Adventist Health Studies

There are two Adventists health studies: Adventist Health Study 1 (AHS-1), and Adventist Health Study 2 (AHS-2).  Both are cohort studies of members of the 7th Day Adventist church, and together span 40 years. This group is studied because they are a blue zone, meaning one of the longest lived populations in the western hemisphere.  AHS-1 consists of 24,000 participants in Loma Linda, California, while AHS-2 consists of 96,500 participants across the US and Canada.

What makes studying the Adventists particularly interesting is their population has so many built in controlling factors, which means, many of their habits, living conditions, and environment (particularly with AHS-1) can be cancelled out.  For example, Adventists don’t smoke, don’t drink, and nearly all get moderate levels of exercise. This allows the study to have a more narrow focus on the differentiators and what results those produce. This is probably the best study of how the choice of being an omnivore vs lacto-ovo vegetarian vs vegan produce different outcomes.

AHS-1 and Fatal Heart Disease

The general population of California was used for comparison, and it was controlled to have samples that matched the Adventists in terms of income level, education level, etc (to help rule out as many confounding factors as possible).  Here is what the study shows:

Notice that even meat eating Adventists only experience 64% of the fatal heart disease compared to their general California peers.  This might be explained that Adventists don’t smoke, don’t drink, eat less meat generally, and have a stronger social network than compared with their controlled Californian peers.  Fortunately, for our purposes, it doesn’t matter why. The most interesting result is what happens when you compare Adventists with themselves. Because this group is so homogeneous in terms of lifestyle, the choice in diet becomes a strong difference.  Compared with themselves, the omnivore Adventists had a nearly 180% higher incidence of fatal heart disease compared to the vegans!    

AHS-1 Omnivore vs Lacto-Ovo-Vegetarian

AHS-1 also looked at risks of other major diseases using the Adventists meat-eaters as the control group.  Compared to their fellow Adventists who ate meat, the dairy and egg eating vegetarians had the following:

  • 55% reduction in risk of hypertension

  • 35% reduction in risk of arthritis and rheumatism

  • 35% reduction in the risk of prostate cancer

  • 45% reduction in the risk of colon cancer

Unfortunately, the particular analysis above didn’t include vegans as a category.  This was addressed in AHS-2.  

AHS-2 Results

AHS-2 Authors’ Conclusion

“In conclusion, in a large American cohort, we found that vegetarian dietary patterns were associated with lower mortality.  The evidence that vegetarian diets, or similar diets with reduced meat consumption, may be associated with a lower risk of death should be considered carefully by individuals as they make dietary choices and by those offering dietary guidance.”

Take-away

Notice there is a clear pattern here, especially with AHS-2.  As the diet shifts from more meat towards more plants (Meat Eaters -> Flexitarian -> Pescatarian -> Lacto-Ovo Vegetarian -> Vegan), there is significant associated improvement in BMI and risks of heart disease, diabetes, hypertension, and hyperlipidemia, some of the most prevalent killer diseases.   

The fact that these studies are so large, for so long, with so many confounding factors controlled means they are one of the most powerful pieces of evidence you can use for friends and family who require evidence you are on the right path. 

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