Coffee
Coffee is a morning ritual for millions, but its high caffeine content acts as a diuretic, increasing urine production and potentially contributing to dehydration. According to a 2023 review in the journal Nutrients, consuming more than 250 mg of caffeine (about two or three cups of coffee) can noticeably increase fluid loss in sensitive individuals. For those with autoimmune diseases like lupus or rheumatoid arthritis, this loss of hydration can worsen symptoms such as fatigue, joint pain, and headaches. During a flare, your body is already under stress, and dehydration can make inflammatory processes even worse. The Mayo Clinic also highlights that caffeine can interfere with medications commonly prescribed for autoimmune conditions, further complicating management. Many people might feel an initial energy boost, but the crash afterward can feel even harsher during an autoimmune flare. Relying on coffee to “get through the day” may actually make things harder on your immune system.
Energy Drinks
Energy drinks have soared in popularity, but research from the American Heart Association in 2024 shows that their combination of caffeine, sugar, and other stimulants can pose real risks. These beverages can severely dehydrate you, especially if you’re experiencing an autoimmune flare. The high levels of caffeine and taurine in many brands act as strong diuretics, leading to increased water loss. A study published in Frontiers in Public Health in 2023 found that energy drinks can raise blood pressure and heart rate, further straining the body’s systems. For people with autoimmune issues, this stress can worsen inflammation and trigger additional symptoms. Even sugar-free versions aren’t much better—artificial sweeteners and additives can irritate your gut and affect hydration. So, while energy drinks promise quick relief from fatigue, they bring a hidden cost for anyone battling autoimmune problems.
Soda
Soda, whether regular or diet, is a sneaky culprit when it comes to dehydration. The Centers for Disease Control and Prevention (CDC) notes that the high sugar content in regular sodas can draw water out of your cells, leaving you more dehydrated. Diet sodas, on the other hand, are packed with artificial sweeteners that can upset gut flora, which is a big concern for autoimmune patients according to a 2024 report from the Autoimmune Association. Both types often contain caffeine, compounding the diuretic effect. The fizz and flavor may be tempting, but the risk of worsening inflammation and fatigue is real. Many autoimmune specialists now recommend avoiding soda entirely during flares to help manage symptoms. Even a single can per day has been linked to increased markers of dehydration in people with chronic illness.
Alcohol
Alcohol is widely recognized as one of the most dehydrating beverages, and the effect is even more pronounced during autoimmune flares. The National Institutes of Health (NIH) published findings in 2024 confirming that alcohol suppresses the release of vasopressin, a hormone that helps your body retain water. This leads to increased urination, which quickly drains your body of fluids. For those with autoimmune diseases, dehydration can make pain, swelling, and fatigue significantly worse. Alcohol can also disrupt sleep and immune function, compounding the challenges of a flare. Even a single glass of wine or beer can have noticeable effects, especially if your immune system is already overactive. Doctors now routinely advise patients with autoimmune conditions to avoid alcohol during active symptoms.
Black Tea
Black tea is often considered a gentler alternative to coffee, but it still contains significant amounts of caffeine—about 40-70 mg per cup, according to the USDA. This caffeine content can be enough to trigger dehydration, especially if you drink several cups throughout the day. A 2023 review in the journal Nutritional Neuroscience found that black tea consumption increased urine output and contributed to fluid imbalance in sensitive individuals. For people experiencing an autoimmune flare, this loss of hydration can lead to increased joint stiffness, headaches, and dry mucous membranes. Some black teas also contain tannins, which can interfere with the absorption of iron and other nutrients crucial for immune health. While the antioxidants in tea have health benefits, the risk of dehydration during a flare often outweighs the positives. Experts suggest limiting black tea during active phases of autoimmune disease.
Sports Drinks
Sports drinks are marketed as a solution for hydration, but their high sugar and sodium content can actually backfire for people with autoimmune flares. The Cleveland Clinic in 2024 reported that these drinks are only beneficial for high-intensity athletes who lose large amounts of electrolytes through sweat. For most people, especially those with autoimmune conditions, the sugar load can pull water from your cells and trigger inflammatory responses. Many sports drinks also contain artificial colors and flavors, which some studies link to gut irritation and immune dysfunction. A study in the Journal of Clinical Medicine in 2023 noted increased markers of dehydration in autoimmune patients who regularly consumed sports drinks. While the promise of quick energy is appealing, the hidden risks make these beverages a poor choice during flares. Water or electrolyte solutions without added sugars are a much safer bet.
Sweetened Iced Tea
Sweetened iced tea is a summertime favorite, but its sugar content is often sky-high—some bottles contain up to 40 grams per serving, according to the FDA. This sugar spike can quickly lead to dehydration, especially for those with autoimmune diseases. A 2024 study in the Journal of Autoimmunity found that excess sugar worsens inflammation and disrupts hydration in people with lupus and similar conditions. On top of that, many iced teas are brewed from black tea, adding a caffeine kick that further increases fluid loss. The combination of sugar and caffeine is a double whammy for anyone in the middle of an autoimmune flare. Even “light” versions with artificial sweeteners can cause gut irritation and make symptoms worse. Autoimmune specialists now warn patients to avoid sweetened iced tea when symptoms spike.
Flavored Waters With Artificial Sweeteners
Flavored waters seem like a smart alternative to soda, but those with artificial sweeteners can cause trouble during autoimmune flares. Research from Harvard Medical School in 2023 shows that some sweeteners—like sucralose and aspartame—may disrupt gut bacteria and increase markers of inflammation. This disturbance can interfere with hydration because a healthy gut helps regulate water balance in the body. Many flavored waters also contain sodium and preservatives, which can add up and contribute to dehydration if consumed regularly. While these drinks are marketed as “better for you,” autoimmune patients should be cautious. The hidden additives can make flares feel more intense, leading to headaches, joint pain, and digestive upset. Sticking with plain water or naturally infused options is a safer choice.
Pre-Mixed Cocktails
Pre-mixed cocktails are convenient but often loaded with sugar, artificial flavors, and preservatives. According to a 2024 consumer health report, many popular brands contain up to 30 grams of sugar per serving, which can rapidly dehydrate your body. These cocktails usually have a high alcohol content as well, doubling the risk of fluid loss. For individuals with autoimmune diseases, this combination can lead to severe dehydration, increased inflammation, and worsened symptoms. The preservatives and colorings can also act as irritants, making flares more difficult to manage. Even “skinny” or low-calorie versions aren’t immune from these effects, as they rely on artificial sweeteners and other additives. Autoimmune experts now recommend steering clear of pre-mixed cocktails during active flares to protect your hydration and overall health.
