How to use healthy foods to boost your immune system
Want to fight off infectious diseases this winter? Consider boosting your immune system with nutritious food.
"What we eat is very important in terms of how our immune system responds to pathogens and how well it can defend itself against a pathogen," said Dr. Simin Meydani, senior scientist and leader of the nutritional immunology team at Tufts University's Jean Mayer USDA Human Nutrition Research Center on Aging.
Micronutrients such as vitamin C, vitamin D, vitamin B complex, zinc and selenium can help "pump up" the body's defenses against colds, flu and even Covid-19, Meydani said, but you won't boost immunity by "eating a large amount of one single nutrient or food component."
Forget focusing on "superfoods." A large variety of foods are needed to provide the micronutrients the body needs to mount a robust cellular immune response, said Stanford School of Medicine nutrition scientist Christopher Gardner.
"There isn't any one food or nutrient to rely on here, but rather it is the interplay of 'harmonious interactions' between the various micronutrients," Gardner said.
Plan your daily menus around a large variety of fresh and colorful red, yellow, orange, blue and green fruits and vegetables, along with some high-quality whole grains, a bit of lean protein and a splash of healthy oils.
Plants and grains are also the basis of the top-rated Mediterranean diet and DASH diet, which stands for "dietary approaches to stop hypertension," or high blood pressure. Both the Mediterranean and DASH diets avoid processed foods and focus on fruits, vegetables, beans, lentils, whole grains, nuts and seeds.
The Mediterranean diet can reduce the risk for high cholesterol, dementia, memory loss, depression and breast cancer, numerous studies found. Meals from the sunny Mediterranean region have also been linked to stronger bones, a healthier heart and longer life. Oh, and it helps with weight loss, too.
In addition to eating well, it's important to stay at a healthy weight, reduce your stress, get quality sleep and regular exercise to keep those natural defenses in fighting shape. Without that healthy baseline, your body will have to work harder to knock out invaders -- and may even lose the match.
If you want to maximize the impact of food on your immune system, you'll need to dramatically increase the amount of fruits and vegetables you eat each day, Meydani advised.
Finding ways to insert fruits and veggies into every meal and snack during the day may do more than pump up your immunity. A 2017 study found a significant reduction in the risk of heart attack, stroke, cancer and early death by eating 10 portions of fruit and vegetables each day.
One in 5 deaths globally -- that's about 11 million people -- occurred because of too much sodium and a lack of whole grains, fruit, nuts and seeds, a 2017 study found.
Eating a lot of unhealthy, "ultraprocessed" foods like ice cream, cookies and pre-made consumer foods may shorten your life -- just a 10% increase in such foods was significantly associated with a 14% higher risk of death from all causes, studies have shown.
Instead, choose leafy greens, tomatoes, fruits, nuts, fatty fish and olive oil -- foods that can support a healthy inflammatory response without sending it into overdrive.
Studies are also finding that fermented foods such as kimchi, sauerkraut or kombucha may also help battle some types of inflammation by improving the microbiome in the digestive system.