10 nutritional myths that experts question – 01/25/2023 – Equilíbrio

Soy milk may increase the risk of breast cancer. Fat-free foods are healthier than high-fat foods. Vegans and vegetarians are protein deficient. Some misconceptions about nutrition seem to linger like those terrible songs you can’t get out of your head.

So, to set the record straight, we asked 10 of America’s top nutrition experts a simple question: What nutrition myth would you like to see disappear, and why? Here’s what they said.

Fresh fruits and vegetables are always better than canned, frozen or dried

Despite the long-held belief that “fresh is best,” research has found that frozen, canned, and dried fruits and vegetables can be just as nutritious as their fresh counterparts.

“They can also be a money saver and an easy way to make sure there are always fruits and vegetables available at home,” says Sara Bleich, outgoing director of nutrition security and health equity at the U.S. Department of Agriculture and professor of policy. in public health at the TH Chan School of Public Health at Harvard.

One caveat: Some canned, frozen and dried varieties contain sneaky ingredients like added sugars, saturated fats and sodium, Bleich said. So read nutrition labels and opt for products that contain as few of these ingredients as possible.

all fat is bad

When studies published in the late 1940s found correlations between high-fat diets and high cholesterol levels, experts reasoned that if you reduced the amount of total fat in your diet, your risk of heart disease would decrease.

In the 1980s, doctors, federal health experts, the food industry, and the media reported that a low-fat diet could benefit everyone, yet there was no solid evidence that it would prevent problems like heart disease or overweight and obesity.

Vijaya Surampudi, an assistant professor of medicine at the University of California, Los Angeles, says that as a result, the vilification of fats has led many people and food manufacturers to replace calories from fat with calories from refined carbohydrates such as white flour and sugar. added.

“Instead of helping the country stay thin, overweight and obesity rates have increased significantly,” he points out.

In reality, Suampudi added, not all fats are bad. While certain types of fats, including saturated and trans fats, can increase your risk of heart disease or stroke, healthy fats – such as monounsaturated fats (found in olive and other vegetable oils, avocados and certain nuts and seeds) and polyunsaturated fats (found in sunflower and other vegetable oils, nuts, fish and flaxseeds) – actually help to reduce the risk.

Good fats are also important for providing us with energy, producing hormones, supporting cell function and aiding in the absorption of some nutrients.

If you see a product labeled “fat-free,” don’t automatically assume it’s healthy, says Surampudi. Instead, prioritize products with simple ingredients and no added sugars.

Caloric deficit is the most important factor to lose weight

It’s true that if you consume more calories than you expend, you’ll likely gain weight. And if you burn more calories than you consume, you’ll likely lose weight – at least in the short term.

But research does not indicate that eating more will consistently cause weight gain, and that this will result in being overweight or obese.

“Rather, it’s the types of foods we eat that may be the long-term drivers” of these conditions, points out Dariush Mozaffarian, professor of nutrition and medicine at Tufts University’s Friedman School of Nutritional Sciences and Policy.

Ultra-processed foods – such as refined starchy snacks, cereals, cookies, energy bars, baked goods, soft drinks and candy – can be especially detrimental to weight gain, as they are digested quickly and flood the bloodstream with glucose, fructose and amino acids, which are converted into fat by the liver. Instead, what it takes to maintain a healthy weight is to stop counting calories and prioritize overall healthy eating – quality over quantity.

People with type 2 diabetes should not eat fruit

This myth stems from confusing fruit juices — which can spike blood sugar levels due to their high sugar and low fiber content — with whole fruit.

But science has found that this is not the case. Some studies show, for example, that people who consume one serving of whole fruit a day — particularly blueberries, grapes and apples — have a lower risk of developing type 2 diabetes. And other research suggests that if you already have type 2 diabetes, eating fruit Whole grains can help control blood sugar.

It’s time to bust that myth, says Linda Shiue, internist and director of culinary medicine and lifestyle medicine at Kaiser Permanente San Francisco, adding that everyone can benefit from the health-promoting nutrients in fruits like fiber, vitamins, minerals and antioxidants.

Plant milk is healthier than animal milk

There is a perception that plant-based milks, such as those made from oats, almonds, rice and hemp, are more nutritious than cow’s milk. “It’s just not true,” says Kathleen Merrigan, a professor of sustainable food systems at Arizona State University and a former US deputy secretary of agriculture.

Consider the protein: Cow’s milk typically has around 8 grams of protein per cup, while almond milk typically has around 1 to 2 grams per cup, and oat milk typically has 2 to 3 grams per cup. While the nutrition of plant-based beverages can vary, Merrigan says, many have more added ingredients, like sodium and sugars, that can contribute to health issues, than cow’s milk.

potatoes are bad

Potatoes are often maligned in the nutritional community because of their high glycemic index, meaning they contain fast-digesting carbohydrates that can spike blood sugar.

However, potatoes can be beneficial to your health, says Daphene Altema-Johnson, food communities and public health program officer at the Center for a Liveable Future at Johns Hopkins University.

They are rich in vitamin C, potassium, fiber and other nutrients, especially when eaten with the skin. They are also inexpensive and available year-round in supermarkets, making them more affordable. Healthier preparation methods include baking, grilling, boiling and air frying.

Do not give almonds to your children in the first years of life

For years, experts have told new parents that the best way to keep their children from developing food allergies is to not feed them common allergenic foods like peanuts or eggs during the first few years of life. But now, according to allergy experts, it’s best to introduce your child to peanut products at an early age.

If your baby doesn’t have severe eczema or a known food allergy, you can start introducing peanut products (such as diluted peanut butter, peanut puffs, or peanut powder, but not whole peanuts) at around 4 to 6 months, when your baby is ready for solids.

Start with two teaspoons of peanut butter mixed with water, breast milk, or infant formula two to three times a week, says Ruchi Gupta, professor of pediatrics and director of the Food Allergy and Asthma Research Center at the Feinberg School of Medicine. from Northwestern University.

If your baby has severe eczema, first ask your pediatrician or an allergist about consuming peanut products around 4 months. “It’s also important to feed your baby a diverse diet in their first year of life to avoid food allergies,” Gupta points out.

Plant protein is incomplete

“‘Where do you get your protein?’ is the first question vegetarians hear,” says Christopher Gardner, a nutrition scientist and professor of medicine at Stanford University. “The myth is that plants are completely lacking in certain amino acids,” also known as the building blocks of protein, he said.

All plant-based foods, however, contain all 20 amino acids, including the nine essential amino acids, says Gardner. The difference is that the ratio of these amino acids is not as ideal as the ratio in animal foods.

So, to get a proper mix, just eat a variety of plant-based foods throughout the day – like beans, grains, and nuts – and thus get enough total protein. Fortunately, most Americans eat more than they need each day. “It’s easier than most people think,” says Gardner.

Eating soy foods increases the risk of breast cancer

They found that high doses of plant estrogens in soy, called isoflavones, stimulated the growth of breast tumor cells in animal studies. “However, this relationship has not been proven in human studies,” points out Frank B. Hu, professor and chairman of the department of nutrition at Harvard’s TH Chan School of Public Health.

So far, science has not indicated a link between soy intake and breast cancer risk in humans. Instead, consuming grain-based foods and beverages – such as tofu, tempeh, edamame, miso and their milk – may even have a protective effect regarding disease risk and survival.

“Soy foods are also powerful in beneficial nutrients related to reducing the risk of heart disease, such as high-quality protein, fiber, vitamins and minerals,” says Hu. The research is clear: feel confident incorporating soy foods into your diet.

Fundamental nutrition advice is always changing

That’s not the case, says Marion Nestle, professor emeritus of nutrition, food studies and public health at New York University.

“In the 1950s, early dietary recommendations for preventing obesity, type 2 diabetes, heart disease and the like advised balancing calories and minimizing foods high in saturated fat, salt and sugar. Current US Dietary Guidelines recommend the same” , she says.

Yes, science evolves, but the basic dietary guidance remains consistent.

As author Michael Pollan summed it up in six simple words: “Eat food. Not too much. Mostly plants.” That advice worked 70 years ago and it still works today, says Nestle. And the recommendation leaves plenty of room to eat the foods you love.

Translated by Luiz Roberto M. Gonçalves