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People from lower socioeconomic backgrounds are three times more likely to develop early-onset dementia. And if those same people lead an unhealthy lifestyle, the risk is 440% higher compared to those of a higher socioeconomic level who lead a healthy lifestyle. The data is from a study carried out by researchers at the Huazhong University of Science and Technology (China) that has been recently published in the journal Lancet Healthy Longevity.
“Our study was one of the first to examine the complex relationships between lifestyles, socioeconomic status and the risk of early-onset dementia in people aged 37 to 60 years. “Both lifestyle and socioeconomic status were significantly associated with early-onset dementia, but the latter much more so,” Gang Liu, professor at the School of Public Health at Huazhong University and lead author of the study, explains by email. . The expert points out that, after adjusting for various risk factors, people with a low socioeconomic level had a 238% higher risk of early-onset dementia compared to those with a high socioeconomic level. Meanwhile, people with three or four healthy lifestyle behaviors had a 40% lower risk of early-onset dementia compared to those with one or no healthy lifestyle behaviors.
For the research, the authors used data from the UK BioBank of more than 440,000 participants between 37 and 73 years old, who were followed up for 12 years, taking into account indicators such as lifestyle habits and a status variable. socioeconomic composed of the combination of level of education, level of family income and level of employment. One of the most surprising aspects for researchers, says Gang Liu, is that only 12% of cases of early-onset dementia associated with socioeconomic status could be explained by lifestyle factors. This suggests that people from a lower socioeconomic background cannot necessarily mitigate the risk of developing early-onset dementia by leading a healthier lifestyle.
“The mechanisms underlying the relationships between socioeconomic inequality and early-onset dementia remain to be discovered in future studies, but what seems clear is that socioeconomic status could itself affect individuals’ cognition,” he reflects. the author. “For example, higher education may result in improved cognitive reserve that may compensate for neurodegeneration; and poverty can also directly affect cognitive ability, since a poor financial situation can generate excessive mental load, stress, anxiety or depression, which some studies suggest may have a link with dementia,” he adds.
“It is a very robust study that gives a twist to what we already knew about the impact of lifestyle, because it seems that socioeconomic status alone is already an important factor in increasing the risk of developing dementia” , says David Pérez, head of the Neurology Service at the 12 de Octubre University Hospital in Madrid and member of the Spanish Society of Neurology (SEN). The neurologist points out that precariousness can affect brain health from multiple dimensions, also at the level of lifestyle: “On the one hand, there is the stress generated by this situation or the greater prevalence of depressive disorders, but in addition, one has it more difficult. For example, to adhere to a Mediterranean diet, you are more likely to do more routine, less motivating, less intellectual work, and you will also do it for longer hours, which means you will have less time to do physical exercise or check your cholesterol or the hypertension”.
The fight against inequality
Early dementia refers to cases of dementia that are diagnosed in patients under 65 years of age. According to a 2021 study, the prevalence of these dementias is around 119 cases per 100,000 inhabitants, so we would be talking about 3.9 million people worldwide. In Spain, although there is no state registry, it is estimated that between 600,000 and one million people would suffer from dementia, of which between 10% and 15% (around 70,000 cases) would be early-onset dementia. In the preamble of the Comprehensive Plan for Alzheimer’s and other dementias 2019-2023, prepared by the Ministry of Health, it is recognized that addressing dementia is “a public health priority and a major social and health problem that has become in the great silent epidemic of the 21st century and in the great challenge for the sustainability of any social and health system.” The qualifier “epidemic” is not trivial. According to WHO data, more than 50 million people worldwide suffer from dementia, a figure that is expected to increase to 75 million in 2030 and 132 million in 2050.
“We must remember that, in Western countries, especially in European countries, in the last two or three decades there has been a reduction in the incidence of dementia that goes somewhat unnoticed because, as the population has aged, the number of cases grows,” reflects David Pérez. The expert explains that this reduction is largely due to the welfare state, “which has allowed many people access to quality public education, quality public healthcare, and a better standard of living. Now we have other pending challenges, such as trying to implement public policies that make us move towards less social inequality, because we already see that this, directly or indirectly, will prevent dementia,” he adds.
For Unai Martín, professor of Sociology at the University of the Basque Country and member of the working group on social determinants of health of the Spanish Society of Epidemiology (SEE), this study is of great importance because, due to its solidity, it highlights table something that experts have been denouncing for decades: that social inequality generates disease and that it is a risk factor as important or more so than others that have normally been given greater significance by science and medicine.
“Many times, even when we understand that inequality is important, we tend to think that the way to act on health inequalities is to act on lifestyle habits. And this study shows that this strategy is a mistake, that if we do not act on the fundamental factor, which is social inequalities, everything else will not be of much use. It is an issue that is difficult for us to understand when it comes to acting; in fact, a large part of public health promotion today is still very focused on habits,” says the expert, who believes that focusing attention on lifestyle habits It is also a way of blaming the victims, of putting the responsibility on them: “It’s just that they smoke more, it’s that they exercise less, it’s that they eat worse, we say, and we try to implement strategies to convince them to stop smoking.” , to exercise, to eat better. But many times people don’t even have the option to eat better or exercise! ”He says.
According to Gang Liu, although the importance of promoting healthy lifestyles at the individual level cannot be ignored, research supports the need for governments to adopt public health measures to improve the burden of dementia to reduce the burden of dementia. social determinants of health and promote equity.
An opinion shared by Unai Martín, who considers that fighting against social and economic inequalities is one of the best possible strategies to face the great challenge of dementia. “It is, first of all, as a matter of social justice. And it is, also, because the improvement of health depends very little on what we do in the health system. The health system is very good at curing illness, at rescuing people when they fall ill, but if we want to improve the health of the population we have to go outside the health system to act on other types of policies (urban, income, education, social, etc.) that reduce inequality, because that will also reduce the burden on the health system,” claims the spokesperson for the Spanish Society of Epidemiology, who regrets that traditionally at the political level it is so difficult to think in the medium and long term, which is precisely what these policies require. “It is very easy to understand that we have to treat a person who has had a heart attack or suffers from dementia, but it is more difficult for us to understand that so that these people do not have a heart attack or do not suffer from dementia, we have to act on factors that could delay or avoid those ailments. That is the key today to improving health,” he concludes.