Author name: Tony Laughton

In this episode of Lifestyle Matters.

This week, Dr Ferghal and I explore the ‘Portfolio Diet’; known for its effectiveness in lowering LDL i.e. ‘bad cholesterol’. This diet is said to be as effective as Lovastatin, which is a cholesterol lowering medication!

Before exploring this further let us gain a basic understanding of what Cholesterol is. Cholesterol is an essential waxy substance in our body that is needed for a variety of important functions including making hormones, building cells, and protecting our brains.

However, it often gets bad reputation, and this is largely due to the LDL (low density lipoprotein) which is the molecule that sticks to damaged parts of our blood vessels. This causes a variety of other cells to latch on to it which eventually forms plaques which can break off at any point and potentially obstruct blood flow to our heart. This obstruction leads to heart attacks.

HDL (high density lipoprotein) on the other hand is a molecule that scavenges excess cholesterol through our body and shuttles it to the liver to get excreted. Hence it is often referred to as the ‘good cholesterol’.

The Portfolio study demonstrated a 30.9% LDL reduction in the cohort that received Lovastatin compared to 28.6% who were on the Portfolio diet. This difference is not clinically significant.

So what exactly os the Portfolio Diet?

• High plant protein – soy – 50gm/ day

• High nuts & seeds – 50gm/ day

• High viscous fibres 10-25gm/ day

• High plant sterols – 2gm/ day

 It is a diet very rich in fibre and would achieve the current recommendation of 40gm of fibre / day in women and 45gram/day in men which most of us do not usually consume.

How does the Portfolio Diet improve LDL levels?

• High fibre: Especially soluble fibre. e.g. fruits, vegetables and oats do not get absorbed in the intestines. Instead, they bind to cholesterol molecules thus reducing its absorption

• High plant sterols : These compete with cholesterol absorption in the gut thereby cholesterol absorption is reduced

But what are plant sterols?

These are naturally occurring cholesterol substances at low levels in plants and fruits. Unfortunately, it is not easy to get enough through our diet hence margarine spreads that are high in plant sterols are recommended.
There has been little evidence supporting this hence the Heart Foundation Guidelines have also recommended consumption of 2-3gm plant sterol / day.

Other potential benefits of this diet include reducing insulin resistance and blood pressure. A study demonstrated a 2 % reduction in blood pressure at 24 weeks compared to the DASH diet (Dietary Approaches to Stop Hypertension) which is quite astounding since this diet’s primary aim was not to reduce blood pressure.

This is undoubtedly not an easy diet to follow but if one can adhere to it strictly, there are certainly many benefits to gain.

In this episode of Lifestyle Matters.

The highs and the lows of the “Low Carb High Fat” diet.

Many people tend to subscribe to the famous “Low Carb High Fat” diet and others swear by it but a pertinent question to ask is whether these individuals do it well or if they are successful? Can the diet really improve diabetes control?

This week on Lifestyle Matters, Dr Ferghal and I take a deeper dive into the “Low Carb High Fat” diet”.

Before insulin was discovered in the 1920s, a low carbohydrate diet was commonly prescribed to patients with diabetes. The logic was that the lower the carbohydrates consumed, the lower the glucose levels in our bodies. The prescription of this diet for diabetes control persisted despite the discovery of insulin! They were not wrong; there have been many studies demonstrating the efficacy of this diet in weight loss and reduction in insulin resistance. Insulin resistance is one of the underlying factors in the development of diabetes.

When we eat carbohydrates, these get broken down into sugar molecules which then triggers off insulin release for it to be taken up by our cells. If we have diabetes, insulin does not work very effectively, thus our glucose (sugar) levels rise. So, we can see why a low carbohydrate diet was prescribed for diabetes control.

However, long term studies have shown that this diet is not as sustainable as we may think it is. Further, their potential adverse effects from this diet which we will explore below.

Firstly, let us study the amount of energy we should obtain from various macronutrients.

As seen in the chart above, 45-65% of energy intake = 225-325gm of carbohydrate / day.

There are a few different types of low carb diets:
• Very low: 20-50gm of carbs/ day (most effective, almost ketogenic)
• Low: < 130gm / day
• Moderate: < 230gm/ day

The reality is this; it is not easy to sustain a very low carbohydrate diet beyond 6-12 months. Many people fall back onto a low and moderate carbohydrate intake which does not produce results as effective as a very low carbohydrate diet. Further, people tend to increase their protein intake while on this diet which commonly is achieved through a higher meat intake i.e. saturated fat.

We know red meat have other detrimental effects to our health as it is classified as a Group 2A Carcinogenic Food by the World Health Organisation.

It is imperative to keep the saturated fat to < 10 % if one were to follow this diet. This is also extremely important for those who suffer with hypertriglyceridemia (where their triglycerides > 500 mg / dL ) as the ability to remove triglyceride enriched lipoproteins are saturated and can lead to pancreatitis. This shows the indirect effects of going on a low-carb diet.

There are other adverse outcomes from consuming a low carbohydrate diet over long term such as:

• Osteoporosis: Various mechanisms have been identified in rat models (watch this space!)
• Deficiency in vitamins and minerals: Dietary fibre, Magnesium, Phytochemicals that are usually found in complex carbohydrates.

In summary, the key message from this is that if a low carbohydrate high fat diet suits one’s lifestyle it is a reasonable choice as it certainly does demonstrate several benefits. However, due to issues with its sustainability and potential negative implications on our health, it may make it less than an ideal diet to stick to beyond a year.

In this episode of Lifestyle Matters.

Can we generate a super fuel in our bodies by eating differently? This week we look at the popular keto diet from a medical perspective.

This diet was originally founded in the 1920s by Russel Wilder to treat epilepsy and it worked! Once anti-epileptic medications were discovered, this diet became less popular until recent times when it became evident that it also helps with weight loss. Truth be told, this diet is still used for some refractory epileptic patients under medical guidance.

A keto diet is essentially a diet we consume to put our body in a state of ketosis. But first, what is ketosis? To understand that we must understand what ketones are.

Ketones are products of fatty acid breakdown e.g., acetoacetate, beta hydroxybutyrate and acetone. These molecules are continuously produced in our bodies in small amounts as part of normal physiological processes.

Ketosis or ketogenesis is a process when our body uses these ketone bodies to provide energy for our cells.

When we eat a well-balanced diet, our body uses carbohydrates as the main source of fuel. So, reducing our consumption of carbohydrates and increasing protein (amino acids) and fat intake allows our body to break down these macronutrients to provide us with energy via processes called gluconeogenesis and ketogenesis respectively.

Ketosis can also happen as part of disease processes e. g . starvation, alcoholism, poorly controlled diabetes and even extreme prolonged exercising. This is obviously dangerous to our health and requires treatment.

Most cells in our body can utilise ketones as a source of energy except our red blood cells and liver. The brain is really good at doing this!

This is how a Keto Diet looks like:

Ketones are called a super fuel because:
100 gm of glucose we can generate 8700 gm ATP
100gm of beta hydroxybutyrate generates 10 500 gm ATP
100gm of acetoacetate generates 9400gm ATP

Apart from being a super fuel, it has various other benefits such as:

• Treating difficult to control epilepsy

• Reduce the risk of neurodegenerative conditions e.g. Alzheimer’s Disease

• Reduces insulin production

• Increases leptin levels (hormone that tells us we are full hence suppressing our appetite) -> weight loss

• Reduces LDL, TGL

• Increases HDL

However, there are some limitations to the Keto diet that suggest that it may not be suitable for everyone.

Those who have certain enzyme deficiencies e. g. pyruvate kinase deficiency, liver failure, and pancreatitis, should not be on this diet due to the high levels of fat and protein intake. There has been also some research to suggest this diet may result in osteoporosis, kidney stones, fatty liver and gout. Further, most studies on the Keto diet have only been conducted over 6 months which means the long-term implications of the diet are still being investigated.

The main point to note is that this is undoubtedly a great diet to follow if it suits one’s lifestyle provided there are no medical contra-indications to it. However, once again it is a diet that we would suggest one to adhere to for a short period (6-12 months) as we have sufficient evidence to support this recommendation, for now at least. Post that period, transitioning to a normal well-balanced diet would be advisable. Ideally, following a whole food predominantly plant-based diet would produce the best outcome.

In this episode of Lifestyle Matters.

Benjamin Franklin said that “The best of all medicines are resting and fasting” and we know today that his words have been supported by scientific evidence. Intermittent fasting has been found to reverse early Type 2 diabetes.

The concept of fasting is not new to many especially if we look at the various cultures and religions around the world e.g., Muslims fast during Ramadan, or the various fasts practiced by Hindus and Buddhists. Even Greek philosophers such as Hippocrates and Aristotle have prescribed fasting for various ailments. This week, we look at how and why intermittent fasting works.

We must first understand what happens during the fed and fasted state. When we eat – (predominantly) carbohydrates get broken down into simple sugar molecules. This triggers an insulin response which promotes the uptake of sugar into our cells. Extra sugar (glucose) gets stored in our muscle and fat as glycogen. Leptin levels (which is our satiety hormone) also increases.

When we fast, glucose and insulin levels reduce. This causes our body to search for an alternate source of energy hence processes such as lipolysis and gluconeogenesis begins.
Later on, ketogenesis occurs whereby ketones are produced from the breakdown of fatty acids which is then used a source of energy i.e. ‘the super fuel’

When we fast for prolonged periods of time, our body enters a state of stress adaption whereby it begins certain processes such as cleaning and repairing e.g. DNA repair, protein quality control, increasing expression of anti-oxidant defences etc. As the body enters a fed state, tissue growth and plasticity then begin. However, when we eat ‘normally’ we do not allow our body to switch from a fed to fasting state. Several evidence have pointed the benefits of allowing our body to go through this metabolic switch and these range from:

• Neurodegenerative health: Potentially reducing the risk of dementia as there is an increase in brain derived neurotrophic factor, increased GABA sensitivity etc.
• Improved heart disease profile: Increases HDL (good cholesterol) reduces LDL (bad cholesterol), reduces resting heart rate and blood pressure.
• Reduces risk of diabetes: Reduced insulin resistance as adiponectin levels are increased and leptin levels reduced
• Reduces cancer growth: Mainly documented in glioblastoma multiforme which is an aggressive type of brain tumor, but other cancers are being studied too e.g. breast, ovarian, prostate.

While most studies have been carried out on animals, there are several others underway involving humans. We have observed over time that the profound benefit of this diet is the metabolic switch that occurs and the benefits we can gain from it whether or not there has been weight loss!

It is important to note that this diet is reasonably sustainable and allows us to eat foods we enjoy in moderation. However, no diet is superior if it is not one that suits our lifestyle, and we must always remember that exercise augments the benefits of any diet we follow.