Wednesday, April 12, 2017

Food for thought - you are what you eat and when you don't

Ben asked me recently about how to eat healthier.  I was delighted with his question as it is a topic I have been digesting ever since I began to deal with my inherited hypercholesterolemia in my 30’s and practicing the intermittent low-calorie fasting over the past 17 months. 

I will try to summarize several complex themes after which you’ll wonder if you should be eating twigs and leaves which are full of fiber, low calorie, gluten-free, plant-based …  I will say that, as a gastroenterologist, you do want your poop to look like twigs and leaves …  If you want to cut to the chase, you can skip to the recommendations at the end of the blog although I’m not sure they will make sense without the background below.

Four background themes
 fast intermittently
-  reduce refined sugar intake
-  reduce total protein intake to daily requirements
- increase plant-based proteins (reduce animal proteins)

Mosley (reviewed a few blogs back) makes a strong case that many ethnic groups practice intermittent fasting as part of their normal cultural routine.  It also has been known for 70 years that if you reduce calories in a rat, they live longer.  Now we know why.  Recent animal studies indicate that fasting turns on several life sustaining processes:  1) increases insulin sensitivity (reversed insulin resistance which is the physiologic driver of metabolic syndrome, obesity and type 2 diabetes), 2) increases stem cell production and autophagy (cellular renewal and cleanup), 3) it increases cancer immunity, and 4) remodels hippocampus (improves memory) ... and you don’t lose physical or cognitive abilities while fasting.  Mosley’s major contribution is to translate this concept into a diet plan that most can tolerate.  I have gotten many friends, spouses, their fathers, their mothers who have had success with this as well.  And, it doesn’t cost anything (except new clothes).

Taubes reviews the physiology, epidemiology and politics of refined sugar, especially sucrose (a double sugar with exactly 50% fructose and 50% glucose), fructose (a fruit sugar) and high fructose corn syrup (55% fructose and 45% glucose).  To make a long story short in the U.S. we are now consuming 114 lbs/year = 17,214 teaspoons of sugar per person per year.  How sweet we are!  This geometrical rise over the past 75 years parallels the mushrooming obesity epidemic.  Further, the excess dietary sucrose and fructose induces constant hyperinsulinism (the fulcrum) that causally links to metabolic syndrome, obesity, type 2 diabetes, fatty (marbling) liver of obesity, hypertension, disease, and to my surprise, also gout, cancer and Alzheimer.  Wow, all the ‘Western’ diseases placed under one saccharine umbrella!  Of course, because the definitive long-term study is impossible, we don’t know if reducing sugar this will reverse these unhealthy trends. Nevertheless, the epidemiological and biochemical evidence is compelling.

Campbell reviews his animal research and his largest ever study of diet, lifestyle and cancer performed in China.  He has found that excess casein (animal-based in milk) protein (20% of calories) promotes cancer in rats exposed to a carcinogen (aflatoxin) where as 5% (normal for body) content does not.  It appears that protein intake in excess of needs – Americans ingest about 3X what they need – leads to higher risk of cancer.  However, if one uses plant based protein even at the higher dose, the cancers don’t grow.  It is both the protein’s quantity and origin.  In populations around the world that eat plant-based diets, cancer is a true rarity.  However, when these same people, e.g. Asians who move to the U.S. and westernize their diet, their cancer rates soar and become ‘Americanized’ within 2 generations.   Campbell directed a huge study in China where they eat less protein and less animal protein than in the U.S.  Even so the findings still confirmed those of his animal studies.  Since only 2-3% of the cause of cancer is due to genetic factors, the majority is due to lifestyle – diet, exercise, environmental exposure.  As I was taught in medical school, we are constantly ‘living in a sea of carcinogens’ and have to maintain our immune defenses.  He suggests that a switch to plant proteins, will stop the second step (promotion) in cancer progression. 

One window into plant-based diets pertains to an amino acid-like compound I used to study in the lab, called carnitine.  One of the scientists at Cleveland Clinic was looking for the causative factor in red meat that hardens the arteries since it is no longer simply cholesterol and saturated fat.  He identified trimethylamine oxide, a degradation product of carnitine produced by colonic bacteria, that causes atherosclerosis in rats.  Does it apply to humans?  When he measured levels in humans and compared it to their degree of coronary heart disease, there was a significant correlation.  Because carnitine is a natural bodily substance, why is a toxic heart-damaging substance produced from it?  It turns out the intestinal bacteria do the dirty job … but only if you are a meat eater!  If you are vegan, you don’t carry the toxin-producing bacteria!  That’s one reason why vegans have less heart disease than meat eaters. 

So what are the principles … and most important what do I eat?  I will address the first but leave you to your own devices to individualize to your palates, to compromise with your desires, to mediate with your significant other … to arrive at your own menu.

1.  Intermittent fasting is an effective way to lose your abdominal fat storage and then maintain a lower weight.  It also reverses insulin resistance (diabetic tendencies), boosts cancer immunity, and improves memory. There are two ways to do it, intermittent 1-2X/week at 500-600 kcal/day divided in two small meals, OR, daily eating two regular sized meals such as brunch at 11 and dinner at 7 and nothing in between.  Despite my antecedent fear of fasting, I find I longer fear fasting or hunger, and its works to burn my abdominal padding.
2.  Limiting your overall protein to your actual needs reduces cancerous cell growth.  The average American is eating 50+% more than needed.  For example, the RDA protein goal is now recommended at 10% of total calories = 50-60 g protein and a 5 oz steak would give you 54 g protein, but they typically come as 8, 12, even 24, and 36 oz supersizes.    
3.  Switching from predominantly animal to predominantly plant protein, as Dr. Campbell and author Michael Pollan (Omnivores Dilemma) suggest, gives you further leeway as you could eat 20% of calories as plant protein (120 grams) and not encourage those cancer cells to proliferate. 
4. Sugar (sucrose/table sugar and fructose/corn syrup) appears to be a very bad player today through its constant stimulation of insulin secretion.  Reducing intake of refined sugars has the potential to arrest the development of metabolic syndrome, diabetes type 2, obesity, hypertension, gout, cancer and Alzheimer.  Whoa, cancer and dementia?  Yes.  The FDA is suggesting a 42 lb limit down 2/3rds from our current intake from 114 lbs/year.  It would mean adjusting taste buds that have been cranked to the sugary max and using artificial sweeteners to help satisfy those jazzed taste buds.  Fructose in fruits is fine. 
5.  Fat used to be the dietary villain.  A lot of this stemmed from bad press from the sugar industry that led us down the wrong path for years.  Once again it is not how much fat, but it rather depends upon the origin with plant-derived being much better than that from animals.  So coconut oil doesn’t turn out to be so bad, at least compared to lard.
6. I think antioxidants may turn out to be very helpful in the long run through its anti-aging and anti-cancer effects.  Many antioxidants are contained in vegetable and fruit skins (phytochemicals and lycophenes).  But to hedge my bet, I’m using one supplement that is naturally found throughout the body, Coenzyme Q10.  I use either ubiquinone or ubiquinol (more expensive) forms at 200-400 mg/day.
7.  I’m personally on a modified Portfolio diet to reduce my hypercholesterolemia.  In a study published in JAMA in the 1990s, it is equivalent to taking Lipitor!  Again, it employs plant-based soy protein instead of beef and milk, plus steel cut oatmeal and psyllium seed (Metamucil) to bind cholesterol and facilitate its passage out the rear.  This strategy reduced my cholesterol by 60 points without medication.

So a lot of food thoughts to ruminate and digest, pardon my cud.  These ongoing research findings have certainly given me pause to think in depth about my diet.  For myself, beyond the Portfolio diet and intermittent low-calorie fasting, I’ve further modified my diet along the principles above.  For protein, I eat mostly soy, fish, and eggs, with occasional chicken and beef.  I eat Chinese style stir fry, mostly vegetables and dofu with small amounts of meat.  I eat many salads with kale, nuts, and butternut squash.  I ingest brown rice with a lower glycemic index (less like refined sugar with a high glycemic index).  And I’m trying to avoid refined sugars which are ubiquitous.  This amounts to less protein, less animal protein, less animal fat, less refined sugar and more plant-based protein.  But as you can guess, I crave a steak once in a while, I like my scoop of gelato … and indulge.  But I feel good, can see my toes, and feel better about what I’m eating, for myself and the planet.

Key books:
1)   Fast life by Michael Mosley MD (physician and journalist for the BBC)
2) The case against sugar by Gary Taubes (award winning science journalist)
3) The China study by T. Colin Campbell PhD (animal and human researcher from Cornell)