If you consume dairy, the video link above is worth watching. In this presentation at the Ancestral Health Symposium from August this year, Mr. Bastos briefly reviews the history of dairy production and how the domestication of cows coincides with the appearance of certain human gene mutation involved in dairy metabolism. He then moves on to discuss the hormonal effects of bovine dairy consumption in humans. He notes that milk contains over 100,000 different substances and the purpose of bovine milk is to assist rapid growth for a newborn calf. Interestingly, he also notes these neonate calves produce very few hormones at this stage in their life and therefore must rely on ingested milk to provide many of the hormones needed in order to rapidly increase size.
So, what is it in milk that promotes growth? The whey fraction in milk promotes insulin release which stores nutrients in tissue throughout the body. This, of course is necessary to supply tissues with needed energy for growth. A bigger concern than temporary spikes in insulin after a meal is an increase in fasting insulin levels, and there is some evidence that fasting insulin levels can rise after only 7 straight days of dairy consumption. Mr. Bastos commented that more studies are needed in this area before any definitive conclusion can be drawn. Additionally, the casein molecule, while not insulinogenic (i.e., insulin producing), will trigger the production of IGF-1, a very potent growth factor. In fact, growth hormone mediates most of it’s effects throughout the body via IGF-1. In addition, bovine milk itself contains hormones that are likely bioactive once absorbed in the human body. Other known endocrine effects to the milk drinker including increases in estrogen and decreases in testosterone and luteinizing hormone (LH). After Mr. Bastos’ presentation, in the question and answer session, someone asked, “When do you think is a good time to stop children from drinking cows milk?” Mr. Bastos turned the question around and asked, “When do you think is a good time to start children drinking cows milk?” Both questions are interesting.
As you might expect, pastoralist cultures of Africa that consume a lot of milk also tend to be very tall. Bodybuilders also recognizes that milk and milk derivatives like whey and casein can support their effort in muscle development. On the flip side, however, there are also concerns that the growth promoters in milk will not only stimulate linear growth (i.e., height) but can also stimulate growth of other tissues, even tumors. A question from the audience later asked Mr. Bastos to explain the apparent paradox then between the Masai, who drink a lot of milk but also have excellent health and very low cancer rates. In reply, he made a important distinction that African pastoralists have a very different lifestyle than many of those currently existing in ‘Western’ societies. Mr Bastos commented that he doesn’t believe IGF-1 itself causes cancer, however, in a stereotypical ‘Western’ environment – containing many genotoxic substances plus poor diet – chronic elevations in IGF-1 levels may increase our risk for cancer by promoting growth of malignancies that otherwise might be destroyed by innate anti-cancer processes. Plus, a nutrient poor diet can also significantly affect cell cycle control and repair mechanisms, which then may trigger more malignant instances. Now, you potentially have a perfect storm: An environment that triggers relatively frequent cell aberrations plus a common dietary staple (i.e., all things dairy) that promotes tissue growth throughout the body. Indeed, IGF-1 promote cell differentiation and growth and thus have been associated with angiogenensis, metastasis, and malignancies.
As a part of the ‘Paleo / Ancestral diet’ movement rapidly growing in popularity, some interpretations suggest adherents give up grains, legumes, and dairy as the basis of a smart dietary strategy. Other approaches are more lenient and recommend reducing dairy consumption and/or limiting it to various milk-product derivatives such as aged cheeses, whey protein, and cream.
We are all responsible to look after our own health and to make the best decisions that align with our estimates of what will yield wellness. If not you, then who? There are other considerations with milk that are not currently discussed in the video or this article. However, if cancer is in your family or simply something you’re concerned about, being aware of this information may help guide your future decisions according to what you prioritize in your life.
Here are some additional notes from the session:
- >95% of milk in EU is now from cows.
- Cows are maintained on a highly unnatural milk production schedule.
- How can milk lead to rapid growth? Maybe insulin.
- Insulin response is 5x higher than expected for glycemic index. Doesn’t matter if it’s skim or whole.
- The good: Whey can increase muscle protein synthesis and glutathione, one of the major endogenous antioxidants the body.
- Betacellulin – Another growth factor in milk. Survives pastorization. Found in cheese.
- IGF-1 in bovine milk is identical to human IGF-1. Not high amounts in bovine milk.
- Cows milk has much higher casein levels than found in human milk. Whey is the main fraction in humans.
- Type of pasteurization matters. Yogurt fermentation decreases IGF-1 by 45%.
- Increasing height associates with increasing risk for epithelial cell cancers.
- Milk may promote premature puberty, a risk factor for breast cancer.
- Prostate cancer shows a high correlation with milk intake.
- Milk may be protective against colon cancer.
- Milk seems to promote acne, at least in people who have insulin resistance.
- What about raw milk? Depends on cow it came from. Was the cow pregnant? Makes a big difference in the amount and types of hormones present in the milk. Grass-fed cows contains CLA which is healthy.
- Cream is likely safer because it doesn’t contain the growth promoting agents founds in other parts of milk. (Yum, cream in my coffee and tea!).
- Aging cheese is a good way to reduce some of these growth promoters.
Have other good dairy links and perspectives? Leave them for all to see in our comments section.