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

Is the old wives’ tale about fish being brain food really true?

Miniature Salmon Prep Board Yes! Your brain is very greasy, but in a good way. More than 60% of it is fat. Unlike the lazy fat stored on the hips or belly, fat in the brain is a worker bee. It makes up the cell membranes that surround each cell and the insulation sheath around neurons that allows thoughts to travel fast from one cell to another. The more fluid and flexible those membranes, the faster you react, the more you remember, and the more creative and clever you are. The most fluid fats are the omega-3s, and the brain must love the omega-3 DHA, because 97% of the omega-3s in your brain are DHA. An accumulating body of research is showing that children, adolescents, and young adults think better, perform better on tests, and react faster when their diets are optimal in DHA. A recent study found that children performed up to 50% better on reading tests when they supplemented with the omega-3s, and studies (including the MIDAS study) find that seniors remember more and might even be at lower risk for dementia and Alzheimer’s when daily intake averages between 220 and 900 milligrams. Note: your body can’t make this fat. It has to come from the diet. That means at least 2 to 3 servings a week of fatty fish, such as salmon, mackerel, or herring. Or, take a fish oil or DHA supplement that lists specifically how much DHA is in each capsule. Photo credit: Stéphanie Kilgast via Compfight

I’ve lost about 30 pounds. Do I have to exercise to keep it off, or can I just continue my diet?

* No diet on the planet will maintain a healthy weight if you don’t exercise. The trick is how much? Most health experts recommend that Americans exercise at least a half hour most days of the week, but people who have lost weight – and more importantly maintained the weight loss – are moving much more than that. They get lots of exercise; the equivalent of an hour or more a day or 28 miles of walking a week, which means they probably have much less time to veg out in front of the TV.  The more weight you have lost and need to maintain, the more you have to move. Researchers don’t understand why a formally obese person must exercise more than an always-lean person to maintain the lower weight, although they speculate it probably relates to some kind of permanent metabolic slowdown that results from having been obese. It’s not fair that you need to move 12,000 steps a day, while your skinny neighbor might need only 8,000 steps, but that’s the reality. To spice up their active lives, weight-loss maintainers turn to variety, with six out of every ten masters incorporating two or more types of exercise into their weekly routines.  Photo credit: Chris JL 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

Does soy increase or decrease my risk for breast cancer?

IMG_8541 The statistics are ominous when it comes to women’s risk for developing breast cancer in the United States. This risk is five-fold higher than Asian women’s risks in Japan and China. When these women migrate to the United States and adopt our eating and lifestyle habits, their risk increases to 60% higher than their counterparts who remained in Asia. Studies provide strong evidence that only 5% to 10% of breast cancer cases are attributable to inherited factors, which means up to 95% of breast cancer might be prevented with changes in lifestyle. Diet is associated with up to one in every two newly diagnosed breast cancer cases. This link between lifestyle and breast cancer has led  researchers to investigate the possible benefits of soy for the prevention of breast cancer. But the link is not a clear one.

Both epidemiological and clinical data show that exposure to estrogen increases breast cancer risk by inducing malignant breast cell growth. Asian women living in Asia have a 40% lower blood estrogen levels compared to Caucasian women living in the U.S., and they consume more phytoestrogens, such as genistein, in soy products. Some studies show that adding soy to the diet reduces blood estrogen levels in premenopausal women. Genistein inhibits the blood supply to cancer cells and curbs metastasis of breast cancer. It also has a structure similar to estrogen, but its binding affinity is several-fold weaker than that of a woman’s normal estrogen, so it could curb estrogen’s effects on initiating cancer. Finally, genistein has beneficial effects on bone, the cardiovascular system, and blood cholesterol levels, thus helping prevent osteoporosis and heart disease.

The confusion arises from the limited evidence that soy also might increase breast cancer risk. Whether soy increases or decreases breast cancer risk might be dose, tissue, and time dependent. Estrogen production varies dramatically throughout a woman’s life span. It is possible that genistein has varying effects on the breast in the presence of high estrogen (during pregnancy), moderate estrogen levels (during pre-menopause), and low estrogen (during childhood and post-menopause). One reason why Asian women living in Asia have low breast cancer risk is that a lifetime exposure to soy provides the protective effect. It also is possible that soy contains other factors other than the phytoestrogens that oppose the estrogenic effects of genistein and actually reduce breast cancer risk. Or, perhaps other environmental factors might be related more to low cancer rates in Asian women than increased soy consumption.

The bottom line? Moderate intake of minimally-processed soy products, such as tofu and soymilk, are safe and possibly beneficial in the prevention of numerous diseases, including breast cancer. But, until more is known, excessive intake of highly-processed soy constituents, such as soy powders or phytoestrogen pills, especially in women with a family or personal history of breast cancer, should be viewed with a cautionary eye.   Photo credit: Mr. Wang via Compfight