Why fresh fruits and vegetables?

My last posting "fruit juices = increased hazard of diabetes" still bothers me. The researchers did not offer any explanation, not even a hypothesis. It reminds me of numerous health and medical science articles that recommend we eat fresh fruits and vegetables but none explain why fresh. We all know freshness means better taste and smell. But scientifically, it does not logically follow that they're healthier than not as fresh fruits and vegetables, although rotten ones, obviously, should be excluded for food poisoning.

So here's my theory, or hypothesis. Many fruits and vegetables have anti-oxidants, those that scavenge free radicals in our bodies. As a chemist, I know that if something is anti-oxidant, it must easily react with oxidant, most notably in our everyday life, oxygen. Have you ever asked yourself why a cut-open apple exposed to air for a few minutes has a layer of "rust"? If you must leave it open for a while, you can put food wrap on it tightly to avoid oxygen exposure, and the rust will not appear. Like apples, many fruits and vegetables have nutrients that chemically react with oxygen, depleting the health benefit due to decreased amount of the nutrient. If they were still on the plant, the nutrient would be continuously produced. But once harvested, time is running to gradually lose the oxygen sensitive nutrient. If you must, store them in a CO2 or nitrogen environment.

Well, here I'm assuming oxygen to be the only chemical that eats aways the good stuff. But it's likely that the nutrient may degrade anaerobically. In that case, eating fresh is the only way to make best use of the healthy plants.

Back to the "fruit juices = increased hazard of diabetes" topic. Science is making progress. But there's always a little gap to reveal the secrets of real nature. There got to be something fruit juice manufacturers are missing. Before the missing part is found, let's eat fresh fruits for the time being.

fruit juices = increased hazard of diabetes

http://www.medscape.com/viewarticle/572861?src=mp&spon=42&uac=46051AK

"April 11, 2008 — Consumption of green leafy vegetables and fruit was associated with a lower hazard of type 2 diabetes mellitus (DM), whereas consumption of fruit juices may be associated with an increased hazard of diabetes among women." Nobody will doubt the first part of the statement. But the second part, highlighted by me, is surprising. The study does not offer an explanation or hypothesis.

"They advise caution in replacing some beverages with fruit juices in an attempt to provide healthier options and in classifying 100% fruit juice as a serving of fruit."

Autism and vaccine?

Whether children should be vaccinated is a hot topic on public forums, such as misc.health.alternative. There's a possibility that children with certain rare disease such as scimitar syndrome should not be vaccinated the same way as normal children are (Ref: http://groups.yahoo.com/group/scimitarsupport/). But it's probably hard to argue that vaccination should be banned altogether.

Now here's something even stronger against this medical practice, a case where the plaintiff claims autism was aggravated by vaccination. ("On March 6, a federal court granted compensation to a Georgia girl because she developed autism-like symptoms after receiving childhood vaccines in 2000. Officials did not say the vaccines caused autism; rather, they concluded the vaccines aggravated a preexisting condition." Source:Medcape.com) Interestingly, the Medscape poll shows that most medical professionals think the ruling is wrong, and physicians are even stronger than nurses in thinking this way, pharmacists in the middle. (Source) Looks like the more knowledge you have, the more likely you'll laugh at the connection.

More news

Health Risk of Vitamine E Supplements

Supplemental Vitamin E May Increase Heart Failure Risk


WHS: Women's Heath Study -- Aspirin and Vitamin E for the Primary Prevention of Cardiovascular Disease
qualified success for aspirin in cardioprevention, but no benefit associated with the use of vitamin E.


Meta-analysis Results Suggest High-Dose Vitamin E Increases All-Cause Mortality
"At 400 IUs, which is the most common marketed dose, the risk of dying is about 10% higher than risk among people not taking the vitamin."
...
Dr.Gibbons, who served as chair of the scientific program committee at the meeting, said he has been urging his patients to stop taking vitamin E for years. Dr. Gibbons said that cardiovascular disease prevention guidelines from "vitamin E is ‘not recommended'. It doesn't get clearer than that — don't take it."

Dr. Miller said there are several theories about why vitamin E increases risk. One theory is that it increases bleeding risk, which would increase the risk of hemorrhagic stroke, while another theory suggests that at high doses vitamin E stops working like an antioxidant that mops up free radicals that attack cells that line blood vessels and instead becomes a prooxidant and actually promotes the production of free radicals.

Still another scenario suggests that high-doses of vitamin E tend to destroy other fat-soluble antioxidants, which disrupts the body's natural antioxidant protection system.


Antioxidant Vitamins May Increase Mortality

March 1, 2007 — The largest analysis of data on antioxidant vitamins ever conducted has shown that beta-carotene, vitamin A, and vitamin E probably increase mortality. Two other antioxidant substances — vitamin C and selenium — had no effect on mortality.

"Vitamin A and beta-carotene seem to have a dose-related effect, with mortality increasing as doses increase, whereas vitamin E does not appear to have a dose-related effect, with all doses associated with increased mortality."

antioxidant vitamins could actually also have prooxidant effects. "We don't know exactly how they are doing harm but rather than preventing cardiovascular disease and cancer, they actually seem to be accelerating these conditions."


Multivitamins Do Not Reduce Risk for Lung Cancer, and Vitamin E May Raise It

February 29, 2008 — The long-term use of supplemental multivitamins does not reduce the risk of developing lung cancer, and high doses of vitamin E may even raise the risk, particularly in smokers.
...
Although consuming higher amounts of fruits and vegetables can reduce the risk for lung cancer, multivitamins and supplements have generally not demonstrated a benefit in reducing this risk.

"Dressed to Kill" and Breast Cancer

The book "Dressed to Kill" was published in 2005 and I was not aware of it till a few days ago. I haven't read it but read some comments and related articles about the same topic, relationship between breast cancer and wearing bras. There're a couple of comments I want to make. Briefly,

1. The relationship is unproven according to American Cancer Society's research (also this). Then how is any study scientific? One of the most compelling review of Sydney Ross Singer et al.'s book is by D. Pilipovich (Kapaau, HI United States). There may be some medical hypotheses that can't be or can't easily be studied by single- or double-blind methods. If ACS does not think this is one of them, then there should be a panel of experts that organize such a study. Singer's study may be too simplistic, not excluding too many confounding factors. But if the cohort number is large enough, it doesn't really matter, although the explanation for the observed relationship may be questionable. This reminds me of some ever-lasting debate in relational databases, such as Oracle. Should one rebuild a table's index or not? In spite of experts' caution, if you rebuild it and it improves performance and it doesn't realistically cause downtime or problem either now or in the near future, do it. By the same token, if a survey of a large number of respondents corroborates the "rumor", give the rumor credit. Even though the theory behind the rumor given by the researchers (Singer and Grismaijer here) is not sufficiently substantiated, the survey result is hard fact and cannot be dismissed unless you find flaws in the survey itself. (I haven't read the book. The theory of lymphatic flow restriction sounds plausible but I wonder why they pick the lymphatic, not for instance blood flow.)

2. Chinese women living in cities generally wear tighter clothing, and possibly tighter bras, and yet have less common occurrences of breast cancer than American women. Do eating more tofu, more exercise (walking and biking) and possibly less smoking explain the difference?

Other articles supporting Singer et al.'s claim:
Bras And Breast Cancer
Health After 40
Bras and Breast Cancer