*For medical professionals only
As the old saying goes, "disease comes from the mouth", diet is indeed a key element of modern people's health.
While much research has focused on the health benefits of a particular food, we also know that there is no one-size-fits-all healthy food that will eliminate all diseases when eaten, but more importantly, the trade-offs and balance of overall intake.
So how much impact can diet have on health? Which of the many diet options works best? The Harvard team published a study in the journal Nature Medicine [1], using follow-up data of more than 200,000 people for up to 32 years, comparing the association of eight dietary regimens with the prevention of chronic diseases such as cardiovascular disease, type 2 diabetes, and cancer.
The results of the analysis showed that these healthy eating regimens were associated with a 20%-42% lower risk of chronic disease, especially those associated with low insulin and low inflammatory levels, and were particularly effective in prevention.
The researchers also analyzed the effects of single foods, and the most "healthy" and the most "unhealthy" were unexpected.
Thesis title map
Although it may sound powerful, chronic diseases are actually very harmful, more than half of premature deaths can be attributed to chronic diseases, and 90% of the annual medical expenditure in the United States is spent on chronic diseases.
High-quality foods, a plant-based diet, and adherence to dietary advice have been shown to reduce the risk of cardiovascular disease, diabetes, and cancer, so dietary regimens such as the Mediterranean diet, vegetarian diet, and high blood pressure prevention diet (DASH) have been added to the U.S. Dietary Guidelines.
But for individuals, people are just one mouth, which one of these routines comes from?
The study we want to talk about today included a total of 205852 participants from the three cohorts of NHS, NHS II., AND HPFS, with a median follow-up of 26 years. The eight dietary regimens/scoring systems compared were Alternative Healthy Diet Index 2010 (AHEI-2010), Mediterranean Diet Alternative Score (AMED), Healthy Plant Diet (hPDI), Hypertensive Prevention Diet (DASH), Diabetes Risk Reduction Diet (DRRD), Cancer Research Gene Society/American Institute for Cancer Research Diet Score (WCRF/AICR), Anti-Hyperinsulinemia Empirical Diet Index (rEDIH), Anti-inflammatory empirical diet index (rEDIP).
Such an old number of solutions really look more complicated, but in fact, it is very similar, and it can be seen from the name that some of them are targeted to specific diseases. Looking at the figure below, you can roughly understand the differences between the various schemes, which can be understood as the preferred food in the diet plan marked in green, and less healthy in red.
Detailed components of different dietary regimens
So let's not talk nonsense and go straight to the conclusion!
As can be seen from the figure below, after multi-factor adjustment, in addition to WCRF/AICR, these healthy diet programs are associated with the prevention of chronic diseases, especially rEDIH and rEDIP, with risk ratios of 0.58 and 0.61, respectively, which can be described as remarkable.
In addition, it is worth mentioning that even dietary programs designed for cardiovascular disease are effective in preventing diabetes and cancer, and vice versa. The so-called universal access, it seems that health is also one.
The relationship between different dietary regimens and chronic diseases
Risk ratios for different subgroups
So what exactly are the ingredients in these diets that make such a difference? The researchers also did a single dietary component analysis, which I was a little surprised to see anyway.
The leftmost part of the figure below shows the association between a single dietary component and disease, and the right side shows the association with disease in a specific dietary plan, which means that the higher the ranking, the more "healthy".
In this order, the foods with the strongest negative correlation with chronic diseases are coffee, whole grains, red wine, desserts, while the foods with the strongest positive correlation are processed meats, low-energy drinks, red meat, french fries, high-energy drinks, eggs.
Dessert! Very healthy! (It's not.)
Association of specific foods with disease risk
This also raises an interesting question, the impact of a single food component is actually complex, for example, alcohol has a strong carcinogenic effect, but on the other hand, moderate drinking has certain benefits for coronary heart disease, ischemic stroke, diabetes and all-cause death. The WCRF/AICR considers alcohol consumption harmful, AHEI-2010 and AMED support moderate alcohol consumption, and drinking alcohol in rEDIP and rEDIH is also considered a good thing (because drinking alcohol is associated with low levels of insulinemia and inflammation).
In rEDIH and rEDIP, the commonly recommended healthy foods cruciferous vegetables and legumes do not seem to be so healthy, which the researchers believe suggests that there is no single magic food, and the focus is on total accumulation.
As for the particularly conspicuous sweets on the list, the researchers believe that the intake of sweets may be negatively correlated with some foods that are not conducive to metabolic diseases, and the flavonoids in chocolate are also a good health ingredient.
In addition, from the subgroup analysis, we can see that young people, women, and people with high BMI have a better diet adjustment effect, and these people can spend more attention on eating.
Subgroup analysis (partial)
But personally, it's a bit impossible to make eating so complicated, and it's enough to maintain a balanced diet and eat more prototype foods!
Resources:
[1] Wang, P., Song, M., Eliassen, A.H. et al. Optimal dietary patterns for prevention of chronic disease. Nat Med (2023). https://doi.org/10.1038/s41591-023-02235-5
The author of this article 丨 Dai Siyu