Here’s my question: Is it possible to make a wholemeal version of rewena paraoa (potato bread) that looks and tastes good? For the past month I have been experimenting. Rewena comes from the Maori word for potato – rewa, and paraoa means bread in Maori. Before Europeans arrived in New Zealand there was no potato, flour or sugar. Kumara, a type of sweet potato, was one of the main carbohydrate or energy sources for Maori. But this tropical plant was hard work to grow in New Zealand’s cool climate. Potatoes are different. Just throw them in the ground and they pretty much grow anywhere – my type of plant. So it was no wonder the potato soon took over from kumara as the staple food.

I figure the rewena recipe developed as most recipes do – by using the ingredients at hand – in this case potatoes, white flour, sugar and salt. I’d love to know how it started. Perhaps someone accidentally left a pot of boiled potatoes sitting in the sun for a couple of days and noticed that it had fermented. It wouldn’t have looked too great but maybe they recognised the yeasty smell and decided it could be made into bread. If anyone knows the true history, please let me know.

Am I the only one who is constantly tidying up recklessly discarded shoes from the front entrance? Here I am again picking up my son’s grubby, child-beaten school shoes. I open the shoe cupboard and am hit by the most awful stench. I sniff the shoes in my hands. Boy, my son’s feet must have stunk at school today. But no. The putrid smell isn’t the shoes; it’s coming from the cupboard. Oh no – it’s the rewena bread!

The other night I boiled a potato in unsalted water, just like the my Nanna’s rewena recipe said. I mashed it and added a teaspoon of sugar and some flour, then put it on the hot water cylinder to ferment overnight. Unfortunately the hot water cylinder is in the stinky shoe cupboard. Goodness knows what sort of spores are floating around in there. Whatever they are, they are NOT GOOD. One night in the stinky shoe cupboard and my innocent potato water, sugar and flour has fermented into a thick, stinking cheesy mass – gross.

In September this year all bread in New Zealand and Australia, except organic bread, will have folic acid added to it. “About time too”, most nutritionists would say, with some even going so far as to say the government has been ‘morally negligent’ in not introducing folate fortification sooner.

Why? Because folate reduces the risk of neural tube defects (NTD’s) such as spina bifida. In the USA and Canada, where bread has been fortified with folic acid since 1998, there has been a 15-50% drop in NTD’s. And Chile, which used a higher dose of folic acid, reported a 40% drop in NTD’s. In addition, a study on babies in Quebec noted a 6% reduction in the prevalence of congenital heart defects in the seven years after fortification compared to no change during the nine years before fortification.

But some people are concerned about media reports that there could be problems with fortification – (See kiwiblog post with NZ Herald excerpts and some fairly heated comments: “…if any government decides to mass-medicate every bread-buying New Zealander with a certain additive, it has to be very sure that the costs to the community don’t outweigh any health benefits…”).

I had a chat with one of them – an imaginary aussie  bloke called Bruce who grew up in Australia and now lives in New Zealand…

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Bruce: Yeah, gidday. So exactly how many babies will fortification save in New Zealand?

Cindy: In New Zealand  20-30 babies are born with spina bifida each year. It’s been estimated that folic acid fortification would save 4-14 babies a year from these NTDs (neural tube defects).

B: So we are going to mass medicate 4 million people to try to prevent 4 –14 cases? Seems a bit skewed unless you are the parents of one of those babies. Can’t you try anything else?

C: Up until now we have told women of child-bearing age to take a folic acid supplement and to eat foods rich in folate, including those that are already fortified such as some breakfast cereals. But not enough are following this advice. Even if they start taking a folic acid supplement as soon as they know they are pregnant it’s probably too late – it’s needed in the first month of pregnancy.

B:What about food? Don’t you nutritionists always tell us the best way to get nutrients is from your food?

C:Food is definitely the best source as the folate is in a natural form that the body is designed to handle. Folate is naturally high in green leafy vegetables like spinach and broccoli but it is destroyed by cooking. Liver, chickpeas, lentils and citrus fruit like oranges are also high in folate. New Zealanders eat on average 250 micrograms of folate a day but the recommended amount is 400 micrograms a day – and 600 micrograms in pregnancy.

B:I’m not into raw spinach, liver or lentils, and I can’t be bothered peeling oranges. Hummus is OK – it’s made from chickpeas – but I’d probably need to eat it for breakfast, lunch and dinner!

C:Exactly! That’s why they want to add folic acid to bread. Everyone eats it.

B: So how much will we get in our bread?

C: We will get about 140 micrograms folic acid from two or three slices of bread, depending on the thickness. If you add that to the 250 micrograms folate you are already getting from food, you have your recommended daily requirement.

B: Sounds simple. But I eat more like eight slices of bread a day: two pieces of toast for breakfast plus a huge bowl of cereal that’s probably already fortified with folic acid, two big sandwiches for lunch and usually a couple of slices at night after training. So I could be getting four or five times the amount. Is that a problem?

C: If it was from foods, in the natural folate form, it wouldn’t be a problem. In fact eating lots of folate from foods is a great idea. Apart from reducing the risk of NTD’s over 30 studies have found that people who eat lots of folate (the natural stuff) have about 40-60% less colon cancer. It also helps reduce homocysteine which is a risk factor for heart disease. And in the Nurses Health Study people who ate the least folate had more breast, colon and pancreatic cancer.

B: But what about folic acid – the synthetic stuff that’s in supplements and that they plan to shove in the bread? I’ve heard it might cause cancer!

C: No-one is saying folic acid causes cancer but some researchers think if you already have some cancerous cells it may make them grow. As Joel Mason, Associate Professor at the Friedman School of Nutrition Science and Policy at Tufts University, said in a  paper published in 2007, “There is a compelling body of scientific evidence suggesting that habitually high intakes of dietary folate are protective against colorectal cancer” but “we may have inadvertently created the opposite effect with folic acid fortification”.

B: How does that work?

C: Professor Mason suggests two possible reasons. 1. Folate is important in making DNA so it could act as a growth factor for cancerous cells. 2 The body has to convert synthetic folic acid to folate. If you are eating lots of folic acid, the conversion mechanism may become saturated leaving left-over folic acid in the circulation. This is not normal for the body.

B: How bad is it? How many Kiwis might get colon cancer from eating all this extra folic acid?

C: Since mandatory fortification in 1998 the USA and Canada have had 4-6 extra cases of colorectal cancer per 100,000 people per year. Chile has reported a similar increase in the European Journal of Gastroenterology & Hepatology but the one of the journal’s editors says it is a “weak, indirect indication of a causal relationship”.

B: So let’s work out 4-6 extra cases per 100,000 in New Zealand’s population of roughly 4 million. That’s potentially 160-240 more people with colon cancer for the sake of 14 less babies with NTD’s. Yeah, I know that sounds pretty callous – sorry.

C: It’s not that simple because we don’t yet have any proof. These results are just associations – like saying that people who drive expensive cars visit the doctor more than people with cheap cars. Does that mean they are less healthy, or that somehow the car makes them sick?  There are all sorts of reasons why colon cancer rates may have increased – more obesity or even better diagnosis which means more cases are reported. But it is causing some public health people to be cautious about rushing into fortification.

B: Well that’s a good thing. I’m not sure about the ethics of a group of ‘experts’ forcing us to take supplements in our food – especially when more than half of us will never get pregnant!

C: So how do you feel about the thiamin (vitamin B1) that’s been added to your bread in Australia for decades?

B: What?!!

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See my follow-up article on Vitamin B12

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References from medical journals:

Eur J Gastroenterol Hepatol. Published online before print February 2, 2009. Abstract
Cancer Epidemiol Biomarkers Prev. 2007; 16:1325-1329
Nutr Rev. 2009,67;206-212
J Natl Cancer Inst. 2009;101:432-435
American Journal of Clinical Nutrition, Vol. 80, No. 5, 1123-1128, November 2004  http://www.ajcn.org/cgi/content/full/80/5/1123

Related media stories:

Kiwiblog – Rich on Food Safety
Katherine Rich: Added risk, any way you slice it – NZ Herald 9/6/09
Bakers furious at ‘mass medication’ of NZ’s bread
Government taking advice on folic acid in bread