The Best Home Remedies May Be Sitting in Your Spice Cabinet

People around the world have been using spice cures for centuries, but now scientists are finding that spices can ease inflammation, activate the immune system, kill bacteria and viruses and even cause cancer cells to self-destruct. Although most studies are preliminary, some research suggests that compounds in spices might help fight everything from Alzheimer's disease and cancer to depression and diabetes. Here's an overview of the potential medicines lurking in your spice rack.

Turmeric: Asia's aspirin

This bright yellow-orange powder, common in Indian curries, may pack more healing power than any other spice. Turmeric is the aspirin of Asia, where it has been used for centuries in Ayurvedic medicine to heal wounds and treat inflammatory illnesses like arthritis as well as at least a dozen other health problems. Made from the powdered root of a tropical plant closely related to ginger, turmeric contains curcumin, a compound that is both a powerful anti-inflammatory and an antioxidant. It's also non-toxic.

Today, scientists are finding tantalizing clues that suggest curcumin might help prevent and treat Alzheimer's disease and cancer. Investigators at the University of California at Los Angeles, studying a mouse model of Alzheimer's, reported that the brains of animals fed curcumin had up to 80 percent fewer of the protein plaques associated with the disease than those of mice given a normal diet. The abnormal clumping of proteins in the plaques is thought to cause Alzheimer's. Teams at UCLA, Harvard and in Japan subsequently discovered that curcumin might fight Alzheimer's in several ways. First, curcumin forms a powerful bond with the amyloid beta protein associated with Alzheimer's that prevents the protein from clumping into plaques in the brain. Second, this bonding capacity enables curcumin to dissolve these plaques. Third, curcumin reduces oxidative damage and brain inflammation that contribute to the disease process.

It's still too soon to know whether curcumin can prevent or treat Alzheimer's in humans, says Sally Frautschy of UCLA's Alzheimer's Research Lab, where many of the studies are being carried out. "The animal models are not precise models of Alzheimer's, so these studies need to be replicated in humans," she says. Frautschy adds that a UCLA team led by John Ringman and Jeffrey Cummings has just completed a pilot clinical trial and researchers are now analyzing results.

Another challenge is finding a form of curcumin that's absorbed by the body, because it doesn't readily dissolve in water. Still, people in India have been getting their curcumin for centuries by cooking turmeric in ghee (clarified butter), which, like any fat, enables this compound to be absorbed. Indians also have some of the lowest rates of Alzheimer's disease ever reported, according to a 2001 study led by Vijay Chandra of the University of Pittsburgh Graduate School of Public Health.

Could India's low Alzheimer's rate simply be a matter of genetics? Genes may well play a role, but research by Tze-Pin Ng and colleagues at the National University of Singapore also points to a diet rich in turmeric. A study of 1,010 people over age 60 who had no dementia found that those who ate curry "occasionally" and "often or very often" scored higher on mental performance tests than those who rarely or never consumed it. Ng, whose study was published in the American Journal of Epidemiology in 2006, also notes that the most typical curry in Singapore is the turmeric-laden yellow curry.

Evidence is mounting that curcumin may help fight many cancers, says Bharat Aggarwal, a professor of cancer medicine at the University of Texas M.D. Anderson Cancer Center in Houston. In addition to reporting that curcumin blocks most of the mechanisms by which prostate cancer cells survive and grow, he and his colleagues have listed nearly 40 animal studies that suggest curcumin may have a strong protective effect against common cancers, including those of the breast, colon, lung, prostate and skin.

"The potential is unlimited," says Aggarwal, who notes that small clinical studies are underway to investigate curcumin in treating colorectal cancer and multiple myeloma. "Curcumin suppresses most of the biochemical pathways that lead to inflammation -- and up to 98 percent of all illnesses are due to the dysregulation of inflammation." Research has shown that curcumin is likely to block a molecular "master switch" responsible for inflammation and many other processes, including the growth of tumor cells. Small clinical trials are also underway to give us a clearer picture of curcumin's potential in fighting Alzheimer's, cancer and other illnesses.

While we're waiting, should we start sprinkling turmeric into the pan every time we sauté onions and garlic? And, if so, how much?

The mice in Frautschy's study were fed the daily human equivalent of a gram, or about a quarter-teaspoon of turmeric. Aggarwal notes that clinical studies have found that a daily dose of up to 12 grams (about a tablespoon) a day for three months is safe. The basic rule of thumb? According to Aggarwal: "Eating turmeric is okay for every day."

Saffron: The priciest spice

This yellow spice comes from the dried and powdered stigmas of Crocus sativus, a fall-blooming purple flower native to southwestern Asia and cultivated in countries including India, Spain, Greece and Iran. The world's most expensive spice, saffron has been used for millennia as everything from an aphrodisiac to a remedy for colds and stomach problems.

It was also used in traditional Persian medicine to treat depression, a fact that inspired Shahin Akhondzadeh and colleagues at the Tehran University of Medical Sciences and the Institute of Medicinal Plants in Iran to test it in a modern clinical trial of 40 subjects. The researchers reported in Phytotherapy Research in 2005 that mildly and moderately depressed adults who received a daily 30-milligram capsule of saffron for six weeks experienced a significant improvement over those who were given a placebo.

Further research suggests that the ancients, who used saffron to treat about 90 illnesses, may have been onto something big. A series of recent studies in animals have found that saffron extracts blocked or slowed the development of colon, skin and soft-tissue tumors.

Chili Peppers: Kicks from capsaicin

All hot peppers, from cayenne to habaneros to the new, ultra-fiery Bhut Jolokia or "ghost chili," get their kick from capsaicin, a compound that triggers the body to produce more heat, and hence, burn more energy.

Teams at Maastricht University in the Netherlands and Laval University in Quebec, Canada, reported in Physiology & Behavior in 2006 that capsaicin and other compounds that trigger this reaction may help fight obesity. But don't cancel your gym membership just yet. Eating even the spiciest salsa will never beat exercise for burning calories.

You might still, however, want to add more spicy food to your diet. Scientists think capsaicin may cause cancer cells to self-destruct while leaving normal cells unharmed.

Researchers at Cedars-Sinai Medical Center in Los Angeles reported in Cancer Research in 2006 that feeding mice doses of capsaicin equal to a human eating 10 habanero peppers three times a week dramatically inhibited the growth of prostate cancer cells. Another research group at the University of Pittsburgh Cancer Institute investigated capsaicin in a mouse model of pancreatic cancer. In mice fed the equivalent of one spicy Indian meal a day, tumors shrank by nearly half after only three to five days.

Ginger: Not just for gingerbread anymore

This aromatic root has been used for centuries in Ayurvedic, Chinese and Tibb-Unani (traditional Islamic) medicine to treat health problems including digestive ailments, arthritis, infectious diseases, fever, high blood pressure, pain and muscle aches. Today, researchers are zeroing in on the biochemical effects of ginger in the body, which may not only help explain its benefits but also begin to lay the groundwork for new and less toxic treatments for a host of illnesses.

Two key compounds in the spice are gingerols, which gives fresh ginger its pungency, and shogaols, which gives dried ginger its zip. Some of the most convincing findings on ginger's health benefits in humans come from studies of morning sickness. A study of 70 women in the first trimester of pregnancy led by Teraporn Vutyavanich of Chiang Mai University in Thailand reported that women who received one gram of ginger per day had significantly less nausea and vomiting from morning sickness than a control group given a placebo.

Ali Badreldin of the College of Medicine and Health Sciences at Sultan Qaboos University in Oman, along with colleagues in the UK and the United Arab Emirates, recently examined 91 studies on ginger conducted around the world over the last decade. In a 2008 review article in Food and Chemical Toxicology, the researchers highlight animal and test-tube studies that have found ginger can lower both blood sugar and cholesterol, contains pain-killing compounds that mimic nonsteroidal anti-inflammatory drugs (NSAIDs) with fewer side effects, eases inflammation from arthritis and protects against ulcers.

Badreldin and his colleagues also note the results of studies in rodents that found that ginger has powerful antioxidant properties that protect against the toxic effects of radiation treatment and skin diseases caused by ultraviolet B radiation.

These studies lay the groundwork for possible ginger-based treatments for diabetes, arthritis and other inflammatory illnesses, protection against radiation sickness from cancer treatment and even cancer itself.

Even if ginger proves effective, these treatments are likely years away. What is known is that ginger has been used medicinally for centuries, underscoring its safety. "Ginger is considered to be a safe herbal medicine with only few and insignificant adverse side effects," Badreldin notes. But he and his colleagues are also quick to say that large, rigorous clinical studies are needed to pinpoint ginger's efficacy in various illnesses and uncover any side effects from long-term use.

If you want to try ginger, how much should you take? The American Academy of Family Physicians notes that no specific studies of doses have been conducted, but clinical studies on nausea generally use between 250 milligrams and 1 gram of powdered ginger root in a capsule, taken one to four times a day.

Is it possible to overdose on spices? Like anything else, spices should be taken with a healthy dose of common sense. Pregnant women should avoid saffron, because in large doses it may induce abortion, and they should consult with their doctors when taking any herbal products. (That's a good rule of thumb for everyone). Ginger can cause stomach upsets. Some studies have found that too much capsaicin from hot peppers can cause stomach problems.

It will take further clinical studies to establish whether and how spices might prevent or even cure disease. Based on recent research, though, turmeric remains one of the most promising and safest condiments in treating a host of illnesses. So don't forget to add it to your next soup or main dish. If it really does help prevent Alzheimer's, it may well help you remember a lot of other stuff too.

Kim Ridley is co-editor of "Signs of Hope: In Praise of Ordinary Heroes." She writes about people creating positive social change for Ode Magazine.