Dear Readers,
You may have heard about an innovative approach to dietary intervention known as precision nutrition (PN). This approach includes individualized meal planning based on your DNA. It is more than what you eat, as it includes physical activity, sleep habits, family medical history, and your microbiome. Your microbiome is the collection of microorganisms (bacteria, fungi, viruses, and parasites) living in certain areas of your body, primarily the intestines. The purpose of the microbiome is to help control digestion, stimulate the immune system and protect us from disease.
The premise of precision nutrition is to manage a chronic illness better, such as diabetes or heart disease. Instead of a one-size-fits-all approach, it can more specifically tell you how your body will respond to certain foods. For instance, it may reveal that you tend to gain weight from consuming saturated fat (animal fat). Or It may show that your body is deficient in vitamin B12, and you need to eat an egg every day.
In the future, PN may help prevent certain diseases or at least delay their onset. For example, suppose that type 2 diabetes runs in your family. Of course, you are concerned about developing the disease, and at age twenty, you visit a Registered Dietitian for instruction in precision nutrition. Your special diet and health plan may stave off diabetes for fifteen years, but remember there are no guarantees in life and health. Would you follow this diet?
Precision nutrition is an exciting concept, but not without challenges. The first and most obvious challenge is cost. DNA analysis costs $1,000, which is cost-prohibitive to most Americans, and insurance does not cover it. This is only the beginning of the process and does not include nutrition education costs. Another challenge with PN is human behavior. We live in a society that almost worships food, and many of us equate eating with happiness. Obesity rates in the US continue to rise with no relief in sight. A paradigm shift is needed to employ our diets as an avenue to good health and consistent well-being.
Precision nutrition is in its infancy, and more studies are needed to determine if it has applications across all populations. Dr. Frank Hu, Professor and Chair of the Department of Nutrition at Harvard states, “To address major public health problems like diabetes, we need to combine public health strategies with precision nutrition technologies.”
Until next time, be healthy!
Dear Dietitian
References • de Toro-Martin, J., Arsenault, B., et al. Precision Nutrition: A Review of Personalized Nutritional Approaches for the Prevention and Management of Metabolic Syndrome. Nutrients. 2017 Aug: 9(8):913. doi:10.3390/nu9080913. • Feldshcer, K. Precision Nutrition: Hype or Hope? Feb 15, 2017. https://www.hsph.harvard.edu/news/features/precision-nutrition-hype-or-hope/ • Precision Nutrition and Type 2 Diabetes Management: Is it Ready for Prime Time? https://www.hsph.harvard.edu/nutritionsource/2018/02/09/precision-nutrition-type-2-diabetes-management-is-it-ready-for-prime-time/ Leanne McCrate, RD, LD, CNSC, is an award-winning dietitian based in Missouri. Her mission is to educate consumers on sound, scientifically-based nutrition. Do you have a nutrition question? Email her today at deardietitian411@gmail.com. Dear Dietitian does not endorse any products, health programs, or diet plans.
Excess calcium
Dear Dietitian,
I am sixty years old, and I’ve always been health conscious. I eat right and exercise three times a week. Recently, I’ve read that too much calcium may increase your risk of a heart attack. Is this true? Also, how much is too much?
Mary
Dear Mary,
How many times did you hear “Drink your milk” when you were a child? Milk is a good source of calcium, which is needed for healthy bones. Our bodies will build bone until about age 18. After that point, we must consume adequate amounts of calcium in our diet or use supplements to maintain healthy bones.
There is controversy among experts about the link between excess calcium and heart attacks, and studies have produced mixed results. Some studies have even found a decreased risk of heart disease with calcium, especially when consumed in the diet.
One theory is that when a calcium supplement is taken, the body uses what it needs, leaving excess amounts in the blood. These calcium bits are deposited onto the walls of the arteries, increasing plaque, which narrows the arteries and reduces blood flow to the heart. When blood flow is reduced, so is oxygen. Ultimately, a section of the heart doesn’t get enough oxygen to survive, resulting in a myocardial infarction (MI), or heart attack.
For adults, the Recommended Daily Allowance (RDA) of calcium is 1,000 mg up to age 50. That amount increases to 1,200 mg per day for women over 50 and men older than 70. Why the age difference? When women go through menopause, the amount of estrogen in the body significantly decreases. Estrogen is needed to hinder bone breakdown. While testosterone in men serves the same function, there is no sharp decrease in this hormone as there is estrogen in women.
How much is too much? The Upper Limit (UL) for calcium intake is 2000 mg for men age 51 and over; for women the same age, the UL is 2500 mg.
Remember that vitamin D is essential for calcium absorption. This vitamin can be obtained from sunlight, fortified milk, and fatty fish like mackerel and tuna. It is also added to soy milk, juice, and fortified cereals.
It is always best to get calcium needs met by diet. One simple reason for this is you are less likely to ingest excess amounts of the mineral this way. Most of us don’t drink a gallon of milk a day or eat 10 cups of kale. Another option is a 50/50 plan. Get half your calcium needs in your diet and take a supplement that contains 500 mg of calcium.
When selecting a calcium supplement, remember that calcium citrate is better absorbed. It’s also wise to choose a supplement with USP on the label. This means the United States Pharmacopeia (USP) has tested the product for potency and absorption.
