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5 Essential Nutrients To Keep Your Immune System Strong

Photo by Brooke Lark on Unsplash

 

 

Article by Sally Shi-po POON (Registered Dietitian)

 

Lately, I have received many inquiries about food and nutrition related to the COVID-19/ Coronavirus pandemic. Put simply, there is no specific food or supplement will prevent you from catching COVID-19. Good personal hygiene practice, such as washing hands frequently and wearing surgical masks, remains one of the means of avoiding infection. In addition, the local government has urged the public to go out less and reduce social gatherings at this stage.

 

Maintaining a healthy lifestyle is the best step you can take toward naturally keeping your immune system strong and healthy. This can be achieved through regular exercise, adequate rest and a balanced diet. There are many nutrients that are involved with the normal functioning of the immune system such as these:

 

1.Vitamin A

Vitamin A is essential for normal vision and immune function. It also helps the lungs and other organs function properly. Food sources of vitamin A include liver, spinach, sweet potato, squash, carrots, cantaloupe, apricots, and mangos. Vitamin A is a fat-soluble vitamin so it is better absorbed when you eat it with healthy fats such as olive oil, nuts, and seeds.

2. Vitamin C

Vitamin C plays a key role in immune function. Consuming five varied servings of fruits and vegetables a day can help you achieve recommended amounts of vitamin C. Food sources of vitamin C include guava, kiwifruits, oranges, grapefruit, strawberries, bell peppers, broccoli, and tomatoes.

3. Vitamin E

Vitamin E acts as an antioxidant and our body needs vitamin E to maintain its immune system healthy. Vegetable oils (such as wheat germ, sunflower, and corn oils), nuts (like almonds and peanuts), seeds (such as sunflower seeds and sesame seeds), and avocado are excellent sources of vitamin E.

4. Zinc

Zinc plays an important role in immune function. Older people who have low levels of zinc might have a higher risk of getting pneumonia. Zinc is found in many foods and you can get recommended amounts of zinc by eating a variety of foods including oysters, crab, lobster, beef, pork, chicken, baked beans, cashews, pumpkin seeds, oatmeal, yogurt, and cheese.

5. Iron

Iron deficiency anaemia can impair immune function and make you less able to fight off germs and infections. You can get recommended amounts of iron by eating a variety of foods including red meat, seafood, poultry, iron-fortified breakfast cereals, lentils and legumes, spinach, nuts, and raisins. Your body absorbs iron from plant-based sources better when you eat it with foods that contain vitamin C, such as oranges, kiwifruit, and tomatoes.

 


Photo by S’well on Unsplash

Why A Colourful Diet Is Good For You

By Sally Shi-po POON (Registered Dietitian)

We’re always hearing that we should “eat the rainbow”, but what does that mean and why is a colourful diet so highly recommended by dietitians all over the world? Not only are they appealing, the phytochemicals that give foods their colour are packed with nutritional benefits. I have grouped the foods into 5 categories according to their predominant phytochemical group: red, orange, green, purple, and white.

 

1. Red

Lycopene is the predominant pigment in red fruits and vegetables such as tomatoes, watermelon and pink grapefruits. It is a powerful antioxidant that may help prevent prostate cancer and heart diseases. Lycopene is better absorbed when it is cooked with some oil, such as tomato sauce with olive oil.

 

Astaxanthin, which is found in the red pigment of crab, salmon and prawns, has been found to have antioxidant and anti-inflammatory effects. Its antioxidant activity was found to be 10 times more than zeaxanthin, lutein and beta-carotene.

 

2. Orange

Beta-carotene is a pigment found in yellow and orange fruits and vegetables, such as carrot, cantaloupe melon, mangoes, orange peppers, pumpkin, and sweet potatoes. In the body, beta-carotene converts into vitamin A, which is needed for good vision, a strong immune system, and healthy skin. Food processing and cooking help release beta-carotene from the food matrix and make it easier to absorb. Moreover, its absorption requires the presence of fat in a meal, such as canola oil, almonds, flaxseed or pumpkin seeds.

 

3. Green

Green cruciferous vegetables such as broccoli, cabbage, brussel sprouts, and kale are good sources of sulforaphane and glucosinolate, which have antioxidant and anti-inflammatory properties.  These vegetables also contain lutein and zeaxanthin, which may help protect eyes from sunlight damage and reduce the risk of cataracts and age-related macular degeneration. Lutein and zeaxanthin are better absorbed with fats, so be sure to eat the vegetables with some avocado, cheese, walnuts, sunflower seeds or olive oil. Green vegetables are also excellent sources of vitamin K and folic acid. Folic acid helps prevent neural tube defects during pregnancy, and vitamin K plays a major role in blood clotting.

 

4. Purple

Anthocyanins are pigments that appear purple or blue, which are found in eggplant (especially the skin), blueberries, blackberries, prunes, plums, black rice, purple sweet potato, and purple cauliflower. The darker the colour, the higher the anthocyanins concentration. Boiling vegetables can increase the loss of water-soluble nutrients such as anthocyanins and vitamin C, therefore baking and steaming are preferred as they can retain more of the nutrients, as well as the flavour and colour.

 

5. White

Anthoxanthins are the white or colourless pigments found in bananas, cauliflower, garlic, shallots, mushrooms, onions, parsnips, and turnips, which may help reduce the risk of heart disease.  Garlic contains allicin, which has antioxidant, anti-inflammatory, antimicrobial, and heart-protective properties. Allicin is produced when fresh garlic is finely chopped or crushed. Garlic provides an alternative to salt in cooking, along with other herbs and spices. Eating less salt is important for preventing high blood pressure, heart attacks and stroke.

 

Including a variety of colourful foods in your diet seems to equal better overall health.  Start planning some colourful recipes tonight and have a healthy start in 2018!

 

Sally’s Nutrition Blog @ Hong Kong Tatler:  https://hk.asiatatler.com/life/why-a-colourful-diet-is-good-for-you#page-1