Sunday, September 20, 2015

Burgers on breasts – what is really going on here?

Recently, a series of advertisements came into the public consequence. These images depict women breastfeeding, with one breast painted to look like a hamburger, doughnut, or can of soda. The message is “Your child is what you eat”, suggesting that the mother’s diet is directly related to the construction of the baby – that is, eat a burger, build a baby from burgers.

Before we get into a discussion of the factual accuracy of the statement, it is worth taking a moment to think about the ads themselves. The ads were most likely produced by the advertising company PAIM, and the logo depicted is that of the SPRS – the Pediatric Society of Rio Grande (Brazil). SPRS is sponsored by Nestle, and there is some evidence that PAIM also holds the Nestle ad campaign for Brazil. But here’s my big question: why are the ads in English? The national language of Brazil is Portuguese, and as of 2011, the best guess for English fluency among educated Brazilians was 8-11% (Glickhouse, 2012). Your milk what you eat should be “Seu leite é o que você come” (if Google translate is accurate). 

Although the images contain the logo for SPRS and a link to the website, the ads are not on the SPRS website. The SPRS website is also in Portuguese. Moreover, the food images just don’t quite match up to typical Brazilian cuisine – burgers commonly have eggs or corn for example, and doughnuts with holes in the middle are not that common in Brazil. So – just who were those ads designed for?
Leaving aside this very big question, the ads have generated considerable international attention and debate. Many mothers have expressed concern about the message: your baby is what you eat. But is it true? Well, the best answer is “somewhat – but not really”, at least as a far as breast milk is concerned.

Breast milk is produced by the mothers’ body (for review, see my prior post here). Generally, the proteins and sugars in the milk are largely independent of what the mother eats. This reflects the synthesis of protein and sugar by specialized cells, called lactocytes, in the breast. Synthesis occurs from glucose, amino acids, and similar. Very few dietary or lifestyle factors appears to influence milk protein, especially milk proteins that are not immunoproteins. 

Total milk fat, at least for humans, is largely independent of the mother’s diet (Villalpando and Del Prado, 1999). However, the fatty acid composition of the milk fat is strongly correlated with the maternal diet.

Probably the best known example is that of DHA. Most pre- and post-natal vitamins contain fish oils or DHA. DHA is a long chain, polyunsaturated fatty acid that cannot be produced by the mother’s body and must be derived from her diet. Ergo, milk DHA is very sensitive to the mother’s diet – more dietary DHA, more DHA in milk. Figure 1 shows an example from our work in the Philippines (Quinn et al., 2012), where we found a dose association between meals of a local fish (bodboron) and milk DHA. If you haven’t heard of bodboron, don’t be surprised – in the US, it is commonly fed to salmon rather than consumed. Working with mothers in Denmark, Lauritzen et al., (2002) also showed a positive association between fish consumption (in this case salmon) and milk DHA. Fish oil consumption has long been recognized as a source of milk DHA (Harris et al., 1984). It is also understood that fatty acids – especially long chain fatty acids like DHA – accumulate in body fat where they can be utilized later. 
Figure 1: Fish consumption and milk DHA content in a sample of Filipino mothers living in Cebu, Philippines (Quinn et al., 2012).

What if a mother is consuming a diet that is very low in fat? There is no substantial evidence that her total milk fat will be lower (Villalpando and Del Prado 1999). This is another one of those instances where mothers’ bodies are amazing – her body will produce certain fatty acids from glucose derived from the carbohydrates in her diet. Humans cannot produce long chain fatty acids like DHA – but the breast and liver can produce medium chain fatty acids – fatty acids with less than 14-16 carbons (Figure 2).  These medium chain fatty acids are routinely incorporated into milk fat, and, when dietary and existing fat stores are insufficient to meet demand, the mother’s body will produce more medium chain fatty acids to maintain milk fat (Rudolph et al., 2007). Thus, total fat is maintained, even if fatty acid composition is altered.

Figure 2: Comparison of two fatty acids - TOP: lauric acid, which has a carbon chain length of 12 and can be produced by the mammary gland and liver, and BOTTOM: DHA, which cannot be produced by the body.

Another concern would be man-made food products, like trans-fatty acids or artificial sweetners (up next!). These have been found in human milk; and there is general concern about the levels of trans-fatty acids in human milk. Product labeling has resulted in lower dietary intakes and a reduction in milk trans-fatty acids in Canadian mothers (Ratnayake et al., 2014); a recent analysis of some 2327 food products in Brazil found that more than half contained trans-fatty acids. The worst offenders were cookies, so if this was really an ad about trans-fatty acids, a cookie would be the appropriate image.

What does it come back to? These advertisements are making the same fictional point we have discussed here before with medical devices. You are a threat to your baby. Your body can’t be trusted. You can’t be trusted to eat right for your baby and thank heavens there is formula so you can’t harm your baby with your hamburgers.  These ads are deliberate, and the target audience is very much open for debate.

Glickhouse R. (2012) Lost in Translation. Christian Science Monitor.

Lauritzen L, Jørgensen MH, Hansen HS, Michaelsen KF. (2002) Fluctuations in human milk long-chain PUFA levels in relation to dietary fish intake. Lipids 37(3):237-44.

Quinn EA, Kuzawa CW. (2012) A dose-response relationship between fish consumption and human milk DHA content among Filipino women in Cebu City, Philippines. Acta Paediatr 101(10):e439-45. 

Ratnayake WN, Swist E, Zoka R, Gagnon C, Lillycrop W, Pantazapoulos P. (2014) Mandatory trans fat labeling regulations and nationwide product reformulations to reduce trans fatty acid content in foods contributed to lowered concentrations of trans fat in Canadian women's breast milk samples collected in 2009-2011. Am J Clin Nutr 100(4):1036-40.

Rudolph MC, Neville MC, Anderson SM. (2007) Lipid synthesis in lactation: diet and the fatty acid switch. J Mammary Gland Biol Neoplasia 12(4):269-81.

Villalpando S, del Prado M. (1999) Interrelation among dietary energy and fat intakes, maternal body fatness, and milk total lipid in humans. J Mammary Gland Biol Neoplasia 4(3):285-95.