Food research is always evolving.
One week we're told that coffee will help us live longer. The next, we're told to cut it out of our morning routine.
The same holds true for chocolate, alcohol, carbs and gluten. The list goes on.
Even so, a few things are generally universally accepted: Added sugar isn't great. And we need to watch our salt intake.
But how true are these long-held beliefs? Here's what recent research tells us.
With regards to sugar, a 10-month study published earlier this year by researchers at the University of California in San Francisco found a workplace ban on sugar-sweetened beverages led to a decrease in consumption in these type drinks, and also helped employees shed pounds.
“(Sugar) is one of the most empty-calorie foods," said Tonya Turner, the associate director of clinical services with the Weight Management Center at the Medical University of South Carolina. “It’s hidden in everything.”
But recent research on salt intake seems to call into question its potential for harm. Experts noted in the journal Progress in Cardiovascular Diseases last year that the association between salt consumption and blood pressure was weak, especially among people who do have normal blood pressure and do not struggle with obesity.
That doesn't mean we shouldn't watch how much salt we're eating.
Jeannie Boyer, a dietitian with the East Cooper Medical Center, said that patients often come in and tell her she shouldn't worry about their sodium consumption because they don't use table salt.
That's a misconception, she explained, because the “majority of the salt that we get is already in the food."
For example, one can of Campbell's Cream of Mushroom Soup contains 870 milligrams of sodium. One can of Swanson Chicken Broth it's 860 milligrams. Both of them are popular ingredients incorporated into many Thanksgiving dishes. The recommended daily consumption of sodium for Americans by the Centers for Disease Control and Prevention is 2,300 milligrams.
But the CDC found, on average, we're eating more than 3,400 milligrams.
Dr. Jerry Back, an internal medicine specialist at Trident Medical Center, said a high-sodium diet can increase stroke risk, kidney disease, heart failure and osteoporosis. The Harvard T.H. Chan School of Public Health notes a link between high salt intake and an increase in stomach cancer.
Experts acknowledge that sodium doesn't pose the same health risk for everybody. The recommended sodium intake for someone with high blood pressure is different than for someone with low blood pressure.
Patients without a family history of high blood pressure and who have low blood pressure themselves don't need to approach sodium with the same level of caution, said Boyer, the dietitian at East Cooper Medical Center.
But this doesn't absolve anyone of the potential for future health risks. “It’s great to know your family history, but also it’s not guaranteed," she said.
In fact, when it comes to both salt and sugar intake, Back, the Trident physician, said he views the substances as health risks if mismanaged.
“If you don’t manage both of those aspects, you're less likely to have success," he said.
Part of the reason sugar has been examined with more intensity in recent years is because of its relationship with obesity, which is associated with health problems like diabetes and heart disease.
Salt itself doesn't provide any calories. According to Boyer, it's the food that contains salt, like bread rolls, that carry additional calories. With sugar, it's the opposite.
Sugar is often referred to as "empty calories" because it provides no nutritional benefit, said Turner, with MUSC. That's why cutting sugar from your diet often has the most impact if you're trying to lose weight. Turner works with diabetes patients and she said this is one of the main areas she tries to focus on with them.
“Unfortunately, sugar is cheap and it is added to a lot of our processed foods," she said.
It often shows up heavily in beverages such as sweet tea and cafe drinks.
Erin Castle, a clinical dietitian with Roper St. Francis Healthcare, agrees with most experts that it comes down to moderation.
A little bit of sugar consumed on a day full of veggies won't wreck your health. And one meal high in sodium won't instantly translate into hypertension. Castle emphasized it's important to pay attention to both.
Here's something else they agree on: Elimination diets that push for completely avoiding sugar or salt (or both) typically aren't effective because they usually don't last.
Instead, experts advise people to be mindful of labels and the nutritional facts of products they purchase and to think about what healthier foods they can add to their diets.
“If you’re focusing on one (ingredient), you’re not seeing that big picture," Castle said. "It's not one thing that’s dictating all of your health.”