Some nutritional standouts can be the opposite of healthy, with links to issues from depression to cancer.
You’ve always heard that it does a body good, but a new study from the British Medical Journal suggests otherwise. Researchers found that women who drank three cups or more daily had a 90% higher risk of death over a 20-year period than women who capped it at a cup per day. They also had an increased risk of bone fractures and higher levels of inflammation and oxidative stress, “a mechanism for premature aging, bone loss and muscle mass loss,” says Karl Michaëlsson, MD, PhD, a professor and researcher at Uppsala University in Sweden. “We definitely need calcium to build strong bones, but the amount needed is under debate,” Dr. Michaëlsson adds. The high sugar content in milk may offset its benefits after a certain amount.
It can be a perfect source of protein and heart-friendly omega-3 fatty acids. Some kinds, though, come from water contaminated with large amounts of heavy metals, especially mercury, which can cause hearing, vision and movement problems. To stay safe, opt for fish from the open sea versus small bodies of water–look for “wild caught” on the label versus “farmed,” and choose smaller varieties, since the biggies accumulate more chemicals. Buy fish and shrimp from the U.S., and avoid imported farm-raised fish–it is under-inspected and tends to have excessive chemical residues. In general, stick to the FDA’s lists: Salmon, shrimp, light canned tuna and tilapia are some of the lower-mercury seafoods, while shark, swordfish and king mackerel are the higher ones.
3. Brown Rice
It should be a smart choice, but researchers have connected some types of rice with increased arsenic in women. Rice soaks up arsenic from its soil, and it especially builds up in the outer bran of brown rice. “Exposure to high amounts of arsenic has been linked to increased risk of cancer and other diseases,” says Diane Gilbert-Diamond, ScD, a researcher and professor at Geisel School of Medicine at Dartmouth College in Hanover, NH. “We can’t give a suggested limit, but one key aspect of all healthy diets is variety,” which helps you get all the nutrients you need while limiting risks. Don’t slash the higher-nutrient brown variety altogether, but opt for lower-arsenic white rice most often, or go for other grains like buckwheat, barley or farro, which have very low levels.
This high-protein, low-fat favorite is a staple of healthy eating. Unfortunately, it can also be the source of a serious health risk: antibiotic resistance. Farmers commonly overuse antibiotics on poultry because they hope it can boost growth and prevent illness in animals living in cramped quarters. This is one reason why people are becoming more resistant to antibiotics. This means we have fewer treatment options when we get sick. Not to mention the treated poultry can also pass infections onto us–especially since they’re becoming resistant to antibiotics, too. So choose meat that is labeled as antibiotic-free.
5. Cooking Oil
Though some varieties offer healthy fats, a review published in June 2014 in Environmental Health found that they also have high levels of phthalates, chemicals known as “endocrine disruptors” that are associated with cancer and a range of other health problems. Phthalates are attracted to fat, so they may accumulate in fattier substances, says Sheela Sathyanarayana, MD, a researcher at the Seattle Children’s Research Institute in Washington. Go for the lower-fat oils, like canola and olive, over higher-fat ones, like palm and coconut. And opt for glass containers—plastic can be heavy on phthalates, too.
6. Fruit Drinks
Don’t be lured by the added vitamin C. According to a study published in PLoS ONE in April 2014, people who drank four or more cups of fruit punch per day had a 38% greater chance of developing depression over the next decade. Sweet drinks may lead to obesity, diabetes and overall poor health, which may contribute to developing depression. So go easy on these drinks, and choose ones sweetened with sugar rather than sugar substitutes, which up depression risk even more.
7. Spicy Foods
Fire-hot fare can improve circulation, decrease blood sugar and boost metabolism. Yet too much of this good thing can backfire, causing stomach pain in some people. Though it’s typically harmless–hot spices stimulate certain brain cells that trigger the sensation of pain–because they increase stomach acid, they can interfere with numerous medications. Note whether you have tummy troubles after noshing on the hot stuff, and talk to your doc about possible interactions if you take medication.
8. Cheap Tea
From preventing cancer to heart disease to dementia, tea seems to be a miracle drink. But a recent study suggests you may want to steer clear of lower-priced brands. They were found to have three times the amount of fluoride, which can cause dental and skeletal problems, as purer, more expensive blends like Assam, Darjeeling and oolong. Frequent tea drinkers should invest in the pricier varieties. “Reducing brewing time to 30 seconds will also decrease the amount of fluoride in the final tea beverage,” says Laura Chan, a researcher and professor at the University of Derby in the U.K.
Not only is this sea plant–with multiple varieties like nori and kelp–loaded with antioxidants, but it’s also a rare food-based source of iodine, which is essential to thyroid health. Therein lies the risk: People “should be careful to not take in too much iodine, since this can also result in thyroid dysfunction,” says Angela M. Leung, MD, a professor at the UCLA David Geffen School of Medicine in Los Angeles. Seaweed “may contain very high amounts of iodine, and thus those should not be consumed in excess,” she says. The recommended limit is 1,100 mcg daily.
10. Brazil Nuts
These mainstays of mixed-nut cans are another food to which “more is better” doesn’t apply. They’re super-high in selenium, an essential nutrient that helps regulate hormones and protect against infection. But eating just half a dozen can put you over the recommended daily max. Over time, a buildup of selenium can cause hair and nail loss, skin rash, weight loss, fatigue, irritability and nerve damage. Keep it to a few per day, or just eat them occasionally if you like to have more at a time.