The recent revelation that Harvard scientists were paid off to downplay sugar’s harms in the 1960s shows how the food industry shockingly manipulated nutrition science for decades. Yet the news media has given the sugar industry too much credit. The real story about how sugar got a pass — while dietary fat and cholesterol were blamed for heart disease — reveals that other industries played a role, as did, surprisingly, many of the country’s leading scientists.

According to an article published Sept. 12 by the journal JAMA Internal Medicine, the sugar industry formulated a game plan in the mid-1950s to capitalize upon an idea gaining traction “among leading nutritionists” that dietary fat and cholesterol cause heart disease. There are only three macronutrients: fat, protein and carbohydrates. Sugar executives recognized that if Americans could be persuaded to adopt a low-fat diet, they would invariably eat more carbs. Think cereal instead of eggs for breakfast, or cookies rather than cheese as a snack. Predicting that some 20 percent of calories would shift towards carbohydrates — a windfall to all the “carbohydrate industries” — sugar executives paid Harvard scientists to water down a 1967 review of sugar’s potential harms and instead pin the blame for heart disease on fat and cholesterol.

Commentators in the past two weeks have seen this as proof that “Big Sugar” is the equivalent of “Big Tobacco,” undermining good science to cover up the evils of a dangerous product. Yes, sugar executives used similar tactics, but the results were hardly so clear-cut.

First, we have to acknowledge that despite these unscrupulous efforts, U.S. consumption of sugar tanked in the decades following that Harvard review. Estimated consumption of “beet and cane sugar” fell by 38 percent between 1970 and 2005, according to the government’s best-available data. Instead, as consumption of sweeteners increased 19 percent during those years, it was high-fructose corn syrup that cleaned up.

All the “carbohydrate industries” profited from the demonization of fat, exactly as anticipated. Consumption of flour and cereal products increased by 41 percent, including a 183 percent increase in products from corn. Overall, as Americans cut their consumption of fat by 25 percent from 1965 to 2011, they increased carbohydrate intake by more than 30 percent.

The JAMA article offered a tantalizing view into how sugar executives enabled this shift, but it’s naive to think that they alone were alert to potential windfalls of the low-fat diet. If one were to search the files of corn or wheat industry executives, certainly letters reflecting similar strategic thinking would turn up. Indeed, as early as 1941, Quaker Oats, General Foods, the American Biscuit Company and others joined forces to found the Nutrition Foundation, which spent millions annually on scientists and research, presumably in the interest of their products. Everyone could see the commercial shift the low-fat diet would create: If fat went down, carbohydrates went up. It was a simple idea.

Also important to note: it wasn’t all fats but specifically saturated fats that got demonized starting with the American Heart Association’s nutritional guidelines in 1961. Instead of saturated fats, such as butter and lard, Americans were told to eat and cook with products made from unsaturated vegetable oils, including Crisco and margarine. Consumption of vegetable oils, which were invented in the early 1900s, exploded during the 20th century. During the same decades that sweeteners increased by 19 percent, vegetable oil consumption rocketed up 91 percent.

The vegetable oil industry also used a variety of “Big Tobacco”-style tactics to influence the science. Wesson oil invested in scientists via its Wesson Fund for Medical Research, including donations to Chicago cardiologist Jeremiah Stamler, who authored that first AHA guideline condemning saturated fats. Stamler also benefited from the largesse of the Corn Products Co., which published a version of Stamler’s pro-vegetable-oils diet book bound in red leather (and including pages of advertisements for corn oil at the back) handed out by the thousands to doctors. The Corn Products Co., along with vegetable oil giant Anderson, Clayton & Co., also donated their products to researchers at the National Institutes of Health to be studied for potential health benefits. In my own research digging through old files, I found quite a few revealing letters, including one from biochemist Fred Kummerow in 1969, chastising the then-medical director of the AHA for posing with a bottle of Crisco oil in an educational film. “This is rank commercialism,” wrote Kummerow.

Yet here’s the rub: We can’t assume that industry money buys the minds of scientists. No doubt there’s some influence, but researchers have their own view of the evidence. Corruption cannot be assumed to be the norm.

Sugar is no doubt bad for health. But during the 50 years that obesity and diabetes have skyrocketed, the major shifts in Americans’ diets were from fats to carbohydrates, and from saturated fats to vegetable oils. Those industries also manipulated nutrition research, and their products also must be considered as possibly culpable for our current ill health. Let’s not oversimplify the story.

Nina Teicholz is a science journalist and author of the book “The Big Fat Surprise.” She wrote this for the Los Angeles Times.