Your body is perfectly designed to detoxify itself, if you treat it right.

The primary detoxification systems of our bodies are the liver, the gastrointestinal tract and the kidneys — supported by the lungs and skin. Their primary tasks are to process the substances we take in and remove the substances that we don’t need.

Thomas Hopkins, M.D., an internist with Sutter Medical Center, Sacramento, says our bodies are extremely effective at their jobs and don’t need much assistance.

“Nothing you can do externally can outperform what the body already does,” Dr. Hopkins says. However, he notes that you can slow down the body’s effectiveness through bad habits and poor dietary choices.

There’s no scientific evidence that fasting or special cleanses are beneficial.

Toni Brayer, M.D., an internist with the Sutter Pacific Medical Foundation, says there are no scientific studies that indicate any benefit to external efforts to detoxify the body.

“Many of these product promotions are really scams,” Dr. Brayer says. “Even herbs or herbal teas with claims of detoxification can be a waste of money. Spend that money on organic produce and healthy grains instead.”

Colonics, cleanses and fasts can be harmful to your health.

Many doctors agree that colonics, the physical flushing of the colon with water, are not only unnecessary, but can be dangerous. There is the possibility of upsetting the balance of helpful bacteria that are meant to live inside the colon, as well as the remote but real chance of a perforation of the wall of the colon.

Many medical experts agree that a one-day fast can feel great. But extending beyond three days can begin to cause harm, especially if you have other medical conditions, such as diabetes or heart disease.

“A fast longer than a day or two can deplete vitamins, minerals and electrolytes,” Dr. Hopkins says. “Fasts can actually deplete the liver of proteins needed to deal with potentially carcinogenic substances.”

You can help cleanse your body with food, water and healthy habits.

Many Americans eat a diet high in fat and processed food, which can slow down the digestive tract, causing feelings of bloating, fatigue and irregular elimination. Dr. Brayer says the cure is a healthy diet focused on fiber, fruits and vegetables, and regular exercise to stimulate the body’s own processes.

Dr. Hopkins says water is also hugely beneficial in cleansing the body.

“Water helps you increase your body’s own natural methods of detoxification,” he says. “One of the best things you can do is to provide your body with a consistent, adequate intake of water.”

Antioxidant foods are another natural way to support the body’s functions. Fruits and vegetables get high praise, as well as nuts and seeds — walnuts, almonds and flax seeds in particular, which also contain beneficial omega 3 oils.

Eliminate your own sources of toxins — including alcohol and caffeine.

Caffeine, alcohol in all forms, fatty processed foods, and too much salt and sugar can upset the natural functioning of the body. In large amounts, they’re toxins that require your body to work harder to process and eliminate.

Dr. Hopkins recommends following these rules for dealing with toxins:

• Limit alcohol to the recommended one or two drinks a day.

• Restrict caffeine to the amount that causes no side effects for you — no jitters, sleeplessness or heartburn.
• Eliminate processed foods and substitute fresh, natural products.
• Reduce or eliminate processed sugar in your diet. If this one seems impossible, try the seven-day Sugar Detox Diet designed to help you stop the cycle of sugar overload.

Develop a long-term plan for keeping your body clean and healthy.

A short-term activity cannot provide us long term health benefits. From a fad diet to a cleanse day at a spa — the results will fade. Your approach to health must be sustainable for the long term.

Dr. Hopkins suggests these basic rules for healthy living:

• Drink adequate water every day.
• Eat a variety of healthy, unprocessed foods.
• Cut down or eliminate potentially toxic food habits, including alcohol, caffeine, excessive salt and processed sugars.

• Exercise regularly and learn about getting the most out of your workout.
• Get enough sleep. Review this checklist for a better night’s sleep.
• Find healthy ways to reduce stress.

If you’re still going to cleanse, choose a short cleanse with plenty of vitamins.

Dr. Brayer says it’s possible that a short, well-supported fast or cleanse can be the boost some of us need to change our dietary habits — like a kickoff for better health.

“Many people who do a short juice fast do feel clear-headed and begin some weight loss that inspires them to continue healthy eating,” Dr. Brayer says.

But beware of extending the fast too long, as it can send your body a signal of food deprivation. This will cause you to hold on to every calorie you consume, slowing your metabolism and making future weight loss more difficult.