Position statement - Dairy foods, calcium and cancer prevention

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Position statement - Dairy foods, calcium and cancer prevention


Key messages

  • Calcium is an important nutrient for bone and dental health, with dairy foods being the major source of dietary calcium in Australia. Dairy foods such as milk, yoghurt and cheese are also good sources of calcium, protein, vitamin A, vitamin B12, magnesium, phosphorus, potassium, riboflavin and zinc.
  • In terms of cancer risk, dairy foods and calcium have shown both protective and harmful effects. Overall the proven health benefits of dairy foods outweigh the unproven harms.
  • The evidence suggests that milk probably protects against bowel cancer, and there is limited suggestive evidence that milk reduces the risk of bladder cancer.
  • There is limited suggestive evidence that milk and dairy foods increase the risk of prostate cancer, and cheese increases the risk of bowel cancer.
  • There appears to be no significant association between the consumption of dairy products and the risk of breast or ovarian cancer.
  • Calcium supplements probably protect against bowel cancer. However diets high in calcium have been linked with a probable increase in the risk of prostate cancer. Therefore there is still insufficient evidence to recommend the general use of calcium supplements for cancer prevention.
  • Dairy foods should be encouraged as part of a varied and nutritious diet as they are essential to maintain good bone and dental health.
  • Cancer Council supports the Australian Dietary Guidelines, which encourage people to eat at least two and a half serves of dairy foods (milk, cheese and yoghurt) each day.
  • Cancer Council encourages people to choose reduced fat varieties of dairy foods where appropriate.

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Rationale

Dairy foods provide the richest source of dietary calcium[1]. Dairy foods contain a high calcium content per serve and this calcium is well absorbed by the body[1]. Calcium from non-dairy sources is less concentrated, and therefore more of the food needs to be consumed to meet recommended levels[2, 3]. Dairy foods also provide significant amounts of other nutrients including protein, vitamin A, vitamin B12, magnesium, phosphorus, potassium, riboflavin and zinc. In addition, dairy products contain conjugated linoleic acid, butyric acid, sphingolipids and 13-methyl tetradecanoic acid which may have anti-cancer properties[4].

The role of dairy foods in bone health is well established. In addition to playing an important role in the prevention of osteoporosis, dairy foods are essential for good dental health. There is also some evidence that dairy foods may play a role in weight regulation[5], prevention of cardiovascular disease and in management of hypertension[6].

Unfortunately, there is a lot of misinformation regarding the relationship between dairy foods and cancer risk. It is important for Cancer Council to evaluate the association between dairy foods, calcium and cancer risk in order to develop clear messages and recommendations. Evidence for the role of dairy foods in cancer mostly relates to prostate, bowel and breast cancers, the most prevalent cancers in Australia, as well as ovarian cancer.

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Background

Dairy foods include foods such as milk, yoghurt, cheese, ice cream, butter, cream and fermented milk. Table 1 shows the calcium content of some common dairy foods.


Table 1. Average calcium content of dairy foods[7]

Food source Serving size Calcium per serve
Regular milk 250 mL 268 mg
Skim milk 250 mL 303 mg
Natural regular yoghurt 200 g 386 mg
Natural low fat yoghurt 200 g 488 mg
Cheddar cheese 40 g 305 mg
Ice cream (standard vanilla) 50 g 26 mg


In addition to dairy foods, calcium-fortified food products are an increasingly common source of calcium in the food supply. Calcium-fortified foods include breakfast cereals (contain up to 268 mg of calcium per serving of 1 cup or 40 g); juice (up to 255 mg/250 mL); white bread (68 mg calcium/two slices or 30 g); and soy milk (298 mg/250 mL). Calcium-fortified cows milk contains 522 mg calcium per 250 mL serving[7].

According to the last National Nutrition Survey in 1995, dairy products were the second greatest contributor to energy intake for both men and women, accounting for about 11% of total energy intake[8]. Dairy products also accounted for more than half the daily calcium intake, with 30–45% coming from milk, about 10% from cheese and about 5% from frozen milk products[8]. The contribution of dairy products to children’s calcium intake was much greater than for adults[8].

Two and a half to four serves of dairy foods per day provide the recommended daily calcium intake for adults[1]. The current Recommended Dietary Intake (RDI) for men is 1000 mg/day for those aged 19–70 years and 1300 mg/day for those aged over 70 years[9]. For women, the RDI is 1000 mg/day for those aged 19–50 years and 1300 mg for those aged over 50 years (post menopausal)[9]. Increased calcium is not required for pregnant and lactating women over the age of 18[1, 9].

The upper dietary intake limit for calcium for adults has been proposed at 2500 mg/day[9]. Toxic effects of calcium have only been seen when calcium is given as calcium carbonate in an antacid form. The resulting hypercalcaemia can cause renal calcification and renal failure[9].

In Australia, dietary calcium intakes are less than recommended. It is estimated that more than 25% of men and 50% of women have a calcium intake below the RDI[8]. Of concern are those not receiving sufficient calcium during the years of bone modelling and those older Australians who are at risk of osteoporosis. Dairy foods provide a number of other important nutrients including protein, phosphorus, magnesium, potassium and zinc which are needed for bone development and maintenance. Vitamin D, which is found in small amounts in fortified dairy products (for Australians the main source of Vitamin D is from exposure to sunlight) plays an important role in maintaining bone health[10, 11].

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Views on dairy and calcium in the major cancer prevention reports

In 2007, the World Cancer Research Fund found there was[12]:

  • probable evidence that milk reduced the risk of bowel cancer, and limited suggestive evidence that milk lowered the risk of bladder cancer
  • limited suggestive evidence that milk and dairy foods increased the risk of prostate cancer and that cheese increased the risk of bowel cancer
  • probable evidence that diets high in calcium increased the risk of prostate cancer and that calcium supplements lowered the risk of bowel cancer.

The World Health Organization concluded in 2003 that there was some evidence that bowel cancer risk was decreased by high intakes of calcium[13]. This hypothesis however, has not been firmly established. Several observational studies have provided support for this theory, and two trials have indicated that supplemental calcium may have a modest protective effect on the recurrence of bowel adenomas.

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Epidemiological evidence

Bowel cancer

Meta-analyses have consistently shown an association between dairy consumption and reduction in bowel cancer risk. Similarly, meta-analyses have demonstrated a link between calcium supplementation and reduction in bowel adenoma recurrence. Table 2 summarises the evidence for a link between dairy consumption and calcium supplementation with bowel cancer and adenoma risk.

A 2012 meta-analysis of 19 cohort studies found that milk and total dairy intake, but not cheese were associated with reduced bowel cancer risk[14]. The study found the strongest effect was for total dairy. The summary relative risk (RR) per 400 g/day of total dairy products was 0.83 (95% confidence interval (CI)= 0.78-0.88). A smaller, but significant effect was seen for milk, (RR= 0.91, 95% CI= 0.85-0.94) per 200 g/day intake and no effect was seen for cheese (RR= 0.96, 95% CI= 0.83-1.12) per 50 g/day. These associations were restricted to colon cancer[14].

An earlier meta-analysis in 2009 of 60 observational studies similarly reported that both high milk and dairy intake were associated with a decreased risk of colon cancer[15]. However, milk was found to have no association with rectal cancer risk. The analysis found that high calcium intake was also protective against bowel cancer, both in dietary and supplement form.

A pooled analysis of ten cohort studies in 2004 found that higher intakes of milk and calcium (from diet and supplements) were associated with a reduced risk of bowel cancer[16]. While cheese intake tended to be weakly positively associated with bowel cancer risk, yoghurt had a weak inverse association, with neither result being statistically significant[16]. Higher intakes of dietary and total calcium were associated with a significant lower risk of bowel cancer[16]. This study estimated that up to 1000 mg/day of calcium is required to protect against bowel cancer[16].

A 2006 systematic review of 12 cohort studies found that nine studies did not show a significant relationship between milk consumption and risk of bowel cancer and two reported a protective effect for bowel and colon cancer[17]. One study with a relatively small cohort (<10,000 participants) found a positive relationship between dairy foods and rectal cancer risk. One study found a borderline positive relationship in women between cheese intake and rectal cancer, while five studies showed no relationship between dairy products and bowel cancer. Overall, consumption of dairy products appears unrelated to colon cancer, although a harmful effect on rectal cancer risk cannot be excluded[17].

Two 2010 meta-analyses investigating bowel adenoma risk found that supplemental calcium was effective for the prevention of adenoma recurrence in populations with a history of adenomas, but not in other populations, and not for any other disease outcomes[18, 19]. Similarly, an earlier meta-analysis of three RCTs investigating the role of calcium supplementation in preventing colon adenoma recurrence showed a significantly decreased risk of recurrent adenoma in the group receiving calcium supplementation[20].

A 2008 Cochrane review of two double-blind, placebo-controlled RCTs suggested that for people with previous adenomas, calcium supplementation reduced the risk of recurrent bowel adenoma. The combined odds ratio for recurrent bowel adenoma for both studies was 0.74 (95% CI 0.58-0.95) for those receiving supplemental calcium[21].

Table 2. Summary of the association between dairy food consumption and bowel cancer risk

Study Outcome Food RR 95% CI
Aune et al. (2012)[14] Bowel cancer Total dairy 0.83 0.78-0.88
Milk 0.91 0.85-0.94
Cheese 0.96 0.83-1.12
Cho et al. (2004)[16] Bowel cancer Dietary calcium 0.86 0.78-0.95
Total calcium (dietary and supplemental) 0.78 0.69-0.88
Huncharek et al. (2009)[15] Colon cancer All dairy 0.84 0.75-0.95
Milk 0.78 0.67-0.92
Carroll et al. (2010)[18] Bowel adenoma recurrence Calcium supplement 0.80 0.69-0.94
Cooper et al. (2010)[19] Bowel adenoma recurrence Calcium supplement 0.82 0.69-0.98
Shaukat et al. (2005)[20] Colon adenoma recurrence Calcium supplement 0.80 0.68-0.93

RR= relative risk, CI= confidence interval

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Prostate cancer

A number of meta-analyses have investigated the link between dairy consumption and calcium intake, and prostate cancer. Over all, evidence suggests that high calcium is associated with increased prostate cancer risk, and there is some limited evidence for a link between dairy consumption and increased prostate cancer risk. Table 3 summarises the evidence for a link between both dairy and calcium.

A 2008 meta-analysis of 23 cohort studies, 26 case-control studies and one RCT investigated the link between dairy products and dietary calcium, and prostate cancer. Over all the meta-analysis found no evidence to support an increased risk of prostate cancer with calcium or dairy products. Analysis of cohort studies demonstrated no association between milk or dairy intake and prostate cancer. However, cohort studies analysing calcium intake and prostate cancer risk were heterogeneous and could not be combined. Similarly, case-control studies found no association between dairy or calcium intake and prostate cancer, but for milk intake were heterogeneous and could not be combined[22].

A 2007 meta-analysis of 13 cohort studies found that high consumption of milk and dairy products was associated with a higher risk of prostate cancer. Sub-analysis of the studies included also demonstrated an increased risk of prostate cancer with milk and cheese specifically[23].

Similarly, a 2005 meta-analysis of ten cohort studies found that men with the highest intake of dairy foods and calcium were significantly more likely to develop prostate cancer than men with the lowest intake[24]. However this result was not significant when only those studies with a validated food frequency questionnaire and those that adjusted for energy intakes were considered. This meta-analysis was recently reviewed in response to criticism that it did not include data from the Melbourne Collaborative Cohort Study (MCCS). The MCCS is a large prospective study, which did not find any association between dairy products, butter, margarine and calcium intakes and the risk of prostate cancer[25]. When the results of the MCCS were included in a meta-analysis the following year, the positive association between a high dairy intake and prostate cancer risk remained, but was no longer statistically significant[26]. This positive association was also attenuated for high calcium intakes[26].

A 2004 meta-analysis evaluated the association between milk consumption and prostate cancer exclusively from case-control studies[27]. A positive association between milk and dairy consumption and prostate cancer risk was found, however many of the studies were found to be subject to bias[27]. In addition, eight of these studies used hospital-based controls, which may not be representative of the general population.


Table 3. Summary of the association between dairy food consumption and prostate cancer risk

Study Food RR 95% CI
Huncharek et al. 2008[22] Dairy 1.06 (cohort studies) 0.92–1.22
1.14 (case-control studies) 1.00–1.29
Milk 1.06 (cohort studies) 0.91–1.23
Calcium 1.04 (case-control studies) 0.90–1.15
Qin et al. (2007)[23] Dairy products 1.13 1.02-1.24
Milk 1.21 1.00-1.47
Cheese 1.18 1.03-1.32
Gao et al. (2006)[26] Dairy products 1.09 1.00-1.20
Calcium 1.32 1.05-1.67
Gao et al. (2005)[24] Dairy products 1.11 1.00-1.22
Calcium 1.39 1.09-1.77
Qin et al. (2004)[27] Milk 1.68 1.34-2.12
Milk and dairy products 1.61 1.22-2.12

RR= relative risk, CI= confidence interval

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Bladder cancer

Two 2011 meta-analyses have investigated the link between milk and dairy consumption and bladder cancer risk. One analysis of the link between milk consumption and bladder cancer risk included six cohort and 13 case-control studies[28]. High milk intake was associated with decreased bladder cancer risk (odds ratio= 0.84, 95% C= 0.71-0.97). The association was higher in Asia than North America, and no association was seen in European populations[28].

The other analysis included six cohort and 12 case-control studies investigating the association between milk and dairy products, and bladder cancer[29]. This analysis found a slight, but non-significant reduction in bladder cancer risk associated with high milk intake (RR= 0.89, 95% CI= 0.77-1.02). This association was significant only United States-based studies (RR= 0.88, 95% CI= 0.79-0.99). There was no over all association between total dairy consumption and bladder cancer risk (RR= 0.95, 95% CI= 0.71-1.27)[29].

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Breast cancer

An early meta-analysis suggested there may link between dairy consumption and increased breast cancer risk. Subsequent studies reported inconsistent results on the association between dairy intake and breast cancer risk, until more recent studies reported a reduced risk of breast cancer associated with dairy and calcium intake. Table 4 summarises the evidence for a link between dairy consumption and breast cancer.

A 2011 meta-analysis analysed the association between dairy consumption and breast cancer risk in 18 cohort studies. The analysis found that increased consumption of total dairy was associated with decreased breast cancer risk. Milk consumption was associated with a non-significant decrease in breast cancer risk[30]. Similarly, a 2010 meta-analysis of six cohort and nine case-control studies found evidence that high calcium intake was associated with a decreased risk of breast cancer[31]. There was a significant amount of heterogeneity among the studies analysed in both meta-analyses[30, 31].

A 2009 report prepared for the Agency for Healthcare Research and Quality found that calcium intake in premenopausal women was associated with a decreased risk of breast cancer in four of the six cohort studies reviewed[32]. The review found no association between calcium intake and beast cancer risk in postmenopausal women[32].

Older analyses have yielded inconsistent results on the association with dairy intake and breast cancer risk[33, 34]. A 2003 meta-analysis of 14 case-control and five cohort studies found the evidence to be inconsistent regarding milk consumption and breast cancer risk[35]. The results suggested that high milk and cheese intake was associated with a non-significant increased risk of breast cancer[35]. Similarly, a 2002 meta-analysis of eight prospective cohort studies did not find an association between milk products, dairy fluids or dairy solids and breast cancer risk[36]. Cheese consumption was associated with a non-significant increase in breast cancer risk[36].

Conversely, a 1993 meta-analysis of 10 case-control and one cohort study on the association between cheese and milk intake and breast cancer risk suggested that higher intakes of milk and cheese were associated with a non-significant increase in breast cancer risk[37].


Table 4. Summary of the association between dairy food consumption and breast cancer risk

Study Food RR 95% CI
Dong et al. (2011)[30] Total dairy 0.85 0.76-0.95
Chen et al. (2010)[31] Calcium (dietary and supplemental) 0.79 0.70-0.89
Boyd et al. (2003)[35] Milk 1.12 0.88-1.43
Cheese 1.30 0.89-1.92
Missmer et al. (2002)[36] Total dairy fluids 0.99 0.97-1.00
Total dairy solids 1.03 0.95-1.11
Milk products 0.99 0.97-1.00
Cheese 1.16 0.98-1.37
Boyd et al. (1993)[37] Milk 1.22 0.91-1.64
Cheese 1.32 0.90-1.93

RR= relative risk, CI= confidence interval

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Ovarian cancer

Studies of the association between dairy consumption and ovarian cancer risk have generally yielded evidence of some link but at a statistically non-significant level. See Table 5 for a summary of the evidence of an association between dairy consumption and ovarian cancer risk.

Two 2006 analyses of dairy consumption and ovarian cancer risk found no statistically significant associations between dairy consumption and ovarian cancer risk[38, 39]. One meta-analysis of three cohort and 18 case-control studies found some that cohort studies tended to show that high intakes of dairy foods (at least four servings) may increase the risk of ovarian cancer, however these results were not significant[39]. In a combined analysis of case controls and cohort studies, the consumption of dairy products, whole milk and yoghurt were positively but not significantly associated with a modest increased risk of ovarian cancer[39]. The consumption of milk, skim milk, and cheese were inversely associated with ovarian cancer risk, but again the relationships were not significant[39]. The other, a pooled analysis of 12 cohort studies found no statistically significant associations between the consumption of dairy foods, specifically milk, cheese, yoghurt and ice cream, dietary calcium intake and total calcium intake and the risk of ovarian cancer .

A 2005 meta-analysis pooled data from two cohort and 20 case-control studies, to evaluate the risk of ovarian cancer associated with milk and dairy product consumption[40]. This meta-analysis found that the consumption of dairy products, whole milk and butter were associated, but not significantly, with increased risk of ovarian cancer[40]. However, overall there was no association between milk and dairy product consumption and the risk of ovarian cancer[40]. Further, a number of the analyses were based on a small number of studies, limiting validity.


Table 5. Summary of the association between dairy food consumption and ovarian cancer risk

Study Food RR 95% CI
Genkinger et al. (2006)[38] Total milk 1.11 0.87-1.41
Hard cheese 1.30 0.96-1.78
Yoghurt 1.04 0.86-1.24
Dietary calcium 1.17 0.93-1.47
Total calcium 1.08 0.84-1.38
Larsson et al. (2006)[39] Dairy products 1.17 0.85-1.60
Milk 0.87 0.68-1.10
Whole Milk 1.25 1.01-1.56
Skim/low fat milk 0.94 0.75-1.17
Yoghurt 1.13 0.96-1.33
Cheese 0.95 0.80-1.12
Qin et al. (2005)[40] Dairy products 1.25 0.76-2.08
Milk 0.81 0.61-1.07
Whole milk 1.22 0.94-1.59
Skim milk 0.89 0.65-1.21
Yoghurt 1.11 0.97-1.26
Cheese 0.93 0.75-1.17
Butter 1.24 0.89-1.70

RR= relative risk, CI= confidence interval

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Potential mechanisms of action for cancer prevention

Bowel cancer

According to the results of experimental studies, the presence of sphingolipids, calcium, conjugated linoleic acid, butyric acid and lactic acid bacteria in dairy products have the potential to reduce bowel cancer.

Sphingolipids are found in regular and reduced-fat dairy products. Evidence from animal studies suggests that sphingolipids suppress early markers of colon carcinogenesis and the appearance of advanced malignant tumours[5].

It has been proposed that ionised calcium or calcium phosphate may reduce colon cancer by binding secondary bile acids and free fatty acids to form insoluble soaps[41, 42]. These insoluble soaps therefore protect the epithelial cells of the colon from potential toxic affects of the bile and free fatty acids[43].

Butyric acid and conjugated linoleic acid may also play a role in protecting against colon cancer[5].

There are several mechanisms by which lactic acid bacteria may inhibit colon cancer. Such mechanisms include the binding/degrading of potential carcinogens; changes in the metabolic activities of the intestinal microflora; and the production of anti-mutagenic compounds or enhancement of the host’s immune response[44].

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Breast cancer

Experimental studies suggest that the presence of calcium, conjugated linoleic acid, butyric acid, branched long-chain fatty acids and milk proteins in dairy products have the potential to prevent breast cancer.

Calcium may neutralise fatty acids and mutagenic bile acids which pass from the intestine to the breast where they can affect oestrogen receptors[45]. Animal studies provide evidence for anti-carcinogenic properties of calcium in the presence of vitamin D. Animals fed diets deficient in calcium and vitamin D develop mammary hyperplasia and hyperproliferation. In addition, supplementation with calcium and vitamin D protects against mammary tumours in rats fed a high fat diet or treated with a chemical carcinogen[34].

Conjugated linoleic acid refers to a mixture of positional and geometric isomers of linoleic acid which are found in dairy products and meat. Animal studies have indicated that conjugated linoleic acid may inhibit the growth and spread of mammary tumours, possibly in a dose response relationship[5]. Epidemiology studies to date have provided inconsistent evidence. One study found no association between conjugated linoleic acid intake and the risk of breast cancer[46], another showed a weak positive association[47], and a third showed a 60% reduction in risk associated with higher intakes of conjugated linoleic acid[48].

Butyric acid and milk proteins may also have anti-carcinogenic properties. Butyric acid, present uniquely in milk fat, induces differentiation and apoptosis, and inhibits proliferation in experimental studies[45].

Branched-chain fatty acids are synthesised by rumen bacteria and are found in milk fat. 13-methyl-tetradecanoic acid has been found to induce cell death in human breast cancer cells by rapid induction of apoptosis[45].

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Ovarian cancer

It is thought that the vitamins found in milk have the potential to protect against ovarian cancer due to their antioxidant or anti-carcinogenic properties[40]. Calcium may play a protective role by down-regulating the production of parathyroid hormone, which reduces mitosis and increases apoptosis[38].

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Potential mechanisms of action for cancer causation

Dietary fat

Previously it was believed that dietary fat played a role in the development of breast cancer, due to the strong correlation between per capita consumption of fat and breast cancer mortality in ecological studies, and because animal experiments showed that a high fat diet increased the incidence of chemically induced tumours. However with increased epidemiological data, there now appears to be little association between cancer in adults and total fat or type of fat[45]. It is biologically plausible that fat may increase breast cancer risk from animal data. Potential mechanisms are thought to be through the development of free radicals, eicosanoids and mutagenic compounds from lipid peroxidation[35].

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Contaminants

The incidence of breast cancer has declined in Israel since three pesticides, previously found in high concentrations in milk, were banned in the 1980s[34]. This decline in breast cancer incidence provided evidence for the role of dairy food contaminants in the risk of breast cancer. Evidence since this time suggests that there is no association between organochlorine exposure and breast cancer[49]. The 20th Australian Total Diet study 2003, formally the market basket survey, found no detection of pesticide residue in samples tested of cheddar cheese, whole milk and vanilla ice cream[50]. The study concluded that dietary exposures to pesticide residues in Australia were all within acceptable health standards[50].

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Insulin Like Growth Factor-I and Growth Hormone

Insulin Like Growth Factor-I (IGF-I) has been suggested as a link between dairy product consumption and breast cancer risk[51]. However the amount of IGF-I consumed daily from milk products is minute compared with endogenous production[45]. There is little evidence to suggest that there is significant absorption from dairy foods, as it is broken down in the gut[34]. It appears that the evidence linking IGF-I in milk and breast cancer risk is weak.

The European Prospective Investigation into Cancer and Nutrition (EPIC) case-control study found that serum concentrations of IGF-I showed no associations with risk of bowel cancer[52]. However, a meta-analysis of nine prospective studies, combined with EPIC data found a modest association between serum IGF-I and bowel cancer[52].

Bovine somatotrophin or growth hormone has been implicated in the development of breast cancer[51]. In some countries growth hormone is administered to cows to increase milk production and it also increases milk IGF-I levels. However bovine somatotrophin has not been registered for use by the Australian Pesticides and Veterinary Medicines Authority for use in Australia. It is approved in the US and 24 other countries, but not approved for use in Australia, New Zealand, Canada or Europe.

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Lactose and galactose

The earliest link between dairy consumption and increased ovarian cancer was attributed to the lactose content of dairy[53, 54]. Lactose is converted to glucose and galactose. It was suggested that galactose consumption coupled with a reduced ability to metabolise galactose in the ovary would result in ovarian toxicity[54]. In addition to lactose, a high consumption of fat may also increase ovarian cancer risk through increased oestrogen levels, but this is inconclusive[40].

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Recommendations

In terms of cancer risk, dairy foods and calcium have been reported as both protective and harmful. The evidence is not conclusive that dairy foods can protect against cancer, nor that they increase the risk. Overall the proven health benefits of dairy foods outweigh the unproven harms.

Dairy foods should be encouraged as part of a varied and nutritious diet as they are essential to maintain good bone and dental health. Cancer Council therefore supports the Australian Dietary Guidelines that encourage at least three serves of dairy foods (milk, cheese, yoghurt) each day.

Cancer Council also encourages people to choose reduced fat varieties of dairy foods where appropriate, as this will help to maintain a healthy body weight and reduce the total and saturated fat content of the diet. In addition, Cancer Council recommends that dairy foods such as cream and butter should be limited, as they contain a large amount of saturated fat.

Cancer Council does not support the use of calcium supplements for cancer prevention, but acknowledges that calcium supplementation provides an alternative source for people unable to consume enough dietary calcium (e.g. those who are lactose intolerant or who follow a strict vegan diet).

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Future research

The relationship between dairy foods and cancer, particularly breast, prostate and ovarian cancer deserves further examination due to the inconsistencies that still exist in the literature. As with many other nutritional factors, there is a need for better quality, well-reported, larger studies that are of longer duration. Studies need to be performed in populations with sufficient variation in dairy food intake.

A better understanding is required of the calcium dose that would be both safe and effective in reducing cancer risk, particularly for prostate and bowel cancer. This requires appropriately designed randomised controlled trials before new public health recommendations regarding the optimal dose and duration of calcium supplementation can be made.

In addition, the protective constituents of dairy foods need to be identified to better understand the protective role of dairy foods, and the literature regarding probiotics and their role in cancer prevention, particularly colon cancer needs to be evaluated.

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Position statement details

This position statement was reviewed and approved by the Public Health Committee May 2007 and updated January 2013.

Development

This position statement has been reviewed by:

  • Caryl Nowson
  • Jacinta Orr
  • Andrew Penman
  • Monica Robotin
  • Carla Saunders
  • Hayley Ralph
  • Craig Sinclair
  • Lucy Smith


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References

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  1. National Health and Medical Research Council. Australian Dietary Guidelines. Canberra, National Health and Medical Research Council. 2013. [1]
  2. Error fetching PMID 10479229: [2]
  3. Weaver C. Dairy nutrition beyond infancy. Aust J Dairy Tech. 2003; 58: 58-60. [3]
  4. Parodi PW. Anti-cancer agents in milk fat. Australian Journal of Dairy Technology. 2003. [4]
  5. Error fetching PMID 15100496: [5]
  6. Error fetching PMID 16434724: [6]
  7. NUTTAB 2010. Food Standards Australia New Zealand. Available from http://www.foodstandards.gov.au/consumerinformation/nuttab2010/. [7]
  8. Australian Bureau of Statistics and Commonwealth Dept of Health and Family Services. National Nutrition Survey: nutrient intakes and physical measurements. Canberra, Australian Bureau of Statistics. 1998. [8]
  9. National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand including Recommended Dietary Intakes. Canberra, Australia, Commonwealth Department of Health and Ageing. 2006. [10]
  10. Osteoporosis Australia and the Australian and New Zealand Bone Mineral Society (ANZBMS). Calcium, vitamin D and osteoporosis: a guide for consumers. 2005. [11]
  11. Error fetching PMID 12149085: [12]
  12. World Cancer Research Fund and American Institute for Cancer Research. Food, nutrition, physical activity and the prevention of cancer: a global perspective. Washington DC, AICR. 2007. [13]
  13. World Health Organization. Diet, nutrition and the prevention of chronic diseases. Geneva, World Health Organisation. 2003. [14]
  14. Aune D, Lau R, Chan DS, Vieira R, Greenwood DC, Kampman E, Norat T. Dairy products and colorectal cancer risk: a systematic review and meta-analysis of cohort studies. Ann Oncol. 2012 Jan;23(1):37-45. [Aune2012]
  15. Huncharek M, Muscat J, Kupelnick B. Colorectal cancer risk and dietary intake of calcium, vitamin D, and dairy products: a meta-analysis of 26,335 cases from 60 observational studies. Nutr Cancer. 2009;61(1):47-69. [Huncharek2009]
  16. Error fetching PMID 15240785: [16]
  17. Error fetching PMID 16290272: [15]
  18. Carroll C, Cooper K, Papaioannou D, Hind D, Pilgrim H, Tappenden P. Supplemental calcium in the chemoprevention of colorectal cancer: a systematic review and meta-analysis. Clin Ther. 2010 May;32(5):789-803. [Carroll2010]
  19. Cooper K, Squires H, Carroll C, Papaioannou D, Booth A, Logan RF, Maguire C, Hind D, Tappenden P.Chemoprevention of colorectal cancer: systematic review and economic evaluation.Health Technol Assess. 2010 Jun;14(32):1-206. [Cooper2010]
  20. Error fetching PMID 15667497: [17]
  21. Weingarten MA, Zalmanovici A, Yaphe J. Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD003548. [Weingarten2008]
  22. Huncharek M, Muscat J, Kupelnick B. Dairy products, dietary calcium and vitamin D intake as risk factors for prostate cancer: a meta-analysis of 26,769 cases from 45 observational studies. Nutr Cancer. 2008;60(4):421-41. [Huncharek2008]
  23. Qin LQ, Xu JY, Wang PY, Tong J, Hoshi K. Milk consumption is a risk factor for prostate cancer in Western countries: evidence from cohort studies. Asia Pac J Clin Nutr. 2007;16(3):467-76. [Qin2007]
  24. Gao X, LaValley MP, Tucker KL. Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. Journal of the National Cancer Institute. 2005; 97(23): 1768-1777. [28]
  25. Severi G, English DR, Hopper JL, Giles GG. Re: Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. Journal of the National Cancer Institute. 2006; 98(11): 794-795. [29]
  26. Gao X, Valley ML, Tucker KL. Response: Re: Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. Journal of the National Cancer Institute. 2006; 98: 795. [30]
  27. Qin LQ, Xu JY, Wang PY, Kaneko T, Hoshi K, Sato A. Milk consumption is a risk factor for prostate cancer: meta-analysis of case-control studies. Nutrition and Cancer. 2004; 48(1): 22-27. [27]
  28. Mao QQ, Dai Y, Lin YW, Qin J, Xie LP, Zheng XY. Milk consumption and bladder cancer risk: a meta-analysis of published epidemiological studies. Nutr Cancer. 2011 Nov;63(8):1263-71. [Mao2011]
  29. Li F, An SL, Zhou Y, Liang ZK, Jiao ZJ, Jing YM, Wan P, Shi XJ, Tan WL. Milk and dairy consumption and risk of bladder cancer: a meta-analysis. Urology. 2011 Dec;78(6):1298-305. [Li2011]
  30. Dong JY, Zhang L, He K, Qin LQ. Dairy consumption and risk of breast cancer: a meta-analysis of prospective cohort studies. Breast Cancer Res Treat. 2011 May;127(1):23-31. [Dong2011]
  31. Chen P, Hu P, Xie D, Qin Y, Wang F, Wang H. Meta-analysis of vitamin D, calcium and the prevention of breast cancer. Breast Cancer Res Treat. 2010 Jun;121(2):469-77 [Chen2010]
  32. Chung M, Balk EM, Brendel M, Ip S, Lau J, Lee J, Lichtenstein A, Patel K, Raman G, Tatsioni A, Terasawa T, Trikalinos TA. Vitamin D and calcium: a systematic review of health outcomes. Evid Rep Technol Assess (Full Rep). 2009 Aug;(183):1-420. [Chung2009]
  33. Error fetching PMID 16526414: [19]
  34. Error fetching PMID 15213021: [20]
  35. Error fetching PMID 14583769: [22]
  36. Error fetching PMID 11914299: [23]
  37. Error fetching PMID 8353053: [21]
  38. Error fetching PMID 16492930: [24]
  39. Larsson SC, Orsini N, Wolk A. Milk, milk products and lactose intake and ovarian cancer risk: a meta-analysis of epidemiological studies. International Journal of Cancer. 2006; 118(2): 431-441. [25]
  40. Qin LQ, Xu JY, Wang PY, Hashi A, Hoshi K, Sato A. Milk/dairy products consumption, galactose metabolism and ovarian cancer: meta-analysis of epidemiological studies. European Journal of Cancer Prevention. 2005; 14(1): 13-19. [26]
  41. Newmark HL, Wargovich MJ, Bruce WR. Colon cancer and dietary fat, phosphate, and calcium: a hypothesis. Journal of the National Cancer Institute. 1984; 72(6): 1323-1325. [36]
  42. Van der MR, Kleibeuker JH, Lapre JA. Calcium phosphate, bile acids and colorectal cancer. European Journal of Cancer Prevention. 1991; 1 Suppl 2: 55-62. [37]
  43. Norat T, Riboli E. Dairy products and colorectal cancer. A review of possible mechanisms and epidemiological evidence. European Journal of Clinical Nutrition. 2003; 57(1): 1-17. [38]
  44. Rafter J. The effects of probiotics on colon cancer development. Nutrition Research Reviews. 2004; 17: 277-284. [39]
  45. Parodi PW. Dairy product consumption and the risk of breast cancer. Journal of the American College of Nutrition. 2005; 24(6 Suppl): 556S-568S. [32]
  46. McCann SE, Ip C, Ip MM, McGuire MK, Muti P, Edge SB et al. Dietary intake of conjugated linoleic acids and risk of premenopausal and postmenopausal breast cancer, Western New York Exposures and Breast Cancer Study (WEB Study). Cancer Epidemiology Biomarkers and Prevention. 2004; 13(9): 1480-1484. [33]
  47. Voorrips LE, Brants HA, Kardinaal AF, Hiddink GJ, van den Brandt PA, Goldbohm RA. Intake of conjugated linoleic acid, fat, and other fatty acids in relation to postmenopausal breast cancer: the Netherlands Cohort Study on Diet and Cancer. American Journal of Clinical Nutrition. 2002; 76(4): 873-882. [34]
  48. Aro A, Mannisto S, Salminen I, Ovaskainen ML, Kataja V, Uusitupa M. Inverse association between dietary and serum conjugated linoleic acid and risk of breast cancer in postmenopausal women. Nutrition and Cancer. 2000; 38(2): 151-157. [35]
  49. Calle EE, Frumkin H, Henley SJ, Savitz DA, Thun MJ. Organochlorines and breast cancer risk. CA Cancer Journal for Clinicians. 2002; 52(5): 301-309. [40]
  50. Food Standards Australia and New Zealand. The 20th Australian Total Diet Survey: A total diet survey of pesticide residues and contaminants. Canberra, Australia, Food Standards Australia and New Zealand. 2003. [41]
  51. Outwater JL, Nicholson A, Barnard N. Dairy products and breast cancer: the IGF-I estrogen and bGH hypothesis. Medical Hypotheses. 1997; 48(453): 461. [42]
  52. Rinaldi S, Cleveland R, Norat T, Biessy C, Rohrmann S, Linseisen J, Boeing H, Pischon T, Panico S, Agnoli C, Palli D, Tumino R, Vineis P, Peeters PH, van Gils CH, Bueno-de-Mesquita BH, Vrieling A, Allen NE, Roddam A, Bingham S, Khaw KT, Manjer J, Borgquist S, Dumeaux V, Torhild Gram I, Lund E, Trichopoulou A, Makrygiannis G, Benetou V, Molina E, Donate Suárez I, Barricarte Gurrea A, Gonzalez CA, Tormo MJ, Altzibar JM, Olsen A, Tjonneland A, Grønbaek H, Overvad K, Clavel-Chapelon F, Boutron-Ruault MC, Morois S, Slimani N, Boffetta P, Jenab M, Riboli E, Kaaks R. Serum levels of IGF-I, IGFBP-3 and colorectal cancer risk: results from the EPIC cohort, plus a meta-analysis of prospective studies. Int J Cancer. 2010 Apr 1;126(7):1702-15. [Rinaldi2010]
  53. Cramer DW, Welch WR, Hutchison GB, Willett W, Scully RE. Dietary animal fat in relation to ovarian cancer risk. Obstetrics and Gynecology. 1984; 63(6): 833-838. [43]
  54. Cramer DW, Harlow BL, Willett WC, Welch WR, Bell DA, Scully RE et al. Galactose consumption and metabolism in relation to the risk of ovarian cancer. Lancet. 1989; 2(8654): 66-71. [44]
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