake and Risk of Systemic Lupus Erythematosus among Women followed in the Nurses’ Health Study Cohorts

The link

https://acrjournals.onlinelibrary.wiley.com/authored-by/Oakes/Emily+G .

This study was impressive for the range of controls used and for the fact that the HRs, while low, were a little higher than in most diet studies. But it was again a study of tertiles only, suggesting that there was no overall significance. Lupus is in any case a rare disease (213 cases out of 204,175 in this study). So the study is NO warrant to avoid UPFs


Women who regularly eat ultra-processed foods (UPFs) have a higher risk of developing a debilitating autoimmune disease, a study has suggested.

In a trial, those who had a diet rich in these foods – which are packed with artificial sweeteners and preservatives – were 56 per cent more likely to contract lupus, which leads to joint pain, skin rashes and fatigue.

And those who regularly consumed artificially sweetened beverages and sugary foods also had a 45 per cent greater risk of developing the condition.

The study, by researchers at Harvard University in the US, also found there was no connection between obesity and lupus – which suggests that the artificial ingredients in UPFs are to blame.

UPFs – such as ready meals, ice cream and some frozen food – have previously been linked to a number of life-threatening diseases, including cancer, Alzheimer’s and heart disease.

Systematic lupus erythematosus is a long-term condition where the immune system mistakenly attacks healthy tissue in the body.

Studies have shown that roughly one in every 1,000 people in the UK has lupus – and 90 per cent of sufferers are female.

While its causes are not fully understood, it has previously been linked to viral infections, certain medications, sunlight and the menopause.

But the research from Harvard, published in the medical journal Arthritis Care And Research, suggests there could be a correlation between the disease and eating foods that contain artificial colourings, sweeteners and preservatives.

However Professor Gunter Kuhnle, of the University of Reading, warned the research may not be conclusive.

‘Ultra-processed food may be one of the risk factors [for lupus] but there are likely to be other factors as well that may be more important,’ he explained.

‘People with a high-fat and high-sugar intake are more likely to have other conditions.

‘They are already less healthy, and that may be one of the reasons why this group of women are developing lupus.’

****************************************************

All my main blogs below:

http://jonjayray.com/covidwatch.html (COVID WATCH)

http://dissectleft.blogspot.com (DISSECTING LEFTISM)

http://edwatch.blogspot.com (EDUCATION WATCH)

http://antigreen.blogspot.com (GREENIE WATCH)

http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)

http://australian-politics.blogspot.com (AUSTRALIAN POLITICS)

http://snorphty.blogspot.com (TONGUE-TIED)

https://immigwatch.blogspot.com (IMMIGRATION WATCH)

http://jonjayray.com/short/short.html (Subject index to my blog posts)

***********************************************

Thursday, July 11, 2024


Air pollution can decrease odds of live birth after IVF by 38%, study finds

Oh Dear! Another "pollution" study that does not measure anything about people and pollution at all. The constancy of these empty reports has become boring. The journal abstract is here:
They have NO data on how much pollutant each person actually breathed in at the time concerned. They have data only on what the weather was like in one place at one time in Perth.

It's the usual failure of control. WHY was time a factor in implantation success? They say it was times of low pollution that generated the improvement. But was that in fact the influence at work?

That low pollution days were also days that were more congenial to exercise was not looked at but it is an easy inference that they were. So maybe what they have really found is that doing light exercise before implantation is beneficial, which is not at all improbable. It was the exercise that conferred benefit, not the low levels of pollution

And the odds ratios were in any case very low, suggesting a high probability of non-replicability

I'll leave it at that



Air pollution exposure can significantly decrease the chance of a live birth after IVF treatment, according to research that deepens concern about the health impacts of toxic air on fertility.

Pollutant exposure has previously been linked to increased miscarriage rates and preterm births, and microscopic soot particles have been shown to travel through the bloodstream into the ovaries and the placenta. The latest work suggests that the impact of pollution begins before conception by disrupting the development of eggs.

“We observed that the odds of having a baby after a frozen embryo transfer were more than a third lower for women who were exposed to the highest levels of particulate matter air pollution prior to egg collection, compared with those exposed to the lowest levels,” said Dr Sebastian Leathersich, a fertility specialist and gynaecologist from Perth who is due to present the findings on Monday at the European Society of Human Reproduction and Embryology annual meeting in Amsterdam.

Air pollution is one of the leading threats to human health and is estimated by the World Health Organization (WHO) to have caused 6.7 million deaths in 2019. Microscopic soot particles have been shown to cross from the lungs into the bloodstream and are transported to every organ in the body, raising the risk of heart disease, gastric cancers and dementia. The contamination has also being linked to reductions in intelligence.

“Pollution is harmful to almost all aspects of human health and it’s no surprise to me that reproductive health is also affected,” Leathersich said. “I’m hopeful that these findings will help to highlight the urgency of the situation – that climate change poses a serious and immediate threat to human reproductive health, even at so-called safe levels.”

The study analysed fertility treatments in Perth over an eight-year period, including 3,659 frozen embryo transfers from 1,836 patients, and tracked whether outcomes were linked to the levels of fine particulate matter, known as PM10. The overall live birthrate was about 28% per transfer. However, the success rates varied in line with exposure to pollutants in the two weeks leading up to egg collection. The odds of a live birth decreased by 38% when comparing the highest quartile of exposure to the lowest quartile.

“These findings suggest that pollution negatively affects the quality of the eggs, not just the early stages of pregnancy, which is a distinction that has not been previously reported,” Leathersich said.

The team now plan to study cells directly to understand why pollutants have a negative effect. Previous work has shown that the microscopic particles can damage DNA and cause inflammation in tissues.

Prof Jonathan Grigg, whose group at Queen Mary University of London uncovered evidence that air pollution particles are found in the placenta, said: “This study is biologically plausible since it has recently been discovered that inhaled fossil-fuel particles move out of the lung and lodge in organs around the body. Reproductive health can now be added to expanding list of the adverse effects of fossil fuel-derived particulate matter, and should prompt policymakers to continue to reduce traffic emissions.”

The link was apparent despite excellent overall air quality during the study period, with PM10 and PM2.5 levels exceeding WHO guidelines on just 0.4% and 4.5% of the study days, the scientists said. Australia is one of just seven countries that met the WHO’s guidelines in 2023, and this study is the latest to show evidence of harm even at relatively low levels of pollution.

Prof Geeta Nargund, a senior NHS consultant and medical director of abc IVF and Create Fertility, said further work would be crucial to better understand the full impact of air pollution, which disproportionately affects those from lower socioeconomic backgrounds.

“In the face of a global fertility crisis, a clear picture of the link between environmental factors such as air pollution and fertility health or treatment outcomes could play an important part in tackling falling fertility rates,” she said.

************************************************

Wednesday, July 10, 2024


Microplastics in Bloodstream Increase Stroke Risk 4.5-Fold: Study

"The study SUGGESTED". Opinion masquerading as fact

The issue of microplastic pollution in the environment is gaining increasing societal attention. Research indicates that once microplastics enter the human body, they can increase the risk of heart attacks, strokes, or even death. What kind of everyday behaviors raise the risk of ingesting microplastics?

Lin Xiaoxu, a U.S. virology expert with a doctorate in microbiology, explained what microplastics and nanoplastics are on New Tang Dynasty TV’s “Health 1+1” program and how to reduce exposure to them.

Plastic is a crucial product in industrial production and is deeply intertwined with daily life. When plastic products break down, they become microplastics or even smaller nanoplastics. Microplastics are plastic pieces smaller than 5 millimeters, while nanoplastics measure below 1 micron (1,000 nanometers).

Sources of Microplastics

Mr. Lin explained that everyday plastic products release microplastics. Synthetic textiles shed fiber fragments, and worn-out tires produce plastic-containing dust. Even seemingly smooth plastic water bottles can shed microplastics during washing.

In nature, sunlight and ultraviolet radiation continuously degrade plastics into smaller particles. Textiles, hygiene products, bottles, bags, particles emitted from factories, tire dust, fishing nets, and more all contribute to microplastic pollution. Humans and other animals ingest some of these particles, while others accumulate and break down in oceans and soils. Marine organisms like shellfish, small fish, and shrimp, especially those near coastlines, are particularly prone to ingesting microplastics.

Mr. Lin emphasized that the main sources of microplastics are industrial waste and wastewater discharge, which can cause significant environmental damage if not adequately treated.

Therefore, before wastewater is released from factories, it must undergo processes like screening, sand removal, sedimentation, biological reactions, chlorination, ultraviolet treatment, membrane technology, etc., to remove over 90 percent of microplastics. However, complete elimination is not achievable. Natural environments may take thousands to tens of thousands of years to fully degrade microplastics.

Health Hazards of Microplastics

Potential Harm of Microplastics to Cardiovascular and Brain Health

“If you ingest something toxic, people usually say to wash it out quickly, but microplastics are very tiny particles that adhere to the surface of the stomach. It’s not guaranteed that washing out will remove them; the body needs to slowly eliminate them, increasing the burden on the body,” Mr. Lin noted.

Studies have found that after exposure to ultraviolet light and microbial degradation in the natural environment, microplastics become more adsorbent, forming complexes with various environmental pollutants on their surfaces, making them more toxic to organisms.

Microplastics, which serve as carriers for heavy metals and pathogens, exhibit various toxicities upon entering the body. Most microplastics ingested through food are excreted via feces, but a small portion can remain in the intestines for days, causing intestinal damage, inflammation, and disruption of gut microbiota. Over time, microplastics can be absorbed into intestinal cells and enter the bloodstream, damaging organs and systems throughout the body. Organs like the liver and kidneys and bodily systems such as the immune, reproductive, and nervous systems are particularly affected. Additionally, excessive inhalation of microplastics can cause respiratory tissue damage and disease.

In March, a study published in the New England Journal of Medicine found that most carotid artery plaques contained microplastics. The study included 257 patients aged 18 to 75 with asymptomatic carotid stenosis. Following plaque removal from the arteries, researchers detected polyethylene in 150 patients (58.4 percent) and polyvinyl chloride in 31 patients (12.1 percent) of removed carotid artery plaques.

Macrophages within the plaques contained visible foreign particles, some with jagged edges and chlorine content. * The study suggested * that patients with detected microplastics had over 4.5 times higher risk of heart attacks, strokes, or death compared to those without microplastics.
*****************************************************

Monday, July 01, 2024


Salt Is OK for People With Heart Failure: Review

Not this old scare again. It has long ago been shown that salt is harmless.

I have written previously on the salt phobia here:

And here:

And here:



Salt restriction, a long-standing recommendation for patients with heart failure, has no proven clinical benefits, according to a review published Wednesday in the European Journal of Clinical Investigation.

While some studies reported possible improvements in quality of life and functionality, the review author, Dr. Paolo Raggi from the University of Alberta, wrote that there is no evidence that severe sodium restriction reduces mortality and hospitalization in patients with heart failure.

The review evaluated randomized controlled trials conducted from 2000 to 2023. Most were small, and a single large trial concluded early due to futility.

“Doctors often resist making changes to age-old tenets that have no true scientific basis; however, when new good evidence surfaces, we should make an effort to embrace it,” Dr. Raggi said in a news release.

How Does Salt Affect the Heart?

Heart failure is a chronic condition that occurs when the heart muscles cannot pump enough blood to meet the body’s needs for blood and oxygen.

Reduction in salt intake is recommended for heart failure because salt draws water. More salt in the blood can increase blood volume, thereby increasing blood pressure, which can then cause further damage to blood vessels and the heart.

Severe reductions in salt intake can also cause a drastic decrease in blood volume, which can be harmful.

Scientists cannot agree on how much salt should be reduced, and this discrepancy is due to differences in data interpretation, Dr. Raggi wrote.

It has also been difficult to conduct a proper study evaluating the long-term effects of salt restriction since low-salt diets are challenging for patients to adhere to, and salt intake is hard to measure.

Several prominent health organizations, including the American Heart Association (AHA), recommend that patients with heart failure consume under 2 grams (about half a teaspoon) of salt daily. The author said that this recommendation likely arose from the conclusions of several trials, including the famous DASH-sodium trial, which found that people who consumed less than 1.5 grams of salt daily had lower blood pressure.

While proponents of the DASH-sodium trial support its findings and recommendations, dissidents argue it was too short and that such salt restrictions are unlikely to be sustainable.

Dr. Raggi wrote that moderating salt intake would benefit people consuming high levels of salt. However, just how much salt should be reduced is unknown. Quality of life does improve with lower salt intake; however, there is no clinical evidence that it results in fewer cardiovascular events and deaths.

While salt restriction clearly lowers blood pressure, especially in hypertension patients, the effect appears to wane with time.

“It has been estimated that tens of thousands of patients (the numbers varying depending on the baseline risk profile of the population enrolled) would have to be followed for 5 to 10years [sic] to prove that a strict sodium intake is associated with a 15% reduction in cardiovascular events. Such a proposition seems unlikely to materialize,” the author wrote.

Even the Cochrane review, seen as the gold standard in research, yielded an inconclusive result.

“The Cochrane review concluded that there was insufficient power to show an effect on mortality, although there might be a reduction in cardiovascular events with sodium restriction,” Dr. Raggi wrote.

He noted that none of the studies included in the Cochrane review and the many studies before it advised that salt intake should be as low as authorities such as the AHA suggested. Therefore, he concluded that questions about appropriate salt intake remain unanswered.

************************************************