Nutrition Archive

Articles

Zero weight loss from zero calorie drinks? Say it ain’t so

Trying to cut back on calories by drinking diet soda or flavored sparkling water may not help with weight loss, and some research suggest it may actually lead to weight gain. But why, and what are the alternatives?

Heavy metals in baby food? What parents should know and do

Worrisome levels of arsenic, lead, and other elements called heavy metals that can harm the developing brain are found in some commercial baby foods, according to a recent report. Here’s what parents should know and can do to protect young children.

"Green" Mediterranean diet: Better than the original?

Research we're watching

Widely considered the healthiest diet for your heart, the Mediterranean diet is rich in plant-based foods and features only small amounts of meat and dairy products. But a variation that includes more green plant foods may be even better for you, a small study suggests.

The study included 294 sedentary, moderately obese people whom researchers randomly divided into three groups. Each received different dietary advice: a standard healthy diet, a low-calorie Mediterranean diet, or a "green" Mediterranean diet. Both Mediterranean diet groups included about a quarter-cup of walnuts daily, and poultry and fish replaced beef and lamb.

A flavanol-rich diet may increase brain function

In the journals

Flavanols give fruits and vegetables their bright colors. They are also found in tea and cocoa. Observational studies have shown that eating foods rich in flavanols is linked with less cognitive decline as people age. New research suggests a possible reason why: flavanols appear to improve blood flow to the brain.

Researchers gave cocoa flavanols to 18 healthy adults in two separate trials. In one, the people consumed a cocoa drink with about 681 milligrams (mg) of flavanols. In the other, they had a cocoa drink with about 4 mg of flavanols. About two hours after having the cocoa drink, participants briefly inhaled air with high concentrations of carbon dioxide to raise their blood level above normal. (The brain's normal response to high blood carbon dioxide levels is to increase both blood flow to the brain and its uptake of oxygen.) The researchers then measured the speed of brain oxygenation and administered a set of mental tasks to assess cognitive performance. People had a faster brain oxygenation response after consuming high amounts of flavanols compared with lower amounts. They also scored higher on the cognitive tests and correctly solved problems 11% quicker.

Why junk food diets may raise heart disease risk

Hamburgers, fries, sugary sodas, and other less healthy foods may cause inflammation, a key player in the formation of artery-clogging plaque.

Eating foods such as red meat and sugary treats may trigger inflammation, raising your risk of cardiovascular disease. But a diet rich in fruits, vegetables, and other anti-inflammatory foods reduces the risk, according to a large Harvard study.

"These new findings help explain why certain foods we consider unhealthy may be contributing to plaque buildup inside arteries," says Dr. Kathryn Rexrode, associate professor of medicine at Harvard Medical School and a co-author of the study, published last year in the Journal of the American College of Cardiology. Inflammation is marked by the release of molecules called cytokines into the bloodstream. These attract immune cells to artery walls, contributing to the development of plaque, she explains.

Low fat, low carb, or Mediterranean: which diet is right for you?

Losing weight sometimes takes experimentation. If you give a diet your best shot and it doesn't work long term, maybe it wasn't the right one for you, your metabolism, or your situation. Genes, family, your environment — even your friends — influence how, why, what, and how much you eat, so don't get too discouraged or beat yourself up because a diet that "worked for everybody" didn't pay off for you. Try another, keeping in mind that almost any diet will help you shed pounds — at least for a short time.

Here's a look at three common diet approaches.

Why stress causes people to overeat

Stress eating can ruin your weight loss goals – the key is to find ways to relieve stress without overeating

There is much truth behind the phrase "stress eating." Stress, the hormones it unleashes, and the effects of high-fat, sugary "comfort foods" push people toward overeating. Researchers have linked weight gain to stress, and according to an American Psychological Association survey, about one-fourth of Americans rate their stress level as 8 or more on a 10-point scale.

In the short term, stress can shut down appetite. The nervous system sends messages to the adrenal glands atop the kidneys to pump out the hormone epinephrine (also known as adrenaline). Epinephrine helps trigger the body's fight-or-flight response, a revved-up physiological state that temporarily puts eating on hold.

Food and mood: Is there a connection?

Here's what the research says about diet and depression.


 Image: © ogichobanov; © Foxys_forest_manufacture/Getty Images

If you've ever found yourself in front of the TV after a bad day, mindlessly digging ice cream out of the container with a spoon, you know that mood and food are sometimes linked. But while stress eating is a verified phenomenon, the relationship between food and actual mood disorders, such as depression, is less clear. Or, to put it another way: can the things you eat influence your risk for depression — and can dietary changes potentially improve your mental health?

"The research regarding dietary factors and depression is still inconclusive," says Patricia Chocano-Bedoya, a visiting scientist in the Department of Nutrition at the Harvard T.H. Chan School of Public Health. But there have been hints that food may play a role in depression.

Can diet heal chronic pain?

The foods you eat (and don't) can determine how well your body fights painful inflammation.


 Image: © autumnhoverter/Getty Images

It's been said that you are what you eat, and that's definitely true when it comes to chronic pain.

"A lot of chronic pain is the result of chronic inflammation, and the evidence is quite strong that your diet can contribute to increased systemic inflammation," says Dr. Fred Tabung, a visiting researcher with the Department of Nutrition at Harvard's T.H. Chan School of Public Health. "But your diet is also one of the best ways to reduce it."

Precious metals and other important minerals for health

Make sure your diet meets the recommended mineral targets.


 Image: © fstop123/Getty Images

Gold, silver, and platinum get all the attention as the world's most precious metals. But they're more precious for the global economy than for human health. Instead, other metals and minerals (metals are one type of mineral) are more important for our health (see "What essential metals do for us"). Indeed, some of them are so important that we can't live without them. "Each one plays a role in hundreds of body functions. It may take just a very small quantity of a particular mineral, but having too much or too little can upset a delicate balance in the body," says Dr. Bruce Bistrian, chief of clinical nutrition at Beth Israel Deaconess Medical Center.

What essential metals do for us

Many metals are used to make strong and durable everyday objects, like copper pipes or iron skillets. But they don't form such strong and durable objects in our bodies. Instead, many essential metals are needed to activate enzymes — molecules with important jobs in the body. And metals have many other essential roles as well. For example:

  • Calcium builds bones and teeth; activates enzymes throughout the body; helps regulate blood pressure; and helps muscles to contract, nerves to send messages, and blood to clot.

  • Chromium helps maintain normal blood sugar levels and helps cells draw energy from blood sugar.

  • Copper assists with metabolizing fuel, making red blood cells, regulating neurotransmitters, and mopping up free radicals.

  • Iron helps make hemoglobin (the oxygen-carrying chemical in the body's red blood cells) and myoglobin (a protein in muscle cells). Iron is essential for activating certain enzymes and for making amino acids, collagen, neurotransmitters, and hormones.

  • Magnesium, like calcium, builds bones and teeth. It also helps to regulate blood pressure and blood sugar and enables muscles to contract, nerves to send messages, blood to clot, and enzymes to work.

  • Manganese helps form bones and helps metabolize amino acids, cholesterol, and carbohydrates.

  • Molybdenum activates several enzymes that break down toxins and prevents the buildup of harmful sulfites in the body.

  • Potassium balances fluids in the body, helps to maintain a steady heartbeat and to make muscles contract, and may benefit bones and blood pressure.

  • Sodium balances fluids in the body, helps send nerve impulses, and helps make muscles contract.

  • Zinc helps blood clot, helps make proteins and DNA, bolsters the immune system, and helps with wound healing and cell division.

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