heart health. Then there is oily fish, like salmon and bluefin tuna, which contain omega-3 fatty acids: Studies have found that those unsaturated fats can reduce the risk of early death among people with known heart disease.
At the opposite end of the spectrum are artificial trans-fats, which are found in many processed and commercially prepared foods. They appear on ingredients lists as “partially hydrogenated” oils. Trans fats can raise LDL (“bad”) cholesterol while lowering the HDL (“good”) kind, and they have been linked to an increased risk of heart disease.
It’s clear those fats should be limited, says Theresa Gentile, a registered dietitian based in New York City.
But beyond that, it’s important to think about overall diet quality, according to Gentile, who is also a spokesperson for the Academy of Nutrition and Dietetics.
She notes that study participants on low-fat diets probably were not eating a lot of red meat, butter or other animal products — which could be beneficial, depending on what is replacing those foods.
You don’t want the substitute to just be bagels and pasta, Gentile says.
The findings are based on an analysis of 40 clinical trials involving more than 35,000 participants in all. The trials tested the effects of seven different dietary programs, sometimes involving other lifestyle changes like exercise and smoking cessation.
Overall, only the Mediterranean diet and low-fat diets proved effective in cutting people’s risk of heart complications or death.
Among participants on the Mediterranean diet, there were 17 fewer deaths for every 1,000 people over a five-year period, versus participants who stuck with their usual diets. Similarly, they suffered 17 fewer heart attacks and seven fewer strokes per 1,000 people.
The benefits were smaller in the low-fat trials, which had participants restrict their fat intake to 20% to 30% of daily calories. Over five years, people on those diets suffered nine fewer deaths and seven fewer heart attacks per 1,000, versus participants who made no diet changes.
Bradley Johnston, of Texas A&M University in College Station, led the analysis.
Both dietitians said the results highlight the benefits of Mediterranean-style eating. Gentile did note, though, that there can be too much of a good thing.
“The Mediterranean diet is also about moderation,” she said.
Nuts, for example, are rich in nutrients, but also calories. A serving of nuts per day means a small handful, Gentile noted — not munching on half a canister.
A heart-healthy diet
If you are looking to start your journey to a healthier diet, the American Heart Association offers these tips:
- a wide variety of fruits and vegetables
- whole grains and products made up mostly of whole grains
- healthy sources of protein (mostly plants such as legumes and nuts; fish and seafood; low-fat or nonfat dairy; and, if you eat meat and poultry, ensure it is lean and unprocessed)
- liquid non-tropical vegetable oils
- minimally processed foods
- minimized intake of added sugars
- foods prepared with little or no salt
- limited or preferably no alcohol intake