Saturday, February 27, 2021

Street lamps can increase your risk of CANCER: People who live near artificial neon lights are up to 55% more likely to be diagnosed with thyroid cancer

The journal article:

Good that the authors made no causal inferences. It is for starters a study of retired people so should not be generalized to other age cohorts.  There was also no way they could control for income so we may be looking at a poverty effect only

The study also used extreme quintiles, which suggests that there was no overall effect in the data

One also wonders why thyroid cancer was singled out.  Was it the only one showing any effect?  Very bad methodology if so

Living in an area with high levels of outdoor artificial light can increase the chance of developing thyroid cancer - with neon lights increasing the risk by 55 per cent, study shows.

Researchers from the University of Texas Health Science Center looked for a link between people developing thyroid cancer and levels of artificial outdoor light.

They looked at data from a cohort of 464,371 participants followed for about 13 years as part of the NIH-AARP diet and health study - then analysed satellite imagery to estimate levels of light in the areas where the people involved in the study lived.   

They found that those in areas with the highest level of night light pollution had a 55 per cent higher risk of developing thyroid cancer than those in low-light areas. 

They believe that one reason for the link is that light at night suppresses melatonin, a modulator of oestrogen activity - which may have an anti-tumour effect.  

Light pollution, also known as photopollution, is the presence of anthropogenic light in the night environment. 

Artificial light that’s excessive, obtrusive and ultimately wasteful is called light pollution, and it directly influences how bright our night skies appear. 

With more than nine million streetlamps and 27 million offices, factories, warehouses and homes in the UK, the quantity of light we cast into the sky is vast. 

While some light escapes into space, the rest is scattered by molecules in the atmosphere making it difficult to see the stars against the night sky. What you see instead is ‘Skyglow’. 

Over the past century, night scapes - particularly in cities - have changed dramatically due to the rapid growth of electric light, study authors said.

Studies have also reported an association between higher satellite-measured levels of nighttime light and elevated breast cancer risk.  

As some breast cancers could share a common link to thyroid cancer, lead author Qian Xiao and colleagues decided to hunt for an association between night light and later development of thyroid cancer.

They used the NIH-AARP Diet and Health Study - featuring data on hundreds of thousands of people aged 50 to 71 - recorded in 1995 and 1996.

Xiao then looked at satellite imagery of each of their homes to determine whether those living in high-light areas were more likely to develop thyroid cancer.

The team then examined state cancer registry databases to identify thyroid cancer diagnoses through 2011 and found 856 cases among the 464,371 volunteers.

'When compared with the lowest quintile of light at night, the highest quintile was associated with a 55 percent higher risk of developing thyroid cancer,' said Xiao.

'The association was primarily driven by the most common form of thyroid cancer, called papillary thyroid cancer, and it was stronger in women than in men,' he found.

In women, the association was stronger for localised cancer with no sign of spread to other parts of the body, while in men the association was stronger for more advanced stages of cancer, the team discovered. 

The association appeared to be similar for different tumour sizes and across participants with different demographic characteristics and body mass index. 

The researchers noted that additional studies are needed to confirm their findings. 

If confirmed, it will be important to understand the mechanisms underlying the relationship between light at night and thyroid cancer, Xiao said. 

The scientists noted that light at night suppresses melatonin, a modulator of oestrogen activity that may have important anti-tumour effects. 

Also, light at night may lead to disruption of the body's internal clock (or circadian rhythms), which is a risk factor for various types of cancer.

'As an observational study, our study is not designed to establish causality,' said Xiao, adding 'we don't know if higher levels of outdoor light at night lead to an elevated risk for thyroid cancer.' 

'However, given the well-established evidence supporting a role of light exposure at night and circadian disruption, we hope our study will motivate researchers to further examine the relationship between light at night and cancer, ' said Dr. Xiao. 

'Recently, there have been efforts in some cities to reduce light pollution, and we believe future studies should evaluate if and to what degree such efforts impact human health.'

The findings have been published in the journal Cancer.

Wednesday, February 24, 2021

Ditch the white bread! Eating more than seven portions of refined grains a day can increase your risk of early DEATH by 27%

Journal reference:

This study is nonsense on stilts.  What they actually found was that people in countries where they ate little white bread had fewer heart attacks and related problems. So Chinese people live longer than Americans?  Problem:  They don't.  Americans live a couple of years longer.

So what is  going on?  All the effects were tiny and hence likely to be unstable.  Most of the hazard ratios were just above 1.00 whereas a figure of over 2.00 would normally be needed to support policy prescriptions.  So ignoring the study would be wisest

From a delicious piece of white toast to a bowl of pasta, many of us enjoy consuming refined grains.

But a new study has warned that eating too many of them can have serious consequences, including an increased risk of heart disease, stroke and even early death.

Refined carbohydrates, including croissants, white bread and pasta, have had the high fibre parts removed, meaning they get broken down faster and lead to rapid spikes in blood sugar levels when consumed.

Based on the findings, the researchers are urging people to consider replacing their favourite refined grains with wholegrain options, such as brown rice and barley.

The Wholegrains Council explained: 'White flour and white rice are refined grains, for instance, because both have had their bran and germ removed, leaving only the endosperm. 

'Refining a grain removes about a quarter of the protein in a grain, and half to two thirds or more of a score of nutrients, leaving the grain a mere shadow of its original self.'

In the study, researchers from Simon Fraser University looked at the effects of following a diet high in refined grains.

Their analysis included 137,130 participants from 21 countries, including those from low-, middle- and high-income areas.

Grains in the participants' diets were categorised into three groups – refined grains, whole grains and white rice.

Refined grains included goods made with white flour, including white bread, pasta, noodles, breakfast cereals, crackers and baked goods.

Meanwhile, whole grains included any foods made with wholegrain flours, or intact or cracked whole grains.

The analysis revealed that participants who consumed more than seven servings of refined grains per day were at a 27 per cent greater risk for early death.

This group was also found to be at a 33 per cent higher risk for heart disease, and a 47 per cent higher risk for stroke.

Professor Scott Lear, who led the study, said: 'This study re-affirms previous work indicating a healthy diet includes limiting overly processed and refined foods.'

Sunday, February 14, 2021

Step away from the omelette: Eating just half an egg a day increases your risk of DEATH by 7%

This finding is from a very carefully analysed study with good controls.  It even allowed for household income, which is unusual.

The analyses were however of quintiles, with most comparisons being with the lowest quintile.  Quintile analyses are always suspicious.  They suggest that there was no overall significance in the data. What would a simple correlation between egg consumption and lifespan show after partialling out confounders?  We are not told.  My guess that it would be so low as to be of no concern.  Complex statistics can conceal as much as they reveal

Boiled, fried, scrambled or in an omelette, whole eggs pose a threat to health and eating more of them increases your risk of death, a study claims.

Researchers found eating just half a whole egg — which includes the yolk and the white — increases the likelihood of dying by seven per cent.

Risk of death increases by a further seven per cent for every half an egg on top of this, so a person eating one egg a day has at 14 per cent greater chance of death than someone who avoids the food.

Chinese researchers who led the study believe high fat and cholesterol levels in eggs are to blame.

They warned that people should use only the whites or switch to healthier egg substitutes, which lower the risk of dying.

Substituting an equivalent amount of nuts or legumes for half a whole egg reduced death rates by up to a third. Poultry, dish or dairy products had a similar effect.

Researchers gave a questionnaire to more than half a million Americans  between 1995 and 1996 and followed them for 16 years.

Data from this study, published in PLOS ONE, shows 129,328 people who filled out the original form died.

Co-author Professor Yu Zhang, of Zhejiang University said: 'In this study, intakes of eggs and cholesterol were associated with higher all cause, cardiovascular disease and cancer mortality.'

Professor Zhang said: 'The increased mortality associated with egg consumption was largely influenced by cholesterol intake.'

The link between eggs and health has been debated for years. They have long been thought of as a healthy dietary addition.

They are included in many country's national dietary guidelines. But the food, specifically the yolk, is high in cholesterol - which is known to be harmful.

Researchers asked the participants about how much cholesterol they had as part of their diet on top of eggs and found an additional 300 milligrams of cholesterol a day were 19 per cent more likely to die over the next 16 years.

Deaths specifically from cancer and cardiovascular disease rose by 24 and 16 per cent, respectively.

There is no cholesterol in the white of a medium-large chicken egg, and around 186 mg in the yolk.

'Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival,' the authors say.  

The NHS says eggs are a good choice as part of a healthy, balanced diet. As well as being a source of protein, they also contain vitamins and minerals.

It says there is no recommended limit on how many eggs people should eat, but advises cooking them without adding salt or fat. Frying can increase their fat content by around 50 per cent.

'This research makes it possible to look at relationships between what people ate in the past and whether that could be related to disease or death in the future,' says Dr Ada Garcia, a senior lecturer in Public Health Nutrition at the University of Glasgow who was not involved in the research, saus.

'The authors took a very careful approach to analysed the data and consider many aspects that could distort the findings.

'The study concluded that retired people who ate more whole eggs seven per cent higher risk to develop cardiovascular disease. The highest consumption of eggs was about half a small egg in 2000 Kcal per day.'

However, she criticises the methodology and conclusions of the Chinese team, saying: 'Being overweight or obese, smoking or consuming too much alcohol and not being physically active are much more important factors to consider for prevention of chronic diseases and related death.

'The conclusions of this study are overblown. Blaming eggs alone for an increased risk of cardiovascular disease is a simplistic and reductionist approach to the concept of diet and disease prevention.'

Saturday, February 06, 2021

Association Between County-Level Change in Economic Prosperity and Change in Cardiovascular Mortality Among Middle-aged US Adults

This is not a particuarly strong study methodologically but  I am putting it up as an all-too-rare study where the effect of poverty is examined  -- with the expected results

Sameed Ahmed M. Khatana et al.


Importance:  After a decline in cardiovascular mortality for nonelderly US adults, recent stagnation has occurred alongside rising income inequality. Whether this is associated with underlying economic trends is unclear.

Objective:  To assess the association between changes in economic prosperity and trends in cardiovascular mortality in middle-aged US adults.

Design, Setting, and Participants:  Retrospective analysis of the association between change in 7 markers of economic prosperity in 3123 US counties and county-level cardiovascular mortality among 40- to 64-year-old adults (102 660 852 individuals in 2010).

Exposures:  Mean rank for change in 7 markers of economic prosperity between 2 time periods (baseline: 2007-2011 and follow-up: 2012-2016). A higher mean rank indicates a greater relative increase or lower relative decrease in prosperity (range, 5 to 92; mean [SD], 50 [14]).

Main Outcomes and Measures:  Mean annual percentage change (APC) in age-adjusted cardiovascular mortality rates. Generalized linear mixed-effects models were used to estimate the additional APC associated with a change in prosperity.

Results:  Among 102 660 852 residents aged 40 to 64 years living in these counties in 2010 (51% women), 979 228 cardiovascular deaths occurred between 2010 and 2017. Age-adjusted cardiovascular mortality rates did not change significantly between 2010 and 2017 in counties in the lowest tertile for change in economic prosperity (mean [SD], 114.1 [47.9] to 116.1 [52.7] deaths per 100 000 individuals; APC, 0.2% [95% CI, −0.3% to 0.7%]). Mortality decreased significantly in the intermediate tertile (mean [SD], 104.7 [38.8] to 101.9 [41.5] deaths per 100 000 individuals; APC, −0.4% [95% CI, −0.8% to −0.1%]) and highest tertile for change in prosperity (100.0 [37.9] to 95.1 [39.1] deaths per 100 000 individuals; APC, −0.5% [95% CI, −0.9% to −0.1%]). After accounting for baseline prosperity and demographic and health care–related variables, a 10-point higher mean rank for change in economic prosperity was associated with 0.4% (95% CI, 0.2% to 0.6%) additional decrease in mortality per year.

Conclusions and Relevance:  In this retrospective study of US county-level mortality data from 2010 to 2017, a relative increase in county-level economic prosperity was significantly associated with a small relative decrease in cardiovascular mortality among middle-aged adults. Individual-level inferences are limited by the ecological nature of the study.