Dairy and Its Effect on Insulin Secretion (and What It Means for Your Waistline)by Mark Sisson

Insulin is an old, old hormone. Evolution has preserved its structure across 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 even been clinically effective in humans), so, clearly, it is a vital hormone. But insulin gets a bad rap in our circles. Why? With metabolic syndrome laying waste to the citizenry and with insulin playing an undeniable role, it’s difficult not to be soured on this hormone.

And yet we need insulin to shuttle all sorts of nutrients into cells, like protein and glycogen into muscles. It’s there for a reason, so to demonize it is misguided. It’s chronically elevated insulin and insulin resistance – you know, the hallmarks of metabolic syndrome – that are the problem. You might have noticed a softening stance on carbohydrates around the paleo and Primal blogosphere. I think it’s simply an acknowledgment that in healthy people with healthy glucose control and healthy insulin responses who engage in glycolytic activity, starch is fine in measured amounts. And if insulin increases to shuttle that starch and protein into the insulin sensitive muscle cells, so be it. That’s why it’s there.

But not everyone (anyone?) lives a perfect Primal existence. And even if you did an understanding of how insulin works and what foods and behaviors affect it’s production should be high priority. Especially for the millions of people immersed in the modern, industrial lifestyle, with deranged metabolisms from years of poor eating habits (i.e. most of us).

Which brings us to dairy and its effect on insulin.

Dairy intake, you see, stimulates insulin secretion. Lots and lots of it – more than can be explained by the lactose (a sugar) content. In fact, the lactose content of dairy doesn’t even have a big insulin effect when compared to other carbs. This is surprising to some, since the general understanding is that insulin is released primarily in response to carbohydrate intake. What gives? Well, in evolutionary terms, think about a growing beast needing to maximize the utility of every drop of the precious liquid. With dairy, it’s the protein plus the carbs that are responsible for the large insulin release. Take milk, the most egregious “offender.” Both skim and whole milk (PDF) elicit significant insulin responses that you wouldn’t predict from looking at their protein and carb contents, and the fat in whole milk doesn’t blunt it (maybe non-homogenized whole milk would be a different story… I don’t know). Cream and butter are not particularly insulinogenic, while milk of all kinds, yogurt, cottage cheese, and anything with casein or whey, including powders and cottage cheese, elicits a significant insulin response. In one study (PDF), milk was even more insulinogenic than white bread, but less so than whey protein with added lactose and cheese with added lactose. Another study (PDF) found that full-fat fermented milk products and regular full-fat milk were about as insulinogenic as white bread.

What’s going on here? It comes down to the amino acid composition of dairy proteins, specifically the amino acids leucine, valine, lysine, and isoleucine. These are the truly insulinogenic proteins, and they’re highest in whey (which is probably why whey protein elicits the biggest insulin response).

This isn’t new. I’ve written about protein’s insulinogenicity before, but dairy goes above and beyond Primal protein sources like meat, eggs, and fish. The question we should be asking is this: if you wish to include dairy in your diet AND have no issues with lactose or casein intolerance are the insulinogenic properties of certain types of dairy still problematic from the standpoint of health and/or weight control?

This study claims they are. Children were given strict diets of either lean beef or skim milk, and the skim milk diet induced hyperinsulinemia and insulin resistance after just seven days. It sounds troublesome, but they used skim milk – a refined, fundamentally altered food. I’m not prepared to render judgment. Another study found that dairy failed to improve insulin and the metabolic risk parameters in overweight and obese subjects, but it again used low-fat dairy instead of full-fat dairy. I’m simply not convinced they’re interchangeable.

If full-fat dairy really did have similarly negative effects on the insulin response that eventually led to the metabolic syndrome, you wouldn’t see studies showing that people who ate the most dairy fat were at the lowest risk for diabetes. You also wouldn’t see the high number of epidemiological studies (I know, I know) linking full-fat dairy intake with lower risk of heart disease and stroke, both of which are strongly linked with insulin resistance.

I think it’s more accurate to say that acute insulin spikes are different from chronically elevated insulin levels, especially when it comes to appetite regulation and metabolic derangement. Consider this study, whose authors gave either whey protein isolate or whey protein hydrolysate to subjects 30 minutes before a pizza meal. Subjects given whey protein isolate, but not hydrolysate, reduced post meal blood glucose and insulin levels, and ate less pizza. The whey still released insulin, but it didn’t linger for very long and it led to improved post meal numbers. It wasn’t chronically elevated. The subjects weren’t hungrier, contrary to what you might expect from someone who’d just experienced a jump in insulin.

No Easy Answer.

Dairy’s not for everyone. I don’t like milk, so I stick to good cheese, pastured butter, cream and the whey in Primal Fuel when I’m in a hurry, while avoiding most straight-up milk, but I think good milk may be fine for many people. As always, experiment. Dairy seems to stall weight loss for some people, so you might try taking it out of the diet if you can’t lean out. Dairy also seems to improve strength and mass gains for lifters, so you might try adding it if you’ve been lifting particularly hard. See what works, and what doesn’t. Insulin doesn’t have to be feared as much as it should be managed, just so long as the rest of your metabolic toolkit – in which insulin takes a prominent position – is in order, you’ve got stress dialed in (or out), you’re getting good sleep, and you’re putting in the necessary physical work.

It’s also important to consider the big picture when judging the suitability of various foods. It helps to tell stories about the food we eat, to think about narratives. Grains aren’t just little morsels of protein, carbs, and fiber bred for our enjoyment. They are baby plant eggs. Those macronutrients are there to sustain the seed’s growth and those micronutrients are there to protect it. They are the plant’s lifeline to immortality. They are literally shaped by the hand of evolution to survive and ravage the digestive tract of the poor sap that swallows them and discourage further consumption. Grain is only food because we deemed it so. Dairy? Dairy is objectively, absolutely food. Its fat, protein, and carbs are there to be consumed, albeit by young cows, sheep, and goats. It’s meant to spur growth, to pack on muscle and fat and weight. And yeah, eating dairy protein causes an insulin spike, but that can be useful if you know what you’re doing.

In the end, personal results matter most. Health outcomes concern us; detached insulin response numbers sitting in a table in some paper mean little if your personal experiences corroborate the evidence that consistently shows that untouched, full-fat dairy likely promotes better glucose tolerance, better weight control, and more resistance to chronic diseases like diabetes and heart disease. On the other hand, those studies mean little to the person whose weight loss stalls after a couple glasses of non-homogenized, raw pastured milk. Try as we might, we can’t – nor should we – ignore our own experiences. Have your experiences with dairy been positive or negative? Let the answer to that question supersede what PubMed says.

Some suggestions:

• Go fermented. Stick to full-fat yogurt, kefir, and cheese.
• Go heavy. Stick to butter, cream, and half-and-half.
• Go pastured. Find a source of pastured dairy. From what I understand, Trader Joe’s carries a cream-top organic milk that hails from the Strauss Family Creamery in Northern California (they never provide sources, but the TJs stuff tastes remarkably similar to the glass bottle stuff from Strauss and the cream has the same consistency), which uses mostly grass and grass silage. Their “European Style Yogurt” also comes from Strauss and is very good (and cheaper than Strauss-labeled yogurt in other stores).
• Go raw. Stick to trusted sources.

What are your experiences with dairy’s insulinogenic effects? They are very real, but do they seem to bother you? Are you worried about insulin spikes in response to dairy protein?

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Vitamin K Builds Bones Better Than Calcium

Many people immediately turn to calcium in the form of supplements or milk in order to boost bone density and prevent osteoporosis. But those sources of calcium are NOT the best way to build bone health. In fact, it’s vitamin K2 that helps boost bone density and prevent osteoporosis even more.

According to recent research*, men and women with the highest intake of vitamin K2 are 65% less likely to suffer a debilitating hip fracture as compared to those with the lowest intake of vitamin K2.

According to recent research**, vitamin K plays a leading role in preventing the following problems commonly associated with aging:

• Osteoporosis and deteriorating bones
• Artery hardening
• Cancer

This latest study on vitamin K2 was led by Professor Bruce Ames Professor of Biochemistry and Molecular Biology, University of California, Berkeley, and a Senior Scientist at Children’s Hospital Oakland Research Institute (CHORI).

Ames hypothesizes that vitamin K2 deficiencies impact the body by the role they play in production of certain proteins. When the body lacks in vitamin K2 these essential functions are compromised. Despite higher functions still being operative, the body responds by accelerating cancers, aging, and neural decay while leaving other critical functions unchanged.

In other words, when the body lacks enough vitamin K2, it goes into emergency mode keeping up only the critical functions needed for immediate survival. The result is that the other vital processes break down leaving the body vulnerable to weak bones, cancers, and artery problems.

According a Tufts University study only 50% of the population gets adequate amounts of vitamin K from their diets. Are you getting enough vitamin K in your diet or is your body silently being depleted, leaving you at higher risk for dangerous disease?

Vitamin K 101

Vitamin K is a fat soluble vitamin with basically three main types; K, K1, and K2. For the purposes of this discussion we’re speaking of K2. A fat soluble vitamin is one that is absorbed in the intestines along with fat. Fat soluble vitamins are stored in the liver.

Vitamin K plays a vital role in blood clotting as well as bone calcification; both vital body functions for healthy living and disease free aging.

The Recommended Daily Allowance (RDA) for adult females is 65 mg and 80 mg for men. For children and infants the RDA is 5 mg.

Common Causes of Vitamin K Deficiencies

Although deficiencies in vitamin K used to be very rare the times have changed. Sadly, as is evident by the Tufts University study, more and more people are becoming deficient in this vitamin too.

Poor diet is one of the factors playing into a vitamin K deficiency (as well as other important vitamin and mineral deficiencies). There are a few common contributors to promoting a deficiency in vitamin K. Are any of these familiar to you?

• Long term use of antibiotics
• Intestinal problems such as chronic inflammatory bowel disease
• Cholesterol lowering pharmaceuticals

Basically since vitamin K is produced by friendly bacteria in the gut, any disruption in the intestines can result in a decreased ability of the body to absorb or produce vitamin K.

This can happen from any problem in the intestines as well as eating foods such as hydrogenated vegetable oils which impact the absorption of vitamin K and the body’s ability to use it.

The disruption of friendly bacteria in the gut from antibiotics, chlorinated & fluoridated water, and fake foods is one reason I recommend almost everyone supplement with a high quality probiotic. I personally use Primal Defense by Garden of Life.

As with any vitamin, mineral, or other nutrient, fresh, whole foods are the very best source. Along with it you’ll get more nutrients and all your body needs to properly assimilate it.

Food Sources of Vitamin K

The best food sources of vitamin K are leafy green vegetables.

There are other foods that offer vitamin K too:

• Spinach
• Kale
• Broccoli
• Brussels sprouts
• Cabbage
• Cauliflower
• Soybeans
• Cow’s milk
• Lettuce
• Asparagus
• Collard greens
• Bok Choy
• Peas
• Parsley
• Green tea
• Lentils
• Split peas

Once again I want to emphasize that eating a variety of these foods in your daily diet is the best way to obtain vitamin K. However if for some reason you can’t consume these or they aren’t enough, consider a high quality vitamin K supplement. Generally speaking a deficiency in vitamin K is usually due to a problem with absorption rather than a lack in the diet.

If you suspect you are vitamin K deficient I urge you to pinpoint the cause and act accordingly.

Symptoms of Vitamin K Deficiency

Symptoms of a vitamin K deficiency can include:

• Easy bruising
• Gastrointestinal bleeding
• Nosebleeds
• Heavy menstrual bleeding
• Blood in the urine

People with certain diseases are more likely to be deficient in vitamin K. These include celiac disease, chronic inflammatory bowel disease, cystic fibrosis, and cholestasis to name a few.

Despite the fact that vitamin K is a fat soluble vitamin there are no well documented or known toxicity problems. However it is not recommended to take supplements of this vitamin if you are taking anticoagulant drugs.

If you not sure if you have a deficiency in this crucial vitamin ask your health care practitioner who can order tests to determine for certain if you are deficient. They can also help guide you based on test results in proper supplementation if needed and getting to the root cause of the deficiency.

Sources

*According to the Framingham Heart Study led by the National Heart, Lung, and Blood Institute (NHLBI)

**Published in the American Journal of Clinical Nutrition in February 2009

MedScape (2011)