By Ross Walker

I often say your genes load the gun but your environment pulls the trigger and although most common diseases are around 30% genetic, it is still environmental factors that play the most significant role in the causation of disease.

Although I believe our level of internal happiness and a regular exercise habit are more important contributors to good health than diet, there is still no doubt that ‘we are what we eat’.

Another very important factor is the influence of modern living on what makes it into our mouth and gastrointestinal tract. Another increasingly important factor is the human microbiome which is the colony of bacteria living in our gut.

An interesting fact is that human beings are strangely only 10% human and 90% bacteria in terms of the number of cells in the body. The vast majority of bacteria are residing in our large intestine.

An important aspect of good health is the diversity of healthy bacteria living in our large intestine. The more diversity, the better our health.

Over the past 50 years there has been a significant reduction in agro-diversity, i.e. the variety of plants and soils used to grow foods, and this has been directly related to reduced dietary diversity. This reduction in dietary diversity has led to a reduction in bacteria and this reduction is directly linked to 21st century diseases such as Type 2 diabetes, obesity, cardiovascular disease and inflammatory bowel diseases. 

To give one recently discovered example, there is an important substance, phosphatidyl-choline (PTC) which is abundant in shell fish, eggs, red meat and poultry.

Gut microbes often convert PTC to trimethylamine (TMA). Once TMA is absorbed across the colon it is oxidised to TMA oxide which promotes atherosclerosis, i.e. the progressive build up of fat in the walls of the arteries, which is the major cause of heart attack and stroke.

But, now here is where the diversity argument comes in, the best studied diet, the Mediterranean Diet, which also contains extra virgin olive oil, balsamic vinegar, red wine, along with a variety of fruits and vegetables, has substances that inhibit TMA production and therefore directly impact on reduced risk for coronary heart disease and stroke, which is clearly shown in people who follow a Mediterranean lifestyle. This is despite the fact that Mediterranean lifestyle does include shell fish, eggs, a degree of red meat and poultry. Thus, a diverse diet can negate the potential bad effects of our gut microbes.

Another vitally important issue is not just the food but the modern containers in which we purchase and store food. 

I defy you to open your fridge or pantry and not find the majority of food in some form of plastic or can.

For the past decade there has been a strong emphasis on BPA (Bisphenol-A) which is a commonly used component lining plastics bottles and cans, not to mention coating other metal products and water supply pipes. BPA and other plastic strengthening products such as phthalates are strongly linked to a variety of conditions such as hormone related cancers, infertility, congenital abnormalities in children, behavioural abnormalities in young children, cardiovascular disease, Type 2 diabetes and obesity. BPA free products are on the rise but the commonly used replacement chemical, BPS, which is also now linked to exactly the same list of diseases seen with BPA.

A recent study has shown the same stimulation of fat cell growth with BPA and BPS.

The bottom line from all of this information is that the food we eat and how our food is packaged has a strong bearing on our health and disease. It certainly does appear that ‘we are what we eat’.