The impact of substituting SFA in dairy products with MUFA or PUFA on CVD risk: evidence from human intervention studies

With the substantial economic and social burden of CVD, the need to modify diet and lifestyle factors to reduce risk has become increasingly important. Milk and dairy products, being one of the main contributors to SFA intake in the UK, are a potential target for dietary SFA reduction. Supplementation of the dairy cow's diet with a source of MUFA or PUFA may have beneficial effects on consumers' CVD risk by partially replacing milk SFA, thus reducing entry of SFA into the food chain. A total of nine chronic human intervention studies have used dairy products, modified through bovine feeding, to establish their effect on CVD risk markers. Of these studies, the majority utilised modified butter as their primary test product and used changes in blood cholesterol concentrations as their main risk marker. Of the eight studies that measured blood cholesterol, four reported a significant reduction in total and LDL-cholesterol (LDL-C) following chronic consumption of modified milk and dairy products. Data from one study suggested that a significant reduction in LDL-C could be achieved in both the healthy and hypercholesterolaemic population. Thus, evidence from these studies suggests that consumption of milk and dairy products with modified fatty acid composition, compared with milk and dairy products of typical milk fat composition, may be beneficial to CVD risk in healthy and hypercholesterolaemic individuals. However, current evidence is insufficient and further work is needed to investigate the complex role of milk and cheese in CVD risk and explore the use of novel markers of CVD risk.

Milk and dairy products: dietary partners for life?

The importance of milk in the human diet as a supplier of energy, high quality protein and other key nutrients, including calcium, is broadly accepted yet in the mind of many there remains uncertainty about whether or not these foods contribute to increased risk of cardiovascular and other chronic diseases. The evidence from long term prospective cohort studies that high milk consumption does not increase cardiovascular disease risk and indeed may provide benefit is now pretty unequivocal, although the effects of butter and cheese and benefits of fat reduced milk and saturated fat reduced milk are less certain. Milk is a crucial supplier of calcium, phosphorus and magnesium for bone growth and development in children and it is concerning that due to reduced milk consumption intake of these nutrients is often sub-optimal, particularly for female children. In addition, specific health issues in pregnant women and the elderly can be alleviated by milk or components of milk and these effects are not all explained by traditional nutrition.

The effects of dairy management and processing on quality characteristics of milk and dairy products

Studies within the QLIF project reviewed in this article suggest that organic or low-input management is more likely to result in milk with fatty acid profiles that are higher in α-linolenic acid and/or beneficial isomers of conjugated linoleic acid and antioxidants with up to a 2.5-fold increase in some cases, relative to milk from conventional production. These advantages are preserved during processing, resulting in elevated contents or concentrations of these constituents in processed dairy products of organic or low input origin. Much of the literature suggests that these benefits are very likely to be a result of a greater reliance on forages in the dairy diets (especially grazed grass). Since the adoption of alternative breeds or crosses is often an integral part sustaining these low-input systems, it is not possible to rule out an interaction with genotype in these monitored herds. The results suggest that milk fat composition with respect to human health can be optimized by exploiting grazing in the diet of dairy cows. However, in many European regions this may not be possible due to extremes in temperature, soil moisture levels or both. In such cases milk quality can be maintained by the inclusion of oil seeds in the dairy diets.

Dietary approaches for weight loss with increased intakes of fruit, vegetables and dairy products

Aim: To assess the effectiveness of specific advice for increasing fruit, vegetable and dairy intake in free-living men participating in a weight loss study.

Methods: Subjects were randomised to one of two 12-week weight loss diets, either the WELL with daily targets of four serves of fruit, four serves of vegetables and three serves of dairy or a low fat diet (LF) with general advice to increase fruit and vegetable intake. Three-day food group diaries and a food frequency questionnaire assessed intake.

Results: Fifty-four overweight/obese male adults completed the study (WELL, n = 27; LF, n = 27; body mass index (mean ± standard deviation), 30.4 ± 2.5 kg/m²; age, 47.7 ± 9.5 years). There was no difference in mean weight change between groups (WELL, −4.8 ± 3.3 kg; LF, −4.6 ± 3.1 kg). Subjects on the WELL diet had greater (mean difference ± standard error) fruit (0.7 ± 0.2 serves/day), vegetable (1.2 ± 0.2 serves/day) and dairy (1.1 ± 0.1 serves/day) intakes than the LF group (measured by the food group diaries) (all P < 0.01). The WELL group reached the daily target for fruit from week 1 (4.7 ± 1.4 serves/day), vegetables by week 6 (4.1 ± 1.5 serves/day) and for dairy by week 8 (3.0 ± 0.8 serves/day).

Conclusions: Providing specific dietary targets to men for weight loss appears to promote greater consumption of fruit, vegetable and dairy foods than providing general dietary advice. Meeting dietary targets appears to require different adjustment periods depending on the food type.

Biotechnology in U.S. agriculture: Trade consequences for dairy products

The emergence of synthetic bovine Somatotropin (bST) is one of the most widely discussed advances in biotechnology. Its potential impacts on milk production around the world could be significant. However, the exact economic impacts of bST in any one region depends on a number of factors, some of which are still highly controversial.

This article sets out to estimate the economic impacts of the adoption of bST in the United States, the single largest milk producer in the Western world. A quarterly econometric model of the U.S. dairy sector is used to forecast the total production, consumption, and excess supply of milk to 1995. The preliminary results indicate that under the assumption of a gradual rate of adoption and a 15 percent milk production response, the United States could be exporting as much milk as New Zealand by 1995. Should the production response rate or the adoption rate be higher, the United States could indeed become a major competitor in the world dairy market by 1995.

Although such a development could adversely impact on other dairy exporters, such as New Zealand, the precise economic impacts on world prices and trade would depend crucially on the position that other major dairy producers, especially the EC, adopt with respect to the use of bST.

Attributable risk analysis reveals potential healthcare savings from increased consumption of dairy products.

With rising burdens of obesity and chronic disease, the role of diet as a modifiable risk factor is of increasing public health interest. There is a growing body of evidence that low consumption of dairy products is associated with elevated risk of chronic metabolic and cardiovascular disorders. Surveys also suggest that dairy product consumption falls well below recommended targets for much of the population in many countries, including the USA, UK, and Australia. We reviewed the scientific literature on the health effects of dairy product consumption (both positive and negative) and used the best available evidence to estimate the direct healthcare expenditure and burden of disease [disability-adjusted life years (DALY)] attributable to low consumption of dairy products in Australia. We implemented a novel technique for estimating population attributable risk developed for application in nutrition and other areas in which exposure to risk is a continuous variable. We found that in the 2010-2011 financial year, AUD$2.0 billion (USD$2.1 billion, €1.6 billion, or ∼1.7% of direct healthcare expenditure) and the loss of 75,012 DALY were attributable to low dairy product consumption. In sensitivity analyses, varying core assumptions yielded corresponding estimates of AUD$1.1-3.8 billion (0.9-3.3%) and 38,299-151,061 DALY lost. The estimated healthcare cost attributable to low dairy product consumption is comparable with total spending on public health in Australia (AUD$2.0 billion in 2009-2010). These findings justify the development and evaluation of cost-effective interventions that use dairy products as a vector for reducing the costs of diet-related disease.

Evaluating the links between intake of milk/dairy products and cancer

Milk and dairy products are widely recommended as part of a healthy diet. These products, however, can contain hormones such as insulin-like growth factor 1, and some studies have suggested that a high intake of milk and dairy products may increase the risk of cancer. This review examines recent studies on this topic, with the evidence suggesting that the recommended intake of milk and dairy products (3 servings/day) is safe and, importantly, does not seem to increase the risk of cancer. on the basis of the studies included in this review, cultured milk, yogurt, and low-fat dairy products should be preferred as the milk and dairy products of choice.

Effect of temperature on the lipolytic and proteolytic activity of Bacillus cereus isolated from dairy products

Bacillus cereus is a bacterium with deteriorating potential for dairy products, by being a psychrotrophic organism producer of lipases and proteases. This study evaluated the psychrotrophic behavior, lipolytic and proteolytic activity at 30°C, 10°C and 7°C of 86 strains of B. cereus lato sensu isolated from dairy products, marketed in Southern Brazil. It was also evaluated the optimal temperature for protease production. No strain grew at 7°C; but at 10°C, 84.9% of strains have grown. Only one strain had lipolytic activity at 30°C, and none at 7°C. At 10°C, 16.3% of strains produced lipases. All the strains presented proteolytic activity at 30°C; and at 10°C, 72.1% had this activity, and at 7°C, only 4.6%, an amount significantly lower (p < 0.05). The temperature of 20°C promoted the highest proteolytic activity, and at 10°C, the lowest activity. B. cereus can produce lipases and proteases at room and marginal chilling temperatures, causing technological defects in dairy products stored under these conditions. © 2008 IFRJ.

Characteristics of the world dairy products market: aspects of interest for Latin America

Includes bibliography