Eating to Boost Your Immune Health
I follow a simple nutrition principle, eat to support health & body. And when it comes to getting enough nutrients, it’s always from whole foods first before supplementation. In some cases, supplementation is necessary.
If you suspect micronutrient deficiencies, eating a varied diet with ample fruit and vegetables or supporting yourself with multivitamins may be beneficial.
Nutrients for Your Immune System
Vitamin C
Vitamins C and E are antioxidants that help to destroy free radicals and support the body's natural immune response.
Vitamin C Sources:
red bell peppers
oranges
strawberries
broccoli
lemons
Supplementation:
Vitamin C is often supplemented to reduce the symptoms of the common cold. Supplementing vitamin C can reduce the duration of a cold by 8-14% in any population when it is taken as a daily preventative measure or at the beginning of a cold. The Recommended Daily Intake (RDI) of vitamin C is 100-200mg. This is easily attained through the diet, so supplementing such low doses is usually unnecessary. Higher doses of vitamin C, up to 2,000mg, support the immune system (for athletes) or reduce the duration of the common cold.
Vitamin E
Vitamins C and E are antioxidants that help to destroy free radicals and support the body's natural immune response.
Vitamin E Sources:
almonds
spinach
avocado
olives
Supplementation:
Maintaining adequate levels of vitamin E can be achieved through very low daily doses of 15mg (22.4 IU) or less. This vitamin E can be acquired through the diet, often making supplementation unnecessary. Older people supplementing vitamin E to improve immunity should take 50-200mg.
Beta Carotene
Beta-carotene is a powerful antioxidant that can reduce inflammation and boost immune function by increasing disease-fighting cells in the body.
Sources:
sweet potatoes
carrots
green leafy vegetables
Zinc
Zinc is a mineral that can help boost white blood cells, which defend against invaders.
Sources:
pumpkin seeds
sesame seeds
beans
lentils
Supplementation:
Zinc has two standard dosages. The low dosage is 5-10mg, while the high dosage is 25-45mg. The low dose works well as a daily preventative, while anyone at risk for a zinc deficiency should take the high dosage.
Allicin
Allicin is the principal bioactive compound present in the aqueous extract of garlic. When cooking with garlic, it is recommended to crush or chop it and leave it for 10 mins to activate the enzyme. When garlic is chopped or crushed, the alliinase enzyme is activated, and allicin is produced.
The benefits of garlic to health have been proclaimed for centuries; however, only recently, it's been proposed as a promising candidate for maintaining a healthy immune system.
Most studies on garlic use a dosage range of 600-1,200mg daily, usually divided into multiple doses. The minimum adequate quantity for raw garlic is a single segment of a garlic bulb (called a clove), eaten with meals twice or thrice daily.
Astragalus
Astragalus membranaceus is an essential herb in traditional Chinese medicine. This Chinese herb has been researched for its cardioprotective, anti-inflammatory, and longevity effects. It has been used in various herbal blends and 'natural' remedies.
Supplementation:
Astragalus membranaceus and Angelicae Sinensis are highly synergistic, meaning they are more powerful when taken together. This combination is traditionally called Dang-Gui buxue tang.
The starting point for preparing Dang-Gui buxue tang in traditional Chinese medicine is 30g of Astragalus membranaceus root paired with 6g of Angelicae Sinensis. This is a 5:1 ratio, which is ideal for extracting the bioactive ingredients of plants.
The main bioactive compound in Astragalus membranaceus is astragaloside IV, which can be supplemented by itself. The standard dose for astragaloside IV is 5-10mg.
Vitamin D
Vitamin D is a micronutrient needed for optimal health throughout your life.
It is a fat-soluble vitamin that dissolves in fat/oil and can be stored in the body for long periods. There are two primary forms, D2 and D3, D3 being more effective.
Vitamin D is also unique because it is both a nutrient we eat and a hormone that our body makes from exposure to sunlight, which is why it is often named the sunshine vitamin.
While vitamin D affects various cells related to bone health – like telling the cells in the gut to absorb calcium and phosphorus – scientists have generated substantial evidence supporting vitamin D as an essential hormone required to regulate many physiologic functions.
Research shows that vitamin D receptors are present in nearly every tissue and cell. Adequate vitamin D is essential for the optimal function of these tissues and cells to carry out important roles, including reducing inflammation, modulation of cell growth, immune function, and glucose metabolism.
Sufficient vitamin D levels are essential for disease prevention, longevity, and optimizing human health.
Research shows that vitamin D supplementation may reduce the risk for viral infections, including respiratory tract infections, by reducing the production of pro-inflammatory compounds in the body.
The primary source of vitamin D is direct sunlight exposure. Unveiling bare arms and legs for 5 to 30 minutes between 10:00 AM and 3:00 PM is often adequate to meet vitamin D requirements. But this can vary depending on skin pigmentation and other factors.
Vitamin D from summer sunlight can be stored in our bodies for an extended period. However, many people cannot store enough to see them through winter.
Variables such as age can also affect the amount of vitamin D converted into the skin. The cholesterol precursor in the skin (7-dehydrocholesterol) for vitamins D2 and D3 decreases as we age. It falls at a rate of 50% between the ages of 20-80. This inhibits the amount of vitamin D3 older people can make.
Thankfully, you don't have to rely solely on the sun. Vitamin D dietary supplements are safe and inexpensive and are becoming widely available. But ideally, exploring whole foods like oily fish and mushrooms can deliver a good source of vitamin D.
Supplementation:
The body produces vitamin D from cholesterol, providing adequate UV light from sun exposure.
For moderate supplementation, a 1,000-2,000IU dose of vitamin D3 is sufficient to meet the needs of most of the population. The safe upper limit in the United States and Canada is 4,000IU/day.
tips
The immune system is a system, not a single entity. For it to function well, it requires balance and harmony. Researchers are still exploring the effects of diet, exercise, age, psychological stress, and other factors on the immune response.
A healthy lifestyle is the best step you can take toward naturally keeping your immune system strong and healthy. Every system in your body, including the immune system, functions better when following balanced and healthy strategies such as these:
Eating a whole food diet with plenty of fruit and veg
Exercising regularly
Staying hydrated
Maintaining a healthy weight
Getting enough sleep
Reducing stress
Drinking alcohol in moderation
Not smoking
