Winter is the time of the year when most of us remember about the healthy foods and in particular those that boost the immune system. It’s certainly the case with us and during the last week or so we’ve been researching the topic, going through massive amount of sources and publications. Why is that all of a sudden, you may ask. Well, like most of you probably, we didn’t think much about that during the festive period – we felt good, enthusiastic, strong and hey… almost almighty. With the New Year’s resolutions made (e.g. losing weight, getting in shape, eating healthier, etc.), the last thing you want is an annoying sickness.
We are not fans of vaccines and all other medicines, on one hand, and firmly believe that prevention is better than cure, on the other. So the first thing we thought about was how to boost our immune systems by consuming certain foods that will help us keep the cold and flu away.
The compilation below is somewhat lengthy (you’ve been warned) and there will be things that you may already know, so feel free to jump to the next section. However you can discover many new and interesting facts – I’ve learnt so much new terminology that I feel I can impress any nutritionist or dietitian. I am also now much more prepared, taking on the task of boosting my immune system. As our regular readers know, we are not nutritional experts, but we are good at researching, especially when it comes to topics that are of great interest to us. So we thought, what’s interesting to us, might be interesting to you, too. Bottom line is (from our point of view) all the products we listed below are easily available and affordable, not difficult to include in any menu, and most importantly, these are the ones we’ll be giving priority to, this season.
Red salmon or Foods rich in vitamin D
Vitamin D (or as many people like to call it – “the sunshine vitamin”) is in fact a hormone which the human body produces following an exposure to the sun. It’s provides the activation key that stimulates into action our T cells (or T-lymphocytes, as they’re officially called, belonging to a group of white blood cells). They play a central role in cell-mediated immunity. And before it gets too complicated we’ll finish by saying that when invaders in our body are detected, we definitely want our T cells to be active.
Ideally, the sufficient intake of vitamin D should come from the combination of the sun rays and a diet high in the sunshine vitamin. But during the winter the angle of the sun is too low, and we, by default, need more vitamin D to avoid catching colds and flu. So it makes sense to help your body by sourcing it from the food we eat.
Foods that are rich in this nutrient are: sardines, mackerel, herring, tuna, salmon, liver, milk and soy milk. Red salmon, also called sockeye salmon or blue-back salmon, is said to be among the best sources of vitamin D. Roasting, poaching or steaming, works better than frying, deep-frying, and sautéing, as the fish maintained the most of the vitamin D, contained in it.
Canned tuna, herring and sardines also have relatively high (although lower compared to fresh) levels of vitamin D. Should you need to choose between oil packed or water (brine) packed, opt for the one in oil, because the oil helps the retention of omega-3s and vitamin D. You have to use the whole can (both, fish and oil) because being a fat-soluble, the vitamin D will be in the oil. Using both is not difficult – use in pasta dishes or salads, and even in pies and pizzas.
One last thing you need to keep in mind, if you want to boost your immunity with vitamin D – alcohol robs it from your liver, so you should try cutting back, at least during the winter months.
Chillie or Foods rich in vitamin C
Vitamin C has antiviral qualities and stimulates antibody production. It increases the number of infection-fighting white blood cells and stimulates the production of interferon, which provides a protective coating to the surface of cells, which in turn, prevents penetration of viruses.
Unlike the fat-soluble vitamins (A, D, E) vitamin C is water- soluble, and that means it doesn’t get stored much in your body, which is good for you (you can’t overdose) but needs to be replaced on a daily basis.
We all know citrus fruits are a great source of vitamin C, however there are other, not so obvious foods, containing it as well. Peppers and chillies (one of my favourite sources) - particularly Serranos, Jalapeños, and Poblanos; berries – especially blackcurrants and rose hips. Then come the spring greens – curly kale, brussel sprouds, broccoli, but also tomatoes, kiwi and mango, and even, believe it or not, potatoes.
We have to add to this list the Cayenne pepper too – it is rich in vitamin C, but also high in vitamin A, B6 and E, and riboflavin, potassium and manganese, or in other words, it’s a real treasure! Cayenne (a.k.a. Guinea spice, Cow Horn Pepper, aleva or bird pepper), also known as red pepper (in its dry form) is famous for its wonders in the circulatory system. It boosts circulation and helps delivering fresh blood, oxygen and nutrients to the heart and other organs in the body. It also provides relief from coughs, sore throats, inflammatory joint conditions, and lessens pain. The cayenne pepper has to be my biggest discovery coming out of this research!
Sweet potatoes or Foods rich in Betacarotene and Vitamin A
Betacarotene has the capacity to convert into vitamin A in the body, which is essential to a number of immune system functions. Carrots, sweet potatoes, pumpkin, squash, spinach and cantaloupe (melon) are very good sources of vitamin A. Carrots and sweet potatoes increase your body’s production of T-cells and natural killer cells (or NK cells), and their role is the rejection of tumors and cells infected by viruses.
Yogurt or Foods with Live Active Cultures
Of course, we all know probiotics (the live bacteria) are beneficial to us, when eaten in an adequate amount.
The most popular types are the lactic acid bacteria and bifidobacteria, which we normally consume as part of fermented foods like yogurt or kefir (also available in pill form). Some studies suggest probiotics may reduce cold and flu symptoms.
But talking probiotics we are talking hundreds of different strains of bacteria, microbes and yeasts, which are offering a variety of potential health benefits. And it is hard to understand which type exactly can help you fight the flu. We still believe there are general health benefits of eating variety of traditionally-fermented foods like yogurt, kefir, kim-chi, kombucha, sauerkraut, and miso, providing this way a wider variety of bacterial strains, and thus offering a wider range of benefits.
Just check for a sign “live and active bacteria” when buying yogurt or kefir, and if available, choose one with as many different strains of cultures as possible.
Capers or Foods rich in Quercetin
Quercetin is one of many thousands of flavonoids – substances that are responsible for plants’ colors, as well as many of their health benefits. Quercetin is a powerful antioxidant, and it is also a natural antihistamine (medicines treating allergies and hypersensitive reactions and colds), and anti-inflammatory. To load up on quercetin-packed produce, include in your menu capers, lovage, apples, red onions, and broccoli, and also black and green tea. Surprising (for me) tomatoes too, contain quercetine, but (as with many other products) consider choosing organic: a recent study found that organically grown tomatoes had 79% more quercetin than conventionally grown ones.
Green tea or Foods rich in catechins
Catechins are a group of antioxidants, believed to keep arteries flexible, increase small vessel circulation, reduce blood pressure and protect against sunburns.
Antioxidants help you keeping your immune system strong, making it easier to avoid colds, flu, and other infections. In this group of foods green tea have the longest list of scientifically proven health benefits, but if you’ve had enough of it (or don’t like it) there is a good news – other sources of catechins are cocoa beans (and chocolate) and red wine!
We were most impressed by the following: Norman Hollenberg, professor of medicine at Harvard Medical School, studied the Kuna people in Panama, who drink up to 40 cups of cocoa a week, and found that the epicatechin that cocoa contains reduces the risk of four of the major health problems: stroke, heart failure, cancer and diabetes. In fact, he believes that epicatechin should be considered essential to the diet and thus classed as a vitamin.
Ginger, garlic, turmeric and horseradish
These products are among the best known, benefiting our health. Probably nothing new for you in this section but we felt our list will not be complete without these essential immune boosters.
Garlic: it’s actually hard to find a disease or condition garlic does not affect beneficially. It has been found to have antibacterial, antiviral, and anti-fungal activity, and it can also significantly boost your immune system.
Ginger: is also used to provide relief from joint pain and inflammation.
Turmeric: is a powerful medicine that has both antiviral and antioxidant properties to help you body fight off potential harmful viruses. It is also believed to help in the prevention of heart attacks, liver disorders, cancer and various medical problems.
Horseradish: since times immemorial it has been the product killing the bad and harmful bacteria. That’s why it became so popular when served with row food or undercooked food, such as beef or sushi (although the Japanese use their variety of horseradish – the wasabi). Today scientists have proved that horseradish is effective against infections, including urinary tract infections, bronchitis, sinus congestion and coughs.
Soups – especially Tom Yum and the old fashioned homemade chicken soup
We actually don’t know if the chicken soup really does all that wonders or whether it does actually possess any healing capabilities, or is its magic all in our heads. The New York Times reviewed various studies in 2007 and concluded that “none of the research is conclusive, and it’s not known whether the changes measured in the laboratory really have a meaningful effect on people with cold symptoms. However, we still like a real, homemade chicken soup, cooked with the bones (preferably using free range organic chicken). It’s just so delicious and heartwarming, that we choose to believe it’s healthy, too.
As for the famous Thai soup the things don’t seem any clearer – Tom Yum Soup has been under various scientific studies because of its belief to have immune-boosting powers to help with cold and flu viruses, but till now nothing is clearly proven. Still, it is possible that the magic soup is “100 times more effective in inhibiting cancerous tumor growth than other foods”. Well, there are thousands different recipes for Tom Yum and we don’t know the exact recipe scientists did base their studies on, so…
I guess you have to stick to your favorite type. The basic broth is made of stock and many fresh ingredients like lemon grass, garlic, lime juice, shitake mushrooms, peppers and crushed chillies are added. You than choose between chicken, prawns or fish to give it the final taste. Or, you can try our Tom Yum Soup.
NB! People with immunity problems, such as thyroiditis, rheumatoid arthritis, lupus, and celiac disease, should talk to their doctors before upping their intake of immunity-boosting foods, because your immune systems are already overstimulated.