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Interacting nutrients

We’re always saying how agrobiodiversity includes all kinds of different things — crops, livestock, wild relatives, pollinators, microbes — which interact in often complex ways. Mess with one part, and you often unintentionally affect another.

Well, it looks like those interactions continue once the products of agrobiodiversity are harvested and eaten. A review described in ScienceDaily today says that people should worry less about individual nutrients and

shift the focus toward the benefits of entire food products and food patterns in order to better understand nutrition in regard to a healthy human body.

For example, there is little evidence, according to the researchers, of long-term health benefits from taking isolated supplements of beta-carotene and B-vitamins, or from reducing total fats.

In contrast, myriad observations have been made of improved long-term health for foods and food patterns that incorporate these same nutrients naturally occurring in food.

So it’s the foodway as a whole, rather than intake of individual nutrients, that needs to be optimized. Which I guess should give pause to those — like me! — who hope that, for example, things like deep yellow sweet potatoes or bananas will solve the problem of vitamin A deficiency.

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Accepting yellow maize in Africa

ResearchBlogging.orgThe cuisines of Italy and southern and eastern Africa don’t have much in common. One thing they do share, though, is the concoction of boiled maize meal which we call polenta, Kenyans call ugali and Zimbabweans sadza. I remember my wife’s excitement — she’s from Kenya — as I first explained to her about polenta when we saw it listed in the menu of a Milanese restaurant in Rome many years back now.

That quickly turned to something close to disappointment — if not disgust — when she saw the stuff, in all its golden goodness. She was expecting it to be white. Yellow maize she associated with hard times, she explained. It came into the country as food aid in bad years when she was a girl, to be eaten by poor people.

I guess I thought this was something that was confined to Kenya, but a paper just out in Food Policy tells a very similar — though perhaps more statistically robust — story from Zimbabwe. ((Tawanda Muzhingi, Augustine S. Langyintuo, Lucie C. Malaba and Marianne Banziger. Consumer acceptability of yellow maize products in Zimbabwe. Food Policy. In Press, available online 31 October 2007.)) The authors surveyed people’s attitudes to yelow maize in 360 households in three rural districts and the two main urban centres.

Yellow maize is rich in provitamin A, and could be a good way of combating vitamin A deficiency in vulnerable groups. But because it is mainly available in imported food aid, and also has a tendency to develop a bad taste if not handled properly, people just don’t like eating it — and don’t grow it. The authors suggest that nutritional education aimed at low-income groups might stimulate local production and consumption. But I think the social stigma associated with it will be difficult to dislodge. At least if my wife’s attitude is anything to go by.

Incidentally, when I talked to Jeremy about this post he said that there is a clear geographic divide in the USA between regions which prefer white and yellow maize, but he couldn’t remember the details. And I wasn’t able to find anything online. Maybe someone out there can help.

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A peach of a result for diversity and nutrition

Nobody eats a peach because they fancy a shot of carotenoids. Or do they? If so, they’d be better off choosing a yellow-fleshed variety. Scientists at Texas A&M University have examined the nutrients in 22 peach and 53 plum varieties and — Lo! — there are significant differences among them. ((Vizzotto, M., Cisneros-Zevallos, L., Byrne, D.H., Ramming, D.W. and Okie, W.R. 2006. TOTAL PHENOLIC, CAROTENOID, AND ANTHOCYANIN CONTENT AND ANTIOXIDANT ACTIVITY OF PEACH AND PLUM GENOTYPES. Acta Hort. (ISHS) 713:453-456.))

The differences in the genotype’s specific antioxidant capacity indicated that the phenolic profiles in the genotypes differ significantly. In general, the wide range of phytochemical content and antioxidant activity (AOA) found indicate that the genetic variability present can be used to develop cultivars with enhanced health benefits.

Meantime, if you can’t wait for new varieties, just pick red fleshed peaches for antioxidant activity and yellow ones for a vitamin A boost. Seriously, this is another little package of data on varietal differences, and as such we welcome it.

Hat tip: Seeds Aside.

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Ersatz coffee

Many thanks to Eliseu Bettencourt for the following ruminations on making coffee substitutes from seemingly inappropriate plants.

A paper published in volume 54 of GRACE about the utilization of lupin seeds for the preparation of a beverage, brought back some dormant thoughts. ((Andrea Heistinger & Klaus Pistrick. ‘Altreier Kaffee’: Lupinus pilosus L. cultivated as coffee substitute in Northern Italy (Alto Adige/Südtirol). Genetic Resources and Crop Evolution 54:1623-1630. DOI: 10.1007/s10722-007-9265-y.))

The paper describes the utilization of Lupinus pilosus L. as a coffee substitute, in a remote village in the North of Italy sitting at 1200 m above sea level. There are also reports of the cultivation of L. consentinii Guss. in the same area. Interesting to note is the origin of the two species. While L. pilosus has its origin in Southern Europe and the Middle East, L. cosentinii occurs in a very restricted area of Southern Portugal, and a bit on the northern coast of Morocco, and in Sicily. The village, Altrei by name, is located on an old mule and cart track, already important in prehistoric time, that connects Venice via the valley of the river Etsch to the Brenner Pass in the north. Apparently the lupins got up there to Altrei via this connection.

Reading this story kind of woke up some old information I had in my head. In 1981, I was on a collecting mission in the province of Galicia, northwestern Spain, for cultivated and wild lupin species. In a remote village we came to talk to an old man whom we asked if he knew the plant and where could we find it. The man had served during WW1 and his eyes were always red and tearful because he had been attacked with mustard gas in the trenches. He knew the lupins quite well and told us that, during the Spanish Civil War, they had tried to roast the seeds of L. angustifolius L. to use as a coffee substitute, but with very poor results due to its bitterness because of the alkaloids.

My mother also told me that they have tried to make flour out of the rhizome of the Hedychium gadnerianum in the Azores during the WW2, but again with very poor results. The plant, originally from the Himalayas, was introduced in the Azores in the middle of the 19th century as an ornamental, becoming a tremendous invasive species and probably the major threat to the endemic flora. However, they were much more successful with roasted barley, which was ground with the help of a bottle and used as a coffee substitute. What people will go through to get a cappuccino in the morning!

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Eat more crap!

It’s a little too preciously written for my taste, but the article at SFGate.com a couple of days back says some sensible things about bugs. Basically, its message is not to be so scared of bacteria on food. They’re agricultural biodiversity too, and can be good for us, essential even. Unfortunately,

the cultural mind-set at large runs directly opposite. So much so that we could be, in effect, cleaning and scrubbing and protecting ourselves to death, as our immune systems whimper and wither and drug-resistant bacteria get nastier and nature always, always finds a way to thwart our silly efforts to eradicate its wild side.

Hence the exhortation in my title, which I’ve nicked from the text of the article. Thanks, Ruthie.