Updated: Oct 1, 2020
More insights from the 2018 Lifestyle Medicine Conference: Professor Catherine Itsiopoulos of Latrobe University spoke about the evidence that we currently have to indicate that a Mediterranean diet can be beneficial in both prevention and management of T2D.
Diabetes is the ultimate cause of about 10% of deaths in Australia. It is a disease with strong associations with obesity, and Australia sits at number three in the world on that score: We are a sedentary society, one third of our calories come from processed junk foods and only 43% of the population do the recommended minimum of 30 minutes per day physical activity. Add to this the preoccupation of both adults and children with computers and phones and modern life isn't looking too healthy!
The nature of T2D is that it is highly inflammatory (ie our immune system is on constant low level alert) and pro-oxidant. (oxidative stress is not a good thing). Visceral fat (around your organs, ie in the stomach area) produces chemicals called cytokines which signal the immune system to fire up and this starts a cascade of signals and reactions. The immune system is designed to attack foreign threats such as bacteria and viruses, but when cytokines send it into a constant alert state there are negative health consequences. An alarming 22% of Australians over 25 years old have T2D or prediabetes (signs that it is developing). 80% of obese diabetes patients go on to have cardiovascular disease (CVD).
So what can help?
Omega three supplementation was one possible answer, however studies have not proved it to be a magic bullet. It can definitely help in mood disorders, cognition and brain health but it does not improve CVD mortality nor retinopathy, nephropathy or glucose control (all on-effects of T2D). The right dose of omega threes can be helpful in improving blood lipid ratios (the type and ratios of cholesterol for example) in CVD however.
Extra virgin olive oil (EVOO)- importantly 'extra virgin' because it retains its antioxidant phenolic compounds when minimally processed - is an integral part of the Mediterranean diet and it improves malondealdehyde significantly. Malondealdehyde is a marker for oxidative stress, so if there is less of it then it indicates that you have less oxidative damage occurring. EVOO can also help to reduce LDL cholesterol (the type we believe causes arteries to block up) and improves HDL cholesterol (which actually clears fats out of the blood).
The Mediterranean diet also includes lots of fresh fruit and vegetables, fish but not much meat, wholegrains, nuts and seeds. It is rich in phenolic compounds in many of those foods. In the Predimed diet study people who followed the diet most closely (the top 20%) versus those who were least compliant (bottom 20%) saw a 37% drop in mortality rate.
EVOO is helpful in a practical way too as its use in dressings and as a cooking oil makes legumes and vegetables more palatable. The Mediterranean diet pattern has moderate amounts of plant protein, moderate amounts of carbohydrate, healthy fats and often helps in weight loss. Losing some weight, if you need to, is a key ingredient in both prevention and management of T2D. After an initial 1.5kg loss, every subsequent kg lost improves your chances of not developing T2D. Any weight loss at all is significant. The Mediterranean diet also reduces glycated haemoglobin (another thing thats bad for your health and which occurs in T2D!) irrespective of weight loss.
Another effect of T2D is that it lowers your carotenoids ( a precursor of vitamin A found in orange and yellow vegetables and fruits) and vitamin C. The Mediterranean diet protects against these losses. It also reduces fat stored in the liver, you may have heard of fatty liver disease?
What else do we know about the Mediterranean diet? Well, it is so called because it is the everyday traditional diet in many places in Southern Europe. It is very affordable since everything is cooked from fresh, simple ingredients and expensive meat is eaten only about once a week, but fish is eaten often. Wine is allowed! In moderation , and preferably red as there are important phenolic compounds (resveratrol) in red grape skins- if you don't like alcohol eat red grapes! Processed foods are avoided, and breads and cereals are wholegrain. Portions are moderate.
What else do we know about those communities where the Mediterranean diet is protective against chronic disease?
Here are some common features: Active social life, strong family life, eating together, being productive and physically active, free range produce, women don't smoke, having a purpose, lots of vegetables, home gardens and positivity.