Experts separate dietary myth from science

ORLANDO, Fla. — Eating patterns, such as the Mediterranean diet and the Dietary Approaches to Stop Hypertension, or DASH, diet, are the most highly recommended for patients with diabetes, but a healthy diet should focus on individual needs and goals, according to a panel discussion here.

“The key message here is that there’s no ideal eating pattern,” Melinda Maryniuk, MEd, RD, CDE, director of clinical education programs for Joslin Diabetes Center’s national and international care alliances, said during the discussion. “The message continues to be that everyone has needs as individuals.”

In the presentation, Maryniuk and Catherine Champagne, PhD, professor and chief of nutritional epidemiology, dietary assessment and nutrition counseling at Pennington Biomedical Research Center in Baton Rouge, Louisiana, categorized various popular diets as “myth” or “science.”

“We’re going to discuss the current fads and diets in nutrition and whether there is evidence to support them,” Champagne said. “We are also planning to describe healthy diets, both high and low fat, and several issues of concern to the public with diabetes.”

DASH diet

Claim: A diet that limits sodium and emphasizes fruits, vegetables, whole grains and low-fat dairy can reduce blood pressure. Science.

Controversy: The diet requires a great deal of work, and purchasing fruits, vegetables and whole grains may be pricey.

Discussion: In studies evaluating dietary sodium levels ranging from 500 mg to 5,000 mg, researchers found that decreased sodium yielded BP reductions that compared favorably with medication. “That’s why the diet is so impressive,” Champagne said.

Bottom line: It is heart-healthy, closely follows U.S. Department of Agriculture dietary guidelines and is good for patients with diabetes. Although not developed for weight loss, it can be successfully used for weight loss.

Mediterranean diet

Claim: A diet rich in healthy fats, nuts, oils (particularly olive oil), fish and fruits/vegetables and low in red meats and saturated fat is heart healthy. Science.

Controversy: A diet high in monounsaturated fat goes against traditional low-fat diets such as the Step One diet; also, the Mediterranean diet is not a structured diet, and there may be “grunt work” involved in obtaining and preparing so many fruits and vegetables.

Discussion: The monounsaturated fat in the Mediterranean diet proven to be superior to the low-fat Step One diet in studies of cholesterol levels.

Bottom line: The diet is reasonable and moderate. “What ties it for No. 1 (with the DASH diet) is that it may provide weight loss, heart and diabetes prevention and control,” Champagne said.

Ketogenic diet

Claim: There is no evidence that a ketogenic diet is useful, and it is not recommended by the American Diabetes Association. Myth.

Controversy: Confusion abounds regarding terms such as low carb, very low carb and moderate carb. Questions persist about safety and long-term effects.

Discussion: A randomized study comparing 12-month outcomes in adults with type 2 diabetes on a moderate-carb diet vs. a very low-carb diet found that although there was more diet drop out in the very low-carb group, these participants also had greater reductions in HbA1c, lost more weight and dropped more medications. Another study comparing a healthy low-carb and a healthy low-fat diet found no appreciable difference between the two.

Bottom line: “Structured and reduced calorie diets work,” Maryniuk said. “Very low-carbohydrate diets do demonstrate benefits for weight loss and glycemic control in many of the studies. Some patients love them, and some don’t. Let your patients be your guide.”

Coconut oil

Claim: Saturated fats from animals should be avoided, but plant-based fats such as coconut oil are safe. Myth.

Controversy: Coconut oil has been likened to medium-chain triglyceride oils. However, it is primarily lauric acid as opposed to capric and caprylic acid, and it behaves more like a long-chain saturated fat in terms of digestion and metabolism.

Discussion: “Because coconut oil increases LDL with no offsetting favorable effects, the American Heart Association has advised against its use,” Champagne said.

Bottom line: Claims of coconut oil improving heart or brain benefits are largely unfounded.

Avoiding dairy

Claim: Dairy and milk should be avoided, or if eaten, only in nonfat form. Myth.

Controversy: Books such as The Cheese Trap portray some forms of dairy as “addictive.”

Discussion: Studies have found an inverse relationship between consumption of milk, yogurt and cheese and type 2 diabetes.

Bottom line: “Total dairy intake has been associated with lower incidence of diabetes in prospective studies,” Maryniuk said. “I should point out that, in the United States, most people only eat half or less than what is overall recommended in terms of dairy.”

Non-nutritive sweeteners

Claim: Non-nutritive sweeteners play a role in weight loss and glycemic control. Science and myth.

Controversy: There is significant controversy on non-nutritive sweeteners’ role in caloric intake, increasing weight gain and safety concerns.

Discussion: “The media is looking for things that are earth-shattering, like that low-calorie sweeteners might cause diabetes or weight gain, but maybe it’s that fast-food meal that you had to offset the calories you cut by choosing a diet soda,” Champagne said.

Bottom line: Studies conducted since 2008 have raised no concerns with respect to exceeding the accepted daily intake of non-nutritive sweeteners among the global population. – by Jennifer Byrne

Reference:

Champagne CL, et al. W209. Presented at: American Diabetes Association 78th Scientific Sessions; June 22-26, 2018; Orlando, Fla.

Disclosures: Maryniuk reports she is on the advisory panel of Foodicine Health and consultant for Diabetes – What to Know. Champagne reports no relevant financial disclosures.