Newsletter #303

Hey friends, this week I’d like to revisit ultra-processed foods, and their impact on health and risk of death.

First of all, what exactly are ultra-processed foods? People, understandably, get very tripped up on this concept.

Some background: Back in 2009, Brazilian nutrition scientist Carlos Monteiro wrote a commentary in which he separated foods into categories based not on calories, or even micronutrients, but rather by levels of processing. He suggested that foods should be classified by the “type, intensity and purpose of food processing.” This is a key distinction, since some forms of processing are perfectly fine (and maybe even in some cases health-promoting).

Yet this concept remains troublesome. The main issue is that ultra-processed foods seem to be a very heterogeneous category. Even within Monteiro’s carefully crafted definition, you can find some products that are relatively nutritious, and may even promote good health due to high levels of fiber, protein, etc. Should we avoid any and all foods that meet the criteria of “ultra-processed?” Or can we pick and choose?

Fortunately, some recent research has started to try to cut through this ambiguity.

A few studies have looked at how intake of ultra-processed foods, as a category, are correlated with all-cause mortality. However, these studies generally failed to separate the effects of individual subgroups of ultra-processed foods, like beverages, processed meats, etc.

To gain some more insight into the impact of ultra-processed foods, researchers performed a systematic literature search of studies that examined the relationship between ultra-processed foods and mortality. They zeroed in on studies that were of a prospective design (meaning participants are followed over a period of time, rather than just a single measurement), and they also sought out studies that looked at specific classes of ultra-processed foods. Through this process, the researchers were able to identify 40 different prospective cohort studies, which included a total of 5,750,133 individuals.

First, they found that higher intake of ultra-processed food in general was linked to higher risk of mortality. Compared to low consumption, those in the highest category of ultra-processed food intake were 29% more likely to die during the study period (average follow-up of ~9 years).

Next, the researchers examined specific types of ultra-processed foods. They found that the highest consumption of processed meat/red meat were linked to a 15% higher risk of all-cause mortality. Both artificially-sweetened and sugar-sweetened beverages were also linked to higher risk of death.

However, consumption of breakfast cereal was not associated with increased risk of death. In fact, those who consumed the most whole-grain breakfast cereal were 23% less likely to die during follow-up, while cereals made from refined grains did not appear to be beneficial.

It is likely that this link also holds for morbidity (meaning the presence of disease), as well as mortality. A large cohort study that followed more than 260,000 subjects for a decade found very similar results. They determined that higher ultra-processed food consumption was linked to higher risk of cancer and cardiometabolic disease, but the association was strongest for animal-based products and sweetened beverages, with no association found for breads and cereals. This may be due to fiber and polyphenols occurring in cereal grains.

Given the extraordinary pervasiveness of these products (it has been estimated that ultra-processed foods make up as much as three quarters of the US food supply), it is probably not practical to eliminate them outright. More research is needed that examines the effects of specific food items, so that we can identify which ultra-processed foods are deleterious and which are more benign. Furthermore, we need to better understand the precise mechanisms through which ultra-processed foods drive adverse health outcomes, so we can devise less harmful or even health-promoting processed foods. This analysis is a good first step in that direction.

Okunoin is the largest cemetery in Japan, with more than 200,000 graves and memorials. It was opened back in 835 AD, and is now an UNESCO World Heritage site.

Although many of these graves are obviously quite old, there are a few modern additions. One includes a memorial sponsored by a termite extermination company, in honor of the innumerable insects that they have slain.

Why? A note affixed close to the memorial explains:

“This stone was erected by Yamada and Co., a company that specializes in termite extermination. This memorial, notable for its size and prominent position within the cemetery, is here to quell the spirits of those termites it kills in the line of duty, in order to maintain harmony with nature.”

The headstone reads, “Termites rest in peace.” Photo by Motokoka.

Like many others out there, we have been experimenting with zone 2 (aka long slow) cardio as a way to enhance cardiorespiratory fitness. You can get your heart rate into this zone through multiple modes of exercise, like biking, rowing, running, etc. However, I have found that it’s hard to get into zone 2 via walking, unless you’re hiking up a pretty steep incline.

One way that you can achieve this, though, is by adding some mass, in the form of a weight vest. We like these because they’re reasonably priced, fairly comfortable, and come in a range of different weights (and colors). I personally find that just adding ten pounds can make an appreciable difference in heart rate. It can also be useful for increasing the difficulty of bodyweight exercise.

This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by our good friend Stephan Guyenet.

What is the true cause of the obesity epidemic? This is an incredibly complicated and multi-factorial problem, but on a high level, it is the result of genetically/metabolically susceptible individuals living in an obesogenic environment and adopting an obesogenic lifestyle (think of the ultra-processed foods we talked about above).

Logically, the most effective solution would be to alter the modifiable risk factors — meaning remove the obesogenic environment. However, this is pretty hard to do on a national or global scale. Maybe impossible!

But could you make some changes to your own food environment?

In this course, Stephan explains how our food environment has changed over time, why it is so crucial for body weight regulation, and highlights some science-based tips for how you can restructure your food environment right now for optimal health.

Wishing you the best,

https://mailchi.mp/humanos.me/newsletter-303