You already know many of the negative effects of sugar on your mind and body. Unfortunately, sugar may also affect your immune system. Being sick is never fun, and your immune system is your body’s way of protecting you from disease, but you must take proper care of it. Many people exercise, eat well, and get quality sleep just to support their immune system and prevent illness. Unfortunately, all this hard work can be undone by poor lifestyle choices, like consuming too much sugar.

Eating too much sugar can affect your immune system, but how much it affects it is still up for debate. So, let’s discuss more in-depth how sugar affects your immune system.

Food affects your health, but sugar may be more sinister than other types of food. Sugar consumption is a factor in obesity, diabetes, and heart disease. However, it also affects your body’s ability to fight infections. White blood cells that fight these infections are affected by sugar, which impedes their ability to effectively destroy harmful viruses and bacteria.

But how much sugar do you have to consume to weaken your immunity? It takes only about 75 grams of sugar to weaken your immune system. For comparison, there are about 39 grams of sugar in a can of soda, so it takes fewer than two cans of soda to weaken your immune response. However, immunity is lowered for a few hours once the white blood cells are impacted. What this means is all the hard work you do to boost your immunity, like taking vitamins, cross-training, and committing enough time to quality sleep, can go to waste if you’re consuming too much sugar.

Of course, the effects are temporary, so if you’re not eating massive amounts of sugar daily, you likely don’t have to worry about your body’s ability to fight infection. However, if you consume a lot of sugar every day, you will have a weakened immunity until your body flushes the sugar and you eat a more healthy and balanced diet.

Is Sugar Bad for Your Health?

Sugar isn’t necessarily bad for your health, although consuming excess sugar can be. The effects of too much sugar on the immune system depend on many factors, including whether the person is already sick with a virus. Ultimately, everything you eat affects your health in some way, but the quantities, not just the type of food, can also have an impact.

You might be told not to eat when you’re sick, especially if you have a fever. However, if you have a cold, you might be told to eat to improve your immunity, so advice out there has been a little confusing over the years. However, fasting can help reduce fevers by preventing inflammation caused by excess sugar consumption. Eating less sugar when you’re sick can help you feel better faster because you’re reducing inflammation in the body by eating healthier foods that fight inflammation rather than cause it.

That being said, the type of sickness also matters when deciding whether or not sugar can be beneficial for you. For example, sugar can help fight viruses but can feed bacterial inflammation, worsening it and causing further sickness. Therefore, it’s mostly a balancing act.

Sugar isn’t necessarily bad for you as it’s not necessarily an immunosuppressant because it depends on the type of infection. But, of course, too much of anything can be a bad thing, so moderation is key.

Fructose is a sugar that’s used in processed foods and is easily broken down when consumed in small amounts. However, high doses of fructose can cause liver damage. Therefore, this type of sugar is not necessarily bad, but overconsumption of it is. Additionally, someone’s ability to break down sugar differs from another’s and is largely influenced by genetics, determining how well someone can tolerate sugar.

What About Sugar Substitutes?

Artificial sweeteners don’t contain sugar and were developed as a “healthy” alternative because they’re calorie-free. However, artificial sweeteners can still alter gut microbiota, creating a glucose intolerance that can affect your health and lead to inflammation. But what is inflammation?

Inflammation is your body’s natural response when white blood cells begin fighting infection from bacteria and viruses. While inflammation is good because it means your body is fighting infection, it can also cause a variety of illnesses and health disorders, including arthritis, diabetes, and mental illness. Therefore, you want to avoid inflammation altogether by consuming healthy foods that fight inflammation or at least don’t cause it.

Sugar and Hormones

While sugar has some immediate effects on immunity, there are also long-term effects. For example, insulin normalizes blood sugar levels, but if you eat large amounts of sugar over time, your body will stop signaling the release of the hormone, causing blood sugar issues. In addition, insulin resistance leads to type 2 diabetes, which directly affects the immune system.

Sugar and Stress

Sugar can impact your emotional health because insulin may overcompensate, pushing your blood sugar levels too low and causing fatigue, irritability, mood swings, and brain fog. It may also elevate your cortisol levels by affecting the adrenal glands, leading to unhealthy weight gain.

Final Thoughts

Sugar is neither good nor bad; it depends on your behavior. Consuming sugar in moderation shouldn’t cause long-lasting damage to your health and wellness. However, eating too much sugar can contribute to a host of health problems that weaken your immunity and cause other effects. For example, eating too much sugar contributes to weight gain and obesity, leading to diabetes and a weakened immune system. At the very least, sugar can cause inflammation and a lower functioning immune system for at least a few hours, so avoiding processed foods and only eating sugar from healthy sources like fruits and vegetables can help you stay healthy.

Additionally, sugar isn’t the only factor to consider when it comes to your immune system. While it can contribute to health problems, your diet is only part of the equation; you must continue to make healthy choices throughout your life and be aware of any history of illness within your family.

Author Bio

Megan Isola holds a Bachelor of Science in Hospitality and a minor in Business Marketing from Cal State University Chico. She enjoys going to concerts, trying new restaurants, and hanging out with friends.


Just 1 in 10 adults meet the federal fruit or vegetable recommendations, according to a study published in CDC’s Morbidity and Mortality Weekly Report (MMWR). This report highlights that very few Americans eat the recommended amount of fruits and vegetables every day, putting them at risk for chronic diseases.

Studies have shown that supplementation with extracts from fruits and vegetables may improve age-related changes.

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