Is Aluminum Foil Bad for You? It Depends

A roll of aluminum foil is a staple in many kitchens, useful for tasks like lining sheet pans and wrapping up leftovers. But aluminum is a metal, after all, and it gets up close and personal with your food. So...is aluminum foil bad for you?

Cooking with aluminum foil does bump up your exposure to the metal. And while most people handle it fine, too much aluminum can cause issues, especially for kids and those with certain medical conditions.

Ahead, we break down the possible risks of aluminum foil use, the safest ways to cook with it and alternatives for aluminum-free cooking.

Every time you cook with foil, a little bit of aluminum latches onto the food you eat. But this is only a small fraction of the aluminum you're exposed to every day.

While most of us don't realize it, aluminum is pretty much everywhere, as it appears naturally in the water you drink and the air you breathe. There's also aluminum in the food you eat, and it's added to some packaged foods as a preservative. In fact, the average American adult takes in about 7 to 9 mg of aluminum daily through food alone, according to the Centers for Disease Control and Prevention (CDC).

Just how much of the metal leaches into your food when you cook with aluminum foil depends on what you're making and how you're cooking it.

Acidic foods (like citrus or tomatoes), high heat and longer cooking times can increase aluminum transfer, says Jackie Newgent, RDN, a Los Angeles-based culinary nutritionist and chef. A September 2019 ‌Food Science & Nutrition‌ study even found that using foil boosted aluminum levels in some foods (like marinated fish) by up to 40 times.

But here's the thing: Even with that increase, most people aren't exposed to harmful levels. The amounts were still under the World Health Organization's tolerable weekly intake (2 mg per kg of body weight), Newgent says. And thanks to your body's efficient filtering system (thanks, kidneys), most aluminum exits your body through poop and pee, according to the CDC.

That said, kids and people with kidney disease should be cautious, Newgent says. Their bodies aren't as good at clearing aluminum, so even levels close to the safe limit might pose risks.

Cooking with aluminum foil is generally safe for most people, Newgent says. But factors like how much aluminum you're exposed to and for how long, your age and your overall health status can influence its effects. Those at higher risk — namely, young kids and people with kidney issues — may experience more side effects.

It's important to understand the potential health risks of cooking in aluminum foil and cooking in aluminum pans so you can make informed choices, she adds. Here's how excess aluminum could affect your health.

"Over the long-term, being exposed to high levels of aluminum may interfere with the absorption of calcium and iron," Newgent says.

Here's why this can cause a big problem: Calcium keeps your bones strong, muscles moving, nerves firing, blood flowing and hormones doing their job, while iron is essential for oxygen delivery to your body and muscles, hormone production and overall growth and development. Basically, these nutrients are crucial for very important bodily functions. So if you're not getting enough of each, your body simply won't work as well.

Similarly, too much aluminum can block a child's ability to absorb phosphate, a key compound for strong bones, says the CDC. Without enough phosphate, bone damage or disease could develop.

"People with kidney issues may not be able to properly filter out excess aluminum, causing it to accumulate," Newgent says.

When your kidneys can't properly flush out aluminum through your pee, it may also negatively affect other systems in your body, leading to bone or brain diseases down the line, per the CDC.

Children with kidney disease are especially vulnerable to aluminum's adverse effects.

Some studies suggest high aluminum intake might raise the risk of Alzheimer's, but others haven't found a clear connection, per the CDC. There's no direct link, but there's a possible risk, Newgent says.

Aluminum foil is affordable and convenient, and if it's been your go-to cooking tool, the idea of switching it up might have you hemming and hawing a bit (we hear you; change is hard!).

But if you have a kidney condition, cook for little ones or just want to roast your veggies with peace of mind, making a swap might be worth it. Fortunately, there are plenty of other options with similar price points that come with fewer health risks. Here are Newgent's top recs:

• ‌Parchment paper, especially unbleached parchment paper‌. "[This is] one of the best alternatives to aluminum foil," Newgent says. "It can be used at temperatures up to 450°F."
• ‌Silicone baking mats and food covers‌: Food-grade silicone is generally safe and can withstand the heat of high cooking temperatures.
• ‌Edible leaves‌: "If you're especially creative, try using edible leaves like corn husks, grape leaves or banana leaves to wrap foods for steaming or grilling," Newgent says. The bonus: Cooking with leaves lends more complex flavors to your food.
• ‌Glassware and porcelain cookware‌: Though a tad pricier, these tried-and-true cooking materials won't leach chemicals or other potentially toxic substances into your food.

As long as you're in good health, you probably don't need to forego the foil completely. By making a few tweaks to your cooking technique and taking simple precautions, you can greatly reduce your aluminum exposure. Here are Newgent's tips for safe cooking with foil:

• ‌Skip acids, extra salt, and spices.‌ They can interact with foil and cause more aluminum to leach into your food, Newgent says. Don't worry about flavor — just add them after cooking, she says.
• ‌Keep cooking length to a minimum and ideally stay below 400°F.‌ High heat and longer cooking times can increase the amount of aluminum that leaches into your food.
• ‌Consider a double wrap‌. "Wrap [food] in unbleached parchment paper, then in foil," Newgent says. This double-wrap method protects your food from direct exposure to aluminum.

Aluminum foil isn't necessarily bad for you. Cooking with aluminum likely doesn't expose you to more of the metal than your body can handle if you're a relatively healthy adult. But if you have kidney issues or cook for young children, it may be worth taking precautions when cooking with the foil and considering some aluminum alternatives.