Very few foods are truly off-limits while breastfeeding. The list of things you need to completely avoid is short: high-mercury fish, excessive alcohol, and any specific food your baby reacts to. Beyond that, most dietary advice for nursing parents is about moderation rather than elimination.
High-Mercury Fish to Avoid
Mercury accumulates in certain large, long-lived fish, and it does pass through breast milk. The FDA advises breastfeeding mothers to completely avoid seven types of fish with the highest mercury levels: king mackerel, marlin, orange roughy, shark, swordfish, Gulf of Mexico tilefish, and bigeye tuna.
That doesn’t mean you should skip seafood altogether. Fish is one of the best sources of omega-3 fatty acids, which support your baby’s brain development. The FDA recommends eating 8 to 12 ounces per week of lower-mercury options. Salmon, shrimp, cod, tilapia, catfish, sardines, and canned light tuna are all considered “best choices.” If you prefer halibut, mahi mahi, snapper, or albacore tuna, limit those to one serving per week since they fall into a moderate-mercury category.
Alcohol
Alcohol passes directly into breast milk at roughly the same concentration as your blood alcohol level. It peaks in your milk about 30 to 60 minutes after you drink. The standard guideline is to wait about 2 hours per standard drink before nursing. So one glass of wine means a 2-hour wait; two drinks means closer to 4 hours.
There’s no amount of alcohol that’s been proven safe for a nursing infant, so the safest option is not drinking at all. If you do choose to have a drink occasionally, timing it right after a feeding session gives your body the most time to clear the alcohol before the next one. Pumping and dumping doesn’t speed up the process. Alcohol leaves your milk as it leaves your blood, so the only thing that helps is time.
Caffeine in Moderation
You don’t need to give up coffee, but you do need to watch the amount. Most experts recommend staying under 200 to 300 milligrams of caffeine per day while breastfeeding. That’s roughly two to three standard cups of coffee, depending on how strong you brew it. A typical 8-ounce cup has about 95 milligrams; a large coffee shop pour can have 200 or more in a single serving.
Babies metabolize caffeine much more slowly than adults, so it can build up in their system. If your baby seems unusually fussy, jittery, or is having trouble sleeping, your caffeine intake is worth examining. Some infants are more sensitive than others. Signs of caffeine sensitivity include restlessness, difficulty settling down, shorter and more fragmented sleep, and sometimes colic-like episodes with extended crying, clenched fists, or back arching. If you notice these patterns, try cutting back and see if things improve over a few days.
Cow’s Milk and Common Allergens
Cow’s milk protein allergy is one of the most common food sensitivities in infants, and the proteins do pass through breast milk. If your baby has it, you may notice symptoms like bloody or mucousy stools, persistent diarrhea, hives, vomiting, or colic that doesn’t improve with typical soothing. Some reactions happen quickly, while others develop gradually over days or weeks, which can make them harder to connect to your diet.
If your pediatrician suspects a cow’s milk protein allergy, you’ll likely be asked to cut all dairy from your diet for two to four weeks to see if symptoms resolve. This means reading labels carefully, since milk proteins show up in unexpected places like bread, processed meats, and sauces. Other common allergens that can occasionally cause similar reactions include soy, eggs, wheat, peanuts, and tree nuts, but there’s no reason to preemptively eliminate any of these unless your baby is showing symptoms.
Gassy and Spicy Foods Are Usually Fine
This is one of the biggest areas of unnecessary worry. You’ve probably heard that broccoli, cabbage, beans, onions, garlic, and spicy foods will make your baby gassy or fussy. The evidence doesn’t support this. Research from Texas Children’s Hospital notes there are no specific foods that have been proven to cause gas in breastfed infants, and spicy foods have not been shown to cause discomfort either.
Some mothers do notice patterns with particular foods and their baby’s behavior, and those individual observations are worth paying attention to. But the mechanism isn’t what most people assume. Gas-producing foods create gas in your intestines through fiber fermentation. That gas doesn’t transfer into breast milk. What can transfer are certain proteins or compounds, which is why true allergens (like cow’s milk protein) cause problems but a plate of broccoli generally won’t. If you suspect a specific food is bothering your baby, try eliminating it for a week and reintroducing it to see if the pattern holds.
Herbs That Can Reduce Milk Supply
Sage and peppermint are the two most commonly cited herbs that can suppress milk production. In fact, sage and peppermint teas are sometimes deliberately used to help dry up milk during weaning, with recommendations of three to four mugs a day for that purpose. A single cup of peppermint tea or a garnish of fresh sage in a recipe is unlikely to tank your supply, but if you’re already struggling with low production, it’s worth being cautious with large or frequent amounts.
Parsley in large quantities (beyond what you’d use as a garnish) is another herb sometimes associated with reduced supply, though the evidence is mostly anecdotal. The key takeaway: normal culinary amounts of these herbs are generally fine, but concentrated supplements or therapeutic doses could make a difference.
Over-the-Counter Medications to Watch
This isn’t food, but it catches many breastfeeding parents off guard. Pseudoephedrine, the active ingredient in many oral decongestants, can reduce your milk supply. The NHS advises against taking it while breastfeeding when other options are available. If you’re dealing with a cold or sinus congestion, saline sprays or antihistamines that don’t contain pseudoephedrine are generally considered safer alternatives. Check the active ingredients on any cold and flu combination product, since pseudoephedrine is often bundled into multi-symptom formulas.
What You Should Be Eating More Of
Breastfeeding burns significant energy. The CDC recommends an additional 330 to 400 calories per day above your pre-pregnancy intake to support milk production and your own recovery. That’s roughly equivalent to an extra balanced snack or small meal. Skipping meals or heavily restricting calories can affect both your energy and your supply.
Focus on nutrient-dense foods rather than worrying about a long restriction list. Your body needs extra protein, calcium, iron, and fluids during this period. If your diet is varied and includes fruits, vegetables, whole grains, lean protein, and healthy fats, you’re covering the basics. A prenatal or postnatal vitamin can help fill gaps, particularly for nutrients like vitamin D and iodine that are harder to get from food alone.