Previous studies on the relationship between dairy consumption and hip fracture risk have reported inconsistent findings. Therefore, we aimed to conduct an algorithmically driven non-linear dose-response meta-analysis of studies assessing dairy intake and risk of developing incident hip fracture. Meta-analysis from PubMed and Google Scholar searches for articles of prospective studies of dairy intake and risk of hip fracture, supplemented by additional detailed data provided by authors. Meta-regression derived dose-response relative risks, with comprehensive algorithm-driven dose assessment across the entire dairy consumption spectrum for non-linear associations. Review of studies published in English from 1946 through December 2021. A search yielded 13 studies, with 486 950 adults and 15 320 fractures. Non-linear dose models were found to be empirically superior to a linear explanation for the effects of milk. Milk consumption was associated with incrementally higher risk of hip fractures up to an intake of 400 g/d, with a 7 % higher risk of hip fracture per 200 g/d of milk (RR 1⋅07, 95 % CI 1⋅05, 1⋅10; P < 0⋅0001), peaking with 15 % higher risk (RR 1⋅15, 95 % CI 1⋅09, 1⋅21, P < 0⋅0001) at 400 g/d versus 0 g/d. Although there is a dose-risk attenuation above 400 g/d, milk consumption nevertheless continued to exhibit elevated risk of hip fracture, compared to zero intake, up to 750 g/d. Meanwhile, the analysis of five cohort studies of yoghurt intake per 250 g/d found a linear inverse association with fracture risk (RR 0⋅85, 95 % CI 0⋅82, 0⋅89), as did the five studies of cheese intake per 43 g/d (~1 serving/day) (RR 0⋅81, 95 % CI 0⋅72, 0⋅92); these studies did not control for socioeconomic status. However, no apparent association between total dairy intake and hip fracture (RR per 250 g/d of total dairy = 0⋅97, 95 % CI 0⋅93, 1⋅004; P = 0⋅079). There were both non-linear effects and overall elevated risk of hip fracture associated with greater milk intake, while lower risks of hip fracture were reported for higher yoghurt and cheese intakes.

Milk, dairy products, and fish are the main sources of iodine in the UK. Plant-based products are increasingly popular, especially with young women, which may affect iodine intake as they are naturally low in iodine; this is concerning as iodine is required for fetal brain development. We, aimed to (i) assess the iodine fortification of products sold as alternatives to milk, yoghurt, cheese and fish through a cross-sectional survey of UK retail outlets in 2020, and (ii) model the impact of substitution with such products on iodine intake, using portion-based scenarios. We identified 300 products, including plant-based alternatives to: (i) milk (n 146); (ii) yoghurt (n 76); (iii) cheese (n 67) and (iv) fish (n 11). After excluding organic products (n 48), which cannot be fortified, only 28 % (n 29) of milk alternatives and 6 % (n 4) of yoghurt alternatives were fortified with iodine, compared with 88 % (n 92) and 73 % (n 51), respectively, with Ca. No cheese alternative was fortified with iodine, but 55 % were fortified with Ca. None of the fish alternatives were iodine fortified. Substitution of three portions of dairy product (milk/yoghurt/cheese) per day with unfortified alternatives would reduce the iodine provided by 97·9 % (124 v. 2·6 µg) and substantially reduce the contribution to the adult intake recommendation (150 µg/d; 83 v. 1·8 %). Our study highlights that the majority of plant-based alternatives are not iodine fortified and that the use of unfortified alternatives put consumers at risk of iodine deficiency.

In this research communication we describe an innovative protocol that combines three pairs of primers, two from the literature and one designed in our laboratory, for application in triplex-PCR on somatic cell DNA to enable identification of the species origin (cow, sheep, goat) of cheeses and yogurts with a detection limit of 0.1%. Mislabeling was detected in 15 out of 40 cheeses and in 18 out of 40 yogurts tested. The suggested procedure is a quick and reliable tool for identifying the animal origin of cheeses and yogurts and it can be used to certify product reliability on the domestic and international market. Additionally, in combination with a serological test it can offer a reliable tool for detecting the presence of cow's whey.

The objective of the study reported in this Research Communication was to investigate the effect of fermentation temperature (37 and 45 °C) and different ratios of Streptococcus thermophilus to Lactobacillus bulgaricus (3 : 1, 1 : 1 and 1 : 3) on Kermanshahi roghan and yoghurt fatty acid profiles (FAP) in order to obtain a product with optimized fatty acid profiles. Kermanshahi roghan is a yoghurt by-product in western Iran (Kermanshah). The results revealed that incubation temperature at 37 °C as compared to 45 °C had a better effect on fatty acid profiles of roghan and yoghurt. Furthermore, the results showed that fatty acid profile of roghan is better than yoghurt at two experimental temperatures. On the other hand, the roghan products made by equal ratio of S. thermophilus and L. bulgaricus (1 : 1) had the best quality of fatty acid profiles. Although a lower incubation temperature increases incubation time, our finding suggests that inoculation ratio 1 : 1 at 37 °C as compared to 45 °C can affect the quality of roghan and yoghurt fatty acid profiles.

The urokinase-plasminogen activator (u-PA), its receptor (u-PAR) and the inhibitors of u-PA (PAI-1 and PAI-2) provide a multi-molecular system in leucocytes that exerts pleiotropic functions influencing the development of inflammatory and immune responses. The objective of the present study was to examine the ability of water soluble extracts (WSE) obtained from traditional Greek yoghurt made from bovine or ovine milk to modulate the expression of u-PA, u-PAR, PAI-1 and PAI-2 in ovine monocytes and neutrophils. WSE were obtained from 8 commercial traditional type Greek yoghurts made from ovine or bovine milk. WSE upregulated the expression of all 4 u-PA related genes in monocytes but the upregulation was much higher in the PAI-1 (10-fold) than in u-PA and u-PAR (3–4 fold) thus, shifting the system towards inhibition. In line with this observation, WSE reduced total and membrane-bound u-PA activity in monocytes. In neutrophils, WSE caused small (50–60%) but significant (P < 0·05) reductions in expression of u-PAR and PAI-2 but had no effect on expression of u-PA, PAI-1 and on total cell-associated and membrane-bound u-PA activity. WSE from yoghurts made from bovine or ovine milk were essentially equally effective in affecting the u-PA system except for the u-PAR gene in ovine neutrophils that was affected (reduced) by the ovine and not the bovine WSE. In conclusion, peptides present in WSE modulated the expression of u-PA related genes but the effect was much more prominent in monocytes than in neutrophils.

Food engineering within the dairy sector is an ever developing field of study purely based on the application of engineering principles and concepts to any aspect of dairy product manufacturing and operations. The last 25 years of science and technology devoted to milk and milk products have led to major advances. The purpose of this paper is to review the history and current status of some engineered milk products and to speculate regarding future trends. Much of the advancement has been directed towards production capacity, mechanisation, automation, hygiene within the processing plant, safety, extensions in shelf life, and new product introductions that bring variety and convenience for the consumer. Significant advancements in product quality have been made, many of these arising from improved knowledge of the functional properties of ingredients and their impact on structure and texture. In addition, further improvements focused on energy efficiency and environmental sustainability have been made and will be needed in the future.

We aimed to examine the longitudinal association of dairy consumption with the changes in blood pressure (BP) and the risk of incident hypertension (HTN) among adults. This study included 2636 Framingham Heart Study Offspring Cohort members who participated in the 5th through 8th examinations (1991–2008) and were free of HTN at their first examination during the follow-up. Data collected at each examination included dietary intake (by a validated FFQ), BP (following standardised procedures) and anti-hypertensive medication use (by physician-elicited self-report). HTN was defined as systolic BP (SBP)≥140 mmHg, or diastolic BP (DBP)≥90 mmHg or anti-hypertensive medication use. We used repeated-measure and discrete-time hazard regressions to examine the associations of dairy consumption with the annualised BP change (n 2075) and incident HTN (n 2340; cases=1026), respectively. Covariates included demographic, lifestyle, overall diet quality, metabolic factors and medication use. Greater intakes of total dairy foods, total low-fat/fat-free dairy foods, low-fat/skimmed milk and yoghurt were associated with smaller annualised increments in SBP and a lower risk of projected HTN incidence. However, with the exception of total dairy foods and yoghurt, these inverse associations with HTN risk were attenuated as the follow-up time increased. For yoghurt, each additional serving was associated with 6 (95 % CI 1, 10) % reduced risk of incident HTN. Total dairy and total low-fat/fat-free dairy intakes were found to be inversely related to changes in DBP. Dairy consumption, as part of a nutritious and energy-balanced diet pattern, may benefit BP control and prevent or delay the onset of HTN.

The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components.

Dairy products are important sources of micronutrients, fatty acids and probiotics which could modify the risk of child asthma and allergy development. To examine the association of dairy product intake during pregnancy with child asthma and allergic rhinitis at 18 months and 7 years in the Danish National Birth Cohort, data on milk and yoghurt consumption were collected in mid-pregnancy (25th week of gestation) using a validated FFQ (n 61 909). At 18 months, we evaluated asthma and wheeze using interview data. We assessed asthma and allergic rhinitis using a questionnaire at the age of 7 years and through registry linkages. Current asthma was defined as self-reported ever asthma diagnosis and wheeze in the past 12 months. All associations were evaluated using multivariate logistic regression. At 18 months whole milk was inversely associated with child asthma (≥5·5 times/week v. none: 0·85, 95 % CI 0·75, 0·97); the reverse was true for semi-skimmed milk (≥5·5 times/week v. none: 1·08, 95 % CI 1·02, 1·15). For yoghurt, children of women who ate low-fat yoghurt >1 serving/d had 1·21 (95 % CI 1·02, 1·42) greater odds of a medication-related ever asthma diagnosis compared with children of women reporting no intake. They were also more likely to have a registry-based ever diagnosis and report allergic rhinitis. Low-fat yoghurt intake was directly related to increased risk of both child asthma and allergic rhinitis, while whole milk appeared protective for early-life outcomes only. Nutrient components or additives specific to low-fat yoghurt may be mediating the increase in risk.

Immune senescence potentially leads to an increased risk of infections. It is desirable to augment the immune system and protect against infections by daily consumption of immunostimulatory food. The present study evaluated whether the intake of yoghurt fermented with Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1 has an effect on resistance to the common cold. We conducted two independent studies, in which fifty-seven (median age 74·5 years) and eighty-five healthy elderly individuals (median age 67·7 years) were participants. In each study, the subjects were divided into two groups based on age and sex and instructed to eat 90 g yoghurt or drink 100 ml milk once per d over an 8- or 12-week period. A meta-analysis of the results of these two independent studies showed the risk of catching the common cold was about 2·6 times lower (OR 0·39; P = 0·019) in the yoghurt group than in the milk group and the increase of natural killer cell activity was significantly higher in the yoghurt group than in the milk group (P = 0·028). In addition, the quality of life score for the ‘eye/nose/throat’ system after intake was significantly higher in the yoghurt group than in the milk group and the improvement of the score was correlated with the promotion of natural killer cell activity. In conclusion, consumption of yoghurt fermented with L. bulgaricus OLL1073R-1 augmented natural killer cell activity and reduced the risk of catching the common cold in elderly individuals.

Experiments studied the effect of yoghurt on the recovery of defence mechanisms against Streptococcus pneumoniae respiratory infection in malnourished mice. Weaned mice were malnourished with a protein-free diet (PFD) for 21d. Malnourished mice were made replete with a balanced diet (BD), yoghurt, or the BD with supplemental yoghurt (BD+Y) for 7, 14 or 21d. The normal control (NC) group was fed the BD whereas malnourished control (MC) mice consumed only the PFD. Mice were challenged with pneumococci at the end of each dietary treatment. MC mice showed increased susceptibility to pneumococcal infection. Blood leucocytes, phagocyte activity and serum and bronco-alveolar anti-pneumococcal IgG and IgA were significantly lower in the MC than in the NC group. Repletion of malnourished mice with the BD for 21d was necessary to obtain a response to infection similar to that of NC mice; however, administration of the BD+Y for 14d was enough to normalise the immune defence mechanisms. Histological examination of MC lungs showed progressive loss of alveolar architecture. Lung injuries were significantly less pronounced in NC mice. Mice treated with the BD+Y for 14d showed histological signs similar to the NC group. The present study showed that administration of yoghurt to malnourished mice induced an early recovery of the immunological parameters studied. Despite the uncertainties about the mechanisms involved and about the human relevance of the effects observed in animal models, the present study provides a strong rationale for the hypothesis that yoghurt consumption by malnourished hosts will accelerate the recovery of the immune mechanisms involved in the protection against respiratory infections

Although dairy products have been found to be associated with an elevated risk of prostate cancer, studies investigating the potential effect of Ca are limited, and findings are inconsistent. The objective of the present study was to test the relationship between the risk of prostate cancer and consumption of dairy products and Ca. The analysis included 2776 men from the French SU.VI.MAX (Supplementation en Vitamines et Minéraux Antioxydants) prospective study, among whom sixty-nine developed prostate cancer during the follow-up period (median: 7·7 years). Food consumption was assessed at inclusion from repeated 24h records and nutrient intake was calculated using a food composition table. A higher risk of prostate cancer was observed among subjects with higher dairy product (relative risk (RR; 95% CI), 4th quartile V. 1st: 1·35 (1·02, 1·78), P=0·04) and Ca intake (RR (95% CI), 4th quartile P. 1st: 2·43 (1·05, 5·62), P=0·04). Nevertheless, we identified a harmful effect of yoghurt consumption upon the risk of prostate cancer (RR (95% CI), increment 125g/d: 1·61 (1·07, 2·43), P=0·02) independently of the Ca content. Our data support the hypothesis that dairy products have a harmful effect with respect to the risk of prostate cancer, largely related to Ca content. The higher risk of prostate cancer with linear increasing yoghurt consumption seems to be independent of Ca and may be related to some other component.

Transit kinetics and survival rates of a bacterial species from yoghurt (i.e. Streptococcus thermophilus strain FBI3) were examined in different digestive compartments of gnotoxenic and human-microbiota-associated mice. The production of the lactose-hydrolysing enzyme (i.e. β-galactosidase) was also investigated within the digestive tract, using a chromosomal reporter system based on luciferase genes from Photorhabdus luminescens under the control of the plac promoter. In both mice models, S. thermophilus cells transited within 2h from the stomach to the caecum–colon compartment of the digestive tract where they displayed a survival rate of nearly 100%. In gnotoxenic mice, luciferase activity was found to increase in the second half of the small intestine and in the caecum–colon compartment when lactose was added to the drinking water provided to the animals. In human-microbiota-associated mice drinking lactose, luciferase activity was similarly increased in the second half of the small intestine but was drastically reduced in the caecum–colon compartment. This feature could be ascribed to the presence of the resident human microbiota.

The effect of yoghurt and soya yoghurt containing Bifidobacterium lactis Bb-12 or B. longum Bb-46 on Ehrlich ascites tumour cell proliferation was investigated in vitro and in vivo. Tumour cells were incubated with B. lactis Bb-12 or B. longum Bb-46 cultivated in de Mann Rogosa Sharpe (MRS) broth medium, or with their centrifuged supernatant fractions or sediments, for 2 h at 37°C. Treatment resulted in the inhibition of tumour cell proliferation by 85·42 (sd 0·78) and 85·10 (sd 1·28) % by intact micro-organisms, 77·61 (sd 0·29) and 71·43 (sd 1·75) % by their supernatant fractions, but only 4·00 (sd 0·19) and 9·09 (sd 1·24) % by the two sedimented bacteria, respectively. The incubation of tumour cells with yoghurt and soya yoghurt containing Bb-12 for 2 h resulted in 83·01 (sd 0·11) and 88·23 (sd 0·06) % inhibition, respectively, while it was 83·82 (sd 0·24) and 86·36 (sd 0·06) %, respectively for the same products containing Bb-46. Corresponding values for plain yoghurt and soya milk (without bifidobacteria) were 32·81 (sd 0·14) and 5·55 (sd 0·12) %, respectively. The differences between yoghurt or soya yoghurt containing Bb-12 or Bb-46 and plain yoghurt, soya milk or control treatments were statistically significant (n 3; P>0·05). Female Swiss albino mice were injected intraperitoneally with the same tumour cells. The lifespan of mice fed diets supplemented with yoghurt or soya yoghurt containing Bb-12 or Bb-46 was prolonged by 16, 23, 34 and 39%, respectively compared with that of the positive control group (n 6; P>0·05). The lifespan of groups fed plain yoghurt or soya milk was prolonged by 15 and 8%, respectively. Prolongation of lifespan was positively correlated with faeces bifidobacterial count in the groups fed yoghurt or soya yoghurt containing bifidobacteria (r 0·917; P>0·05).

The effects of activation of the lactoperoxidase (LPO) system by H2O2–NaSCN and hydrogen peroxide (H2O2) on the accessibility of sulphydryl groups (SH) in skimmed milk, and on the dynamic rheological properties of the resulting yoghurt were investigated. Four different concentrations of each reagent (20–80 mg H2O2–NaSCN/kg milk and 100–400 mg H2O2/kg milk) were compared. Clear negative correlations were noted between the accessibility of SH groups and both LPO activation rate and H2O2 concentration. Also the native PAGE pattern of the heat-treated samples showed that with increase in the H2O2–NaSCN and H2O2 concentrations, the level of interaction between β-lactoglobulin (β-lg) and κ-casein (κ-CN) decreased. The complex modulus (G*) of skimmed milk yoghurts declined gradually with the decrease in the concentration of accessible SH groups accordingly. Tan δ values of yoghurt samples were found to be different from the control, but close to each other, indicating that protein interaction forces taking place in the formation of gel networks of treated yoghurts were different from the control.

We previously described the effects of intake of dairy products on plasmid dissemination in the digestive tract of gnotobiotic mice associated with human faecal flora (HFF) and found that yoghurt, heat-treated yoghurt (HTY) and milk reduced population levels of transconjugants compared with findings in mice fed a standard mouse diet. In the case of lactose intake, transconjugants were not detected. The aim of the present study was to assess the possible interrelationships between these observations and other variables (bacterial ecology, pH, moisture, enzyme activities, short-chain fatty acid (SCFA) contents, lactic acid contents). Much of the interest of the present comparison lies in the fact that the animals were homogeneous in terms of age, gender, food and intestinal microflora, owing to the gnotobiotic mouse model maintained in sterile isolators. We observed no variation in SCFA and lactic acid contents or in the population levels of strictly anaerobic strains of Bacteroides and Bifidobacterium, and of the facultative anaerobic recipient Escherichia coli PG1 strain. The main modifications were the reduction of population levels of transconjugants in mice receiving yoghurt, HTY and milk, and concomitantly an increase of β-galactosidase and a decrease of β-glucosidase activities, compared with control mice fed a standard diet. Total inhibition of plasmid transfer was observed in HFF mice consuming lactose, and concomitantly the two enzyme activities (β-glucosidase and β-galactosidase) were increased, compared with the findings in control mice fed a standard diet. In axenic mice consuming lactose, plasmid transfer occurred, β-galactosidase was not detected and β-glucosidase was decreased. It is therefore proposed that these two enzyme activities influence plasmid transfer and persistence of transconjugants in the digestive tract of HFF associated mice. When both activities were increased there was a total inhibition of plasmid transfer (case of lactose intake). When β-galactosidase increased and β-glucosidase decreased (case of yoghurt, HTY and milk), plasmid transfer occurred at a lower efficiency than in the control group, resulting in lower population levels of transconjugants.