Mediterranean Diet and Gut Health

You may know about the Mediterranean diet and its health benefits. But many details might be less familiar. Guts UK will explain the benefits of the Mediterranean diet. We’ll compare it to the Western diet and explain how you can follow it, should you wish to.

What is the Mediterranean diet?

The Mediterranean diet is a dietary pattern based on the eating habits of people in Spain, Italy, and Greece. It largely consists of whole plant foods, including fruits, vegetables, whole grains, legumes, as well as sources of healthy fats like nuts, seeds, and olive oil. It contains moderate amounts of fish, poultry, and dairy, and low amounts of sugar and red meat. Because of its focus on plant-based foods, the Mediterranean diet is high in fibre.

Interest in the Mediterranean diet grew when it became clear that people in those countries had lower heart disease rates. This was despite them eating about the same total fat as people in the UK.  Studies show that a diet partly influences cardiovascular health differences. A typical Western diet has more saturated fats, sugars, and processed foods, and less fibre.

History

Dr Ancel Keys was the first to highlight the health benefits of the Mediterranean diet. His initial “Seven Countries Study” looked at the diets of more than 11,000 men aged 40 to 59. This study followed them for over 15 years.  It showed several key patterns. One was the low death rate from heart disease in Southern Mediterranean countries. It also showed differences in the type of dietary fat men ate. Men with higher dietary monounsaturated fat ratios had lower death rates than those with saturated fats. Researchers noted that men in Mediterranean countries ate much more plant food than those in Northern Europe.

Later important studies, like the Lyon Diet Heart Study and the PREDIMED trial, widened Keys’ findings. They also showed that following a Mediterranean diet can lower the risk of heart disease. It can also reduce the chances of recurring cardiovascular events in those already diagnosed with heart disease.

In the Lyon Diet Heart Study, people on a Mediterranean-style diet had 70% fewer cardiac events than those on a control diet. The Mediterranean diet was high in polyunsaturated omega-3 fatty acids and low in saturated fat. The control diet used in the study was like a typical Western diet. It had more meat, refined grains, saturated fat, and cholesterol. It also had fewer fruits, vegetables, legumes, and omega-3 fats.

Results from the PREDIMED trial upheld these findings. People on the trial’s healthy, whole-food Mediterranean diet had about a 30 percent lower rate of cardiac events. Researchers looked closer at people with a diet high in plant foods. They called it a “pro-vegetarian” Mediterranean diet. They discovered a 41 percent drop in risk of death during the trial. These results show that the largest benefits of the Mediterranean diet come from eating more whole plant foods and healthy fats.

Researchers linked these results to a high intake of olive oil, which is higher in monounsaturated fat. These plant-rich diets naturally gave people more fibre. This research helped shape public health campaigns, like the UK’s “five-a-day” initiative.

Experts recognise that the Mediterranean diet supports good health. There are some advantages related specifically to gut health:

Bowel cancer

Bowel cancer is the second leading cause of cancer deaths, following lung cancer. There are clear differences in the number of new cases across the world. Dietary patterns, along with other environmental and lifestyle factors, influence these differences. The Mediterranean diet has more fibre. Adding 7g of fibre to your diet daily can lower your risk of bowel cancer by 8%. The dietary pattern also includes less red and processed meat. Researchers link this type of meat to bowel cancer.

Stomach cancer

Some evidence shows that a Mediterranean diet might help protect against stomach cancer. Researchers need to do more studies to fully understand this benefit.

The gut microbes

The Mediterranean diet has more fibre than typical Western diets. Fibre is key for gut health. It boosts the number of beneficial bacteria in our gut. Examples are Lactobacillus and bifidobacteria.

The average person in the UK falls short of the recommended fibre intake. A typical UK diet offers on average 16g of fibre daily. That’s just over half of the recommended 30g for adults. The amount children need is lower.

General health benefits

Evidence has shown that every extra 7g of fibre in the daily diet is associated with a reduced risk of these common chronic diseases:

• Cardiovascular disease by 9%
• Heart attacks by 9%
• Strokes by 7%
• Incidence of Type 2 Diabetes by 6%

The Mediterranean diet includes different food groups. This makes it easier to adapt to various cultures and traditions.

To adopt the Mediterranean diet, try these food groups and their recommended portions. These follow the Mediterranean diet rules from the PREDIMED trial:

• Vegetables*: 2 or more daily portions (a portion is 80g). Examples include broccoli, bok choy, peas, turnip, tomato, courgette, aubergine, asparagus.
• Fruit*: 2-3 or more daily portions (a portion is 80g). Examples include strawberries, kiwi, plum, grapes, fig, guava, apple and orange.
• Legumes: 3 or more portions per week (a portion is 80g cooked, and roughly 20-30g dry). Examples include chickpeas, lentils, peas and beans.
• Nuts and seeds: 1 or more portions of 28g per week. (e.g. sunflower seeds, peanuts, poppy seeds, sesame seeds, walnuts, pumpkin seeds and cashew nuts).
• Wholegrains: 3 or more servings per day. (e.g. buckwheat, pearl barley, wholemeal bread, wholemeal pasta, oats and brown rice).
• Fish or seafood: 3 or more servings of 100g per week. (At least one or more should oily fish e.g. salmon, mackerel, pilchards, sardines or trout).
• Fats and oils: choose unsaturated fats such as olive oil over saturated fats. Saturated fats can be found in foods such as cream, butter, and meat, particularly red and processed meat.
• Alcohol: In the traditional Mediterranean diet, people drink 100ml to 300ml of red wine daily with meals.

This is different from the current UK advice on alcohol intake, which advises that no level of alcohol is completely safe, and those who do not drink are not advised to start. Click here to add up what alcohol you drink.

• Red and processed meat: Fewer than 1 serving a week.

In the UK, the NHS recommends, at most, 70 grams per day.

* This should include a variety. All types count: Fresh, frozen, and tinned in natural juice or water. Soup is another choice but aim to opt for low or no added salt.

The Mediterranean diet has many features that are better for the environment. You can make simple changes to your eating habits to support sustainability.

• Eating less meat and dairy can hugely reduce our carbon footprint. The EAT Lancet report suggests moving to a more plant-rich diet could cut global agricultural greenhouse gas emissions by more than half. If you choose milk alternatives, make sure they are calcium-fortified. Some forms of milk alternatives are lower in calcium and using these may not give you enough for your body’s needs.

• Eating more plant-based food and reducing animal-based foods has been suggested as a key change for the health of our environment. This doesn’t mean you have to eat a vegan diet. It simply means adding more plants to your plate and, in turn, eating fewer animal-based foods.

• Avoiding food waste by planning meals. Only buy what you need and watch portion sizes.

• If you choose to eat fish, buy from certified sustainable sources.

Should I avoid carbohydrates altogether?

No. Eating fewer carbohydrates might help some people control diabetes. Wholegrain carbohydrates, like wholegrain rice, quinoa, and oats, are very important for our health. They provide energy, fibre, and vitamins. Eating carbohydrates regularly can lower the risk of common chronic diseases.

Is sugar bad for me, and should I avoid it altogether?

No. Consuming added sugars in moderation is okay. Food does more than nourish us; it brings joy and holds value, meaning, and sentiment. A sugar-free diet can make meals feel dull. It might also increase the desire to eat foods containing added sugar. This could create a poor relationship with food and make it tough to maintain a healthy diet over time. Aim to have a diet low in added sugar most of the time, with space to enjoy it on occasion.

Is fruit sugar bad?

No. As with the above point, it can be unhelpful to view foods as either ‘good’ or ‘bad’. Sugar in whole fruit occurs naturally. It’s packaged with fibre, vitamins, and minerals. You should include whole fruit in your diet on a regular basis. Fruit juice sugars can harm our health if we drink too much. This is because they lack the fibre found in whole fruits. Guidelines say to limit fruit juice to one portion a day, which is 150ml.

Does a Mediterranean diet have equal benefits when accounting for a person’s sex and ethnicity?

While evidence shows benefit overall independent of sex and race, there is some data that suggests the degree of effect may differ between genders. However, this data is limited and inconsistent. Further research is needed.

How does this research relate to advice from the NHS on diet (the Eatwell Guide)?

The two diets have some small differences. But the Mediterranean diet forms the basis of the NHS Eatwell Guide. The Mediterranean diet is widely studied for its health benefits. It is often seen as a healthier option than the typical UK Western diet, benefiting both people and the planet.

To learn more about healthy eating, visit our information here.

How strict do I need to be if I want to follow this diet?

Healthy eating focuses on what you eat most of the time. So, straying from a strict Mediterranean diet now and then is fine and normal. The best way to change your diet sustainably is to make gradual tweaks to your meals. Avoid setting rigid rules from the start. If you’re not eating much fibre now, your bowel may handle a slower increase better. Adding fibre too fast can lead to more gas and discomfort until your bowel gets used to it.

Can I follow the Mediterranean diet in the UK during the winter months?

Yes. Dietary principles remain the same. Tinned and frozen fruits and vegetables may help in the winter, when fresh produce is out of season. Examples include:

• tinned tomatoes
• tinned ratatouille
• jars of roasted peppers
• frozen mixed vegetables and fruit
• tinned fruit in natural juice 

I have heard that drinking any amount of alcohol is unhealthy. Why is alcohol counted in the Mediterranean diet?

Red wine is often part of Mediterranean diets. It’s usually enjoyed in small amounts and during meals. Some studies link moderate alcohol intake to certain health outcomes. But others suggest there is no completely safe level of drinking. This follows current UK guidance. It says there is no safe level of alcohol intake. It also advises that people who don’t drink should not start for health reasons.

To learn more about alcohol and the digestive system, visit our information here.

What about other traditional diets – are they healthy too?

Research in non-Mediterranean areas is less common. But traditional diets from Asia, Latin America, Africa, and the African diaspora focus on whole grains, fruits, vegetables, and pulses. Pulses include chickpeas, lentils, peas and beans. These are widely cited in research to have associated health benefits. They are well-known for their fibre content, which has proven benefits for gut health.

If this diet is so good for health, why don’t more people follow it?

These days, people everywhere are moving away from traditional diets. They’re choosing cheaper, quicker, and more processed foods instead. This is a complicated situation. Changes will involve wider aspects than a person’s diet. Environment, money, education, and time to follow healthy diets can affect choices. Sometimes, traditional foods are hard to find when people move to a new country. Healthy foods can cost more or take longer to prepare, which makes it harder to choose them. Not everyone has the privilege of consistent access to healthy foods. The structure of society, the economy, and food security also play a part. There is a need to increase the affordability of, and access to, healthier foods. Some people might not tolerate certain foods. This can also limit their choices. In these situations, it’s key for people to work towards healthier eating habits. They should also ask for help from registered health care professionals when needed.

The Mediterranean diet and other plant-rich diets offer benefits for the gut and overall health. Most people can add some parts of these diets to their daily routine. Just remember to make changes slowly. This gives our guts time to adjust, especially when increasing fibre intake. A fast increase in fibre could lead to bloating and wind. Making gradual changes will also make it more likely that these changes last over time. Aim to do what you can within any restrictions you may have and seek support where needed.

If you would like to know more about fibre, visit our fibre information here.