By Dr. Mercola
The Globe and Mail1 recently published an article outlining "the 5 numbers that most impact your health."
I think they have the right idea, but but I disagree with their test selections.
If you really want to monitor your health, I believe the numbers you should be tracking are the seven listed in the table below.
These are far more important than tracking your total cholesterol, blood pressure, or BMI, as recommended by the Globe and Mail.
Let's take a closer look at these values and what they may reveal about your health.
1. Fasting Insulin (I) 2. Cholesterol/HDL Ratio (C) 3. Percentage Body Fat (F) 4. Serum Ferritin (F) 5. Waist/Hip Ratio (WH) 6. Uric Acid Level (U) 7. Vitamin D Level (D)
1. Fasting Insulin Level
Your fasting insulin level reflects how healthy your blood glucose levels are over time. Insulin helps sugar move from your blood into your cells, where it can be used or stored. Chronically elevated blood glucose leads to insulin resistance and numerous chronic diseases, including diabetes and heart disease. Elevated blood glucose and insulin resistance are epidemic today. An estimated one in four Americans are either insulin resistant or diabetic.
One of the most frequent causes of elevated glucose (and insulin resistance) is consumption of too many grains and sugars. Fructose has been shown to be especially harmful due to the way it disrupts the lock-and-key fit between insulin and its cellular receptor sites. Fructose is a powerful endocrine disruptor, capable of rapidly inducing insulin resistance when consumed in what, by today's standards, is a relatively small amount (25 grams or more per day).
Your fasting insulin level can be determined by a simple, inexpensive blood test. A normal fasting blood insulin level is below 5, but ideally you'll want it below 3. If your insulin level is higher than 3 to 5, the most effective way to optimize it is to reduce or eliminate all forms of dietary sugar, particularly fructose.
You can also use a simple glucose test to check your fasting glucose level. Just realize that it's possible to have low fasting glucose but still have significantly elevated insulin levels.Generally speaking, a fasting glucose under 100 mg/dl suggests you're not insulin resistant, while a level between 100 and 125 suggests you're either mildly insulin resistant or have impaired glucose tolerance (sometimes referred to as pre-diabetes).
2. Cholesterol/HDL Ratio
Cholesterol has been demonized for the past few decades, thanks to a landmark study by Dr. Ancel Keys in 1953 that has been used to justify a low fat diet approach to achieve health. This study resulted in cholesterol's being blamed for just about every case of heart disease in the last 20 years. But the fact is, cholesterol is most likely not going to destroy your health (as you have been led to believe), and is also not the cause of heart disease. Most of the recent credible science has debunked Keys' theory, but the cholesterol myth stubbornly persists in the mainstream because it's so deeply embedded in our culture.
We now know that your body actually requires cholesterol to manufacture vitamin D from sunlight, to synthesize sex hormones, and for proper brain function. Measuring total blood cholesterol tells you practically nothing about your heart disease risk. More value can be derived by looking at the relative types of lipids circulating in your bloodstream, and today we have sophisticated tests that can measure these. The following two ratios are far better indicators of heart disease risk than total cholesterol alone:
- Your HDL/Cholesterol ratio: HDL (high-density lipoproteins) to total cholesterol percentage is a very good predictor of heart disease risk. Just divide your HDL number by your total cholesterol. Ideally, this number should exceed 24 percent; below 10 percent predicts an increased risk for heart disease.
- Your Triglyceride/HDL ratio: Divide your triglyceride number by your HDL. This ratio should ideally be below 2.
3. Percentage Body Fat
Body composition, meaning your relative amounts of lean body mass to body fat, is a powerful way to measure your overall health. There is a strong correlation between higher body fat and negative health outcomes, such as heart disease and stroke. And percentage of body fat says more about your overall fitness than body weight or body mass index (BMI). BMI can be particularly misleading, causing fit bodybuilders to be classified as overweight as it does not take into account the higher weight of muscle compared to fat. Also, increased organ or abdominal adipose tissue in particular (a "beer belly") has been shown to be more strongly associated with heart disease and a variety of chronic diseases than just weight in relation to height.
The most common way to assess body fat percentage is the skinfold measurement technique, which utilizes a skinfold caliper. (Skinfold measurement is the method most widely used by fitness trainers.) The American Council on Exercise provides the following percentage body fat guidelines2 for men and women:
Category Women Men Essential Fat 10-13% 2-5% Athletes 14-20% 6-13% Fitness 21-24% 4-17% Acceptable 25-31% 18-24% Obesity >32% >25%
For even greater accuracy, you can resort to hydrostatic weighing, where you get weighed under water. This measures the density of your body, which is then used to calculate how much body fat you have.
Another technique that is gaining support by medical and fitness experts is the bioelectrical impedance analysis (BIA). To measure body impedance, an electrical signal is passed through your body. Impedance is greatest in fat tissue, which contains low amounts of water, while fat-free mass, which contains up to 75 percent water, allows the signal to pass through fairly unimpeded. This measurement, along with other factors such as your height, weight, and body type, is then used to calculate your percentage of body fat, fat-free mass and other body composition values.
There are now bathroom scales that use this technology. I picked one up from Eat Smart3 that I have been using for the last four months. I find it's a simple way to monitor my body fat percentage. It may overestimate a bit as it has me at 13.5 percent when I tested between 11 and 12 percent using other methods, but it is very accurate in measuring day to day variability, and can be an excellent and inexpensive way to monitor your progress on optimizing your body fat so it is line with your health goals.
4. Serum Ferritin
You probably already know that iron is an important nutrient for your body. But you might not be aware that iron is a double-edged sword—both too much and too little can lead to major health problems.
Iron serves many functions in your body, but one of the most important is carrying oxygen throughout your body by binding to hemoglobin molecules in your bloodstream. Without proper oxygenation, your cells quickly begin to die. If you don't have enough iron in your body, you end up with iron deficiency anemia, a common problem among children and menstruating women. But your body also has a limited capacity to excrete iron, so it can build up in your tissues if you're getting too much in your diet.
Processed foods fortified with iron and multivitamins with iron can contribute to iron overload over time. The problem with excess iron is that it's also a very potent oxidative stressor, causing dangerous free radicals that can damage your heart and your DNA, and lead to diseases such as cancer. Therefore, you should regularly check yourself for iron overload with a serum ferritin test. This blood test measures iron's carrier molecule—a protein called ferritin found inside your cells upon which the iron is stored. If your ferritin levels are low, it means your iron levels are also low, and vice versa. Use the following guidelines to interpret your serum ferritin level:
- The healthy range of serum ferritin is between 20 and 80 ng/ml
- The ideal serum ferritin range is 40 to 60 ng/ml
- Below 20, you are iron deficient; above 80, you have an iron surplus.Ferritin levels can go really high. I've seen levels over 1,000, but anything over 80 is likely to be a problem.
It is VITAL to appreciate that about one in five men and postmenopausal women have iron levels that are too high and are actually causing premature disease and death. If you or someone you love has triple digit ferritin levels you need to lower them ASAP. The higher the number the worse it is, with numbers over 250-300 being particularly dangerous. Fortunately there is a very simple way to lower it. I would not advise using supplements like phytic acid (IP6), which can bind other helpful minerals. The single best way to lower your iron is to simply donate blood. If you have risk factors that prevent you from having your blood accepted for donation, you can have your doctor write you a prescription for a therapeutic phlebotomy.
5. Waist Size
There is scientific evidence4 that BMI (body mass index) is a very flawed measurement when it comes to predicting your risk of dying from heart disease. Waist size provides a far more accurate benchmark for predicting your risk of death from a heart attack and from other causes. Determining your waist size is easy. With a tape measure, measure the distance around the smallest area of your abdomen, below your rib cage and above your belly button. The following is a general guide for healthy waist circumference:
- Men: 37 to 40 inches is overweight; greater than 40 inches is obese
- Women: 31.5 to 34.6 inches is overweight; greater than 34.6 inches is obese
The reason why this is a better indicator of heart disease risk is because your waist size is related to the type of fat that is stored around your waistline, called "visceral fat" or "belly fat." This type of fat is strongly linked to type 2 diabetes, heart disease, stroke, and other chronic diseases. It is thought that visceral fat is related to the release of proteins and hormones that cause inflammation, which can in turn damage your arteries and affect how you metabolize sugars and fats. An expanded waistline is associated with insulin resistance, high blood pressure, lipid imbalance, cardiovascular disease, thickening of the walls of your heart, and even increased risk for developing Alzheimer's disease decades later.
6. Uric Acid Level
You may already know that elevated uric acid levels cause gout. But did you know uric acid can serve as a marker for fructose toxicity?
Fructose, when over-consumed, is very taxing to your body's metabolic processes. One of the by-products of fructose metabolism is uric acid, so when you consume too much sugar—particularly concentrated fructose—your uric acid levels may rise. Fructose turns you into a uric acid factory! Elevated uric acid is thought to explain much of the damage fructose causes in your body. This is especially pronounced if you are particularly fructose-sensitive, as I am. I'm grateful to Dr. Richard Johnson, author of The Sugar Fix, for bringing the uric acid link to my attention. As an aside I have helped proof his new book, The Fat Switch, which is beyond phenomenal and will also be available shortly.
The connection between fructose consumption and increased uric acid is so reliable that a uric acid level taken from your blood can actually be used as a marker for fructose toxicity. I now recommend that a uric acid level be a routine part of your blood screening.
According to the latest research, the safest range for uric acid is between 3 and 5.5 milligrams per deciliter, and there appears to be a steady relationship between uric acid levels and blood pressure and cardiovascular risk, even down to the range of 3 to 4 mg/dl. As you know, two-thirds of the U.S. population is overweight, and most of these people likely have uric acid levels in excess of 5.5. Some may even be closer to 10 or higher. Dr. Johnson suggests that the ideal uric acid level is probably around:
- 4 mg/dl for men, and
- 3.5 mg/dl for women
7. Vitamin D Level
Vitamin D deficiency is at epidemic levels in the United States, but many Americans—including many physicians—are still unaware of the implications. In the U.S., the late winter average vitamin D is only about 15 to 18 ng/ml, which is considered a very serious deficiency state. In fact, 85 percent of Americans may be deficient in vitamin D, including more than 95 percent of all seniors.
Vitamin D influences about 3,000 of the 30,000 genes in your body, which is why it's involved with the expression of so many diseases, from cancer to autism to heart disease and rheumatoid arthritis, just to name a few. A study by vitamin D expert Dr. William Grant, Ph.D., found that about 30 percent of cancer deaths could be prevented each year with higher levels of vitamin D. Beyond preventing cancer, researchers have estimated that increasing vitamin D levels could prevent diseases that claim nearly one million lives globally each year. Vitamin D also fights colds and flu because it helps your immune system defend against bacteria and viruses.
You should regularly check your vitamin D level, but you must obtain the correct test. There are two vitamin D tests: 1,25(OH)D and 25(OH)D. Of the two, 25(OH)D (also called 25-hydroxyvitamin D) is the better marker of overall vitamin D status.
The following ranges were obtained in a large-scale clinical study by evaluating healthy people in tropical or subtropical parts of the world, where they are receiving healthy sun exposures. It seems more than reasonable to assume that these values are in fact reflective of an optimal human requirement. When getting your vitamin D level tested, please realize that many commercial labs are using old, outdated reference ranges, and that their "normal" is likely to be far below these optimal and clinically relevant values.
(Holick MF. Calcium and Vitamin D. Diagnostics and Therapeutics. Clin Lab Med. 2000 Sep;20(3):569-90)
If your vitamin D level is too low, the best way to increase it is with exposure to natural sunlight, in appropriate amounts. If that's not feasible, you can opt for an oral vitamin D3 supplement. Just remember that if you supplement orally, it is even MORE important to have your blood levels checked regularly, as there is a wide variation in how efficiently people absorb vitamin D orally.
While the latest research indicates adults need about 8,000 IU's of vitamin D per day to achieve vitamin D levels of 40 ng/ml, you need to monitor your levels carefully in order to determine the dosage you need in order to reach and maintain optimal levels, as this is highly variable. There is no magic dosage when it comes to vitamin D; rather it's the serum level that really matters.
For more information about vitamin D testing, refer to my comprehensive article on the topic. I also strongly recommend you watch my one-hour vitamin D lecture, included at the top of this section.