Genetically modified yeast

Roger wrote:
“….is there not a danger that with quality wine being more controllable there will be less variety and if every year is a top vintage year will that undermine the different values of wines etc”?

I’ll agree that certain yeast strains can actually enhance the aromatics of a wine, but for this to be accomplished certain precursors have to exist in the grape. So the quality of the fruit at harvest will determine how effective the yeast strain performs and thus the quality of the wine.

Salute

Bill, you don't believe that organic food is better for you?

Far be it from me to put words in Bill's mouth, but here's my take: the label "organic" as defined by my government has little, if anything, to do with how good the food is for you ...

Apparently Bill S has authoritative company: the toxicology group in UC Davis's Food-Science faculty (Winter and Davis especially), known for extensively assaying crop toxins, both manmade and natural, had this ambivalent conclusion in a very broad survey paper (relevant summary in final excerpts below). I recommend the full sources mentioned here, they are eye-opening and more is online.

While many studies demonstrate qualitative differences between organic and conventional foods with respect to pesticide residues and nutrients, it is premature to conclude that either food system is superior to the other. Pesticide residues [and] naturally occurring toxins, nitrites, and polyphenolic compounds exert their health risks or benefits on a dose-related basis, and data currently do not exist to ascertain whether the differences in the levels of such chemicals between organic foods and conventional foods are of health significance.

More:

"Natural is often equated with safe and wholesome. ... That pesticides may prevent the development of hazardous natural toxins was new information and not believed by some consumers (Bruhn et el., 1998). Consumer education is needed in this area." -- Christine Bruhn [UC Davis], in Jackson, Knize, and Morgan, Impact of Processing on Food Safety. Advances in Medicine and Experimental Biology series, Springer, 1999. ISBN 0306460513.


My summary of some details on natural toxins in Winter and Davis's recent survey paper:

"Glycoalkaloids are naturally occurring toxins produced from plants such as potatoes and tomatoes, and they provide insect resistance." Their levels increase in potatoes under stress. Attempt to breed "an insect-resistant potato variety was abandoned when it was determined that glycoalkaloids were detectable at levels that could potentially cause acute toxicity in humans." Linear furanocoumarins in celery develop at elevated levels "under stressful conditions such as fungal attack ... Linear furanocoumarins are known for their ability to cause contact dermatitis and are considered possible human carcinogens." Breeding to enhance pest resistance in celery also caused "10- to 15-fold increases in linear furanocoumarin levels, which can cause photophytodermatitis in grocery-store workers."

Mycotoxins are further naturally occurring toxins thought to be affected by pesticides. "Development of mycotoxins in food crops could be altered through the use of fungicides as well as through the use of insecticides to prevent primary insect damage, thereby minimizing the opportunities for secondary fungal colonization of damaged plant tissue. Aflatoxins are frequently detected in several food products, including corn and peanuts, and can be potent mutagens, carcinogens, and teratogens. Fumonisins have been implicated epidemiologically as mycotoxins that could cause human esophageal cancer and have been shown to cause cancer and liver damage in rats, pulmonary edema in pigs, and leukoencephalomalacia in horses. Tricothecene mycotoxins frequently contaminate grain products, and low to moderate consumption of these toxins, particularly deoxynivalenol, may cause immune-system problems and gastrointestinal toxicity in animals (Murphy and others, 2006)."

-- Carl K. Winter and Sarah F. Davis, Journal of Food Science, November/December 2006.

"Natural is often equated with safe and wholesome. ... That pesticides may prevent the development of hazardous natural toxins was new information and not believed by some consumers (Bruhn et el., 1998). Consumer education is needed in this area." -- Christine Bruhn [UC Davis], in Jackson, Knize, and Morgan, Impact of Processing on Food Safety. Advances in Medicine and Experimental Biology series, Springer, 1999. ISBN 0306460513.

Am I understanding then that toxins may occur naturally in organic (or any other) grown fruit (possibly under stress because such and such preventative measure was not taken) in levels exceeding the toxicity of possible residues due to non-organic spraying.

There is a new way to look at things!

Am I understanding then that toxins may occur naturally in organic (or any other) grown fruit (possibly under stress because such and such preventative measure was not taken) in levels exceeding the toxicity of possible residues due to non-organic spraying.

That's exactly the point, Jackson, and it's not so much new as unfashionable (it contradicts conventional consumer thinking as Bruhn pointed out in 1998). Actually the picture is complex (another thing popular wisdom sometimes has trouble with, in my experience anyway):

-- Davis and Winter also point out that organically-grown produce can have higher levels of nutrients than carefully compared conventional produce;

-- Natural toxins can be important but it varies greatly with crop type (a biochemist friend, for instance, stopped eating peanuts and, especially, processed corn foods such as tortilla chips, after reading in depth -- and sending me some creepy articles -- I gather toxin-producing fungal growth as cited earlier also causes cosmetic damage to corn; such corn is diverted to processed rather than whole-kernel uses).

-- Much depends on pesticide type and proper use. I believe for example some of the best pesticides (not necessarily the cheapest or most used) are extremely insect-selective, nontoxic to other animals; certain plants evolved such chemicals as natural defenses and originally the best pesticides were made from such plants -- I'm thinking of Pyrethrum flowers and synthetic versions based on them

I take Winter and Davis to say mainly that available hard data don't support an automatic health advantage from organic produce, though it may be true in specific cases.

Am I understanding then that toxins may occur naturally in organic (or any other) grown fruit (possibly under stress because such and such preventative measure was not taken) in levels exceeding the toxicity of possible residues due to non-organic spraying.

There is a new way to look at things!

Keep in mind that one of the biggest classes of toxins is that of the vegetable alkaloids, all of which are obtained from plant sources. Now, most of those plants such as belladonna, nightshade and foxglove we don't eat, but of course we do eat some close relatives such as the potato and tomato. Another interesting factoid: Prof. Bruce Ames of UC Berkeley, the inventor of the eponymous Ames test -- used for decades to determine what is carcinogenic and what isn't -- got the bright idea to test various foods in his test for carcinogens. He found that bananas contain over 50 different carcinogens. Also, one of the most carcinogenic molecules ever found (benzo[a]pyrene) is a component of the char produced by grilling meats.
So why aren't we all consumed by cancer? Probably because we've evolved to survive a diet that contains those carcinogens . (It's also important to understand that the Ames test uses bacteria, and even the best animal studies use rats and pigs, so no one really knows if those molecules are carcinogenic in humans -- our livers may detoxify them). However, all of this points to a clear distinction between "natural" and "good for you." Strychnine is perfectly natural, after all, as is amanita phalloides.

Mark Lipton

all of this points to a clear distinction between "natural" and "good for you." Strychnine is perfectly natural, after all, as is amanita phalloides.

There's a good bit of wisdom. In checking heavy-metal data for another thread, I saw mentioned the phenomenally poisonous batrachotoxin, saxitoxin, ricin, and "Amazon-valley arrow poisons" which seem to be a whole specialty in themselves, from all the literature references.

All 100% natural and pesticide-free.