A major thrust in nutritional science over the past few years has been to dissect the chemicals contained in food to, supposedly, glean the likely health effects of that food. This approach works to a point. It might, for instance, be useful for say determining that one fruit or vegetable is more nutrient-dense than another. One could also use it to, say, determine which types of fish offer most in the way of health-giving omega-3 fats.
However, looking at individual nutrients can sometimes cause us to lose sight of the overall nutritional attributes of a food. For example, we might ‘fortify’ flour with nutrients, but that should not detract from the fact that the resultant foodstuff is still pretty much bereft of nutritional value. And we can load margarine with cholesterol-reducing ‘stanols’ and ‘sterols’, but that should not blind us to the fact that these are still embedded in a highly-processed, chemicalised and, in my opinion, crappy, food.
I believe I came across another example of how focusing on nutritional ‘trees’ can sometimes cause us to lose sight of the wood this week. Researchers from the University of Maryland in the USA presented a study at the American Chemical Society in which they assessed the levels of antioxidant nutrients in pizza prepared in a variety of ways. Longer fermentation of the pizza base caused a considerable rise in antioxidant levels, as did higher cooking temperature and longer cooking time.
What I think is interesting about these findings is that they support the idea that food preparation can affect the nutrient levels in food. And, contrary to popular opinion, higher cooking temperature and longer cooking time were found to boost antioxidant levels. I do not have the details of this study, so I do not know what specific antioxidants were measured. For all we know, the levels of other antioxidants or nutrients generally may have fallen as a result of longer fermentation and cooking times and higher cooking temperatures.
And also, it needs to be borne in mind, I think, that pizza not a particularly healthy food (see below). Higher levels of certain antioxidants in pizza do not necessarily transform it from nutritional zero to hero. The problem is, the food industry has a habit of using nutritional data of this sort to make health claims about foods that should really be left on the shelf.
Why the nutritional attributes of pizza leave me feeling flat ” 28th November 2004
With its emphasis on fresh fruits and veggies, fish and olive oil, the Mediterranean diet is generally regarded as an altogether healthy feeding regime, and one that seems to be particularly effective in the warding off heart disease. While I am generally enthusiastic about this is way of eating, I am not so keen on certain foods such as pizza and pasta that have sometimes been associated with the Mediterranean diet on account of their Italian origins.
The consumption of the refined flour on which these foods is based can induce biochemical changes in the body that have been linked with conditions such as diabetes, obesity and heart disease. I was therefore interested to read a recent report in the British Medical Journal which alerted me to a study in which pizza-eating was found to protect against heart attacks. Could it be that pizza is not such a roundly unhealthy food after all?
In an effort to get to the bottom of what has been coined the ‘Italian enigma’, I turned my attention to the original research on which the BMJ report was based. In this study, published in this month’s edition of the European Journal of Clinical Nutrition, the association between pizza eating and heart attack risk was assessed in a group of about 1000 Italians, roughly half of whom had recently suffered a heart attack. The results of this study found that, compared to individuals who did not eat pizza, those eating it at least once a week had a reduced risk of heart attack of about 40 per cent. For those eating pizza at least twice a week, heart attack risk appeared to be slashed by more than half.
It is important to bear in mind that a study of this nature does not necessarily prove that pizza is protective for heart disease, as those eating pizza may have a reduced risk of heart disease due to favourable differences in what are known as confounding factors (such as smoking habits, alcohol consumption and body weight). However, even when such things were accounted for, the apparent protective effect of pizza remained.
Analysis of the main ingredients of pizza (such as tomato and olive oil) and their relationship with heart disease did not yield a satisfying solution to this conundrum either. What further analysis did reveal, however, was that the pizza-eaters in the study had a generally higher dietary intake of a range of heart-healthy nutrients such as omega-3 fats, folate and potassium. It appears that it is not pizza per se, but the tendency for pizza lovers to eat a relatively nutritious diet, that is the most likely explanation for the Italian enigma.
My advice to those wishing to eat pizza would be to opt for thin-crust varieties (these are less likely to cause the sort of carb-loading in the system that can be so disruptive to the body’s biochemistry) accompanied by a salad for nutritional balance. While recent reports suggest that pizza is a healthy food, a close look at the dietary data in this area has left me feeling flat.
