If someone were to ask me to answer in one word the primary reason South Asians have a high risk of heart disease, diabetes, excess body fat, fatigue, and a number of other health conditions…my answer would be insulin. Insulin is the hormone wreaking havoc on my South Asian patients. In fact if there is one critical scientific concept I would want you to take away from reading this blog or my book, it would be the role of insulin in your body. I'm going to explain insulin at the most basic level since the majority of my patients and lecture attendees are not familiar with this. For those of you who find this information too basic, I assure you that future posts will expand on insulin in more detail so you will soon become an expert in this area. Understanding insulin will help explain why the rice or chapatis you eat on a daily basis are far more fattening than eating ghee. It will also explain why so many of my vegetarian patients who consume so little fat, struggle to actually lose body fat. Take it from someone who tracks his South Asian patient's diets meticulously during consultations, in conjunction with their body weight and labs. The numbers tell the story over and over, and will turn your prior understanding of a healthy diet upside down.
Now what's the first image that comes to your mind when you think of insulin? Most people picture a diabetic injecting insulin to control their blood sugar. Indeed, insulin is the sugar regulating hormone secreted by a flat mango-shaped digestive organ called the pancreas. There are many different images people have used to describe insulin's role. Let's just think of it as a hormonal key that likes to store away energy, in particular glucose and fat, into various compartments. In Hindi or my native tongue, Bengali, we use the word “conjus” to describe someone who is thrifty and hates to spend money. Insulin is a perfect example of a “conjus” hormone that immediately stores away glucose and fat, rather than “spending” it or burning it for energy. If you've got high levels of insulin in your body like the majority of South Asians, your body is in constant thrifty mode, persistently stashing fuel into various compartments, in particular muscle, liver, and fat.
Fuel Partitioning: Where is that rice or chapati (indian flat bread) being stored?
Let's say you've just eaten a plate of white rice or a whole wheat chapati, which is essentially just glucose or sugar packaged into what we call carbohydrates (aka “carbs”). Your body will break this down into glucose and this rise in blood sugar is going to trigger your pancreas to release insulin. Insulin will immediately take the excess glucose out of your bloodstream by pushing it into your major storage compartments, muscle, liver, and fat. In particular, after a high-carb meal (which is virtually every South Asian meal) when insulin levels are high, 60-70% of the glucose goes into muscle, about 30% goes to the liver and about 10% goes to fat.
Key point: Muscle is the primary storage compartment for glucose after you eat.
When the system works under normal conditions, insulin is a lifesaver because it keeps your blood glucose levels under control by storing excess sugar into your compartments, in particular muscle.
What Happens With Insulin Resistance?
Recall how I said insulin is a hormonal key. What happens when the locks on your storage compartments stop working? This is insulin resistance. After you've eaten that plate of rice or chapati, insulin is trying to open the door to the muscle cell (your major storage compartment), but the muscle cell no longer responds. It has become “resistant” to insulin…thus the term “Insulin Resistance.” All your compartments don't usually become resistant at one time. The typical sequence in most cases of insulin resistance for our three major compartments is as follows:
Muscle becomes insulin resistant first–>Liver next–>Fat last
How does your body respond to this? It goes into panic mode since the trusty muscle cells aren't accepting blood glucose any more. Your pancreas responds by producing more insulin, a state we refer to as compensatory hyperinsulinemia. This excess insulin may be able to bully some of that glucose into your muscle cells, but most of it is now trafficked to your liver and fat cells. What happens at your liver and fat cells is key to understanding some of the physical and lab abnormalities so many of my South Asians face, so let's take a look:
1. Liver: When excess glucose arrives at the liver, the high insulin levels trigger the conversion of glucose into triglycerides, which is the storage form of fat. These triglycerides are packaged as lipoproteins, which transport cholesterol through your bloodstream. So glucose is actually transformed into fat (triglycerides) by the liver and exported into the blood stream as cholesterol.
2. Fat: When glucose enters fat cells, they are also converted and stored as triglycerides. These stored triglycerides eventually overfill the fat cells, causing them to expand like balloons, which in turn causes your belly, thigh, and buttocks to swell.
Key point: Excess glucose from carbohydrates in your diet (rice, chapati, sweets, etc.) contribute to increased cholesterol production by your liver and increased body fat due to overfilled fat cells. This is why so many of my vegetarian Indian patients who consume loads of carbohydrates have some of the worst cholesterol panels and struggle with weight loss.
How Does Insulin Resistance Progress?
The chronically elevated insulin levels resulting from insulin resistance actually makes insulin resistance worse. The muscles become increasingly insulin resistant, and then eventually other cells like your liver and fat cells follow. Now that excess blood sugar doesn't have many places for storage, so your blood glucose gradually rises. The progression goes something like this:
Insulin resistance–>initial increase in blood glucose (prediabetes)–>further increase in blood glucose (type 2 diabetes)
The goal is to prevent insulin resistance or detect it as early as possible. This is your best chance at reversing it completely. Catch it at prediabetes or ideally before that (we'll discuss how in future posts). Even in my type 2 diabetes patients, if we catch it early we can often eliminate or at least minimize the amount of oral medications necessary to control blood sugars. Unfortunately over time as type 2 diabetes progresses, the pancreas wears out. It can no longer produce sufficient insulin. It's been working overtime for years to make up for your high-carb lifestyle. When this happens, oral diabetes medications are no longer enough. You now require injectable insulin.
How Do You Prevent Insulin Resistance?
This is what this blog and my book focus on, but a basic list is below:
Lower excessive carbohydrates in an effort to keep insulin levels down
Stay physically active. I'm not just talking 3-4 trips to the gym each week. You need 8-10,000 daily steps and then layer your gym workouts on top of this foundation of walking
Add muscle. Recall how I said muscle absorbs the majority of your glucose after a meal. You need to add strength/muscle to keep glucose low, insulin low, and in turn body fat low. This is why women often struggle with fat loss. Their workouts are too focused on cardio.
Manage stress: Stress triggers increased fat storage and makes insulin resistance worse. It is often the final barrier to fat loss we tend to push aside, but needs to be emphasized
Prioritize sleep: All of you night owls who can't disconnect from your screens need to get to bed earlier. Insufficient sleep has been shown to take normal healthy, young adults and turn them prediabetic within a few short weeks. In other words, less sleep means more insulin resistance