Help your body protect itself

Despite all the germs and toxins to which we are constantly exposed, most of us remain healthy thanks to our immune system, a special circulatory system that runs throughout the body. However, our immunity is increasingly being challenged as new infections such as SARS and monkeypox appear, AIDS remains a prevalent threat and the ever-present flu viruses continually mutate among humans and birds.

We also are vulnerable to attacks from within ourselves. For example, new research suggests that prolonged stress reduces our ability to fend off infectious diseases. And we can compromise our natural immunity by how we respond to injury, disease, aging, cell damage and genetic mutations.

Here's how the immune system works. The tissues of the body are bathed by lymph, a transparent fluid rich in certain protective white blood cells called lymphocyte. Most are known as B cells and T cells, but there are others as well, all with different functions. These cells move in and out of the lymphatic and blood systems, their goal being to destroy any harmful foreign molecules. The can do this in several ways: by making antibodies that attach themselves to these hostile invaders and mark them for destruction; by orchestrating an attack on anything that's harmful, such as cancer cells; or by making and secreting products that help control the body's enemies, including cytokines, cytotoxins and chemokines. The body invokes whichever of these mechanisms are necessary.

Studies show that eating the right foods may fortify the immune system against viral diseases such as colds and flu and perhaps other conditions.