Feed Cows in Shape of Heart

Can you get heart-healthy dairy if you feed cows differently?

News coverage suggests that people at risk of heart and circulatory diseases could lower their risk by eating butter, milk and cheese from cows on a special diet. But does the study support this claim?

07 February 2020

The research

Research suggests that feeding cows differently can produce dairy products that are lower in unhealthy saturated fat and higher in healthy monounsaturated fat. And a small study suggests that eating these dairy products could reduce risk of heart and circulatory disease compared with eating standard butter, milk and cheese.

The researchers, from The University of Reading, changed the makeup of dairy products by feeding cows a special diet high in monounsaturated fat. When they gave the dairy products produced from these cows to people at moderate-risk of heart and circulatory diseases they found that the rise in LDL-cholesterol was not as great as it was for the group consuming standard milk and dairy products.  Blood vessel health was also better than when they ate traditional dairy.

The researchers fed dairy cows with a type of vegetable oil which is high in monounsaturated fat so that the milk, and butter and cheese they produced from this milk, had lower saturated fats and higher levels of monounsaturated fats.

They gave one group of people traditional dairy products, and the other group the modified products. The participants didn't know which they were eating (the researchers had already done a study to make sure the new and standard dairy tasted the same), and everyone ate the same amount of fat overall. There were 54 people in the trial, all at a moderate risk of heart and circulatory diseases.

It's important to note that the study at how the change in fat composition of the butter, milk and cheese affected the participants' risk of heart and circulatory diseases. It didn't make any comparisons with a low-fat diet or with eating lower-fat versions of dairy products.

The researchers found that the participants had a lower increase of bad (LDL) cholesterol and healthier blood vessels when they had the modified dairy products compared to traditional dairy products.

Too much "bad" cholesterol it can build up inside the walls of the blood vessels. This clogs them up, causing narrowing of the arteries which increases your risk of having a heart attack or stroke.

How good was the research?

The study was well designed - neither trial participants nor the researchers knew the type of dairy products they were having, and everyone got to eat both types of dairy at some point. But this was a small study , so there needs to be more research and larger trials in order to create more reliable data.

The study was made up of men and women aged between 25-70 defined as having a moderate risk of heart and circulatory disease, so it may not show how the changes would affect people with a higher or lower risk.

Commenting on the study, Paul Evans, Professor of Cardiovascular Science, University of Sheffield, said: "Further studies are also required to know if modified butter and cheese can benefit patients with pre-existing cardiovascular diseases including those recovering from a heart attack or stroke."

Graham Burdge, Professor of Nutritional Biochemistry at the University of Southampton, also said that the changes in people's heart and circulatory health after eating the modified dairy was "modest", and  "the authors do not indicate whether their approach alone would be sufficient to bring about meaningful changes in the health of the general population.  Overall, this study is a commendable first step in a long programme of research."

The BHF view

BHF Senior Dietitian Victoria Taylor says: "It's promising to see how natural changes to the fat content of some of our favourite dairy products could help to lower our cholesterol and risk of heart and circulatory diseases.

"Switching from foods high in saturated fat – such as biscuits, cakes and fatty meats – to foods with more unsaturated fat – such as oily fish, nuts and seeds – can also reduce cholesterol levels.

"Whether the type of dairy product, such as butter rather than milk or cheese, has a greater or lesser effect also needs to be explored further."

Media coverage

The story was covered by some newspapers and websites, such as The Times and Farming UK.

The coverage was mostly accurate, although  the Times' headline "Cows on a diet 'produce healthier milk'") could be misleading. The cows weren't on a diet, they were fed vegetable oil, which is quite high-calorie.

The Times did provide balance to its story by including expert advice the effect was still relatively small and that it was important to remember that cheese probably was not going to be the best solution to a healthier heart.

delargiehatestaked.blogspot.com

Source: https://www.bhf.org.uk/informationsupport/heart-matters-magazine/news/behind-the-headlines/can-you-get-heart-healthy-dairy-if-you-feed-cows-differently

Share this post