字幕列表 影片播放 列印英文字幕 This video is brought to you by Squarespace Not too long ago, we've been led to believe that dairy undoubtedly does a body good. And, we've been quite receptive to it, even as far as labeling it as its own fundamental food group. But, as society tends to do to nutrition, today, those long-held dairy beliefs have been heavily challenged. In this video, we're going to dive into the research to better understand this notorious cattle concoction. First, let's break down the contents found in dairy and its potential benefits. One of the most important contents is dairy's high-quality protein. The dairy proteins whey and casein are both extremely popular within the fitness industry as protein powder supplements aiding in muscle growth. The research specifically on whey have linked it to improving insulin function, lowering triglycerides and lowering blood pressure. Casein has its own unique property, being a slow-digesting protein that supports not only muscle growth, but also muscle preservation. Dairy also contains immune system-supporting proteins known as immunoglobulins. The high protein in dairy can also help improve satiation, thus help you eat less and lose weight. We also have a good dose of healthy fats in dairy like conjugated linoleic acid, which might help suppress appetite, omega-3 fatty acids, purported to impose numerous cardiovascular health benefits, and trans-palmitoleic acid, believed to have protective properties against diabetes. Dairy's fat composition, though, is heavily influenced by a cow's genetics and diet. Dairy produced by organic grass-fed cows tend to carry more of these healthy fats, while conventional grain-fed cows produce dairy with more saturated fats. And of course, dairy also contains many important MICROnutrients, like calcium, potassium, fat-soluble vitamins A and D, vitamin B12, riboflavin, iodine, and magnesium. Clearly, dairy is quite stacked with health benefits. But what about its potential health risks? The one clear risk we know for sure is the common issue of lactose intolerance, where one lacks the enzymes to properly digest and absorb the dairy sugars galactose and lactose. Instead, it passes directly into our large intestines, causing issues like stomach cramps, bloating, and diarrhea. Some even report sinus infections and mucus development. Roughly 65% of the human population have some degree of lactose intolerance. Its highest prevalence is among people of East Asian descent, where it affects more than 90% of adults. On the other hand, in populations with a longstanding dependency on dairy products, like Northern Europeans, lactose intolerance is as low as 5%. Another purported risk is cardiovascular disease. Dairy does contain saturated fats and cholesterol, both of which in high consumption are linked to heart disease. But this is more so a matter of excessive consumption rather than a problem attributed to dairy itself. At moderate dairy intakes in an overall healthy diet, cardiovascular disease isn't much of an issue. One systematic overview of 10 cohort studies concluded that drinking milk may actually decrease the risk of heart disease. And as mentioned before, dairy from organic, grass-fed cows contain more of the healthy fats that can actually improve cardiovascular health. What about claims that dairy is acidic? Some researchers have hypothesized that dairy might acidify our bodies from its high protein and phosphate content, potentially landing to a detrimental bone health. However, the scientific literature does not support these claims since dairy does not produce acid when metabolized nor cause metabolic acidosis. Overall, acid-base changes in our bodies are not directly influenced by our diet. There are more observational studies, though, showing that dairy consumption doesn't exactly harm nor improve our bone health, quashing old beliefs that milk makes stronger bones. The biggest point against dairy made by anti-dairy advocates is dairy's hormone content. Two of which are estrogen and bovine growth hormones. The theory is that both are potential causes for cancer. But is that actually true? Fortunately, these hormones are broken into peptides by the liver before ever getting into our blood circulation. It's only in extremely high consumption levels do we see an actual change in our own blood levels of these hormones. But based on a mice study, we're talking about concentrations 1000 times more than what's found in milk. On top of that, bovine growth hormone, specifically, isn't even biologically active in humans. Essentially, unless you're directly injecting these hormones into your body, they're not going to do much of anything. However, another hormone found in dairy, known as insulin growth factor 1, or IGF-1 for short, is a bit different. Our body itself creates IGF-1 since it is rather important for cognitive development and bone growth. IGF-1 also has the desirable function of stimulating the growth of lean muscle tissue. But it also stimulates the growth of cells in general… potentially even CANCER cells. High dairy consumption, especially from cows given a synthetic version of bovine growth hormones, do in fact increase blood IGF-1 levels by anywhere between 2 to 10%. However, the current research on the relationship of IGF-1 and cancer is… inconsistent. Some show an increased risk association while others show a potentially lower association risk. These inconsistencies are likely not concerning enough to undermine the evidence-supported cognitive and anabolic benefits of IGF-1. Also, practically any other protein-rich food can increase IGF-1 levels, so it isn't exactly a dairy-unique issue. In the big picture, we might be better off to have at least some dietary IGF-1, in which dairy can help. In terms of cancer and dairy in general, findings again remain inconsistent. The American Institute of Cancer Research concluded that milk probably protects against certain cancers like colorectal cancer while having only limited evidence linking milk to cancers like prostate cancer. Even then, dairy-related cancer findings are only associations. We have no data showing any causal relationships. Clearly, more research is definitely needed in this matter. Now, let's revisit: based on the findings, is dairy good or bad? The answer, is, unsurprisingly, “it depends.” First and foremost, it depends on your personal dairy and lactose tolerance. Avoid dairy if you have clear adverse reactions to it. Keep in mind though, not all dairy products are the same. Some dairy items, like swiss cheese and concentrated whey protein supplements, have very little lactose and galactose in it, making it tolerable for some dairy sensitive individuals. It will be up to you to try out different dairy products to see what you can personally tolerate. Outside of tolerance, dairy being good or bad depends again on the dairy product. Generally, highly processed, high-calorie dairy products filled with sugar ARE overall bad for you and should be avoided when possible. Fermented dairy products, on the other, like plain yogurt and cultured cheeses, are exceptionally great, even containing probiotics that can help support a healthy gut. Products like milk, cottage cheese, and sour cream, all fall somewhere in between. In my opinion, it's clear that the overall benefits of dairy abundantly outweigh the overall potential harms. We KNOW that dairy contains many nutrients vital to both our health and fitness. Outside of lactose intolerance, we have seen very mixed evidence supporting the severity of dairy's harms. That being said, for the people that can tolerate it, moderate dairy intake overall is indeed good for you and can be a solid piece to your dietary puzzle. Fortunately, even if you choose to avoid dairy for other reasons, like ethical reasons or simply not finding it tasteful, then that's completely fine. There are plenty of other non-dairy food choices that can provide the very same nutrients that make dairy great. Ultimately, the choice of consuming dairy or not, are in your hands. And you know what else is in your hands? The complete customizing and design of your own very website when you make it with Squarespace! I've personally have been fenagling with my own website design on Squarespace and I couldn't be happier with how it's coming along. For all you health and fitness buffs watching this video, I'm sure some of you aspire to have people listen to your thoughts or maybe even run your own online personal training services. If that's the case, then you should head to Squarespace.com to start your free trial and make your brand-new website today. Plus, once you're good to launch, you can go to squarespace.com/picturefit to save 10% off your first purchase of a website or domain. I hope you all enjoyed this video. Please thumbs up and share it with your dairy-loving friends! Subscribe if you want more. And as always, thank you for watching and GET YOUR PROTEIN!