Many health-conscious people have thought for years that ultra-processed foods are not good for our health and many have completely or mostly eliminated them from their diets. Now scientists are starting to realise that ultra-processed foods are probably not as harmless as they thought they were.
Recent research has found links between “ultra-processed” foods and obesity, high blood pressure, IBS and even cancer. Two recent studies, published in the BMJ, a leading general medical journal, have also found links between diets high in ultra-processed foods and risk of both cardiovascular disease and early death. The studies are observational, which means that they couldn’t directly prove a cause and effect.
The studies used a food classification system called NOVA, which puts foods into four categories:
- Unprocessed foods such as fruits, vegetables, legumes, milk, eggs, meat, poultry, seafood, fermented milk such as yoghurt, whole grains, natural juice, coffee and water.
- Processed cooking ingredients such as salt, sugar, honey, vegetable oils, butter and lard.
- Processed foods such as condensed milk, cheeses, cured ham, canned fruit, bread, beer and wine.
- Ultra-processed foods containing ingredients and additives such as colourings, anti-caking agents and emulsifiers, for example packaged baked goods such as cookies and croissants, sugary cereals, ready-to-eat meals containing food additives, instant soups and processed meats such as salami and hot dogs.
In the first study, researchers asked more than 105,000 French middle-aged adults to fill out six 24-hour dietary questionnaires. They found that for every 10% of a respondent’s diet that was made up of ultra-processed foods, there was just over a 10% increase in rates of heart disease, cardiovascular disease and cerebrovascular diseases such as stroke. The more unprocessed or minimally processed foods they ate, the lower the risk.
In the second study, researchers asked almost 20,000 Spanish university graduates to complete a 136-item questionnaire. They found that those who consumed more than four servings a day of ultra-processed foods had a 62% greater risk of death during the study period than those who ate less than two servings per day. Each serving of ultra-processed food raised risk of dying by 18%.
A possible explanation for this, according to researchers, is that these foods are often high in saturated fat, calories, sugar and salt and low in key nutrients like fiber. But they also suspect that it is due to the wide range of chemicals and additives found in these foods.
There is also the fact that people tend to over-eat ultra-processed foods, leading to weight gain. Another study found that subjects who ate an ultra-processed diet consumed about 500 calories more per day than those whose diets were rich in whole foods.
According to researchers, about 60% of Americans’ total daily calories come from ultra-processed food. However, they say that it is not necessary to cut them out completely, as it appears that health risks only start cropping up once you consume more than two servings per day.