Can eating too many carbs result in heart disease, weight gain and inflammation?
Videos below updated December 2022.
Mixed messages and guidelines that not every doctor believes in.
It’s October 2015 and I am wading through the research and books on eating a very low carb diet.
“Eat lots more saturated fat, but very little carbohydrate”, was Professor Noake's advice last year at the annual sports medicine conference in Dublin.
But what about our arteries and blood pressure, and cholesterol? I thought Saturated fat was like smoking-dangerous?
The Japanese diet is based on rice, the Polynesian's on yucca and it hasn't affected them, I ponder.
Prof. Noakes suggests it's because they haven't abused carbohydrates, such as sugar, starch and alcohol, like most western societies.
Global warming is my other concern- should we not be putting our planet first and ditching or least reducing the animal products we consume altogether, or maybe we just need to eat more of the animal, like the liver and tripe?
But there are none meat eaters behind the 'fat is good and carbohydrates are bad' motto. This group includes health professionals who remain concerned that saturated fat consumption causes heart disease. They advise a diet high in fat using olive oil, nuts and avocados, combined with fish and vegetables.
So why eat a low carb high fat diet?
The old pyramid has been replaced by the Portion Plate which has lowered the intake of carbohydrates. See diagram below.
The late Dr Atkins believed that the well-known 'Food Pyramid' based on high complex carbohydrates, moderate protein and low fat should be turned upside-down; putting animal fats at the base as the most nutritious of foods. His contemporary, Dr Dean Ornish disagreed, and continues to promote a plant based diet.
There are quite a few nutritionists and doctors that have challenged the Food Pyramid and the more recent Portion Plate (see below). Each of these health professionals- Prof Phinney, Prof Noakes, Dr Eric Westman, Jeff volek- quote scientific evidence supporting high fat, moderate protein and low carbohydrates to achieve a state of nutritional ketosis where one burns fat as fuel, not glucose.
Nina Teicholz's book 'The big fat surprise' revealed the disagreement among nutritionists and doctors in the 1970's on whether saturated fat caused heart disease. The evidence just wasn't clear, nor was the evidence relating to cholesterol levels and predicting a heart attack.
Nina Teicholz also explains that a Mediterranean diet is a label for an array of eating habits including one high in animal fats such as pork, cheese and eggs, but usually inclusive of olive oil.
Cross-section of an artery around the heart muscle showing a ruptured plaque at the bottom of the picture. There is a blood clot inside the plaque extending up into the hallow lumen (tube) of the artery. The plaque usually ruptures because of inflammatory cells weakening the surface layer.
What about high cholesterol or lipids?
Dr Aseem Malhotra, a cardiologist from the UK, has been promoting Extra Virgin olive oil and the Mediterranean diet as the safest and most successful means of lowering ‘bad’ lipids ( Triglycerides and LDL-cholesterol) and preventing heart disease.
But if food is our medicine, why are we not ditching lipid-lowering drugs, such as Statins, for a better diet?
This remains a controversial topic mainly due to the so-called 'Plaque Stabilising' effects of Statins which goes beyond lowering cholesterol, and helps prevent the plaque rupturing. Nonetheless, Dr. Maholtra's argument is worth listening to.
The National Institute of Clinical Excellence (NICE) in the UK recommend fat from unsalted nuts and seeds, oily fish, olive oil and rapeseed oil, along with exercise to treat high cholesterol (this only applies if you have never had a heart attack, don't have diabetes or kidney disease, and are motivated to change your diet).
The Portion Plate: Wholegrain carbohydrates are now represented in equal quantity to fruit and vegetables.
Are there any examples of a high fat diet treating disease?
The high fat, low carbohydrate diet has been used to treat children with intractable epilepsy, which, in a lot of cases, successfully controls seizures where drugs cannot.
Physician and kidney specialist, Dr Jason Fung would add type-2 diabetes and pre-diabetes as a second example. Patients with type two diabetes become intolerant to carbohydrates, producing high levels of insulin to deal with the sugar-load (insulin resistance). ]
The 'low carbohydrate way of eating' lowers the sugar load which reduces the over-production of insulin, which in turn reduces weight gain and hunger, reduces blood pressure and inflammation. You can listen to Dr Fung's Podcast below.
Another case to consider is the 'French Paradox' . In the 1980's it was observed that the French people who eat an array of saturated fats from meat and offal, to delicious cheeses, did not develop heart disease at the same rate as their Americans who were also eating lots of fat . This finding was attributed to regular red wine consumption which contains the polyphenol, Resveratrol.
Also modern day foods are battered and fried or prepared in unhealthy oils. We eat cakes and buns high in unhealthy fats and full of sugar, not really comparable to eating meats and cheese….
Fats are complicated and as you will see in teh table below each fat is made of a combinations of different fat categories.
What about the polyunsaturated fats that the department of health recommend we eat?
All fats are made up of a combination of saturated, monounsaturated and polyunsaturated fats. We refer to the dominant fat when describing it as one or the other i.e. olive oil is made up predominantly of monounsaturates (yellow)
Prof. Stephen Phinney a physician who has studied the high fat-low carbohydrate diet for over 30 years, argues that oils high in polyunsaturates (but not long-chain omega 3 fish oils) are the very fats that can cause inflammation( Inflammation occurs when our immune system that normally fights infection, continues producing cells to deal with an infection that is no longer there).
This is a cross section of an artery showing a large plaque to the left side of the picture. It is intact and the lumen clear. The plaque is made of lipids, surrounded by inflammatory cells called macrophages, which normally help us fight infection.
Prof. Phinney also points out that studies demonising saturated fats are carried out in patients who are still eating 'high' levels of carbohydrates along with saturated fat--macaroni cheese, fried potatoes and cakes being good examples. He believes that eggs, cheese and fatty cuts of meat contain healthy saturated fats and satisfy hunger, as long as you do not eat lots of sugar-producing carbohydrates. Prof. Phinney and many others believe that the over-eating of carbohydrate and the associated weight gain increases plaque in our arteries, not saturated fats.
Summary
Most of us eat as we please either through choice or lack of motivation to do otherwise. We ignore health guidelines-- over-eating, and over-drinking. Or, we follow a type of diet that we feel is healthy based on what we have read or been taught by our family.
Over the next few months I will reading and thoughts on: a healthy low-carbohydrate/high-fat diet and why you may want to take it seriously; the possible causes of inflammation including polyunsaturates, wheat and grains; and foods that can affect our genes and in turn the genes of our children. I will also have a look at better known diets for preventing heart disease called the DASH and Ornish diets, and the benefits of fasting.
Have a listen to the talks below to understand more about the low carbohydrate, moderate protein, high fat diet.
I suggest you listen to Dr Eric Westman’s video first. Enjoy!
Dr. Eric Westman explains the ketogenic diet to patients.
Prof. Noakes who once was an advocate for carbohydrate loading, explains his turn around.
Prof. Stephen Phinney
References
Cardiovascular disease: risk assessment and reduction, including lipid modification. NICE guidelines [CG181] Published date: July 2014 Last updated: January 2015
Effect of cutting down on the saturated fat we eat on our risk of heart disease. Cochrane review 2015.
The Big Fat surprise: why butter, meat and cheese belong in a healthy diet. Nina Teicholz.
The Art and Science of Low carbohydrate living: An expert guide to making the life-saving benefits of carbohydrate restriction sustainable and enjoyable. Jeff Volek PhD, RD, Prof Stephen Phinney, MD PhD