The study, which was carried out in partnership with academics from International Hellenic University and University of Thessaly in Greece, analysed Mediterranean, New Nordic, Japanese, Atlantic, Chinese, Persian and Mexican diets to present a systematic review of the physiological effects of regional diets among adults at high risk of cardiovascular disease.
Findings suggest that eating a regional diet may reduce certain cardiovascular health risks, with a Mediterranean diet appearing to offer the widest range of benefits.
Traditional diets were compared against the average modern diets of the same region. The study found that following the latter caused a reduction in body weight for most participants, however it recommends that further research is carried out to increase the existing body of evidence.
Traditional regional diets are sustainable dietary patterns that make use of locally sourced food. Characteristics of the diets include:
- Japanese diet: a high consumption of soy products, fish and shellfish, vegetables (pickles in particular), seaweed, mushrooms, fruit, and green tea. Specific condiments include dashi (soup stock) and fermented seasoning (soy sauce, miso, vinegar, mirin, and sake), with rice and soup consumed as part of the meals
- Chinese diet: similar to the Japanese diet, including pickled vegetables, dry- and brine-slated vegetables, jellyfish, fish-balls and salted fish, soups, poultry, tofu and tofu by-products (koji), rice and rice snacks, fermented sauces, and eggs (salted and thousand-year-old)
- New Nordic diet: rich in high-fibre plant foods (fruits, berries, vegetables, whole grains, nuts), rapeseed oil, fish, and low-fat milk products. Salt, sugar and saturated fats are rarely consumed
- Mediterranean diet: a high intake of vegetables, legumes and fruit, grains and nuts, olive oil as the main cooking fat, plenty of fish and shellfish as well as regionally grown herbs
- Persian diet: a great variety of rice-based dishes (rice with stew, cooked rice, mixed pilaf, rice in a high-protein dish, vegetables stuffed with rice and kofta or tahchin), soups and pottages, and many desserts, some which are rice- or semolina-based (halva, digcheh, milk-rice pudding, rice cookies, rice flour pudding, or saffron rice pudding)
- Mexican diet: rich in grains and tubers, maize products (corn tortillas), legumes, vegetables, fruits, meats, herbs and condiments. Typical dishes include a variety of corn-based dishes that are mainly cooked with chillies, onions, garlic and herbs (e.g., tamales), beans, squash, meats, rice, citrus fruits, full-fat milk, vegetables, Mexican cheeses, and lard. The diet is low in refined grains and added sugars
- Atlantic diet: based on a frequent consumption of bread, cereals (including whole grain), rice, pasta, potatoes, fruit, vegetables (including vegetable soup) and olive oil, a daily intake of dairy products, frequent consumption of nuts (preferably chestnuts or walnuts), fish (in particular cod) and seafood. Eggs, lean meat, and pulses are also eaten on a weekly basis (two to three times), whereas fatty meats and cured sausages, butter and margarine as well as desserts, sweets, pastries, cakes, and ice cream are sparingly consumed
Collectively, the traditional diets suggest an increased consumption of fruits and vegetables, and this often coincides with a reduction in sugar and the adoption of healthier eating habits. Research is unanimous on the positive effects of low sugar intake on cardiovascular health, with benefits spanning from improved gut bacteria to the attainment of a healthy body weight.
Dr Markos Klonizakis, Reader in clinical physiology at Sheffield Hallam University and study lead, said: “It is extremely difficult to design, fund and carry out a large scale, dietary intervention so it is really important that comparative reviews such as this are carried out, to make the most of what the completed studies can give us, in an impartial manner.
Our findings clearly suggest that traditional, regional diets can benefit those wishing to avoid cardiovascular disease – with the Mediterranean diet offering more benefits than any other. It is down to researchers and policy makers to find out how these diets can be offered and explained to people both in their countries of origin but in other countries as well. Hopefully, our work will pave more way to larger, properly-designed studies, the number of which remains small, for most of these diets.”
Cardiovascular disease is the leading cause of chronic disease globally and unhealthy diets have become an ever-increasing factor in this development. Nutrition-based lifestyle changes is the primary recommendation in the prevention of chronic disease amongst people at risk, such as those who are obese, physically inactive, smoke, follow unhealthy diets or drink excessive amounts of alcohol.
Chronic diseases – including cardiovascular and heart disease, stroke, cancer, diabetes and chronic lung disease - are collectively responsible for almost 71 per cent of deaths worldwide, over 41 million in total. Among these, 15 million are considered ‘premature’ deaths, occurring amongst people aged between 30 and 69 years old and could potentially be avoided.
In addition to analysing the effect of regional diets on cardiovascular health, the study also reveals the impact on wider chronic diseases. For instance, the research indicates that a Mediterranean diet can be effective complementary therapy for individuals with diagnoses of cancer, mental health problems or diabetes. Similarly, following the New Nordic diet can improve the metabolic control of people at risk of diabetes.