Diet

“Let medicine be thy food, and food be thy medicine.” [Hippocrates (460-377 B.C.)]

Hippocrates` words are as true today as they were 25 centuries ago. However, this topic causes more disagreement and frayed tempers than any other aspect of disease prevention, wellness and anti-aging practice. You will probably get a different opinion for every practitioner you speak to.

It is important to think of this not as going on a diet to lose weight, but more of a way of shopping for, preparing and eating meals.

Basics

Let’s start right at the beginning.

Food is made up of three main components; protein, fat and carbohydrates. The old food pyramids used to consider that all fat was bad, you need a bit of protein and most of your diet should be made up of carbohydrate. As always, life isn’t that simple. Not all fats are bad and absolutely not all carbohydrates are good for you. The average male needs to consume ~2500kCal and the average female ~2000 kCal per day. This will vary enormously depending on the degree of activity anyone performs. For example a man running marathons or doing heavy manual labour can utilise up to 6-7000 KCal. In addition, the human body needs a minimum of about 1.5L of fluid per day to function normally. Most sources recommend we need a lot more than this to maintain optimum health, but evidence for this is lacking. However, it would seem sensible to drink the often quoted 6-8 glasses of filtered water per day, as it certainly won’t be harmful.

The other main starting point is to look at different areas of the world and see if the population there live long and healthy lives. There are several populations that conform to this and the two most studied live in Okinawa (Japan) and in Greece. The diets attributed to producing these affects have been popularised as the Mediterranean and Okinawan diets. Of course, diet is probably only one factor of many. It is probable that genetics and lifestyle factors have a lot to do with how long you are going to live.

Both of these diets are relatively high in carbohydrate, low in meat consumption and high in fish. Otherwise they are quite different. The Mediterranean diet contains a lot of pulses, tomatoes and olive oil, whereas the Okinawan diet contains soy products, cruciferous vegetables (e.g. broccoli, bok choy), rice - and even more fish!

So where does the average western diet differ so badly?

Carbohydrates

Well, let’s start with carbohydrates. Currently, they have the reputation of being the bad, fattening part of our diet - witness the Atkins diet. The crucial point with carbohydrates is how “refined” they are, or what the “glycaemic index”(GI) is. What this means is how quickly they are digested and released into the bloodstream. If this happens quickly, then rapidly there is a rise in blood sugar and therefore insulin is released to push the sugars into the cells. Not only does this increase the likelihood of obesity it also makes your blood sugar drop quickly in an hour or two, when the sugar rush is finished and there is no “slow-release” of other foods. Then you feel hungry and eat a snack. If this happens repeatedly over many years the body becomes increasingly resistant to insulin and you can develop “Metabolic syndrome” and type II diabetes. These are known to cause an increase in age-related cellular dysfunction, heart disease, strokes, kidney failure, and many, many more disease processes. It really is best not to get into that state in the first place. What about “complex carbohydrates”? These are usually found in natural state foods that have not undergone processing by food manufacturers. The nutrients are released more slowly and there is no sudden peak in sugar and insulin levels. You also feel fuller for longer.

Examples of refined, high GI foods:

* White bread.

* Sweets/lollies.

* Carbonated drinks.

* Short grain, white rice.

* Some breakfast cereals (ricicles, cornflakes, special K, particularly anything with sugar coating or chocolate flavouring).

Examples of unrefined, low GI foods:

* Vegetables.

* Nuts.

* Pulses.

* Wholemeal bread.

* Cereals (granola/muesli, bran flakes, weetabix).

Fats

What about fats? Lots of research is currently being directed at this area. Many fats are being found to have therapeutic affects and previous “villains” are perhaps not so bad after all.

Types of fats include:

* Saturated (animal) fats.

* Unsaturated fats which may be poly-unsaturated or mono-unsaturated.

* Trans-fatty acids.

Fats can effect the following areas:

* Blood cholesterol and lipid levels.

* Blood pressure.

* Inflammation.

* Brain and nerve tissue function.

* Development and behaviour in children.

* Blood vessel flexibility.

It should be your aim to understand what fats are best avoided altogether, which can be consumed safely in moderation and which should be taken for health benefits. You should also be able to remember in which foods you can find these, and so buy produce that will keep you healthy, not increase the likelihood of disease.

Cholesterol

It is a gross over-simplification to say that cholesterol is “bad”. We need cholesterol to make a great many of the body’s hormones, without which life would be impossible. However, elevated levels of cholesterol in the blood are clearly linked to the development of cardiovascular disease, possibly increasing the risk of some cancers and worsens mortality figures. Conversely, lowering blood cholesterol decreases the risk of heart attacks, strokes and all cause mortality. This is clearly shown in people with raised cholesterol and increasing evidence points to this being the case in people with a “normal” cholesterol.

A diet that is rich in saturated (animal fats) and cholesterol may have a detrimental effect on certain people’s lipid profile, whereas one that is high in good oils such as olive oil may improve it. This used to be a cornerstone of dietary advice, but this may not always hold true. High animal fat and protein diets with a very low carbohydrate intake, such as the “Atkins Diet” have now been studied in a bit more detail. Contrary to conventional wisdom, the levels of total cholesterol, HDL (good cholesterol), LDL (bad cholesterol) and triglycerides may actually improve! We can look at this in more detail later, but I think it is wise to monitor your lipid profile closely if you are going to adopt a strict Atkins or Ketogenic diet. In addition, there are other long-term effects of being on this kind of diet that are probably detrimental to health.

Trans-fatty acids (TFAs)

These are the bad guys! Suffice it to say that they don’t really exist in natural foodstuffs. What is a TFA? It is the result of heating a vegetable oil in a certain way to make it change its structure. The reason that they exist is because they are remarkably stable, and therefore allow products that are manufactured with them a long shelf life. They are primarily found in baked goods, biscuits, margarines and ready-meals. Multiple excellent studies have shown them to be highly detrimental. Many countries stipulate that products containing TFAs must have this clearly labelled. The give away is usually on the labelling when “hydrogenated vegetable oil” or just “vegetable oil” is present on baked goods. Try to avoid if at all possible, and even press for change in the legislation as they can be hard to spot. New York has just become the first city to ban TFAs!

Poly-unsaturated fatty acids (PUFAs)

These can either be omega-3 (n-3) or omega-6 (n-6). Omega-3 oils are found in cold water fish and are generally accepted to be good for you. For vegetarians, flaxseed oil is a good source of omega-3 oils. The beneficial effects of n-3 oils are primarily on the cardiovascular system. They help with:

* Reducing blood pressure.

* Decrease inflammation in joints as well as in blood vessels.

* Decrease platelet stickiness that contributes to heart attacks and strokes.

* Lower blood fat levels.

* Decrease atherosclerosis.

* Help modulate mood and behaviour.

The fish that are richest in n-3 oils are from cold waters and include:

* Salmon.

* Tuna.

* Mackerel.

* Herring.

* Sardines.

* Hoki.

Please be aware that the larger the fish, the higher up the food chain it is, and therefore the greater the risk of mercury contamination. I would also urge you to consume fish that is either harvested in a sustainable way, or is not under pressure from over-fishing. Small pelagic fish (sardines, anchovies and herring) are abundant, low risk for mercury toxicity and cheap. In contrast, most tuna populations are on the verge of collapse (with the exception of skipjack tuna), expensive and have significant mercury contamination.

Omega-6 oils are found in other vegetable oils such as canola, sunflower and margarines. Our current western diet is overweight in omega-6 oils. It is estimated that for optimal health, a ratio of n-6 to n-3 oil intake, should be no more than 6:1 and probably as low as 3:1. Most people consume foods with a ratio of between 20:1 to 50:1. This is thought to be “pro-inflammatory”. The type of chemical messengers that the body uses to create inflammation are formed from n-6 oils. The messengers that are “anti-inflammatory” are formed from n-3 oils. Often the oils used in bought foods contain hydrogenated vegetable oils. These have been partially altered to be more saturated (see TFAs) and are more stable. Recent research suggests that these could be positively harmful.

Mono-unsaturated fats (MUFAs)

Olive oil is an omega-9 MUFA. This should be your primary source of fat. I recommend you use olive oil as your cooking oil and also for salad dressings. There is good evidence to support the health benefits of olive oil, particularly if it is cold pressed extra-virgin (this means there are no chemical processes used to help extract it that may alter it’s structure). It is a rich source of phytonutrients and anti-oxidants. Olive oil can:

* Decrease your risk of heart disease.

* Improve your cholesterol and blood lipid profile.

* Decrease inflammation.

* Help prevent obesity and metabolic syndrome.

Other sources of MUFAs are nuts and avocados.

Protein

Should make up approximately 30% of your total calorie intake. It is preferable to get this from non-animal sources such as beans and pulses, fish or dairy produce but some meat intake is not detrimental to health. Try to use lean cuts of meats, which will allow you to get your protein without consuming extra saturated fats. We would encourage you to spend more for your meat and eat it less frequently. This way you can afford to buy good cuts of meat from animals that have been raised in a manner that is not intensive, do not use antibiotics or hormones indiscriminately, and have been slaughtered in a humane and hygienic fashion. Many meat industries are poorly regulated can therefore offer the cheap, poor quality meats that are created by using these methods. Again, it pays to read the labels, or better still, get to know your local butcher. We recommend The Omnivore's Dilemma: The Search for a Perfect Meal in a Fast-food World by Michael Pollan, as a good insight into the industrialisation of food.

Phytonutrients

A diet rich in plant foods has been associated with good health and long life. There are strong associations with a decreased risk of cancers, heart disease, blood pressure, neurodegenerative diseases and diabetes/metabolic syndrome. Lots of these benefits were thought to be due to the anti-oxidant content of fruits and vegetables. Recent studies have therefore looked at taking these antioxidants and supplementing them individually to people, then measuring whether the health benefits follow. The results have largely been conflicting. It seems likely that the mechanisms for these health benefits are far more complicated. It is probable that these factors act in concert and in combination, and probably modulate cell-signalling pathways and growth factors. More sophisticated supplements will be developed as a greater understanding of these components evolves. We currently recommend supplements for which there is a good body of proof. We also suggest it is best to try and consume as many fruit and vegetables in your diet as you can tolerate. Uncooked or lightly steamed vegetables are usually better as the phytochemicals can be de-activated by prolonged cooking. Two exceptions to this rule are tomatoes and carrots – both these are significantly better for you when cooked! I highly recommend the Linus Pauling Institute website for an in depth explanation of these facts.

Superfoods

Following on from the phytonutrient section, there are certain things that I would encourage everyone to include in their diet.

Berries

Dark berries contain massive amounts of anti-oxidants and are packed with the flavanoid subclasses: anthocyanidins and flavanols.

Fish

Deep sea cold water fish from a renewable resource at least a couple of times per week. Farmed fish may not have any benefit as the oils depend on a natural diet and cold waters.

Flaxseed oil (FSO)

Ground flaxseeds are the best, sprinkled over foods or cereals. If you use FSO then ensure it has some of the husk/seed left in as this has the lignan secoisolariciresinol diglycoside (SDG) which is an essential component for it’s beneficial effect.

Olive Oil

A rich souce of n-9 FA which have anti-inflammatory, lipid modifying and anti-platelet effects.

Nuts

Contain long chain fatty acids (LCFAs), anti-oxidants and trace elements. Brazil nuts are the best source of selenium.

Dark Chocolate

Try to buy with a minimum cocoa content of 70%, contains the flavanoid procyanadin with powerful anti-oxidant effects.

Green tea

Contains a flavanol, epigallocatechin-3-gallate (EGCG), which can inhibit metalloproteinases, and acts as a potent anti-oxidant among several possible other mechanisms. Populations that consume high volumes of green tea have a lower incidence of many cancers and heart disease. Green Tea also prevents age and UV related skin damage. Recent research has shown that the active components in green tea can be maximised by consuming it with vitamin C.

Black tea

Particularly Oolong, has high levels of polyphenols, catechins and isoflavins. Mostly inactivated by the addition of milk or when consumed with dairy products.

Red wine and grapes

Particularly the cultivars grown in cooler climates such as Pinot Noir, which contain high quantities of resveratrol, a substance that has similar effects at a cellular level to a calorie restricted diet. The methods used in Sardinia and Southwest France help preserve the polyphenol content. Resveratrol has been shown to increase the lifespan of yeasts, fruit flies and worms in a similar fashion to caloric restriction. Grapes and grape product also contain other flavans, anthocyanins, quercetin, myricetin and kaempferol which have beneficial effects on lipid profile, oxidative stress profile, inflammation and platelet function. Needless to say, wine should be drunk in moderation and supplementation is the way to go.

Tomatoes

Contain lycopene which is particularly effective against prostate cancer and probably has general anti-cancer and a cardiac protective effects as well. The anti-inflammatory effect is also of benefit in rheumatoid arthritis. Activity is increased by 6 times when cooked.

Cruciferous vegetables

Bok choy, broccoli, cauliflower and brussel sprouts. Best of all are broccoli sprouts: 1 sprout has the same quantity of sulforophane as a whole head of broccoli. Thought to be potent anti-cancer agents, particularly for breast cancer.

Miso soup and soy products

Good source of phyto-oestrogens, that may have a role in breast cancer prevention if introduced into the diet early in life. Proven to improve the appearance of age and sun damaged skin. Recent reports suggest that one component is particularly effective at decreasing abdominal fat and therefore the risk of metabolic syndrome and type II diabetes.

Garlic and onions

Contain allium that has been shown to be protective in stomach, colorectal and prostate cancer.

Turmeric

Turmeric contains curcummin, a highly exciting compound that we will be hearing a lot more about in the future. Curcummin has been shown in the lab to kill cancer cells, repair many forms of genetic damage and assist cells resist aging processes. Protects against photo-aging of the skin.