Soy and flaxseed oils in cows’ diets improve milk quality, researchers confirm

Publicado em 08 maio 2021

Brasilia [Brazil]May 8 (ANI): Brazilian researchers show that the inclusion of soy and linseed oils in the diet of dairy cows made the fatty acid content of their milk even healthier for human consumption. It also increased the levels of omega-6 and omega-3, which, when properly balanced, play a key role in preventing cardiovascular disease.

Cardiovascular disease is one of the world’s biggest public health problems. In Brazil they are one of the leading causes of death. According to the Ministry of Health, around 300,000 Brazilians die each year from heart attacks, 30 percent of which die.

Research by Arlindo Saran Netto, professor at the Faculty of Animal Science and Food Technology of the University of Sao Paulo (FZEA-USP) in Pirassununga, State of Sao Paulo, shows that consumption of these oils by dairy cows lowered the level of saturated fat in their milk and increased levels of unsaturated fatty acids that help reduce LDL, known as “bad cholesterol”

;An article published in the journal PLOS ONE reports on the results of research supported by FAPESP (Research Foundation FUNDACAO DE AMPARO A PESQUISA DO ESTADO DE SAO PAULO). The study was part of a series led by Saran Netto for more than five years to improve food quality and develop novel types of milk and meat.

“The quality of the milk available on the market is good. In our research we want to create more ways to ensure that milk is beneficial to human health in novel ways. Many consumers want to follow a certain diet,” Saran Netto told Agencia FAPESP .

The study showed that supplementing the cow feed with these two oils resulted in an omega-6 / omega-3 ratio of 2.7: 1 in the milk. Given the opposing effects of the two fatty acids, a healthy diet should be balanced.

The World Health Organization (WHO) recommends between 5: 1 and 10: 1, but 50: 1 could result from a diet consisting mostly of ultra-processed foods low in fish and vegetables, creating an imbalance and increasing the risk of heart disease increases cancer.

Like other mammals, humans cannot synthesize omega-6 or omega-3 and must get them from food. “Future studies should evaluate the health benefits of omega-fortified milk in the human diet,” the article concludes.

In the human metabolism, omega-6 and omega-3 compete for the same elongase and desaturase enzymes. Higher omega-6 levels impair the metabolism of omega-3. Too much omega-6 can increase blood pressure and triglyceride levels, among other things. Omega-3 can have anti-inflammatory effects and reduce blood lipids. Recent research has shown that diets with the right amounts of both play an important role in disease prevention.

The researchers worked with 18 lactating Holstein dairy cows for 94 days. All animals were fed the same diet for the first ten days, followed by three experimental periods of 28 days. The control was a normal dairy cow diet with no added oil. Then soybean oil was added at 2.5 percent as a source of omega-6, followed by 2.5 percent linseed oil as a source of omega-3. Both oils represented 2.5 percent of the total dry matter and replaced corn.

These values ??were chosen because in previous studies of the group they improved the fatty acid profile of the milk without significantly changing the yield. Milk samples were then analyzed for fat, protein, lactose and total solids.

Research by the group published by Saran Netto in 2016 showed that adding rapeseed oil to the diet of dairy cows also changes the fatty acid profile of their milk and makes them healthier.

Another study, also funded by FAPESP, experimented with sunflower oil, organic selenium, and vitamin E supplements that improved animal health, milk yield and preservation, and showed that children who consumed milk had increased levels of selenium and vitamin E. Had levels in the blood.

Historically, cow’s milk has been an important source of nutrients for human consumption. It is rich in proteins, calcium, magnesium, selenium and vitamin B12, among other things.

However, over the past few decades, demand has declined, particularly in the US and Canada, for a number of reasons, including health and dietary reasons. For example, the fat in milk can cause allergic reactions and usually contains saturated fat, which has been linked to weight gain and obesity. Therefore, much scientific research has been devoted to the adjustments needed to meet consumer demand for a healthier product.

With an annual production of 34 billion liters, Brazil ranks fifth among the world’s leading milk producers. Dairy products are one of the most important segments of the food industry. The annual milk consumption averages 170 liters per capita, which is below the average for industrialized countries (250-300 liters). UHT (Long Life) milk is the most widely consumed dairy product, but cheese sales have risen sharply in recent years.

The types of milk obtained from Saran Netto and his group are not yet available in Brazil, although research is more than complete. The main reason, he said, is logistical difficulties in distribution and industrial processing that have delayed commercialization.

“In many cases the same truck collects milk from several farms. This hinders the development of the product as we cannot mix normal milk and milk from cows with a certain diet. Likewise in the industry: we need a separate production line for special milk”, he said.

“There is not yet enough consumer demand to guarantee sales volumes that would allow separate processing.” In the future, he hopes to be able to market milk with added omega-3 fatty acids and antioxidants.