No doubt: Dairy products have issues.
The issues with dairy are not as bad as they are with grains. After all, the consumption of the seeds of grasses was an entirely foreign practice, introduced very late in the human experience—we have spent less than 0.4% of our time on this planet consuming seeds of grasses, despite their dominant dietary role today, thanks to the lobbying of Big Agribusiness, Big Food, and the bungling of the USDA and U.S. Department of Health and Human Services. Grains are physiologically inappropriate for consumption by Homo sapiens at any time, in any form. Wild, hunting, primitive humans did not consume it for the first 99.6% of our time here.
But consumption of dairy products has a human precedent in consumption of the milk of female humans, i.e., infants are meant to breastfeed for up to 4 years after birth. Consumption of the products of mammary glands is therefore not a practice foreign to us human mammals. What IS foreign is 1) consuming the product of bovine or other non-human mammary glands and 2) continued consumption after age 4.
Our yogurt-making, by the way, with fermentation extended to 36 hours to amplify counts of L. reuteri, reduces (but does not eliminate) some of the undesirable features of dairy since it consumes virtually all the lactose and converts it to lactic acid (thus the tartness), thereby reducing the pH that denatures (breaks down) the casein protein (though the residual immunogenicity, or immune-triggering potential, of the resulting peptides is uncertain). You can further disable dairy issues by either straining in cheesecloth to drain off the whey or just pour out the excess whey that results when you scoop out some of the yogurt. Recall that whey is insulin-provoking, or insulinotrophic, an effect that can contribute to insulin resistance and stalled or failed weight loss, despite its (puzzling) popularity as an additive to smoothies. By using organic dairy, you further cut back on the hormonal content, as well as potential antibiotic, growth hormone, or other exposures. Choosing full-fat is also important, as the fat is the healthiest component of dairy. Making the yogurt, especially using the methods we use with higher fat, extended fermentation times, and addition of prebiotic fibers to heighten bacterial counts and increase content of bacterial metabolites such as butyrate, reduces, though does not eliminate, the issues with dairy: little to no lactose, denatured casein, reduced whey.
Of all the issues with dairy, however, it is probably the casein prevalent in North America, so-called casein beta A1, that is the most concerning component. Human milk contains the casein beta A2 form (as do goat and sheep). A2 products from cows have been available in Australia, New Zealand, and parts of Western Europe for years. The casein beta A1 protein is immunogenic and has been associated with issues including initiating rheumatoid arthritis and type 1 diabetes (along with the gliadin protein of wheat/rye/barley and the zein protein of corn) and sudden infant death syndrome. Although just one amino acid differs between the two forms of casein, it means a big difference in immune-stimulating potential.
Awareness of these issues has prompted some dairy farmers to work towards converting their livestock to A2 cows—not an easy issue, as it means allowing A1 cows to age and die off, then purchasing cows genetically tested (costly) to be A2, a process measured in years. But it’s happening. I’ve now seen A2 milk (but not cream, half-and-half, butter, or other products) in Orlando, New York, Chicago, and now even Milwaukee. (If it’s in Milwaukee, it means it should be in most major and secondary cities.)
So just be aware that A2 dairy products are just starting to make their way to the North American market, another option for you to choose that further reduces the potential toxic components of dairy. Because it is uncertain whether our denatured casein beta A1 in yogurt remains immunogenic, converting to A2 milk and, perhaps in future, half-and-half and other products, is now an option.