Dietary Supplementation with Milk Lipids Leads to Suppression of Developmental and Behavioral Phenotypes of Hyperexcitable Drosophila Mutants

Dietary modifications often have a profound impact on the penetrance and expressivity of neurological phenotypes that are caused by genetic defects. Our previous studies in Drosophila melanogaster revealed that seizure-like phenotypes of gain-of-function voltage-gated sodium (Nav) channel mutants (paraShu, parabss1, and paraGEFS+), as well as other seizure-prone "bang-sensitive" mutants (eas and sda), were drastically suppressed by supplementation of a standard diet with milk whey. In the current study we sought to determine which components of milk whey are responsible for the diet-dependent suppression of their hyperexcitable phenotypes. Our systematic analysis reveals that supplementing the diet with a modest amount of milk lipids (0.26% w/v) mimics the effects of milk whey. We further found that a minor milk lipid component, α-linolenic acid, contributed to the diet-dependent suppression of adult paraShu phenotypes. Given that lipid supplementation during the larval stages effectively suppressed adult paraShu phenotypes, dietary lipids likely modify neural development to compensate for the defects caused by the mutations. Consistent with this notion, lipid feeding fully rescued abnormal dendrite development of class IV sensory neurons in paraShu larvae. Overall, our findings demonstrate that milk lipids are sufficient to ameliorate hyperexcitable phenotypes in Drosophila mutants, providing a foundation for future investigation of the molecular and cellular mechanisms by which dietary lipids modify genetically induced abnormalities in neural development, physiology, and behavior.

Updating the fatty acid profiles of retail bovine milk in China based on an improved GC-MS method: implications for nutrition

The importance of food components to potential benefits and risks to human health is gradually being consumer awareness. Milk is an important part of the lipid content of the human diet, and there are few detailed reports on the fatty acid (FA) profiles of retail milk. In the study, we developed a gas chromatography-mass spectrometry (GC-MS) method to simultaneously determine 82 FAs, including 11 even-chain saturated FAs, 10 odd-chain saturated FAs, 9 branched-chain saturated FAs, 30 monounsaturated FAs, and 22 polyunsaturated FAs; this was applied to analyze samples (186 samples) of commercially available milk from 22 provinces throughout China and to evaluate the nutritional value of these samples based on FA-related indices. The results showed that the overall composition of milk FAs among the different regions was numerically similar, and minor FAs showed few differences. When considering the retail milk FA composition and dairy fat intake in China, regional variations have a limited impact on FA consumption. Moreover, milk accounts for approximately one-third and <10% of the maximum recommended intake of saturated FAs and trans-FAs in consumer diets, respectively. This study provides an updated report on the composition of FAs and the nutritional value of retail milk across China, which can serve as a reference for producers for future research on regulating milk FAs, for consumers to select milk, and for nutrition departments to formulate relevant nutritional guidance recommendations.

Seasonal variation in fatty acid and triacylglycerol composition of bovine milk fat

The aim of this study was to assess the effects of seasonal variation on the changes of the fatty acid (FA) and triacylglycerol (TAG) composition of bovine milk fat (MF) in a nonseasonal milking system. Weekly milk samples were collected from 14 dairy factories and pooled per week as representative samples of the average Dutch bovine milk. The sample collection started in May 2017 and finished in April 2018, resulting in a total of 52 samples, corresponding to each week of the year. The samples were analyzed for MF content (%) and FA and TAG composition using gas chromatography with flame-ionization detection. The increased intake of C18:3 cis-9,12,15 through grass feeding in spring and summer was associated with major changes in MF FA composition, including reduced proportions of de novo synthesized FA and presence of several rumen biohydrogenation products and conjugated linoleic acid isomers in MF. These changes in seasonal FA composition had an effect on TAG seasonal variation. The TAG seasonal variation showed that all TAG groups were significantly different between months. The low molecular weight and the medium molecular weight TAG groups increased in winter and decreased in summer, whereas the high molecular weight TAG groups increased in summer and decreased in winter. Based on pooled monthly samples, MALDI-TOF-mass spectrometry allowed the analysis of even- and odd-chain TAG species in MF based on their total carbon number and number of double bonds. These analyses indicated saturated TAG species to be greatest in winter, whereas monounsaturated, polyunsaturated, and odd-chain TAG species were greatest in summer. Our study showed that TAG seasonal variation in a nonseasonal milking system is influenced by the variation in FA composition throughout the seasons.

O’Sullivan M, Kerry JP, Kilcawley KN. A Cross-Cultural Evaluation of Liking and Perception of Salted Butter Produced from Different Feed Systems

Perception and liking among Irish, German and USA consumers of salted butter produced from different feed systems-outdoor grass (FS-GRSS), grass/clover (FS-CLVR), and indoor concentrate (FS-TMR)-was investigated. A consumer study was conducted in all three countries. Irish and German assessors participated in ranking descriptive analysis (RDA), whereas descriptive analysis (DA) was carried out by a trained panel in the USA. Volatile analysis was conducted to identify differences in aroma compounds related to cow diet. Overall, there was no significant difference in overall liking of the butters, among USA, German and Irish consumers, although cross-cultural preferences were evident. Sensory attribute differences based on cow diet were evident across the three countries, as identified by German and Irish assessors and trained USA panelists, which are likely influenced by familiarity. The abundance of specific volatile aromatic compounds, especially some aldehydes and ketones, were significantly impacted by the feed system and may also contribute to some of the perceived sensory attribute differences in these butters.

Dairy farming system markers: The correlation of forage and milk fatty acid profiles from organic, pasture and conventional systems in the Netherlands

The relationships between the fatty acid (FA) composition in forage and milk (F&M) from different dairy systems were investigated. Eighty milk samples and 91 forage samples were collected from 40 farms (19 organic, 11 pasture and 10 conventional) in the Netherlands, during winter and summer. The FA profiles of F&M samples were measured with gas chromatography. The results showed that the F&M of organic farms were significantly differentiated from the F&M of other farms, both in summer and winter. The differences are likely due to the different grazing strategies in summer and different forage composition in winter. The Pearson's correlation results showed the specific relationship between individual FAs in forages and related milk. A PLS-DA model was applied to classify all milks samples, resulting in 87.5% and 83.3% correct classifications of training set and validation set.

Human health implications of organic food and organic agriculture: a comprehensive review

This review summarises existing evidence on the impact of organic food on human health. It compares organic vs. conventional food production with respect to parameters important to human health and discusses the potential impact of organic management practices with an emphasis on EU conditions. Organic food consumption may reduce the risk of allergic disease and of overweight and obesity, but the evidence is not conclusive due to likely residual confounding, as consumers of organic food tend to have healthier lifestyles overall. However, animal experiments suggest that identically composed feed from organic or conventional production impacts in different ways on growth and development. In organic agriculture, the use of pesticides is restricted, while residues in conventional fruits and vegetables constitute the main source of human pesticide exposures. Epidemiological studies have reported adverse effects of certain pesticides on children's cognitive development at current levels of exposure, but these data have so far not been applied in formal risk assessments of individual pesticides. Differences in the composition between organic and conventional crops are limited, such as a modestly higher content of phenolic compounds in organic fruit and vegetables, and likely also a lower content of cadmium in organic cereal crops. Organic dairy products, and perhaps also meats, have a higher content of omega-3 fatty acids compared to conventional products. However, these differences are likely of marginal nutritional significance. Of greater concern is the prevalent use of antibiotics in conventional animal production as a key driver of antibiotic resistance in society; antibiotic use is less intensive in organic production. Overall, this review emphasises several documented and likely human health benefits associated with organic food production, and application of such production methods is likely to be beneficial within conventional agriculture, e.g., in integrated pest management.

Temporal changes in milk fatty acid distribution due to feeding different levels of rolled safflower seeds to lactating Holstein cows

The objective of this experiment was to follow the time-course changes of the milk fatty acids (FA) and particularly conjugated linoleic acid (CLA), n-3, and n-6 FA in response to feeding whole rolled safflower seed (SS). Eighteen cows were blocked by milk production, days in milk, and parity, and randomly assigned to 1 of 3 diets by replacing whole cottonseed with SS. The control diet contained no SS (SS0), whereas the other diets contained 3% of dry matter as SS (SS3) or 6% SS (SS6). The study was conducted for 8 wk. Cows fed SS produced more milk than SS0, with SS3 producing more milk than SS6, but without a change in milk fat yield or milk fat %. Except for C8:0 FA, changes in milk FA were not observed until the third week of SS feeding. The C8:0 began decreasing during wk 1 of SS feeding and continued to decline to wk 8. Short-chain FA (C6:0 to C11:0) and medium-chain FA (C12:0 to C16:1) concentrations decreased in milk when cows were fed SS, whereas long-chain FA (C18:0 and higher) increased after wk 3. The milk long-chain FA increased from wk 3 until wk 5 and then reached a plateau with little difference between SS3 and SS6, whereas the short-chain FA decreased more in milk from cows fed SS6 than SS3. Total CLA increased slightly less than 5× in milk from cows fed SS compared with SS0. Over the same time frame, n-3 FA declined and n-6 FA increased in the milk from cows fed SS, with no difference between SS3 and SS6. This study indicated that SS fed at 3 and 6% of DM had the potential to increase milk production and the CLA in milk, but with a corresponding increase in n-6 FA.

Comparison of Molecular Species Distribution of DHA-Containing Triacylglycerols in Milk and Different Infant Formulas by Liquid Chromatography-Mass Spectrometry

Long-chain polyunsaturated fatty acids (LC-PUFA) are an important nutritional lipid and have potential in being able to promote human health. Docosahexaenoic acid (DHA, C22:6ω3) is often added in infant formulas to meet the nutritional requirement of formula-fed infants. A comprehensive survey on DHA-containing triacylglycerol (DHA-TAG) molecular species has been conducted for seven infant formulas (IFs) sourced from Australia, Europe, and the USA as well as bovine milk and human milk. Using LC-triple quadrupole MS and LC-LTQ-orbitrap MS we were able to identify and quantify 56 DHA-TAG species in these samples; the fatty acid structure of these species was assigned using their MS(2) spectra. The species composition of DHA-TAG was found to be different between bovine milk, human milk, and IFs and also between different brands of IFs. Bovine milk and human milk contain DHA-TAG of smaller molecular size (728-952 Da), whereas five out of the seven IF samples contain species of broader mass range (from 728 to 1035 Da). Our study indicates that two types of DHA were used in the seven IF products surveyed and that there is very large difference in molecular species distribution in different IF products that may influence the fine nutritional profile and biological functions of IF products.