It’s cold and flu season again. But don’t take the next sniffle lying down, says registered dietitian Elizabeth Somer.
The immune system is your body’s No. 1 line of defense against the onslaught of viruses, bacteria and other germs that are in abundance this time of year.
That system is turned on or off in part by what you eat and how you supplement. Eating right helps maintain a strong immune system, Somers says, and consequently, you’re less likely to get sick and if you do, the symptoms will be milder and you’ll recover more quickly.
We asked her what foods, supplements and herbs people should make sure to consume this winter:
Q: What should we eat to prevent the common cold?
A: While an apple a day won't keep the doctor away, heaping the plate with broccoli, spinach and oranges might be just what the doctor ordered. Colorful fruits and vegetables are sources of the antioxidants, including beta carotene, vitamin E, selenium and vitamin C. The antioxidants work together to boost the immune response and increase resistance to infection, colds and flu bugs. Ample intake of beta carotene-rich foods, such as carrots, apricots and broccoli, also maintains the skin and mucous linings in the nose and lungs, which are the body's first line of defense against germs. Most people don’t get enough of these foods and would do well to double or even triple current intake to at least 8, and preferably 10, servings daily. Simple immune-boosting snacks include:
- Smoothie made with persimmons, OJ concentrate and yogurt
- One-half honeydew melon filled with lemon yogurt
- Top low-fat ice cream with a cup of thawed blueberries
- Dunk baby carrots in peanut butter or red pepper slices in hummus
- Stuff dried plums with almonds for a sweet and chewy alternative to a candy bar
- Quench your thirst with OJ or tomato juice instead of soft drinks
- Pack a black bean burrito with baby spinach, tomatoes and salsa
- Add frozen or leftover vegetables to canned soups
Next, cut back on meat and full-fat dairy products, as well as many processed foods in order to keep saturated-fat intake low. While low-fat diets stimulate the immune system and help ward off the common cold, typical American diets high in saturated fat increase a person's susceptibility to colds and the flu.
Q: What nutrients help us stay well this time of year?
A: Vitamin E is important, with studies showing that vitamin E increases resistance to the flu and reduces the risk for upper respiratory infections. However, it looks like you need at least 100 IU or more, which is virtually impossible to get from diet alone, so you would need to supplement with this nutrient.
Although the antioxidants are your first line of defense, other vitamins and minerals also affect a person's resistance to colds and infections. Studies from Loma Linda University in California and Oregon State University report that increasing vitamin B-6 intake in some people raises blood levels of the vitamin and enhances the immune response. You can increase your intake of this vitamin by eating more bananas, avocados, and dark-green leafy vegetables. The minerals, including iron, selenium, copper and zinc, also boost immunity. These minerals are found in whole grains and cooked dried beans and peas.
Q: What about vitamin C? I’ve heard that it cures the common cold. Is there any truth to that?
A: While you can get all the vitamin C you need from foods to help you prevent the common cold, you might need to supplement with this vitamin once you feel a cold coming on. A large number of studies have verified that vitamin C might not prevent the cold from happening, but it does help curb its severity and duration. The effective dose here is about 500 milligrams to 2,000 milligrams daily, starting at the first signs of a cold and taken in divided doses. That’s only for adults; young children are much more susceptible to toxicity effects from vitamins and minerals, so keep their intake to within recommended levels or discuss higher doses with your physician.
Q: Are there any other supplements that might help us once we’re sniffling?
A: Possibly. Although controversial, there are a few studies showing that zinc lozenges might help curb the symptoms of a cold. Taking one or two of these daily is worth a try. Nasal zinc gel seems to shorten the duration of a cold, while zinc nasal spray does not. However, watch out for overdoses here. More than 50 milligrams of zinc daily over time actually might suppress the immune system and could interfere with your body’s efforts to get well.
Airborne: This popular supplement contains a mix of 17 vitamins, minerals and herbs, including hefty amounts of vitamin C (and also vitamin A if you take more than one tablet a day). There are no studies to prove this supplement works, although this didn’t stop Americans from spending an estimated $300 million on this supplement last year. If there is any basis for the claims, it is probably because of the high vitamin C. But you can buy a handful of vitamin C pills for the price of one Airborne tablet. Although Airborne claims it can “repel germs in an airplane, restaurant, or other crowded places”... sorry, nothing you swallow can do that.
Q: What about garlic? I’ve heard it’s good for fending off a cold.
A: People have been using garlic for centuries (think Egypt at the time of the Pyramids) to prevent infection, but it’s only recently that scientists isolated numerous sulfur-containing compounds in garlic that have potent antibacterial and possibly antiviral effects. These sulfur compounds destroy germs' ability to grow and reproduce, much in the same way as penicillin fights infections. A well-designed study of nearly 150 people supports the value of garlic for preventing and treating the common cold. In this study, people received either garlic supplements or placebo for 12 weeks during “cold season” (between the months of November and February). Those who received the garlic had significantly fewer colds than those who received placebos. Plus, when faced with a cold, the symptoms lasted a much shorter time in those receiving garlic compared to those receiving placebos.
The trick is getting enough, without sacrificing your social life. While some researchers suggest as many as 10 cloves a day, others say that as few as two to three cloves is enough, especially if combined with a diet full of fresh fruits and vegetables and high in vitamin C. That’s as simple as adding a few cloves to pasta sauces, stews, soups, or salad dressing. When it comes to garlic supplements, most clinical studies have used aged garlic extract (AGE) or enteric-coated, dried garlic tablets (dose: 600 to 1,200 milligrams daily in divided doses).
Q: What about herbs? I see a lot of herbal supplements promising an immune boost and a solution to the common cold.
A:Echinacea: This herb contains active substances that enhance the activity of the immune system, relieve pain, reduce inflammation and have antiviral and antioxidant effects. While some studies have found no effect, others show that taking echinacea, especially beginning at the very first signs of a cold, can help reduce the severity and duration (taking echinacea regularly has no effect). Different products use different parts of the echinacea plant. A study performed by ConsumerLab.com (an independent company that tests the purity of health, wellness and nutrition products) found that of 11 brands of echinacea purchased for testing, only four contained what was stated on their labels. About 10 percent had no echinacea at all; half were mislabeled as to the species of echinacea in the product; and more than half of the standardized preparations did not contain the labeled amount of active ingredients. This is one reason why the effectiveness of echinacea differs dramatically from one product to another. To ensure you get what you paid for, buy products made by reputable, established companies that distribute their products through trustworthy and knowledgeable establishments. When possible, select products with guaranteed potency or standardized extracts. Either the capsules or the drops, taken several times during the day, are worth a try (i.e., 1 to 2 grams dried root or herb as tea, 2 to 3 mL of standardized tincture extract, or 300 milligrams of powdered extract containing 4% phenolics).
Astragalus: This herb has antibacterial and anti-inflammatory functions. It also is sometimes used topically for wounds. In addition, studies have shown that astragalus has antiviral properties and stimulates the immune system, suggesting that it is effective at helping prevent colds. Doses from 1 to 25 grams a day are used. Higher doses might suppress the immune system.
Goldenseal: This herb contains a compound called berberine that kills many types of bacteria and might activate white blood cells, making them more effective at fighting infection and strengthening the immune system. It also is used topically for sores and skin infections. Often it is combined with echinacea. As a capsule or tablet, take 500 to 2,000 milligrams up to three times daily.
Ginseng: A few studies show a reduction in cold symptoms with Siberian ginseng. But, evaluation of commercial products found that as much as 25 percent of Siberian ginseng supplements had no measurable ginseng at all. Purchase Siberian ginseng and all herbal products only from reputable manufacturers. Dose: As a dried root — 500 to 3,000 milligrams daily in capsules or tea.) Cold-fx is a supplement that contains American ginseng. A Canadian study found it reduced the number of colds, as well as their severity and duration. In a second study of nursing home residents, eight of the placebo takers but only one of the cold-fx takers got the flu. Consult your physician before taking if you have high blood pressure, are pregnant or have sleep apnea.
Licorice root: This herb can soothe a sore throat, but also can contribute to high blood pressure, low potassium levels, and should not be used by people with heart disease, who are pregnant or breast-feeding, or if taking medications such as prednisone.
Q:What about once we have a cold? Are eating chicken soup and drinking tons of water just old wives’ tales?
A: Chicken soup — as made by grandma — does help curb the symptoms of a cold! It contains several ingredients that affect the body's immune system, according to a 2000 study from the University of Nebraska Medical Center. Specifically, it has anti-inflammatory properties that could explain why it soothes sore throats and eases the misery of colds and flu. Add a bunch of vegetables to it and you have a one-two punch for getting well fast.
You can't flush a cold out of your system, but drinking plenty of liquids can help. Water, juice, clear broth or warm lemon water with honey helps loosen congestion and prevents dehydration. But, steer clear of alcohol, coffee and caffeinated sodas, which interfere with the immune system’s job of restoring health.
The bottom line:
To avoid a cold:
Eat eight or more colorful fruits and vegetables every day
Cut back on saturated fat
Consider taking extra vitamins C and E
Once you’re sniffling:
Boost vitamin C and possibly zinc
Eat more garlic
Consider certain herbs, such as echinacea and goldenseal
Drink lots of water and eat lots of homemade chicken-and-vegetable soup
Diet is one part of the anti-cold battle. Also remember to keep stress at bay, exercise daily and moderately, wash your hands frequently (the cold virus can live on hard surfaces for up to 24 hours, so it’s not just immediate contact with a sniffler that can do you in), get enough sleep, get your flu shot and don’t smoke. Finally, if your cold has not abated within a week, check with your doctor to make sure you haven’t developed a secondary bacterial infection.
For more information on herbs and supplements, go to the National Institutes of Health’s Office of Dietary Supplements Web site: ods.od.nih.gov