Diet is vital for optimal health and should not be viewed simply as a means to achieving weight loss. Dr Simon Poole discusses what practitioners should be advising patients about good nutrition
It is important to talk to patients about nutrition in a holistic way. I think too much of our time in medicine is spent trying to put people back together and offer treatments, without fundamentally addressing some of the major causes of the problems. It’s our responsibility to support and educate.
We know that diet contributes to chronic diseases. A review released by Cancer Research UK in 2013 showed that 30–40% of cancers are caused by dietary factors and more than 50% of acute myocardial infarction cases are down to lifestyle issues. Blood pressure, metabolic syndrome and obesity are also conditions to which nutrition and lifestyle contribute. We are sitting on a lifestyle pathology and obesity epidemic time bomb.
We live in a fairly hostile environment. Over the last few years we have created an environment for food and nutrition where we have an excess of ready calories, very much in the wrong form. The average length of time a person takes to make a choice to purchase a ready meal when shopping is two to three seconds.
The amount of people who actually look at the nutritional information on a ready meal is extremely low, and a meal for one could contain 131% of your maximum daily recommended saturated fat. I would contend that this should be illegal.
However, it’s not just about obesity. There are more scary statistics; one being that in the last 16 days, 6,000 more Britons have been diagnosed as diabetic. In the same time period, a further 10,000 have joined the 5.5 million who are already obese.
Although there are many fads about diet and nutrition that do the rounds, fundamentally the diet that gives you the best chance of longevity—of reducing the risks of obesity, cancers and heart disease—are derived from the Mediterranean Diet.
Professor Ancel Keys—the physician to Eisenhower—was very much involved in the US army war machine, ensuring that troops in the field were given adequate nutrition.
After the war, he toured the Mediterranean and found that many of the chronic lifestyle diseases which are part of the current day Standard American Diet (SAD) were much less common in Mediterranean countries.
A good diet needs to reduce the risk of illness and obesity, and needs to contribute to healing. There is more interest these days in how people heal after surgery and more research is taking place into how hospital food can help and support people in healing. We know that nutrition is extremely important post-surgery and it can also contribute to psychological wellbeing—the incidence of depression on poor diet is much more significant.
Diet also contributes to aesthetics. We are beginning to understand a little more about the way antioxidants in our food react on a cellular level, in terms of cellular ageing and appearance. Diet contributes to longevity. There are currently studies underway measuring how long you can expect to live, based on diet and lifestyle.
A good diet is simple. A lot of people think about diet as purely a way to lose weight but we should think about diet in a more holistic way. It’s about optimum nutrition, and decreasing the risks of cancers and heart disease. The word “diet”, comes from the Greek word diaita; meaning “way of life”. This is how the Mediterranean Diet exists—it is a way of life and a relationship to food.
The advice given in the 90s to follow a low-fat, high-carbohydrate diet has been shown to be fundamentally flawed. If you talked to dieticians in the 80s and 90s, they would say fat is bad, so you need to increase your carbs and decrease your fats.
However, we now know that this has adverse effects on your lipid profile, so there are lots of reasons why we should no longer be advocating that.
The Atkins philosophy to follow a low-carb, high-fat diet has also been scientifically discredited in terms of how good it is. It does achieve some weight loss in the first three to six months, but after that the weight tends to go back on. Research also shows that it’s associated with increased risks of metabolic syndrome, blood pressure problems, obesity and cardiovascular disease.
Also in the 90s, polyunsaturates were promoted as being good for you—there were even margarines which were signposted as being high in polyunsaturates. One of the problems with what Ancel Keys discovered in the Mediterranean was that he could see that saturated fat was associated with an increase in cholesterol, and therefore probably an increased risk of cardiovascular disease, so he promoted the idea of increasing our consumption of unsaturated fats.
In the Mediterranean Diet, they consume a lot of monounsaturated fats. But access to monounsaturates on a commercial scale in the United States was very limited because they couldn’t grow olive trees everywhere; the largest source of fat in the Mediterranean.
The government decided to promote polyunsaturates, so the Western diet is very high in omega-6 polyunsaturates. These are now being shown to adversely affect how omega-3s behave and to cause an inflammatory response in the body. We consume an excess of polyunsaturate omega-6s in our diet.
Not all fats are the same. There are saturated fats, polyunsaturates—omega-6s and omega-3s—and there are monounsaturates, otherwise known as omega-9s, which are in olive oil, avocados, and some other foodstuffs.
Not all saturated fats are the same. They can behave very differently in the body. The Mediterranean diet has some saturated fats in dairy produce, but sheep and ewes’ saturated fat is made up of predominantly small-chain and medium-chain fatty acids. These are better for you than the long-chain fatty acids in cow dairy, which we know to be harmful.
Frying in oil is unsafe. This has been disproven, particularly if you don’t go above smoking point when frying the oils.
Not all calories are the same. Calories are burned differently. The definition of a calorie is what energy you get when you burn something. How the calories behave in the body is very different.
How livestock are fed is important. It’s been shown that if you feed a pig on a varied, balanced diet, the profile of the fat from the meat of that pig is phenomenally healthy. It contains over 50% of oleic, monounsaturated fat—the same fat found in olive oil—because it grazes on fresh foods, herbs, acorns and various other natural products.
Where we source our food matters. It’s been shown that, for example, if you mass produce tomatoes under glass in Holland, they will contain approximately 30% fewer lycopenes than if you grow them exposed to UV light in the sunshine.
There are some benefits of supplements, but there are also problems with them. There are some cases where supplements are clearly useful, such as taking folic acid in pregnancy, or vitamin D and calcium for people with osteoporosis. However analysis of using supplements has shown a greater risk of disease and mortality than if you don’t take supplements.
Change is coming though. The European Food Safety Authority is going to tighten up the laws around not only foods, but also around supplements, in what can be claimed. From 2014 onwards, they will require far greater demonstration of evidence that supplementation gives any benefits.
People’s knowledge of what constitutes a good diet is very poor—in the UK, we are still not getting our five-a-day and which diet is the best to lose weight is also a recipe for confusion. Doctors’ knowledge and awareness is also very poor. In the US, doctors at medical school receive around 16 hours’ training on nutrition. In the UK, we have no formal training on nutrition.
The Epic study—a multi-centre study into rates of disease, particularly of cancers and also cardiovascular disease—showed that frying in olive oil was not associated with an increased risk of illness or death. The science of olive oil is becoming more widely understood, not only of the monounsaturated fats but also antioxidants. They contain polyphenolic antioxidants, which have been shown to reduce the risks of LDL oxidation.
If, for example, old olive trees were cut down to create a dense, industrialised cultivation system, then irrigated and supported to maximise the yield, with the resulting oil mixed with olive oil from Tunisia or Turkey, the polyphenolic antioxidant levels would drop dramatically. Olive oil available in the supermarket is nutritionally very poor.
The olive tree that is stressed needs antioxidants in it to protect itself from the environment, just like we need antioxidants to protect ourselves from free radicals. So if you de-stress the tree, you rapidly diminish the nutritional value of the antioxidants in those foods. You can map this across other foods, such as the tomato.
A Predimed study released in 2013 showed that adherence to a Mediterranean diet supplemented with olive oil and nuts is more powerful than statins in reducing the risks of cardiovascular disease. But because you can’t put the Mediterranean diet in a pill, it won’t be promoted in the same way by pharmaceutical companies.
An independent study funded by the Atkins Foundation, compared a low-fat, high-carb diet, a low carb diet and the Mediterranean diet and evaluated weight loss over a period of six years. Results show that the Mediterranean diet is superior in terms of long-term weight loss.
More recently, research released at the Canadian Cardiovascular Congress showed that a combination of the Mediterranean diet with high intensity interval training showed significant benefits in blood pressure, fitness and weight loss.
The Mediterranean diet is fundamentally a low-GI, high-fibre, low saturated fat, low sugar, high monounsaturated fat, high omega-3s, low-salt diet which is rich in antioxidants, phytochemicals and minerals.
We should recommend the Mediterranean diet because of the evidence behind it. It is the gold standard diet—it’s easily understood and fulfils the responsibility that we all have for holistic patient care. Whenever we talk about offering surgery, therapy or intervention, we need to do it responsibly in the context of helping and supporting people to have optimum nutrition and diet.
Dr Simon Poole is a GP, author and authority on the Mediterranean diet