Insights on eating for gut health by a vegetarian cardiologist

diet gut health Jul 17, 2019

A few years ago, I was searching for a physician who was informed about how nutrition can affect our health. This was surprisingly hard to find. Then a friend recommended her physician, Hooman Yaghoobzadeh, MD, who has also been distinguished by New York magazine as one of the best doctors in New York and by Castle Connolly as one of America's best doctors.

Knowing how confused most people are about how to eat, I sat down with Dr. Yaghoobzadeh to ask him about how he eats and why. For this month's gut detox theme, Dr. Yaghoobzadeh also advises on how we can eat to support our gut health. 

I hope you find at least one idea that can optimize your health. I was reminded of a few!

—Sophia Ruan Gushée


What is your specialty?

I am a Cardiologist and Internist, trained at University of Pennsylvania and New-York Presbyterian/Weill Cornell Medical Center. 

For how long have you been vegetarian, and how/why did you choose a plant-based diet?

I refer to it as eating a Whole Foods Plant Based Diet (WFPBD) as opposed to vegetarian or vegan: You can be vegan, and eat white bread and jam all day long. 
I was born in Iran and ate a Mediterranean diet until moving to the states, where a 'western diet' prevailed since it was so available, cheap, and addictive. Over the past 30 years, my diet would be what most people would catergorize as 'healthy.' However, in retrospect, there was highly processed food AND animal protein at 90% of meals. 
I started to investigate healthier diets about 8 years ago when presented with patients who had early and aggressive vascular disease secondary to genetic causes. I did a 'deep dive' into the literature and concluded this is the best foundational diet for not only cardiovascular disease but for overall human health. I would recommend it to my patients but was unsatisfied with the practical advice I would be able to give them. Therefore, I 'put myself' on the diet for 1 month, and then it was off to the races.
I felt better, lost weight, and objectively my 'numbers'—like inflammatory markers and cholesterol—went from excellent to outstanding! 
I eat seafood 2-3 x a week, partly because it makes this way of eating MUCH more practical, And partly because I believe it leads to cardiovascular and cerebrovascular health.  

How has science changed its understanding of how health can be influenced by nutrition and other environmental factors?

Nutritional sciences really developed in the 1950's-60's when the 'nutritional problem' of the day was curing severe 'protein-calorie' malnutrition in third world countries and figuring out how to feed astronauts. These clinical questions led to science and scientific solutions that focus and revolved around individual micro-nutrients and calories. The science tried to identify individual micronutrients that are responsible for health and their mechanisms.  
Currently, not only in the USA, but around the world, nutritional problems are no longer about protein-calorie malnutrition. In fact, the VAST majority of the problem now is calorie over nutrition even in Africa. 
At the same time that we are getting too many calories, we are also being poisoned by sugar and chemicals involved in food processing. Concurrently, the much needed fiber, which evolutionarily has been multiples in amount to what we are consuming today, is devoid in modern diets.  
Fiber is necessary for gut health, serving as the 'prebiotic' for our microbiome as well as many other functions. Presented with the current obesity epidemic, the nutritional sciences have now (slowly) changed their approach. There is more research into dietary patterns leading to health. The most recent breakthroughs have come through discoveries about our micro-biome and their role in our health.
Medical schools are starting to teach about nutrition and hopefully there will be a major shift in the way the medical community views diet and nutrition over the next 20 years. We are also starting to understand that eating a WFPBD is not only essential for human health but our planetary health as well (


What do you wish more people knew about diet and health?

  1. Our diets are the #1 modifiable factor leading to poor health. Science suggests that dietary patterns are responsible for at least 30% of all modern day diseases and deaths in the US. These are completely preventable outcomes.
  2. It is not hard to move towards a WFPBD plus fish. It does not need to be all or nothing.
  3. At the very least, look at sugar, high fructose corn syrup, and other 'sweateners'; and processed meats, like bacon and sausage, as toxic and carcinogenic. When you categorize them in this way—the way you would approach cigarette smoking—then 'everything in moderation' is not a fitting guidline.
  4. One of the main ways to reduce our exposure to the chemical processing inherent in modern food is to reduce our exposure to animal products including dairy and eggs given that modern animal husbandry is SO INTENSLY knotted with chemical exposure and processing.
  5. The main difference between animal proteins and plant proteins is that animal proteins are Protein+Fat (mostly saturated) and plant proteins are Protein+FIBER+fat (mostly unsaturated). Therefore, the main benefit of moving from animal products  to whole plants is that you create caloric space in your diet to have more fiber. The average American has 15 grams of fiber a day, a healthy Mediterranean diet has 30 grams of fiber and a WFPB diet has 60grams of fiber a day. You cannot just 'add' this much fiber without creating the caloric space.  
  6. It is not about the individual micronutrients found in 'healthy' foods: 99.9% of well done, randomized, controlled, double-blinded, prospective studies looking at individual micronutrients given as supplements show no improvement in real outcomes, EVEN WHEN fiber has been studied. It is about hundrends/thousands of micronutrients/compounds that are found in Whole Foods juxtaposed in just the right amounts with fiber that lead to human health.

What do you wish more people knew about gut health?

There is an essential symbiotic relationship between what we eat, our microbiome, and our health. One example is "Fiber eating bacteria (firmicutes) eat fiber and make short chain fatty acids which are the preferred fuel for our gut cells lining our intestines. When these gut cells are well nourished with short chain fatty acids, they make Mucin (glycocylated proteins), which act as a mucous barrier keeping our gut microbiome 'away' from our gut lining. 
When there is less fiber, there is less short chain fatty acid production and fuel for the gut cells. Therefore, they make less mucin. In addition, with more protein in the diet, protein eating bacteria flourish and eat away the mucin (glycosylated proteins). This degradation in the mucin barrier between bacteria and 'self' leads to increased bacterial 'interaction' with gut cells, which activates the immune system and increases inflammation.
This is the scientific explanation behind the 'leaky gut' that lay people refer to as a cause of increased systemic inflammation. Inflammation is an essential and integral part of pathways leading to ALL modern day disease! In this way, not only can diet directly lead to disease, but it can lead to microbiome changes that magnify disease.  

What are 3 tips we can follow to support our gut?

  1. Eat unprocessed foods. 
  2. Eat more plants
  3. Increase variety of plants in your diet

What advice do you have about boosting our body's natural detox mechanisms?

The majority of toxic compounds in our body will be stored in fat cells given their hormonally active nature. There are many reasons to lower body fat percentage and this is probably one of them. Having said that, weight loss probably mobilizes lots of these compounds (as fat cells shrink), and eating a healthy diet for weight loss is probably important. Increasing fiber would help any gut mechanisms that lead to detoxification. Our kidneys and liver are our main ‘ detoxification ‘ organs and keeping them healthy are of paramount importance. Guess what is the healthiest diet for the liver and the kidneys? ....a WFPBD

It's been hard for me to get comfortable with supplements since it's not a regulated industry. But do you think there are supplements worth taking? 

I am not a supplement fan. In fact almost all studies looking at supplements in a prospective, double-blinded, placebo-controlled trials show that supplements do not reduce disease (as stated above).
Modern lifestyles can lead to vitamin D deficiency, and that is one that I regularly check and supplement. I sometimes give magnesium for muscle cramps and other supplements to prevent migraines. In these situations, we identify symptoms that should improve and if they do not, then we stop the supplements. 


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