We hear a lot about what to eat and what not to eat — but some foods are worse than others. And there are certain eating habits and foods that weaken your immune system altogether. While you may not want to deprive yourself completely of indulgences like chocolate and sugary snacks, it’s also best not to make sugar the key staple of your diet. After all, keeping your immune system in shape, so to speak, helps keep you healthy and protect you from illnesses. While other factors come into play, too — like lifestyle, including exercise, your sleep patterns, and work-life balance — what you eat plays a big role when it comes to keeping your immune system functioning well.
“Studies have shown that without healthy eating patterns, our overall health is at risk,” Crystal Zabka-Belsky, resident dietitian at Clean Eatz Kitchen, tells TZR in an email. “Physically, our bodies are more likely to see an early onset of aging and an increased risk of chronic disease comorbidities. Meaning, we may be fighting conditions like heart disease, diabetes, and obesity all simultaneously with weakened immunity in tow.” And your immune system affects your mental health, too. “Mentally, we are at a greater risk for anxiety, depression, and emotional eating tendencies if healthy nutritional patterns are not established,” she adds.
Zabka-Belsky shares that healthy eating habits include consistency, balance, and variety. “Consistent meal and snack times — combined with portion control — teaches the body to have healthy boundaries with food,” she explains. “Balance among food groups will promote macronutrient levels that make sense for weight management. Incorporating a variety of foods from each food group will increase our ability to achieve intake of a broad range of vitamins, minerals, and antioxidants.” Ahead, Zabka-Belsky and other experts advise what not to eat too much of in order to keep your immune system in check.
Consuming Too Much Sugar
Dr. Daryl Gioffre, celebrity nutritionist, founder of Alkamind, and author of Get Off Your Sugar and Get Off Your Acid, says that sugar is a big factor when it comes to weakening the immune system. “Sugar is one of the most acidic substances you can put in your body, and the average person is eating 130 pounds of it every year,” he tells TZR in an email. “That equates to 38 teaspoons a day, and after 6 teaspoons, your body can’t metabolize it anymore. Over time, this will wreak havoc on your body, and weaken your immune system health.” In fact, within seconds of eating it, sugar literally paralyzes your immune system, he explains, and weakens the ability of your germ-fighting army for up to five hours. In addition, it can lead to other health problems, including type 2 diabetes and heart disease. “Dialing back sugar consumption is not only going to improve overall immune health, but it’s also one of the most effective ways to gain energy, lose weight, lower inflammation, and increase your longevity,” adds Gioffre. “Sugar also weakens our gut microbiome, which is where 80% of our immune system lives.” And speaking of gut health…
Neglecting Your Gut Health
“Neglecting your gut health can have massive impacts on your immune system, good and bad,” registered dietician Naria Le Mire tells TZR in an email. “The microbiome in your digestive tract has a unique relationship with your immune system. Your complex microbiome in your digestive tract can be impaired by the foods you eat, stress, and sleeping habits.” Specifically, diets low in fruits, vegetables, and whole grains — and high in refined carbohydrates and fat (specifically saturated and trans) — can weaken this system, resulting in chronic inflammation (which is what can cause harm) and an impaired immune system, she explains. Taking probiotics, in supplement form or naturally, is one way to help your gut stay healthy. She says, while healthy eating habits may vary from person to person, certain dietary habits can support a healthy lifestyle and prevent non-communicable chronic conditions, such as obesity, diabetes, and heart disease. “Having a variety of complex carbohydrates (whole grains, fruits/vegetables), healthy fats (fatty fish, olive/avocado oil), and protein (chicken, tempeh, turkey, fish, tofu) can support a healthy immune response via a strong microbiome,” Le Mire says.
She adds that healthy eating habits can dictate not only an individual's health status, but also their quality of life (short- and long-term). “Think about it: How do you feel when you're sick and have a fever? Not well, not even close,” says Le Mire. “A healthy lifestyle has more benefits than meets the eye. Respecting your body (AKA machine) and fueling it to be strong can help it support you when you're at risk for becoming sick. As I always tell my clients, ‘Treat your body right and it'll treat you right back — it's a relationship.’” She recommends thinking about your body as a car and asking yourself: What do you typically do to ensure your car does not leave you on the side of the road? Perhaps you provide it with gas or charge (electric cars), oil changes, tune-ups, and so on. “Well, what happens when you avoid providing the fuel it needs and neglecting the services it requires,” she says. “Simple — it breaks down. Same with your body. It's a machine, and in order for it to help and protect you, you need to fuel it right. So honoring your gut health, practicing stress management techniques, and getting adequate sleep is a wonderful start.”
Not Eating Enough Fruits & Vegetables
As kids, we’re told to eat our fruits and vegetables — but, as adults, we don’t always listen to that. “Not getting enough fruit and vegetables in our diet is an eating habit that may weaken our immune system and is often overlooked,” nutritionist Tamarah Ulysse, who works at the EatWell Exchange, tells TZR in an email. “They carry a lot of our soluble fiber, antioxidants, vitamins, and minerals that help boost our immune system and aid in fighting infections efficiently. As adults, it is recommended that we consume 3 cups of vegetables and 2 ½ cups of fruit daily.” She adds that healthy eating habits are all about living a balanced lifestyle where we make choices that will allow us to nourish our bodies with nutrients that have health benefits and are enjoyable. “This healthful diet looks like adding different colors of fruit and vegetables on our plates, choosing more whole grain options, choosing leaner proteins and healthful fats, and fixing a more balanced plate when eating,” she says. “The consequences of not creating healthy eating habits are costly and, at times, can be life-threatening.”
Eating Too Much Salt
Zabka-Belsky points out that, as highlighted by the Harvard School of Public Health, overconsumption of highly processed foods often leads to weakened immunity. This includes high salt intake coupled with low fiber, vitamin, and mineral intake. “High salt intake contributes to an increased risk for high blood pressure, heart disease, and stroke,” she says. Ulysse seconds that. “If you're not properly managing high blood pressure, this can lead to atherosclerosis, which is a disease caused by the hardening and thickening of the arteries,” she says. This is where healthy eating habits come into play, she explains. “They’re important to have because the choices we make with our diet eventually lead to the habits we create that'll help fuel our bodies and properly maintain our systems,” she says. “A healthy habit that can allow your body to maintain a stable blood pressure is choosing foods low in sodium and being mindful of how much salt is being used when cooking.”
Drinking Too Much Alcohol
Ryan Andrews, registered dietician and principal nutritionist and adviser at Precision Nutrition, says that moderate and heavy alcohol consumption is associated with a lowered immune response. “Alcohol can cause disruptions in immune pathways that can impair the body's ability to defend against infection,” he tells TZR in an email. And many people may not know they are drinking in excess. According to the Centers for Disease Control and Prevention (CDC), binge drinking is defined as 4 or more drinks for males and 5 or more drinks for females. With the sober curious movement gaining more and more popularity, it’s easier than ever to go alcohol-free, or at least cut down or abstain for a while. “However, no magical superfood, supplement, diet plan, or exercise routine can ensure you’ll stay healthy,” says Andrews. “When it comes to your immune system, your daily actions can make a meaningful difference. By consistently practicing healthy behaviors, you can reduce your exposure and susceptibility, help optimize your immune function over time, and better prepare your body to fight off foreign invaders.”