How Can I Beat Back a Blue Mood This Winter?

Cold and dark days make it common to feel a dip in serotonin levels. Omega-3 fatty acids, found in oily fish (such as salmon and sardines), have been shown to improve cognitive function. Lentils, meanwhile, are a rich source of the amino acid tryptophan, a precursor to serotonin.

What Foods Should I Eat to Up My Immunity?

Citrus is bursting with vitamin C, and your body absorbs extra cold-fighting antioxidants from the combo of pink grapefruit, which also contains the phytochemical lycopene.

I Have a Sore Throat and Feel a Cold Coming On. Help!

Indoor air breeds colds and coughs, but common-sense therapies -- like eating fruits and veggies and scrubbing hands clean -- are still the most effective way to keep germs at bay this winter.

Studies have shown that green tea (steeped 3 to 5 minutes) is the best food source of catechins, plant compounds that halt oxidative damage to cells. Flavor it with fresh, anti-inflammatory ginger and pomegranate for an extra nutrient punch.

Natural Winter Remedies: Licorice

Licorice (Glycyrrhiza glabra) has immune-boosting and throat-soothing properties that make it an excellent addition to cough and cold formulas.

How to use: For coughs, make a tea that combines mullein leaf with a pinch of licorice. Safety note: People who have high blood pressure should avoid this herb or use the deglycyrrhizinated form (look for "DGL" on packaging).

Natural Winter Remedies: Sage

Common culinary sage (Salvia officinalis) can help to ease sore throats and dry up sinuses.

How to use: For a sore throat, make a strong tea by pouring 4 ounces of water over 2 teaspoons of dried or fresh sage. Cool to room temperature. Gargle until the mixture is gone. Repeat three times daily. For drippy sinuses, drink a cup of regular-strength sage tea.

Natural Winter Remedies: Yin Chiao

This centuries-old Chinese formula stars a number of immune-boosting herbs and can help ease cold symptoms such as sneezing and congestion.

How to use: Use at the first sign of illness; follow package directions or consult with a TCM practitioner.

Natural Winter Remedies: Tulsi

Believed to boost overall health, tulsi (Ocimum sanctum) -- also known as holy basil -- contains antiviral and antibacterial compounds. It may help prevent illness when used over time.

How to use: Tulsi makes a delicious tea; look for it in packaged form or brew your own with loose tulsi. Aim for two to three cups daily.

Natural Winter Remedies: Mullein

Mullein (Verbascum thapsus) has expectorant and soothing properties that make it a cough treatment supreme.

How to use: For coughs, try mullein tea: Pour a cup of boiling water over a tablespoon of mullein leaves; let steep for 20 minutes and strain. Add honey and lemon to mask the bitter taste. Treat ear infections with drops of oil infused with mullein and garlic.

Natural Winter Remedies: Eleuthero

Also known as Siberian ginseng, this well-studied herb (Eleutherococcus senticosus) can help your body resist the effects of stress and boost your immune system.

How to use: Take in tincture or capsule form, or make an immunity chai by blending eleuthero with cardamom, ginger, and cinnamon. Simmer for 20 minutes and strain; drink two to three cups daily.

Natural Winter Remedies: Eucalyptus

With antibacterial and expectorant properties, eucalyptus (Eucalyptus globulus) can loosen congestion and help you breathe easier.

How to use: Pour near-boiling water into a pot. Add a few drops of eucalyptus essential oil, turn off heat, and drape a towel over your head and the pot. Breathe for five minutes. Safety note: Do not use essential oils internally.