This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here because the All LED Lighting site has gone dark. This material is Copyright 2013-2015 by UBM Americas.


Wednesday Roundup: Blue Food

This week: lighting food blue circumscribes men's appetites, the case of the vanishing Chinese LED entrepreneurs, and blue light considered harmful to dark skies.

Dark-sky group says blue light hurts
Last week the International Dark-Sky Association announced changes in the criteria by which makers of outdoor luminaires are awarded the IDA Fixture Seal of Approval (FSA). Such lights must have a coordinated color temperature of no more than 3,000K. As we have been discussing, "Exposure to blue light at night has known negative effects on ecology and is thought to cause certain kinds of chronic disease in humans," the IDA said in a press release.

A 2010 IDA whitepaper concluded that blue-rich white light from LEDs causes 15-20% more light scattering than sodium lamps, either HPS or LPS.

I wasn't able to learn what will become of the FSA certifications awarded to luminaires above 3,000K CCT before this change went into effect.

Ideally, cities and towns that had installed high-CCT outdoor lights will replace them over time with lights at 3,000K or below.

A countertop LED grow unit
We have written about LED lighting used in commercial indoor farming operations, but this unit profiled by Treehugger is intended for home use. The CounterCrop is "designed to help you grow greens, vegetables, and herbs efficiently using commercial-grade LEDs and an automated hydroponics system, while only drawing about 65 watts of power."

The LEDs "imitate daylight patterns and key spectrums of sunrise and sunset to help your plants grow great indoors," according to the project's Kickstarter page.

The CounterCrop will cost somewhere in the vicinity of $379 when it is in production. At the moment, Kickstarter backers can get one by putting up $194. (The first early-bird offer, now sold out, was at $134.) It looks highly likely that the project will fund; it has raised nearly $67,000 of its $75,000 goal with 38 days left to run. Delivery is slated for June, barring production delays.

Case of the vanishing Chinese LED entrepreneurs reports, "In recent years, many Chinese LED manufactures have shut down or company heads have fled." A search of the site, and more broadly, didn't turn up definitive news of earlier disappearances by LED company founders. The latest to scarper was Zhong Gang, CEO of Lihefeng Photoelectric Technology in Shenzhen. The company's suppliers say they have been unable to contact him since Nov. 17. The company owes suppliers $1.6 million and has not paid wages in three months.

Blue light causes men to eat less
New research suggests that the way food is lit influences how much a man is likely to eat (but not a woman). University of Arkansas researchers report in the journal Appetite that men served a hearty breakfast ate less if their meal took place under blue lighting. This "one weird little trick" didn't work for women, apparently because they don't rely so much on visual cues to determine how much and what to eat. The lead researcher is quoted: "Blue lighting can decrease the amount of food eaten by men, without reducing the acceptability of the food."

The researchers surmise that the rarity of naturally occurring blue foods makes blue a warning sign. is among the numerous online sources that agree. "Of all the colors in the spectrum, blue is an appetite suppressant. Weight loss plans suggest putting your food on a blue plate." But women, apparently, rely more on smell and less on sight than men do in determining what is good to eat.

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