Can I trust the Daily Value amounts for vitamins? What if my nutrient needs are different than that?

FacesI had a friend years ago who swore if he cut back to less than a few grams of vitamin C a day, he’d get sick. I argued that dose was several hundred times the recommended intake, but sure enough, he’d catch a cold every time he stopped taking supplements.

Hidden within the data of most research studies is this hint of individual nutritional variation. Researchers report on averages, but a hard look at the raw data shows people are responding all over the charts to the same dose. For example, chromium picolinate, on average, has little effect on weight loss. Yet, some people respond quickly remarkably to this mineral, while others show no effect at all.

Individual variability was considered when developing the Recommended Dietary Allowances (RDAs). Age, gender, life stage (puberty, menopause, and reproductive status, such as pregnancy and lactation), body size, and lifestyle are the main variances that distinguish one group from another when establishing nutrient needs and the RDAs. An “Estimated Average Requirement” (EAR) is set based on the amount of a nutrient needed by most people to be healthy, then a safety factor is added. Thus, the RDAs are designed to exceed most people’s requirements, and aim to satisfy at least 97.5% of the population. (A percentage that is guesstimate at best.) A “Tolerable Upper Limit” (UL) for safety of a nutrient is even less clear, since even less is known about individual variability in UL than is known about variability in requirements. Seldom are medical conditions, or even the genetic susceptibility to chronic disease, used as criteria for establishing nutrient requirements. And, the concept of nutritional or biochemical individuality is still in the dark ages.

Current discoveries into mapping the human genome might well be the key to unlocking the mystery of nutritional individuality. The three billion nuceotides distributed sequentially among 23 pairs of chromosomes provide a staggering field for nutrient variations. If the metabolic pathway influencing nutritional requirements for each of the 40+ nutrients (not to mention the 1,000s of phytochemicals!) was affected independently on even two sites at a single genetic locus, we could expect that the number of variations in nutritional variability could be in excess of 200 trillion!

Each of us is genetically unique in our nutritional needs. But, while each of us might not fit the “normal range,” we haven’t a clue as to what to do about that. Until human genome sequencing explains this topic, it’s easy for the message to be misused to justify taking megadoses of vitamins, going on low-carb fad diets, injecting growth hormone, or other senseless, and potentially harmful, practices. Yes, you are unique. Just how unique is still a mystery. Photo credit: Creative Commons License micadew via CompfightI

 

I’ve been hearing a lot about a supplement called DHEA. What is it?

PillsCreative Commons License DHEA is a steroid hormone produced in the adrenal glands and a building block for the sex hormones – estrogen and testosterone. Levels of  the hormone drop at a rate of about 3% a year; by the time people reach 70-years of age, they have only about 10% to 20% of the DHEA they had in their 20s. People take DHEA supplements in the hopes of improving mood and sleep patterns, increasing energy and libido, counteracting stress, preserving muscle, strengthening the immune system, and helping prevent heart disease and cancer. (Dosage? No one knows. Most studies used about 50mg daily.)

But, there are risks, including an increased risk for acne, prostate cancer, aggressiveness, and liver damage. Long-term consequences are unknown. In addition, the purity and strength of supplements are not regulated. Supplements made from wild Mexican yams claim to contain the building blocks for DHEA, but there is little or no evidence that the body converts these compounds into DHEA. Unless people are advised by their physicians to take DHEA, supplementing with this hormone is a buyer-beware decision. I recommend a natural alternative, which is: A few studies show that people who meditate have higher DHEA levels than nonmeditators. Photo credit:  Keith Ramsey via Compfight

What is your opinion of the product, Juice Plus?

Summer color Juice Plus may be touted as the “next best thing to fruits and vegetables,” but don’t be fooled. Dehydrating produce shrinks it by about 90%, but it still would take 15 capsules to supply the equivalent of a half cup serving of broccoli, while Juice Plus recommends 4 capsules a day. Hmmm, that’s about as much broccoli as you’d get in a small sprig. And, remember…you need 8 to 10 servings of colorful fruits and vegetables every day. That’s 15 capsules times 10. YIKES! Yes, the company adds some extra vitamin C, beta carotene, and other nutrients to make up the difference, but you’ll still be missing out on the fiber and 100s of 1,000s of health-enhancing phytochemicals identified so far in produce., not to mention the cost to your pocketbook. There is no short cut when it comes to vegetables. Just bite the bullet and make a pack with yourself to include at least 2 servings of real fruits and vegetables at every meal and at least 1 at every snack. Period.   Photo credit: Silke Gerstenkorn via Compfight

I just heard about a product called “Juice Plus.” Is this as good as eating fruits and vegetables?

Panier "bio" No! Save your money and buy real fruit, not dried-orange capsules or blueberry pills. Juice Plus+ comes in a variety of flavors, such as Orchard Blend capsules made by freeze-drying seven fruits. These products are typically sold through multi-level marketing programs. They claim to contain beneficial “live enzymes.” But enzymes are proteins produced by living cells and, when swallowed, are digested like any other protein. They don’t make it past the digestive tract to enter the bloodstream and body. These products also claim to boost immunity. There are no well-designed research studies (other than those conducted by the company, which of course has a vested interest that can bias results) to support these claims. If highly-processed fruit powders can boost immune function, imagine how much more effective real fruit would be! Granted, the capsules probably have some of the original antioxidants found in real fruit, but it’s difficult to say how much, since Juice Plus+ capsules have no nutritional labels. You can’t tell how much vitamin C or any of the 100s of 1000s of phytochemicals found in real fruit remains after the freeze-drying process. Keep in mind that it is impossible to cram 5 to 10 servings of fruits or vegetables into a fraction of an ounce of dried fruit powder, so it’s no wonder this product relies heavily on testimonials, not scientific studies published in peer-reviewed journals. Stick with Mother Nature’s real stuff and skip the hype of these capsules or any other processed product that promises to replace real food. Photo credit: jalb via Compfight

My friend tells me chromium supplements will help me lose weight. Is this true?

vitamin bottlesTheoretically, chromium should aid weight control, since this trace mineral enhances insulin activity, the hormone that regulates blood sugar and fat levels while stimulating protein synthesis in muscles. It made sense when preliminary research found that athletes lost more body fat and gained more lean tissue (i.e., muscle) when they took chromium supplements.  These initial studies were seriously flawed and subsequent studies did not support the chromium-weight loss connection. If there is any benefits of chromium to weight loss, they are minor at best. However, some people report some weight loss when they increase chromium intake, so there might be something to this issue; unfortunately, with so many pieces still missing in the puzzle, we just don’t know.

There is evidence that many Americans’ diets are low in chromium, so increasing your intake by eating more whole grains, bran breakfast cereals, canned vegetables such as green beans, broccoli, raisins, nuts, mushrooms, oysters, chicken, meat, seafood, and other chromium-rich foods is important for overall health. Boosting your chromium intake with better food choices or supplements (limit the dose to no more than 200 micrograms a day) will help manage blood sugar, which could help side-step diabetes later in life. Whether it will transform your body into that lean, muscular number in the supplement ads is highly unlikely. But then, I bet you already knew that!

Photo credit: Creative Commons License Shannon Kringen via Compfight