Tag Archives: obesity

Organic Milk, Grass-fed Cows and Omega-3 Fatty Acids

The skeptical cardiologist has to admit that when he drinks milk or puts it in his coffee or cooks with it he almost exclusively drinks “organic”, non-homogenized milk obtained from dairy cows which are grass-fed and spend most of their lives grazing in a pasture.. In previous blogs I’ve laid out the evidence that supports that dairy products in general do not increase the risk of heart and vascular disease and, in fact, may lower that risk.

Full fat dairy has gotten a bad rap because it contains high levels of saturated fat. However, just as total fats were inappropriately labeled as bad , it is now clear that all saturated fats are not bad for the heart.

Although I recommend full fat dairy products to my patients I haven’t emphasized the organic or grass-fed aspect because I didn’t think there was enough good evidence that this is healthier than other kinds of milk and it is more expensive. There is evidence from small studies that cows consuming a more natural diet of grass and legumes from a pasture have higher levels of omega-3 fatty acids in their milk than those confined indoors and eating corn.

I keep my eyes (and ears) open for papers in this area.. One such paper appeared in the online peer-reviewed publication PLOS recently. I was driving to the hospital, listening to NPR when I first heard about it. Melissa Block was interviewing NPR correspondent Allison Aubrey . Her take, in a more subdued written form here is similar to many news outlets.

Allison summarized the findings as follows

The researchers compared organic and conventional milk head-to-head. They analyzed about 400 samples over an 18-month period, to account for seasonal differences. And the samples were taken from, you know, all different parts of the country. And they found that organic milk had about 62 percent more of the heart healthy omega-3s, compared to conventional milk.

When asked for an explanation she said

It really comes down to watch what the cows were eating. Organic milk is produced from cows that spend a lot more time out on pasture, and they’re munching on grasses and legumes. And these greens are rich in omega-3 fatty acids. So as a result, the milk they produce has more omega-3 fatty acids.

Wait a minute! I said , you’re confusing “organic” and “grass-fed” or “pasture raised ” they are two totally different things although they can overlap. I totally get the concept of a healthier diet for the cows increasing omega-3s in their milk but I haven’t seen anything that would suggest reducing pesticide or antibiotic usage does that. The radio did not respond. Also, I asked, is it possible to use the term omega-3 without prefacing it with “heart healthy”?

Once you start demanding to know more about the conditions of the cows that made the milk you drink things can become complicated. A cow can be grass-fed but not pasture raised, meaning that it stayed indoors and was fed hay. A cow can be outside “grazing ” but be given corn to eat. Prior to looking at the PLOS one article, I did not assume organic implied anything about how the cows were fed or grazed.

It turns out that in 2010 the USDA announced guidelines that mandated, among other things, for a dairy to be called “organic”, its dairy cows had to spend at least 120 days grazing on pasture.Thus, there is some correlation between organic and pasture raised/grass-fed but not a complete one.

The PLOS one study looked at geographical variation in the difference between organic and conventional milk fatty acid content. Northern California was the only region in which there was no significant difference. The authors speculated that this was because conventional farmers in Norther California usually have cows that roam on the pasture and eat grass and legumes. Thus, it appears the differences between organic and conventional milk are primarily due to what the cows were eating rather than the presence or absence of pesticides, antibiotics, GMOs, or hormones.

Allison Aubrey went on to say

But you know, I should say that there’s a trade-off here because in order to get all these extra omega-3s, you’ve got to drink whole milk. And you know, if you opt for the low-fat dairy – say, 1 percent fat -you’ve skimmed off most of these omega-3s. So the question is, you know, can you afford the extra calories in fat. If you choose the whole milk, you might need to trim a few calories from elsewhere in your diet.

To which I responded “Yes, by all means drink whole milk, there is no evidence that it adds to obesity. You will naturally want less calories down the line and you will get the benefit of good saturated fats.”

I'll continue to pay extra to drink milk from Trader's Point Creamery that I pick up at Whole Foods. I like their milk because I've visited their farm in Indiana and talked to their (plastic surgeon) owner and I like what he says on the website about their milk (ignoring the part about a “better immune system”.

We let our cows graze on 140 acres of pesticide free pasture, which results in milk with more healthy fats like Omega 3 and CLA (conjugated linoleic acid). Grassfed milk also contains more nutrients like beta carotene and vitamins A and E than milk produced using standard feeds. To all of us this means more nourishment and a better immune system for our bodies.

I’m going to end with the summary from the PLOS one article (DMI=dry matter intake, LA=linolenic acid, an omega-6 fatty acid) which emphasizes the importance of grazing and forage-based feeds not the organic aspects of milk.

We conclude that increasing reliance on pasture and forage-based feeds on dairy farms has considerable potential to improve the FA profile of milk and dairy products. Although both conventional and organic dairies can benefit from grazing and forage-based feeds, it is far more common—and indeed mandatory on certified organic farms in the U.S.—for pasture and forage-based feeds to account for a significant share of a cow’s daily DMI. Moreover, improvements in the nutritional quality of milk and dairy products should improve long-term health status and outcomes, especially for pregnant women, infants, children, and those with elevated CVD risk. The expected benefits are greatest for those who simultaneously avoid foods with relatively high levels of LA, increase intakes of fat-containing dairy products, and switch to predominantly organic dairy products.

Breakfast is Not The Most important Meal of the Day: Feel Free to Skip it

It always irritates me when a friend tells me that I should eat breakfast because it is “the most important meal of the day”. Many in the nutritional mainstream have propagated this concept along with the idea that skipping breakfast contributes to obesity. The mechanism proposed seems to be that when you skip breakfast you end up over eating later in the day because you are hungrier.

The skeptical cardiologist is puzzled. Why would i eat breakfast if I am not hungry in order to lose weight? What constitutes breakfast? Is it the first meal you eat after sleeping? If so, wouldn’t any meal eaten after sleeping qualify even it is eaten in the afternoon? Is eating a donut first thing in the morning really healthier than eating nothing? Why would your first meal be more important than the last? isn’t it the content of what we eat that is important more than the timing?

The 2010 dietary guidelines state

eat a nutrient-dense breakfast. Not eating breakfast has been associated with excess body weight, especially among children and adolescents. Consuming breakfast also has been associated with weight loss and weight loss maintenance, as well as improved nutrient intake

The US Surgeon General website advises that we encourage kids to eat only when they are hungry but also states

Eating a healthy breakfast is a good way to start the day and may be important in achieving and maintaining a healthy weight

A recent study anayzes the data in support of the “proposed effect of breakfast on obesity” (PEBO) and found them lacking.
This is a fascinating paper that analyzes how scientific studies which are inconclusive can be subsequently distorted or spun by biased researchers to support their positions. It has relevance to how we should view all observational studies.

Observational studies abound in the world of nutritional research. The early studies by Ancel Keys establishing a relationship between fat consumption and heart disease are a classic example. These studies cannot establish causality. For example, we know that countries that consume large amounts of chocolate per capita have large numbers of Nobel Prize winners per capitaChocolate Consumption and Nobel Laureates
Common sense tells us that it is not the chocolate consumption causing the Nobel prizes or vice versa but likely some other factor or factors that is not measured.

Most of the studies on PEBO are observational studies and the few, small prospective randomized studies don’t clearly support the hypothesis.

Could the emphasis on eating breakfast come from the “breakfast food industry”?
I’m sure General Mills and Kellogg’s would sell a lot less of their highly-processed, sugar-laden breakfast cereals if people didn’t think that breakfast was the most important meal of the day.

My advice to overweight or obese patients:
Eat when you’re hungry. Skip breakfast if you want.
If you want to eat breakfast, feel free to eat eggs or full-fat dairy (including butter)
These foods are nutrient-dense and do not increase your risk of heart disease, even if you have high cholesterol.
You will be less hungry and can eat less throughout the day than if you were eating sugar-laden, highly processed food-like substances.

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