The latest research confirms: The higher the children's education, the longer their parents live

Since ancient times, people have been striving for longevity. Ancient people pursued longevity by seeking immortals, visiting Taoist temples, cultivating their minds and maintaining health. Modern people have the blessing of various scientific research methods and statistical methods, and have found more scientific ways to achieve longevity through endless related research.

As the saying goes, "The immortal touches my head, and the thesis grants me longevity." In previous studies, countless scholars have explored the correlation between various factors such as diseases, lifestyles, and physical characteristics and longevity, and some studies have delved into the molecular mechanisms of some longevity factors.

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However, a recent article in a Nature journal took a different approach, pointing out that children’s education level is the reason for their parents’ longevity. For every 4.2 years of education a child receives, their parents’ life expectancy increases by 3.23 years, and their own probability of longevity increases by 30% to 59%, regardless of income or occupation. In other words, an increase in children’s education is an independent factor in their parents’ longevity [1].

How should we understand this research and what is so powerful about it?

Determining causality is a challenge

The correlation between occupation, income, education and other indicators of socioeconomic status and longevity is not new. Many studies have already proven that these indicators can cause differences in life expectancy. In general, people with higher income, career achievements and education tend to live longer [2,3].

However, previous studies were observational and could not determine the causal relationship between these factors and longevity. In other words, people only observed that people with high socioeconomic status also lived longer, but what was the cause and what was the effect? ​​In fact, it is difficult to tell through these studies——

It may be that educational experience affects cognitive behavior, and educational experience itself becomes the cause of longevity;

It is possible that educational experience itself does not affect life expectancy, but the resulting increase in income and improvement in social status are the reasons for longevity;

It may also be that these long-lived people have better physical fitness, and this physical fitness leads to better academic performance, admission to good schools, good jobs, and high incomes. In other words, improved socioeconomic status is only the result, and longevity is the cause .

Like this, although there is a correlation between a specific factor and the result, the influence of other factors cannot be ruled out, and the causal relationship cannot be determined. This can almost be said to be an inherent defect of observational research. If the logical thinking is not rigorous, it is easy to make attribution errors, making jokes such as the crowing of a rooster causes the day to dawn and not wearing a seat belt reduces the incidence of cancer.

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The study shared in this article not only found a correlation between children's education and their parents' longevity, but also determined a causal relationship between the two, which is amazing. But how did it do that?

One analytical approach: Mendelian randomization

The analysis method used in this article, Mendelian randomization, is a statistical analysis method that can detect and quantify the causal relationship between related factors . The principle of this method is a bit confusing to explain directly, so we will explain it in conjunction with the case in this article.

It is known that the improvement of socioeconomic status is related to longevity. Socioeconomic status is divided into three aspects: education, occupation, and income. If you want to verify the impact of education on longevity, what should you do?

In simple terms, researchers need to first screen out genetic variants that represent education level from the gene database. These variants must be unrelated to occupation and income, and cannot directly lead to longevity. Next, if statistical analysis finds that these genetic variants representing education level are also related to longevity, it can be proved that education level is the cause of longevity, and this causal relationship is not affected by occupation and income.

The conclusions drawn by this method are reliable because the genetic variants screened are determined before birth and can only be causes, not results . Since the variants found cannot directly lead to longevity, these variants can only be associated with longevity by affecting education level. Therefore, as long as it is determined that these genetic variants are related to longevity, education level will be the direct cause of longevity, and there is no need to worry about inversion of cause and effect or attribution error.

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How education affects life expectancy

After demonstrating the scientific nature of the research method, looking back at this paper, we can see that the author has done a very detailed job and verified all the possibilities that most people think of. The conclusions are:

1. Education has an independent impact on the longevity of parents and individuals;

2. The main reason why socioeconomic status affects life expectancy is education, not income or occupation;

3. Educational experience affects life expectancy by influencing lifestyle, diet, and disease. The authors analyzed 25 lifestyle factors and 34 diseases that affect longevity, and found that smoking, obesity, hypertension, coronary heart disease, myocardial infarction, heart failure, and stroke are the most important mediating factors between education and longevity. Other diseases such as Alzheimer's disease, type 2 diabetes, lung cancer, chronic obstructive pulmonary disease, breast cancer, etc. will also be affected to varying degrees by educational experience and affect life expectancy.

Although this study is based on people of European descent, the scientific argumentation and huge sample size ensure the credibility of the research results. It at least shows that although the social resources and economic status of each person and each family vary greatly, we can still narrow or even eliminate these gaps and live well by improving the educational experience of ourselves and our offspring.

References

[1] Ye CJ, Kong LJ, Wang YY,et al. Mendelian randomization evidence for the causal effects ofsocio-economic inequality on human longevity among Europeans [published onlineahead of print, 2023 Jun 29]. Nat Hum Behav. 2023;10.1038/s41562-023-01646-1.doi:10.1038/s41562-023-01646-1

[2] Chetty R, Stepner M,Abraham S, et al. The Association Between Income and Life Expectancy in the United States, 2001-2014 [published correction appears in JAMA. 2017 Jan3;317(1):90]. JAMA. 2016;315(16):1750-1766. doi:10.1001/jama.2016.4226

[3] Marioni RE, Ritchie SJ,Joshi PK, et al. Genetic variants linked to education predict longevity. ProcNatl Acad Sci US A. 2016;113(47):13366-13371. doi:10.1073/pnas.1605334113

Author: Doctor Feidao Duanyu

Review | Tao Ning Associate Researcher, Institute of Biophysics, Chinese Academy of Sciences