For the past 10 years, research has been giving vegetable oils like soybean and sunflower a poor reputation.
These oils have been taking the blame for causing inflammation and increasing your risk for chronic illness.
However, a new study published in the Lancet Diabetes & Endocrinology medical journal suggests that the omega-6 polyunsaturated fats found in these vegetable oils may actually reduce your risk of developing type 2 diabetes.
“Our findings suggest that a simple change in diet might protect people from developing type 2 diabetes, which has reached alarming levels around the world,” Jason Wu, PhD, a lead author of the study and a senior research fellow at the Food Policy group at The George Institute for Global Health in Australia, said in a press statement.
What the study uncovered
The study consisted of nearly 40,000 adults from 10 different countries.
Slightly more than 4,000 participants developed type 2 diabetes.
Their blood work was tested for levels of two specific omega-6 markers, linoleic acid and arachidonic acid.
Until now, high markers in the blood for omega-6 fats were considered a health risk, not a benefit.
Varying levels of arachidonic acid showed no change in one’s risk for type 2 diabetes.
This latest research found that people whose omega-6 linoleic acid markers were highest were 35 percent less likely to develop type 2 diabetes.
“This is striking evidence,” explained Dr. Dariush Mozaffarian, a senior study author and professor at the Friedman School of Nutrition Science and Policy at Tufts University in Massachusetts. “The people involved in the study were generally healthy and were not given specific guidance on what to eat. Yet those who had the highest levels of blood omega-6 markers had a much lower chance of developing type 2 diabetes.”
The recommended consumption of omega-6 fats are quite low, at about 5 to 10 percent of your total caloric intake.
Linoleic acid, like amino acids from protein, isn’t produced naturally in the body. It therefore must be consumed in your diet.
“Some scientists have theorized that omega-6 is harmful to health,” Wu told Healthline. “But based on this large global study, we have demonstrated little evidence for harms, and indeed found that the major omega-6 fat is linked to lower risk of type 2 diabetes.”
Contradicting past research
For those following nutritional science closely over the past decade, this claim on the benefits of omega-6 fats could seem a bit unsettling. It directly contradicts what most of today’s leading voices in the nutrition world have been teaching.
The concerns around soybean overconsumption, particularly for countries like the United States, is that it’s hiding in nearly everything on the shelves of today’s grocery stores.
A 2013 Healthline story reported: “Because it’s cheap and has certain functional properties, soybean oil and soy protein have found their way into all sorts of processed foods, so most people in the U.S. are consuming significant amounts of soy without even knowing about it.”
The story revealed that more than 90 percent of soy produced in the United States is genetically modified and sprayed heavily with the pesticide Roundup.
Unlike Eastern countries such as Japan, actual whole soybeans are a rarity in the U.S. diet.
Instead, the oil is highly processed using the chemical solvent hexane. It accounts for 7 percent of the U.S. diet.
“Anthropological research," wrote nutrition guru Chris Kresser, MS, LAc, “suggests that our hunter-gatherer ancestors consumed omega-6 and omega-3 fats in a ratio of roughly 1:1. It also indicates that both ancient and modern hunter-gatherers were free of the modern inflammatory diseases, like heart disease, cancer, and diabetes, that are the primary causes of death and morbidity today.”
Kresser continues: “At the onset of the industrial revolution (about 140 years ago), there was a marked shift in the ratio of n-6 to n-3 fatty acids in the diet. Consumption of n-6 fats increased at the expense of n-3 fats. This change was due to both the advent of the modern vegetable oil industry and the increased use of cereal grains as feed for domestic livestock (which in turn altered the fatty acid profile of meat that humans consumed).”
Take it with a ‘grain of salt’
The takeaway may simply be to step back and focus on the bigger picture of your diet, versus focusing too much on the smaller details.
“I’ve been a dietitian for 28 years,” Susan Weiner, RD, CDE, a registered dietitian and diabetes educator, told Healthline. “It’s not surprising. These statements suggesting you should eat none of one thing and all of another thing, like omega-6 fats being ‘bad’ for you, catch on like wildfire. The real research is not the headline. It’s not black and white.”
Weiner, the 2015 AADE Diabetes Educator of the Year, says she teaches her clients to think of foods like a dimmer switch, a constantly fluctuating and flexible mindset with a focus on simply eating more whole foods.
“It’s not simply what we are eating, but also how we are eating. It’s about awareness. No foods are completely taboo. You have to a have mindful consideration. Things change all the time,” she said.
In today’s world — where dogmatically restrictive diets are aplenty (low-carb or low-fat, etc.), — it’s easy to fall into the mindset of “eat this and not that.”
Weiner says that simply sets people up for disordered eating as well as binge eating on whatever food or food group was being restricted.
“It’s such a mess, and it really doesn’t need to be,” Weiner said of today’s confusing world of nutrition education. “If we go back just a little bit to our body cues, it’s really straightforward to just eat these things from real food, in the reasonable amounts.”
However, Weiner does agree that omega-3s offer the most overall health benefits, like reducing anxiety, preventing cancer, and treating asthma, while omega-9 fats can improve overall insulin sensitivity and decrease inflammation.
Should you spend money on fish oil supplements to be sure you’re getting plenty?
Weiner says not necessarily.
“It’s really easy to be getting this in your diet if you’re eating plenty of whole foods,” she said.
Foods highest in omega-3 fats include several types of seafood, as well as chia seeds, flax seed, and walnuts.
Easy sources of omega-9 fats include hazelnuts, almonds, safflower, macadamia nuts, olive oil, and avocados.
“We want to get more omega-3s and perhaps less 6,” suggests Weiner. But that doesn’t mean one should be avoided or excluded entirely while the other is consumed excessively.
She also recommends simply cooking with less oil overall, and instead enjoying the actual flavor of your foods while adding simple herbs and spices.
In the end, the message is simple: There’s no one perfect source of fat, but nutritional research is always in flux.
For decades, dietary fat was feared and avoided, replaced with more processed carbs and sugar. Now fat is considered in many nutritional approaches to be the hero.
“That’s why we all have to relax a little bit,” Weiner laughs.