Stethoscope listening to a heartbeat

Is the ketogenic diet safe for the heart?

Stethoscope listening to a heartbeat

I was asked the other day whether or not eating a low carbohydrate, high fat diet such as a ketogenic diet would be safe for the heart. My answer was YES. However, honestly, up until about two years ago this would not have been my answer.

I remember about 15 years ago when the Adkins diet was a popular diet. Some of my family and friends were on this diet and had great results with it. I however, gave them a hard time, ‘yes you will lose weight but you will die from a heart attack’.

The theory was that eating all that saturated fat would increase cholesterol levels, which would increase the risk for atherosclerosis or clogging of the arteries and then heart attacks. We have since learned that this is not true. As I discussed in another blog, it was shown that people who switched from eating saturated fat to vegetable oils, which at the time was thought to be the healthier type of fat, actually had an HIGHER risk of heart attacks and death. (Ramsden 2016) (Ramsden 2013)

Those studies however, just looked at changing the types of fat that were eaten, i.e. stopping saturated fats and start using vegetable oils, not increasing the amount of fats in the diet. So what happens to cardiac risk factors (obesity, specifically waist circumference, hypertension, diabetes, high triglycerides and high systemic inflammatory markers such as CRP) when start eating more fats and fewer carbohydrates as in low carbohydrates diet? Several studies, which were recently published, answered just that question.

The first was a study published in the journal Obesity Reviews in 2012. This study reviewed 23 studies with a total of 1,141 obese patients eating a low carbohydrate diet for weight loss. They found improvement of all major cardiovascular risk factors associated with eating a low carbohydrate diet.   Specifically, the study found a significant decreased in weight, body mass index and abdominal circumference. Systolic and diastolic blood pressures were also decreased.   Markers for diabetes were improved including, fasting plasma glucose levels, gylcated hemoglobin (HgA1c) and insulin levels. Cholesterol levels were also improved; with lower levels of triglycerides and increased levels of HDL. Lastly the marker of inflammatory, CRP levels, were also improved (Santos, 2012)

Another study looked at very low carbohydrate or ketogenic diet specifically. This study reviewed a total of 13 studies, in which a total 1577 individuals were randomized to either very low carbohydrate diet or a low fat diet. The very low carbohydrate diet group had significantly greater weight loss, improvement of diastolic blood pressures, lower triglycerides and higher HDL levels. Fasting blood glucose, insulin levels, HgA1c and CRP all showed improvement in favor of the very low carbohydrate group compared to low fat groups. (Bueno, 2013)

The LDL levels in the very low carbohydrate group were increased, as expected from eating more saturated fats. However, as discussed in a prior post, it is not the LDL particle itself that is the problem: instead, it is the size of the particle that matters. There are actually two different types of LDL based on size. There is small and large size LDL. The small LDL particles are the ones that are believed to be harmful, or more prone to cause the clogging of the arteries that is of clinical concern. When LDL is exposed to high carbohydrates and high triglycerides, it is more likely to become oxidized or damaged, making the LDL a small dense particle. Whereas, it has been shown the type of LDL particles that are elevated when the diet contains a higher saturated fat (not the inflammatory vegetable oils) combined with carbohydrate restriction, are the larger sized LDL particles, which are the less artherogenic than the small dense LDL. (Krauss, 2006)

Then lastly, a study published in the journal Circulation, used carotid ultrasound as a way to measure atherosclerosis. The participants were randomized into a low fat diet, a Mediterranean type diet or a low carbohydrate diet. After 2 years of dietary intervention, they found that all 3 groups had a significant regression of the atherosclerosis plaques. This suggested that the low carbohydrate diet is at least as effective as the other diets in showing regression. The study did not have the power to show differences between the groups, but there was a slight trend for the greatest improvement seen in the low carbohydrate diet. (Shai, 2010)   Thus, based on this study eating a low carbohydrate diet does not increase risk of atherosclerosis disease; instead it may actually decrease it.

So yes I have to apologize to my friends and family who were ahead of the game. They were right all along. Based on these studies and others, I now come to realize that going on a low carbohydrate, high fat diet such as ketogenic diet is indeed safe for the heart. Not only may the ketogenic diet help you lose weight, it may also improve your cardiovascular risk factors and does not increase your risk of atherosclerosis.

Need help with a ketogenic diet? First step is filling out this form and then I will be happy to help.

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Bibliography

Bueno, N. B. (2013). Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. British Journal of Nutrition (110), 1178-1187.
Krauss, R. (2006). Seperate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia. American Journal of Clinical Nutrition (83), 1025-1031.
Ramsden, C. E. (2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from the Minnesota Coronary Experiment (1968-73). British Medical Journal, 353, 1-17.
Ramsden, C. E. (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. British Medical Journal, 346, 1-18
Santos, F. (2012). Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obesity Reviews, 13, 1048-1066.
Shai, I. (2010). Dietary Intervention to Reverse Carotid Atherosclerosis. Circulation, 121, 1200-1208.

Not all fats are created equal

Fat are not the enemy part 2

fatty foods

Our bodies need dietary fats:

Our brain and body needs dietary fat and dietary cholesterol to function. Fats are the building blocks for our cells membranes. Fats are carriers for the fat-soluble vitamins A, D, E, and K. Our body’s hormones (testosterone, progesterone, DHEA, estrogens, aldosterone along with others) are produced by dietary cholesterol. Eating healthy fats can decrease hunger by the release of the hormone CCK that signals satiety and decreases the cravings for foods.

Our brain needs dietary fats:

More importantly, our brains require a diet of fat for it to work properly. Our brains are composed of 60 percent fat. The majority of which is made up from the omega 3 fatty acid, docosahexaenoic acid (DHA). The brain relies on fats for communication between nerve cells. Studies have show that a deficiency of omega 3 fatty acids has been associated with increased risk for depression, anxiety, and bipolar disorder. Eating high quality fats has been reported to improve cognition, focus and memory. Specifically one study, showed that people who ate the highest levels of fat (monounsaturated and polyunsaturated) had a 44% decreased risk for developing mild cognitive impairment.

Not all fats are not equal:

With that said not all fats are created equal however. Out of these categories there are some that are fats that are better than others.

Fats are broken down into different categories

  1. Saturated (meat, lard, eggs, coconut oil, butter)
  2. Unsaturated
    1. Monounsaturated fats (olive oils, avocados, peanuts, almonds)
    2. Polyunsaturated fats
      1. Omega 3 fatty acids (herring, salmon, flax seed, nuts)
      2. Vegetable oils (corn, safflower, soy, and sunflower oils)
    3. Trans fatty acids (margarine, shortening)

The best fats are the monounsaturated fats and polyunsaturated fats that contain omega 3 fatty acids. Saturated fats, previously felt to be the ‘bad fat’ has since been shown to actually be beneficial to the body. The unhealthy fats are the trans fatty acids and vegetable oils.

The saturated fats along with omega 3 polyunsaturated fatty acid have also been shown to decrease inflammation, where as the omega 6 polyunsaturated fatty acid increase inflammation. In a prior blog post, I discussed that increasing the amount of omega 3 compared omega 6 fatty acids in your diet has been shown to be helpful in migraine patients. The polyunsaturated fatty acid that contain a higher ratio of omega 6 compared omega 3 fatty acids, which should be avoided include corn oil, safflower oil, soybean oil, sunflower oil and cottonseed oil

Saturated fats, specifically, have gotten a bad rap in the past for the concern that it could increase the risk of atherosclerosis or clogged arteries in the heart. As discussed in another blog post, actually it was found that people who switched to vegetable oils instead of saturated fats had HIGHER risk of heart attacks and death.

So where are the best sources of these healthy fats?

  • Fatty fish: sardines, mackerel, herring and salmon contain a high level of omega 3 fatty acids
  • Nuts: pecans, walnuts, almonds and macadamia nuts are a great source of healthy unsaturated fats.
  • Seeds: pumpkin, sesame, chia, and flax seeds
  • Avocados
  • Whole eggs
  • Olive oils: preferably extra -virgin
  • Coconut oil
  • Grass feed butter and other animal products

 

Bibliography

Freeman, M. E. (2006). Omega-3 Fatty Acids: Evidence Basis for Treatment and Future Research in Psychriatry. Journal of Clinical Psychriatry, 67, 1954-1967.
Lawrence, G. D. (2013). Dietary Fats and Health: Dietary Recommendations in the Context of Scientific Evidence. Advances in Nutrition, 4, 294-302.
Ramsden, C. E. (2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from the Minnesota Coronary Experiment (1968-73). British Medical Journal, 353, 1-17.
Ramsden, C. E. (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. British Medical Journal, 346, 1-18.
Roberts, R. E. (2010). Polyunsaturated Fatty Acids and Reduced Odds of MCI: The Mayo Clinic Study of Aging. Journal of Alzheimer’s Disease, 21, 853-865.
fatty foods

Fats are no longer the enemy

Debunking the myth that saturated fats are the cause of heart disease

Fats have gotten a bad rap in the past. You know the storyline that we all have been told over the years: fats make you fat and they are the cause of high cholesterol and coronary heart disease.

It all started back in 1961 when the Framingham Heart Study came out showing a correlation between high serum cholesterol and an increase risk for coronary heart disease health and strokes. Since then we all, doctors included, have been convinced that fats, particularly saturated fats should be avoided. This led to a major push by medical, governmental and public health messages to encourage people to switch from eating diets of saturated fats (butter, meats and eggs) to using vegetable oils and low fats foods.

However research in the last decade have challenged that thought process. One such study was published in The American Journal of Clinical Nutrition. This review looked at prior studies that had been preformed on diet of saturated fat and the risk of coronary heart disease and stroke.   It actually showed that there was no evidence that dietary saturated fat was associated with an increase risk of coronary heart disease or stroke.

Next, more evidence that saturated fats are not the problem was shown when the data from a couple of randomized studies; the Sydney Diet Heart Study and Minnesota Coronary Experiment (MCE), were reanalyzed. These studies were designed to test whether replacement of a diet of saturated fats with one using a vegetable oil (linoleic acid) would reduce the risk of coronary heart disease and death by lowering cholesterol. Both studies showed that despite the fact that switching from saturated fats to this vegetable oil resulted in a decreased the cholesterol levels, there was not a decrease the risk heart disease or deaths. Instead the opposite was shown. There was actually an increased risk of death and heart attacks in the vegetable oil group.   Further more in the MCE study, the participants who had the greatest reductions in serum cholesterol had the highest risk of death. Additionally, the MCE study showed that despite lowering the cholesterol levels, there not any improvement in the atherosclerosis at autopsy.

So if eating saturated fats leads to an increase in cholesterol but not an increased risk of heart diseases then what is the cause of atherosclerosis coronary heart disease? To better understand this, let’s take a look of what we mean when talk about cholesterol.

When you get your cholesterol check it will have it broken down into total cholesterol, HDL, LDL and triglycerides. HDL is typically been considered the good or Healthy type cholesterol, and LDL is the bad or Lousy type of cholesterol. However it is not the LDL itself that is the problem, or cause of atherosclerosis.  It is when the LDL becomes oxidized that it causes atherosclerosis. Oxidation occurs which sugars attach to the LDL molecule making it nonfunctional. When it is dysfunctional it attaches to the lining of the arteries, which then results in an inflammatory response and eventually atherosclerosis plaques formation. So what is the cause of oxidation of the LDL molecules? The very things that we were told to eat to prevent heart disease; carbohydrates i.e. sugar and vegetable oils such as Linoleic acid or corn oil.

So I know it is a hard habit to break but one that is essential to your health. Stop eating those “low fat” foods, ditch the vegetable oils and margarines.   Go ahead use real butter and don’t feel guilty about eating those eggs and bacon.  Your brain and your heart will thank you for it.

Bibliography

Lawrence, G. D. (2013). Dietary Fats and Health: Dietary Recommendations in the Context of Scientific Evidence. Advances in Nutrition, 4, 294-302.
Ramsden, C. E. (2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from the Minnesota Coronary Experiment (1968-73). British Medical Journal, 353, 1-17.
Ramsden, C. E. (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. British Medical Journal, 346, 1-18.
Siri-Tarino, P. E. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. The American Journal of Clinical Nutrition, 91, 535-546.