The Atlantic diet: How it compares to its Mediterranean counterpart and what benefits it might have

Stock image of steak and vegetables
The Atlantic diet also places an emphasis on fresh, minimally processed foods. Photo credit: Getty Images

By Taibat (Tai) Ibitoye for The Conversation

The Mediterranean diet has long been seen as one of the most beneficial diets out there. It’s been associated with many health benefits, including lower risk of cardiovascular disease and other chronic diseases (including cancer), better sleep and even good gut health.

But a recent study suggests that a slightly modified version of this diet - named the "Atlantic diet" - may also be beneficial for your health.

The Atlantic diet draws inspiration from the traditional eating habits of people living in northwestern Spain and Portugal. Like the Mediterranean diet, it's characterised by eating local, fresh and minimally processed seasonal foods - such as vegetables, fruits, fish, wholegrain, nuts, beans and olive oil. But unlike the Mediterranean diet, the Atlantic diet also includes moderate amounts of meat and pork products, as well as starchy vegetables such as potatoes.

According to this latest study, the Atlantic diet may reduce the risk of metabolic syndrome. This is the combination of high blood pressure, high blood fat levels, obesity and high blood sugar - all of which can lead to heart disease, stroke and type 2 diabetes. 

The researchers conducted what's known as a secondary analysis. This meant they analysed data from a previous study on the Atlantic diet, the GALIAT Atlantic Diet study, in order to better understand its effects. This was a six-month randomised clinical trial, which included more than 500 participants who were grouped together by family.

As part of the GALIAT trial, families were placed into two groups. One group followed the Atlantic diet. They were also taught about the diet and given cooking classes to help adhere to it. The second group, who acted as the control group, followed their usual diet and lifestyle.

The study lasted for six months. At the beginning of the study and after six months, researchers collected information on participants' food intake using a three-day food diary, as well as their physical activity levels, any medications they took and other variables such as weight if they smoked.

In the initial GALIAT diet study, the researchers found that the Atlantic diet group lost weight - whereas those in the control group gained weight. The Atlantic diet group also saw improvements in their levels of one type of cholesterol - though other types of cholesterol remained the same. There were also no changes in their blood pressure and blood sugar. 

In the recent secondary analysis of this study, the researchers found that overall, participants who had followed the Atlantic diet had significantly lower risk of developing metabolic syndrome compared to the control group. They also found that following the Atlantic diet lowered risk of obesity, improved waist circumference and levels of cholesterol (specifically high-density lipoprotein).

But though the Atlantic diet had an overall effect on lowering risk of metabolic syndrome, it wasn't shown to have much effect on specific aspects of metabolic syndrome. Specifically, the researchers did not see any benefit from the Atlantic diet on blood pressure, blood sugar and blood fat levels.

Overall, the study shows that consuming the Atlantic diet may be helpful for managing weight - which may in turn lower risk of some long-term chronic conditions (such as cardiovascular disease).

Balanced diet

This is not the first time the effects of the Atlantic diet have been researched. 

Previous studies have shown that the Atlantic diet is associated with lower levels of inflammation, blood fat levels and blood pressure among adults living in Spain. Another study also found that Spanish people who paired the Atlantic diet with regular physical activity had a lower risk of cardiovascular disease, lower cholesterol and lower rates of obesity.

But while research does show some potential benefits in adhering to the Atlantic diet, these results may not hold true for everyone.

First, most studies on the Atlantic diet - including this latest one - only included participants of Spanish or white European descent. This means we don't know whether the Atlantic diet will be equally beneficial for ethnic groups who are at greater risk of metabolic syndrome - such as people of south Asian, Black African and Caribbean descent.

It's well established that regularly consuming fruits, vegetables, wholegrains, nuts and fish provides a wide range of essential vitamins, minerals, fibre and antioxidants that are vital for good health. While the Atlantic diet is said to contain plenty of these foods, there's no clear information from this latest study on portion sizes or what quantity of certain foods participants consumed in order to reduce their risk of metabolic syndrome. 

Another thing worth mentioning is that the GALIAT study gained a lot of media attention at the time. This may have influenced the participants'' eating and lifestyle habits as a result, making them adhere more strictly to it - making it appear the diet had a greater affect than it actually might in reality.

And, even though participants in both groups had similar characteristics at the start of the study (such as how physically active they were on average, or if they smoked), the researchers were unable to adjust their findings to fully account for all the factors that might influence a person's risk of developing metabolic syndrome.

The participants in the Atlantic diet group were also provided with the food they needed in order to stick with their diet. But in a real-world setting, not everyone can regularly access or afford the kinds of foods the Atlantic diet consists of. This makes it difficult to know whether the findings will still stand outside of a controlled environment.

At the end of the day, the ideal diet to follow for improving metabolic health is one that includes a wide range of foods from each of the main food groups: fruits and vegetables, starchy carbohydrates (opting for wholegrain alternatives where possible), protein, dairy or dairy alternatives and healthy fats that you find accessible, affordable, enjoyable, as well as nourishing. 

Taibat (Tai) Ibitoye is a senior lecturer in public health and a registered dietitian at the University of Hertfordshire.

The Conversation