Omega-3 fatty acids are the fourth most common supplement after multivitamins, calcium and vitamin C, according to the Council for Responsible Nutrition, an industry trade group.

WSJ: Fish Oil Provides Little Benefit for Pregnant Women

Duffy MacKay, vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, a trade group for the supplement and energy-drink industries, called the study "a new, emerging hypothesis, " but said the researchers were drawing large conclusions from small studies of mice, bacteria and human biomarkers.

WSJ: New Health Culprit Carnitine Found in Red Meat

Duffy MacKay, vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, a trade group for the supplement and energy drink industry, called the Nature study "a new, emerging hypothesis, " but said the researchers were drawing large conclusions from small studies of mice, bacteria and human biomarkers.

WSJ: New Health Culprit Carnitine Found in Red Meat