(ARA) - A beautiful bouquet of flowers may be one of the healthiest gifts you can give -- and we're not talking calories.

Flowers and plants have been used for centuries to provide people with food, clothing, shelter, medicine and oxygen, as well as to express emotions ranging from love and support to grief. But now, research is adding up that suggests flowers and plants are closely linked to human well-being.

As early as 1789, medical personnel noted that impoverished patients who had to work to pay for their care seemed to recover more quickly when they worked in a hospital's kitchen garden as opposed to working in cattle sheds or other surroundings.

More recent studies have reinforced this early observation. A 1996 study conducted by Virginia Lohr and others showed that rooms and offices decorated with plants and flowers help reduce stress, as measured by decreased blood pressure and pulse rates. In research with breast cancer patients, a common restorative activity -- walking in a garden -- improved patients' ability to focus on tasks and significantly lowered their stress levels.

One of the best known studies, by Dr. Roger Ulrich, showed that patients recovering from gall bladder surgery who viewed plants from their hospital windows had shorter hospital stays, took fewer potent analgesics for pain and received fewer negative nursing comments than their counterparts who viewed a building from their windows.

Additional research by Diane Relf of the Virginia Polytechnic Institute also shows:

-- People communicate better in the presence of flowers or plants, and they tend to eat more food more slowly when flowers are on the table.

-- Flowers restore people from mental fatigue and enhance self-esteem.

-- Certain types of potted plants, as well as the growing mix used with these plants, remove some pollutants from a room's atmosphere.

-- Placing plants and flowers in a room significantly increases humidity, which reduces some of the effects of dry air such as common colds.

-- Other studies have shown that plants can improve the self-concept of prison inmates and help relax psychiatric patients. And native plantings have been used to help immigrants adjust to new surroundings.

It's easy to add a touch of tranquility, freshness, beauty and well-being to someone's day -- just send flowers.