Letters from the July 29, 2006, issue of Science News

Squeeze, please

It would seem to me that instead of looking to minimize the effect of grapefruit juice in slowing the metabolism and elimination of drugs, one could cut drug dosages by taking advantage of it (“Nabbed: Culprit of grapefruit juice–drug interaction,” SN: 5/20/06, p. 317). Grapefruit juice costs less than any drug and has far fewer possible side effects. This could only benefit the patient by lowering drug exposure and costs.

Shmuel Engelsohn
Jerusalem, Israel

“This is probably not a good strategy,” says researcher Paul B. Watkins of the University of North Carolina at Chapel Hill. Both the ingredients in juice and people’s reactions to them are too variable to guide a precise reduction in drug doses.—B. Harder

Let’s drop the little one?

While reading “Gripping Tale: Metal oozes in nanotubes’ grasp” (SN: 5/27/06, p. 326), I pondered what would happen if fissionable elements were the core crystals of the nanosqueeze. Would nanoreactors or nanobombs be possible?

Victor Lawnicki
Louisville, Ky.

Florian Banhart of the University of Mainz in Germany notes that a nuclear-fission bomb or reactor requires a critical mass of kilograms of fissionable material—way too much to enclose in a nanotube.—P. Weiss.

Dim view

The lenses in our eyes yellow as we age. Does this affect the light-mediated regulation of our body clocks (“Light Impacts: Hue and timing determine whether rays are beneficial or detrimental,” SN: 5/27/06, p. 330)? Could it explain any age-related dysfunction?

Mike Speciner
Acton, Mass.

Indeed, it could. The progressive browning of tissue in the eye can end up “acting like yellow-tinted sunglasses,” says Elizabeth R. Gaillard of Northern Illinois University. Moreover, the eye’s lenses thicken and the pupils shrink with age, further limiting how much light reaches the retina, notes Mariana Figueiro of Rensselaer Polytechnic Institute’s Lighting Research Center. Such physical changes “can mute the light-dark signal sent to the body’s master clock, presumably contributing to major sleep disturbances in seniors,” says Figueiro.—J. Raloff