Many people around the world are still using biomass as a fuel for cooking and heating. Inefficient combustion of solid fuels is the primary cause of indoor household air pollution, estimated to be responsible for 4.3 million premature deaths in 2012 (7.7% of total mortality).
The World Health Organization’s latest global air quality guidelines point out that indoor air pollution causes a health burden that mostly affects people in low- and middle-income countries. Many global development agencies are working with governments of developing countries to reduce household air pollution. For example, China’s Relocation Program in the poorest provinces is a significant part of China’s poverty eradication plans. This large-scale program relocates millions of residents in absolute poverty to places with better living conditions, including fuel type.
In the United States, rural residents do not live as long as their urban counterparts. This disparity has been widening for decades. Around 1970, urban life expectancy was 70.9 years, compared with 70.5 in rural areas, but by 2005–2009, the difference was greater (78.8 versus 76.8 years). In our research recently published in the IJE, we found that the gap in life expectancy would be even wider today if declines in cardiovascular disease (CVD) mortality had not dramatically slowed around 2010.
How individual and neighbourhood socioeconomic disadvantages jointly affect health-related behaviour
In our study recently published in the IJE, we found that socioeconomically disadvantaged individuals were more likely to have worse health-related lifestyle behaviour than their neighbours, even if they lived in neighbourhoods with little overall socioeconomic disadvantage.
We also observed a “double jeopardy” effect: an unhealthier lifestyle was found among people with greater individual disadvantage residing in disadvantaged neighbourhoods.
Autism spectrum disorder (ASD) comprises a heterogeneous group of impaired neurodevelopmental conditions. The aetiology of ASD is complex and largely unclear, with some recent evidence suggesting the possibility of transmission of risk across multiple generations.
Our study, recently published in the International Journal of Epidemiology, evaluated the associations between birth characteristics of parents and the subsequent risk of ASD in their children.
Smoking, alcohol misuse and behaviours that result in obesity (such as an unhealthy diet and insufficient physical activity) have strong negative effects on individual health. Because these health behaviours are very common among people in Europe, smoking, alcohol and obesity also largely influence mortality rates and life expectancy in Europe.
However, the impact of these three lifestyle factors on life expectancy is likely changing over time. Smoking, obesity and alcohol misuse, like true epidemics, tend to first become more common in a population, followed (eventually) by a decline in their prevalence and associated mortality.
We are in the midst of a global recession as a result of the COVID-19 pandemic and attendant lockdown measures. Both the pandemic and the lockdown have each, on their own, worsened health outcomes. This fact has been relatively well covered by the media. What is missing from this discussion is that the resulting recession, forecast to be the largest in generations, will itself, in all likelihood, worsen health outcomes among the broader population.
Fetal undernutrition followed by abundant food after birth might be a recipe for disaster — it is linked to increased risk of obesity and cardiometabolic diseases later in life. The Dutch famine birth cohort study is a tragic “natural experiment” that exemplified this phenomenon. It observed that people born to mothers who experienced a transient period of severe famine during pregnancy, followed by a return to normal diet postnatally, had an increased risk of obesity and cardiometabolic diseases.
This mismatch between a poor fetal nutritional environment and a rich postnatal nutritional environment might cause fetal adaptive responses to become maladaptive, leading to greater cardiometabolic risk in adulthood. This is known as the developmental mismatch hypothesis.
However, is developmental mismatch still a pertinent health issue affecting cardiometabolic risk in contemporary well-nourished populations, who are not facing famine or drastic environmental stresses? In these populations, fetal undernutrition is more likely to result from uteroplacental insufficiency than maternal malnutrition.
Yuxian Ma, Olesya Ajnakina, Andrew Steptoe and Dorina Cadar
Dementia is a major health challenge that could steal away the opportunity for successful ageing of the population. A priority is to identify lifestyle factors that may reduce the risk of dementia, or even prevent it. The modifiable risk factors for vascular diseases — such as smoking, excessive alcohol intake, lack of physical activity, low intake of antioxidants and high intake of saturated fats — are receiving greater attention in this area because of their association with cognitive impairment and dementia in older people.
Obesity, which is linked to lifestyle behaviours, is an important modifiable risk factor. In our recent study carried out at the UCL Department of Behavioural Science and Health, we found that being overweight or obese was associated with a greater risk of developing dementia.
While organised mammography screening programs were being gradually introduced across various countries, researchers could study the impact of screening on breast cancer mortality by comparing mortality in areas with and without screening. Now that screening has been fully implemented in most Western countries, researchers can only compare women who participate in screening with those who do not participate.
Women who do not participate in screening may seem to be a good choice as a comparison group, as they are not affected by screening. But the question is: can non-participants reflect how breast cancer mortality would have developed in women in general without the introduction of screening?
We need to be cautious. It is not the virus that leads to interstitial lung disease and death. It is our immunological response, the “cytokine storm”, that causes severe illness.
This is comparable to the devastation of the respiratory syncytial virus, persistently responsible for bronchiolitis in the very young, killing tens of thousands worldwide each year.
If the vaccine is both effective and safe, enough people will be immune, and transmission from them to the rest of us will be much diminished. Indeed, if enough people are immune — generally about 60% (“herd immunity”) — either through exposure or vaccination, transmission ceases.