 Instead of just looking at individual studies, or individual reviews of studies, what if you looked at a review of reviews? In my last video, I covered the beverages. With the majority of reviews that found some effects either way, finally at least some benefits to tea, coffee, wine, and milk, but not to sweetened beverages such as soda. As I explored in depth, this approach isn't perfect, or it doesn't take into account things like conflicts of interest, such as industry funding of studies, but can offer an interesting kind of bird's-eye view on what's out there in the medical literature. What did the data show for food groups? You'll note the first thing the authors did was split it up into plant-based foods and animal foods. For the broadest takeaway, we can look at the totals. The vast majority of studies on whole-plant foods show either protective, or the very least, neutral effects, where as most reviews of animal-based foods identified deleterious health effects, or at best, neutral effects. Let's break these down, though. The plant foods consistently rate uniformly well, reflecting the total, but the animal foods vary considerably. As you can see, if it wasn't for dairy and fish, the animal foods total would swing almost entirely neutral and negative. I talked about the effects of the dairy industry funding in my last video, as well as substitution effects. Those who drink milk may be less likely to drink soda, a beverage even more universally condemned. So the protective effects may be relative, arising not necessarily from what they're consuming, but rather from what they're avoiding. This may best explain the fish findings, after all the prototypical choices between chicken and fish, not chicken and chickpeas. Not a single review found a single protective effect of poultry consumption. Even the soda industry could come up with a 14% protective effect, but despite all the funding from the National Chicken Council and the American Egg Board, chicken and eggs got big fat goose eggs. Also, like the calcium and dairy, there are healthful components of fish. The long chain of egg-three fatty acids is not for heart health. In the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date, increasing the fish oil fats had little or no effect on cardiovascular health. In fact, if anything, it was the plant-based omega-3s found in flaxseeds and walnuts that was protected. But the long chain of omega-3s are important for brain health, thankfully. Just like there are best of both worlds non-dairy sources of calcium, there are pollutant-free sources of the long chain of omega-3s, EPA, and DHA as well. The bottom line is that when it comes to diet-related diseases such as obesity, type 2 diabetes, mental health, bone health, cardiovascular disease, and cancers, even if you lump all the animal foods together and ignore any industry funding effects and just take the existing body of evidence as face value, 9 out of 10 study compilations show that whole plant foods are, in the very least, not bad, whereas about 8 out of 10 of the reviews on animal products show them to be not good.