Without a doubt your habitual carrot consumption is the cause of your yellowing skin. The same fat-soluble pigments (carotenoids) that account for the deep orange color of carrots are responsible. In general, carotenoids are beneficial to health and can protect the skin from sun damage. For example, lycopene, a carotenoid which is responsible for the red color of tomatoes, and the green pigments in spinach, broccoli, and other green vegetables will all make your skin slightly less sensitive to the sun. (In April 2008, British researchers reported that consuming lycopene-rich tomato paste reduced sun damage by 33 percent).
The yellow or orange color you notice on your palms (called carotenemia) is often seen in infants when they start to eat solid foods and get too many that contain beta carotene - usually from carrots, pumpkin and other yellow and orange vegetables. The color change is harmless but has to be distinguished from jaundice, which also causes yellow or orange skin. Eating too much beta carotene doesn't cause the whites of the eyes to yellow, while jaundice does, but if skin color changes in an infant, it's best to see a pediatrician to make sure that the problem is just too many carrots or too much pumpkin.
Your color change is not at all dangerous and will fade quickly when you reduce your consumption of carrots. I suggest that you do just that - not because the carotene has turned your skin yellow, but because it's important to eat a variety of fruits and vegetables. The greater the variety of natural colors in your diet, the better off you'll be nutritionally. Carrots all the time sounds a bit monotonous, enjoy a rainbow of produce!
Andrew Weil, M.D.