You don't have to eat fresh fruits or vegetables

Common advice is that you must eat fresh fruits and vegetables. I've long wondered why fresh, other than they seem to taste better and look better. Do they offer more nutrients? Belgian scientists' 2007 research shows that nutritional value varies with time of storage, but not necessarily always going down. See Figures 2 and 3 of the article for six kinds of fruits or vegetables. The only one that almost constantly loses antioxidants may be bananas. The take-home message is that you don't have to eat fresh, as long as they're not rotten.

Toxicity of herbs

It's not uncommon to hear people say herbs or Chinese herbs have no side effects, or even, are not toxic. The Chinese article 中药使用者 安全意识待提高 (Chinese herb users need better awareness of safety) is excellent for technically inclined laymen (the type of people capable of reading an encyclopedia of a specific field of science). Better informed herb users may say mineral types of Chinese medicine could be toxic but herbs are generally OK. The said article dismisses that too. Toxicity may be inherent to the medicine itself, or express it when combined with others, or it has negligible toxicity alone, but happens to be used with another that has the same specific toxicity, so the end result adds up.

One good way to avoid toxicity, or at least minimize it, is to take less. If you can take the medicine by means other than orally, seriously consider it. I once concocted my wrist pain "soup". I looked up all individual herbs I used and knew that 细辛 (Manchurian Wildginger) is toxic. Since it's used on the skin, not taken orally, and with below limit amount, I consider it completely safe.

We're all used to looking up chemical, biological, physiological properties of meterials, chemicals, or medicines on Wikipedia, which, unfortunately, sometimes fails to document toxicity, as in the case of Ginkgo. It *is* documented at Baidu Baike in Chinese. If you only read English, more reading is needed. One of Dr. Weil's articles talks about its high-dose side effects.

Tilapia may harm more than help

Dr. Weil's short note warns against eating farm-raised tilapia. It's said that tilapia contains little Omega-3 but a lot of Omega-6, which our bodies already have too much of to strike a balance with Omega-3. He recommends salmon, especially the wild Alaskan type. His comment corroborates with Wikipedia which probably cited this 2008 arcitle. That aritlce says (my bold text), "This analysis revealed that trout and Atlantic salmon contained relatively high concentrations of n-3 PUFA, low n-6:n-3 ratios, and favorable saturated fatty acid plus monounsaturated fatty acid to PUFA ratios. In contrast, tilapia (the fastest growing and most widely farmed fish) and catfish have..."

Frequent shoppers are healthier

An interesting article published in the April 2011 issue of J Epidemiol Community Health, Frequent shopping by men and women increases survival in the older Taiwanese population, is not too surprising. I didn't see the full article (not published yet?). But I think the reason frequent shoppers are healthier may be that they walk and use brains a lot, contributing to improvement of physical and mental health. What's a little surprising is the finding that "Highly frequent shopping may favour men more than women". Is it because shopping frequency varies much more among men than among women?

Sun UV to trigger Vitamin D and skin cancer: intensity matters?

I've never read a report about this but I have had this suspicion for a long time. On the one hand, we need to expose our skin to the sunlight, preferably on a daily basis, in order to let the body synthesize enough vitamin D. On the other, we don't want so much exposure as to cause skin cancer. All reports or articles I know simply advise moderation in exposure time. But I have a hypothesis that intensity, or rather, local intensity multipled by time of exposure, matters more. Suppose the UV light coming to your skin is x lux's in intensity and it lasts y seconds. The chance of you getting skin cancer on that spot is proportional to x*y. If this hypothesis is true, then we have a good strategy to achieve both goals at the same time, getting enough UV and avoiding skin cancer: alternate the part of your body exposed to the sun, and never let the sun light come to one small part of the skin for an extended period of time.

[Update]
Also see

Is there too much radiation from X-ray exams?