The relationship between milk consumption, insulin and our health can be confusing. It’s easy to see why: The most common types of dairy products undeniably increase our insulin levels, and elevated insulin levels have been linked to dozens of diseases – most of them even. When insulin levels are high, your body holds on to body fat. And insulin resistance, in which your body does not respond to insulin and has to release large amounts of the hormone, makes it difficult to lose body fat and is the causative factor for a large number of degenerative diseases.
So dairy products are bad, right? No, on the contrary.
Insulin is an old, old hormone. Evolution has preserved its structure for hundreds of millions of years and hundreds of thousands of species. Fish, insects, reptiles, birds, and mammals all secrete insulin with fairly similar amino acid arrangements (insulin from certain species of fish has been clinically effective even in humans), so it is clearly a vital hormone that life needs to thrive and thrive.
What is insulin good for?
We need insulin to get all kinds of nutrients into cells, like protein and glycogen into muscles.
We need insulin to activate certain antioxidant systems.
We need insulin to optimize our cognitive function.
In other words, insulin is there for a reason, and “spikes” are normal as long as they go down. It is chronically increased Insulin, especially Fasting insulin (high levels of insulin in the absence of food) and insulin resistance, which are harbingers of disease.
When you are insulin resistant, insulin is less effective at transporting nutrients into cells.
If you are insulin resistant, these insulin-dependent antioxidant systems cannot be turned on.
When your brain is insulin resistant, like the brains of Alzheimer’s patients, your cognition suffers.
Insulin isn’t the problem. The problem is incorrect, dysregulated insulin signaling.
Which brings us to dairy products and their effect on insulin.
The intake of dairy products stimulates insulin secretion. Depending on the type of dairy product, it may or may not stimulate insulin at all. And although we usually think of insulin-stimulating carbohydrates, with Dairy products, it is the combination of protein (whey and casein) and carbohydrates (lactose) that stimulates insulin secretion.
- Both skimmed and whole milk produce significant insulin responses that you would not predict based on their carbohydrate content; You also need to consider the protein content.
- Cream and butter are not particularly insulinogenic because they are mostly high in fat and contain very little lactose or protein.
- Cheese has different effects on insulin depending on the cheese, with protein content being the main determinant. Cream cheese has very little insulin action because it is mostly fat. Cottage cheese has the greatest effect on insulin because it is mainly made up of protein. Brie has very little effect; Cheddar has something higher.
- Yogurt and kefir trigger moderate insulin spikes.
In one study, milk was even more insulinogenic than white bread, but less so than lactose-added whey protein and lactose-added cheese. Another study found that fermented whole milk products and normal whole milk are about as insulinogenic as white bread.
What’s going on here? It depends on the amino acid composition of milk proteins, especially the amino acids leucine, valine, lysine and isoleucine. These are the truly insulinogenic proteins, and they are highest in whey (which is probably why whey protein causes the largest insulin response).
That’s not new. I’ve already written about the insulinogenicity of proteins, but dairy products go way beyond the original sources of protein such as meat, eggs, and fish. The question we should be asking ourselves is: How important is the acute insulin response?
Do Insulin Spikes Make a Food Unhealthy?
A glass of milk and a comparatively high-calorie slice of white bread produce the same insulin response, but the comparisons stop there.
The milk provides you with bioavailable protein, lots of calcium, healthy milk fats, riboflavin, B12 and small but significant amounts of other vitamins and minerals. This protein will improve muscle protein synthesis. This calcium improves skeletal health. These fats improve the metabolic rate. This riboflavin will help you convert the fats and carbohydrates into usable energy. All of these lead to better metabolic health.
The slice of white bread gives you carbohydrates and little else. Perhaps some industrial fortification vitamins and minerals in a form that your body has difficulty assimilating.
The two foods do not have the same metabolic effects, although they do have similar effects on insulin.
Or let’s look at kefir, a food high in milk proteins that stimulate insulin secretion. When you feed kefir, the insulin goes up. And yet, feeding kefir to rodents directly increases their insulin sensitivity, lowers their blood pressure, and lowers their waist circumference. There was an insulin spike, but insulin signaling improved. Food is much more than just its effect on insulin levels.
Does milk cause insulin resistance?
A 2019 review of available research posed precisely this question. After reviewing 30 randomized controlled studies, the authors came to the conclusion that the intake of dairy products “has a positive effect on HOMA-IR, waist circumference and body weight”. On average across the studies, subjects randomly selected to eat dairy products improved their insulin sensitivity, decreased their waist size, and lost their body weight.
This study found that dairy products increased insulin resistance, but there are some loopholes. The children were given a strict diet of either lean beef or skimmed milk, and the skim-milk diet induced hyperinsulinemia and insulin resistance as early as seven days. It sounds like a chore, but they used skimmed milk – a refined, radically modified food. The dairy group also ate 13% more calories than the meat group. Given that excessive calorie intake is a reliable way to trigger insulin resistance, I’m not convinced that milk was the culprit.
Another study found that dairy products improved blood pressure but did not improve insulin and other metabolic risk parameters in overweight and obese individuals, but low-fat dairy products were used instead of full-fat dairy products. Again, the insulin counts didn’t get any worse; they just haven’t improved.
If whole milk products really did induce insulin resistance, we would see it in the literature. You wouldn’t see any studies showing that people who consumed the most milk fat were the least likely to have diabetes. You also wouldn’t see any studies suggesting that, if anything, dairy products reduced the risk of diabetes and heart disease.
Acute insulin spikes differ from chronically elevated insulin levels, especially when it comes to appetite regulation and metabolic disorders. Insulinogenic foods and insulin spikes can be problematic if you’re insulin resistant, but dairy products seem to improve insulin resistance.
Will Milk Work For You?
Milk is not for everyone. I don’t like milk, so I stick with good cheese, pasture butter, cream, and the whey in it Primary fuel I avoid most of the direct milk when I’m in a hurry, but I think good milk can be fine for a lot of people. Experiment as always. Dairy products seem to delay weight loss in some people, so you could try removing them from the diet if you can’t lean back. Dairy products also seem to improve strength and mass gains for strength athletes, so you could try adding them if you’ve been working out particularly hard. See what works and what doesn’t. Insulin doesn’t have to be feared as much as it should be treated as long as the rest of your metabolic toolbox is in order, you turn stress on (or off), sleep well, and do the necessary physical work.
In the end, personal results count the most. Health outcomes affect us; Detached insulin response numbers tabulated in a publication mean little if your personal experience corroborates the evidence consistently showing that pristine, full-fat dairy products are likely to have better glucose tolerance, better weight control, and greater resistance to chronic diseases such as diabetes and heart disease promote disease. On the other hand, these studies mean little to the person whose weight loss stagnates after a few glasses of unhomogenized, raw, pasture milk. As hard as we try, we cannot ignore our own experiences. Have your experiences with dairy products been positive or negative? Let the answer to that question replace what PubMed says.
A few suggestions:
- Go fermented. Stick with full-fat yogurt, kefir, and cheese.
- Go hard. Stick with butter, cream and half and half.
- Go to the pasture. Find a source of pasture milk products, which are higher in micronutrients and omega-3 fatty acids.
- Go raw. Stick to trustworthy sources.
What is your experience with the insulinogenic effects of dairy products? They are very real, but do they seem to bother you? Worried about insulin spikes in response to milk protein?
Thank You For Reading!