New publication by our team

 

Pasture versus indoor feeding systems differentially affect the composition of polar lipids of Cheddar cheeses and their antiplatelet properties against platelet-activating factor

Highlights

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  UHPLC–HRAM-MS/MS revealed feeding-dependent cheese polar lipid profiles.
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  Pasture feeding increased bioactive polar lipid species in Cheddar cheese.
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  Clover-fed cheese exhibited the greatest antiplatelet activity in vitro.
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  Phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin species may antagonise PAF.
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  Feeding strategy influences the functional properties of dairy products.

Abstract

Bovine feeding systems alter milk lipid composition, but their effects on cheese polar lipids (PL) and platelet-modulating activity remain incompletely characterised. 

This study compared PL profiles and in vitro antiplatelet activity of full-fat Cheddar cheeses from cows fed indoor total mixed ration (TMR), perennial ryegrass pasture (GRS), or perennial ryegrass-white clover pasture (CLV).

Fifty-four Friesian cows were assigned to TMR, GRS, or CLV (n = 18/group) throughout lactation. Cheeses were manufactured in triplicate per treatment, ripened for 270 days, and PL were isolated. Lipid composition was analysed using C30 reversed-phase UHPLC-high-resolution accurate-mass tandem mass spectrometry. 

Inhibition of platelet aggregation induced by platelet-activating factor (PAF), ADP, and thrombin was assessed. CLV cheese PL showed the greatest inhibition of PAF-induced aggregation, with an IC₅₀ of 85.9 ± 7.4 μg, compared with 126.9 ± 25.2 μg for GRS and 129.5 ± 28.9 μg for TMR (p = 0.04), representing 32–34% lower IC₅₀ values. GRS and TMR did not differ significantly. Neutral-lipid fractions were inactive, while effects against ADP- and thrombin-induced aggregation were weak. 

Phosphatidylethanolamine (PE) was the predominant PL class (48–67%), followed by phosphatidylcholine (PC; 14–20%) and sphingomyelin (SM; 7–22%). 

Statistical analysis distinguished TMR from pasture-derived cheeses and identified treatment-dependent differences in PE, PC, SM, phosphatidylserine, and phosphatidylinositol. Several molecular species were associated with lower PAF IC₅₀ values. 

Overall, bovine feeding regimen influenced Cheddar PL composition and selective in vitro inhibition of PAF-induced platelet aggregation. White-clover pasture produced PL with greater anti-PAF potency, warranting further investigation.

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This is a study on the impact of different diets to the functional properties of cheese in relation to the aggregation of platelets. We can suggest that specific diet components affect the lipid composition and the anti-thrombotic bioactivities of cheeses. 

We are what we eat; the milk is what the cows eat!

a very interesting paper : Enhancing the fatty acid profile of milk through forage-based rations, with nutrition modeling of diet outcomes

Abstract

Consumer demand for milk and meat from grass-fed cattle is growing, driven mostly by perceived health benefits and concerns about animal welfare. In a U. S.-wide study of 1,163 milk samples collected over 3 years, we quantified the fatty acid profile in milk from cows fed a nearly 100% forage-based diet (grassmilk) and compared it to profiles from a similar nationwide study of milk from cows under conventional and organic management. We also explored how much the observed differences might help reverse the large changes in fatty acid intakes that have occurred in the United States over the last century. Key features of the fatty acid profile of milk fat include its omega-6/omega-3 ratio (lower is desirable), and amounts of total omega-3, conjugated linoleic acid, and long-chain omega-3 polyunsaturated fatty acids. For each, we find that grassmilk is markedly different than both organic and conventional milk. The omega-6/omega-3 ratios were, respectively, 0.95, 2.28, and 5.77 in grassmilk, organic, and conventional milk; total omega-3 levels were 0.049, 0.032, and 0.020 g/100 g milk; total conjugated linoleic acid levels were 0.043, 0.023, and 0.019 g/100 g milk; and eicosapentaenoic acid levels were 0.0036, 0.0033, and 0.0025 g/100 g milk. Because of often high per-capita dairy consumption relative to most other sources of omega-3 fatty acids and conjugated linoleic acid, these differences in grassmilk can help restore a historical balance of fatty acids and potentially reduce the risk of cardiovascular and other metabolic diseases. Although oily fish have superior concentrations of long-chain omega-3 fatty acids, most fish have low levels of α-linolenic acid (the major omega-3), and an omega-6/omega-3 ratio near 7. Moreover, fish is not consumed regularly, or at all, by ~70% of the U. S. population.


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our views
It is a great paper showing the impact of feeds on the quality of milk.
Alas, the ratio of omega-6/omega-3 is not giving us the complete cardiovascular risk picture;  it is a good start though.