Junk Meal Stiffens Arteries, Olive Oil Meal Does Not: Study
A small Montreal Heart Institute study presented this week found that one junk-food meal left men’s arteries dilating 24 percent less than before they ate, while a Mediterranean meal of salmon, almonds and vegetables cooked in olive oil caused no such drop. Both meals were high in fat. Here is what the researchers did, what the result does and does not show, and how it fits what we already know about olive oil and the heart.
What the study found
The work comes from the cardiovascular prevention and rehabilitation center (ÉPIC) of the Montreal Heart Institute, affiliated with the Université de Montréal, and was presented on October 30 at the Canadian Cardiovascular Congress in Toronto by Dr. Anil Nigam, its research director. Twenty-eight non-smoking men ate a Mediterranean-type meal first and, a week later, a junk-food meal. The researchers used ultrasound to measure how well the men’s arteries widened, a standard test of the health of the blood vessel lining, known as endothelial function.
| Meal | What was on the plate | Calories from fat | Artery response |
|---|---|---|---|
| Mediterranean | Salmon, almonds, vegetables cooked in olive oil | 51 percent, mostly mono- and polyunsaturated | Dilated normally |
| Junk food | Sausage, egg and cheese sandwich, three hash browns | 58 percent, mostly saturated, no omega-3 | Dilated 24 percent less than when fasting |
“Poor endothelial function is one of the most significant precursors of atherosclerosis,” Nigam said, as quoted by FoodNavigator. The university’s release adds a twist: men with higher blood triglycerides seemed to benefit more from the Mediterranean meal than men with low levels. “We believe that a Mediterranean-type diet may be particularly beneficial for individuals with high triglyceride levels,” Nigam said, as quoted by HealthDay, with people who have metabolic syndrome as an example.
What it does not show
- It is small: 28 men, all non-smokers, and no women.
- It measures a short-term response over a few hours, not heart attacks or long-term health.
- It compares whole meals. Olive oil was one part of the Mediterranean plate, along with oily fish and nuts, so the result cannot be pinned on the oil alone.
- It was a conference presentation. As HealthDay reminded readers, results presented at medical meetings are usually treated as preliminary until they appear in full in a peer-reviewed journal.
Why it is still interesting
The useful point is that fat content alone did not decide the result. Both meals got about half their calories from fat, yet only the one built on saturated fat blunted the arteries. That matches the long-standing advice to swap saturated fats for unsaturated ones rather than simply cutting fat, which is the sober version of the olive oil and heart story we laid out in Olive Oil and Heart Health: The Honest Version. It is also a reminder that pouring olive oil over a poor diet is not the same thing (Added olive oil is no heart panacea). The Mediterranean plate worked as a whole.
Olive oil marketing loves a single study, and this one will turn up on labels and websites as “olive oil protects your arteries.” That is not what it tested. What it supports is duller and more useful: cook the vegetables in olive oil, eat the fish and the nuts, and skip the sausage and hash browns more often than not.
This is general information, not medical advice. If you have heart disease, high cholesterol or high triglycerides, or you are thinking about a major change in diet, talk to your doctor first.