advertisement



Q & A Library


Print this page | Sign up for free e-bulletins
 | Bookmark This Page

Q
What's the Best Indoor Light?

I recently replaced my incandescent bulbs with energy-saving fluorescents. But a friend told me that the 'cool white' spectrum of light they produce can actually be bad for us; and that full-spectrum light, such as what plant lights give off, is healthiest. True?

A
Answer (Published 6/27/2011)

First, full-spectrum light is not the same as the light given off by grow lights used for plants. I personally prefer full-spectrum light to other types of artificial light because I like the way it looks, but while researching your question, I found that "full-spectrum" is a marketing term, not a technical one.  

Related Weil Products
Dr. Weil on Healthy Aging - Your Online Guide to the Anti-Inflammatory Diet! - Everything you need to get started eating a healthful, satisfying diet is here - including eating and shopping guides, over 300 recipes, and an exclusive version of Dr. Weil's Anti-Inflammatory Food Pyramid! Start your 14-day free trial now - and start eating anti-inflammatory today!

Full-spectrum light bulbs are supposed to provide light that resembles natural daylight, which manufacturers claim, explicitly or implicitly, is healthier than ordinary artificial light. These products can cost several times as much as those that have identical lighting effects but are not identified as full-spectrum.

According to investigators at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute, full-spectrum light won't affect health in ways different from other electric light sources. They note that research has shown that while our sleep/wake cycle is strongly regulated by the solar light/dark cycle, "other activities including mental awareness, mood, and perhaps even the effectiveness of the immune system go through regular daily patterns" and that exposure to light is the most important environmental stimulus for regulating these circadian cycles and synchronizing them to the solar day. The LPC experts said that short wavelength (blue) light is the type that is particularly effective in influencing our physiology.

This means that to maximize efficiency in affecting the circadian system, the LPC researchers said that a light source should not mimic a full spectrum, but instead should maximize only short wavelengths, which are at the blue end of the visible spectrum. Even if a full-spectrum light source includes short wavelength light, "it will not necessarily ensure proper circadian regulation because, in addition, the proper intensity, timing, and duration of the light exposure are all equally important . . ."

Full-spectrum lights may offer some psychological benefits, according to the LPC experts, but no biophysical explanation for any positive effect has been found.

Since no adverse health effects have been linked to indoor lighting, I wouldn't worry about your fluorescent fixtures. You'll do more good for your health by making an effort to get some direct sunlight as often as possible (given climatic conditions in your area), not only to optimize your body's production of vitamin D, but also to boost your mood and normalize your sleep/wake cycle. (You should also be sure to sleep in complete darkness.)

Andrew Weil, M.D.

Creative Commons License Some Rights Reserved Creative Commons Copyright Notice
A portion of the original material created by Weil Lifestyle, LLC on DrWeil.com (specifically, all question and answer-type articles in the Dr. Weil Q&A Library) is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

The Weil Vitamin Advisor
Get your FREE personalized vitamin recommendation & supplement plan today!

Dr. Weil on Healthy Aging
Your Online Guide to the Anti-Inflammatory Diet. Start eating for your health - begin your free trial now.

Dr. Weil's Spontaneous Happiness
Achieve emotional well-being
in just eight weeks!
Start your 10-day free trial now!

Vitamin Library
Supplement your knowledge with Dr. Weil's essential vitamin facts. Learn why they are necessary and more.

Dr. Weil's Optimum Health Plan
Your 8-week plan to wellness.
Begin your journey today!
 

Dr. Weil's Head-to-Toe
Wellness Guide

Your guide to natural health.
Use the Wellness Guide today!

Dr. Weil's Anti-Inflammatory Diet Food Pyramid
Our interactive tool can help improve overall health through diet.

Condition Care Guide
Learn about health conditions from acne to vertigo, and Dr. Weil's view of the best treatment options for each.

Healthy Recipes
Discover a treasure trove of healthy, healing foods and creative, delicious ways to prepare them.

Q&A Library
Over 2,000 questions from you
and their corresponding answers
from Dr. Weil.

 
Copyright © 2014 Weil Lifestyle, LLC
Information on this web site is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this web site for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment.

Ad Choice
Advertising Notice

This Site and third parties who place advertisements on this Site may collect and use information about your visits to this Site and other websites in order to provide advertisements about goods and services of interest to you. If you would like to obtain more information about these advertising practices and to make choices about online behavioral advertising, please click here