These claims are questionable at best. Here's the scoop: HCA — short for hydroxy citric acid — is an ingredient found in many weight loss supplements. It's derived primarily from the Garcinia cambogia plant. Citric acid is a substance involved in the metabolism of carbohydrates. HCA (a modified form of citric acid) is believed by some to inhibit the enzyme that allows carbohydrates to be stored as fat. It is suggested that, in the presence of HCA, excess carbohydrates would be expended instead of being stored as fat. A decrease in appetite is purported to be a side effect of this process, which further promotes weight loss. This certainly sounds good in theory. But... in 2009, a popular brand of dietary supplements for weight loss containing HCA as the main active ingredient was recalled after the U.S. Food and Drug Administration (FDA) issued a safety warning. The FDA received 23 reports of liver problems among those who took them, as well as other problems such as seizures and cardiovascular problems, and one death occurred. Since then the makers of the brand have stopped using HCA in their formulas, but HCA remains the active ingredient in several weight loss supplements that are currently available.
Studies on the effectiveness of HCA in animals and humans indicate mixed results. A study using rats found that high daily doses of HCA led to testicular atrophy and other toxicities, while other studies using smaller doses of HCA have found no adverse effects in lab animals. In human trials, there are studies that have found HCA as an effective weight loss supplement, while other studies have found that HCA does not prevent fat storage or promote weight loss.
Although some web sites claim HCA is safe, the truth is, we really don't know. Considering the 2009 recall of products containing HCA and the lack of information on long-term effects, is HCA worth the possible risks associated with it?
You may want to consider speaking with a health care provider to develop an effective weight loss plan. If you are a Columbia student on the Morningside campus, you can make an appointment with a health care provider and/or nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can do the same by calling 212-305-3400 or logging on to the Student Health Service web portal. You can also check out the Get Balanced! and CU Move initiatives, to help you reach your nutrition and physical activity goals.
Dear Just wondering,
Dolomite, or calcium magnesium carbonate, is a common mineral extract that occurs as crystals in large rock beds of limestone. Calcium carbonate is a cheap calcium supplement with a high percentage of calcium by weight, but the body has difficulty in breaking it down for use. Though dolomite in powdered form is soluble in weak acids, stomach acid doesn’t do the best job of dissolving it, especially in people with decreased stomach acid secretions (e.g., sick and elderly people). Other forms of calcium like calcium citrate are easier for the body to absorb.
In addition to being a less effective source of calcium, dolomite may be hazardous to your health. Dolomite deposits also contain other elements such as barium, lead, and iron and manganese carbonates as impurities. In the early 1980s, concern arose regarding heavy-metal contamination of calcium supplements when a study found high concentrations of lead in dolomite supplements. Since it may contain the toxic elements mercury and lead, dolomite is not a recommended source for calcium and magnesium — other forms of these minerals are available that would be safer to take.
See Iron, calcium, and constipation, oh my! for more info about calcium supplements. If you have questions about your individual nutritional needs or want more advice on nutritional supplements, talk with a health care provider or nutritionist. Students at Columbia on the Morningside campus can make an appointment with a nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can reach out to the Center for Student Wellness and the Student Health Service.
You can add citrus fruits such as lemons, oranges, and grapefruits to your list of pectin-rich foods. Strawberries and other fruits and vegetables also contain some pectin, but not as much as apples and fruits in the citrus family. Pectin is also added to certain foods, such as jams/jellies, because it acts as a thickening agent since it becomes gel-like when dissolved in water.
Pectin is a water-soluble dietary fiber. It can be found in most plants. Pectin slows the passage of food through the intestine and helps to lower blood cholesterol levels. In the intestine, it's believed that pectin fibers bind to bile (produced by the liver from cholesterol), which is then excreted from the body. Evidence supports the use of pectin for treating diarrhea, while studies are also being conducted to determine pectin’s potential benefits for preventing and treating certain types of cancer.
For additional information on fiber, check out the Related Q&As below.
It might be a good idea to seek further guidance from a nutritionist. If you are a Columbia student on the Morningside campus, you can make an appointment with a nutritionist by calling 212-854-2284 or logging on to Open Communicator. If you are on the Medical Center campus, you can reach out to the Center for Student Wellness or Student Health.
Dear Ginkgo User,
In fact, there’s currently no research to suggest any connection between taking ginkgo and increased blood pressure. You said that the change in your blood pressure is recent? If so, it’s recommended you speak to your primary care provider — quick changes in health markers such as blood pressure could indicate an underlying problem. It is possible that other factors may have contributed to this situation. Columbia students on the Morningside campus can make an appointment with Medical Services using Open Communicator. Columbia students at the Medical Center can make an appointment at Student Health.
In terms of the research on ginkgo and blood pressure, most has been related to whether or not ginkgo is effective at lowering blood pressure. This, too, has proved inconclusive. You mention that ginkgo is working as a memory enhancement tool for you. That’s great! Just make sure that your primary care provider, in addition to any other health care professional you see, knows all of the medications (this includes supplements) you take.
More research needs to be done on memory enhancement and ginkgo. There has been some research that indicates improvements in blood flow to the brain, thus enhancing memory in people who suffered impairment; but, there is no proof that ginkgo will improve memory in people who have not had an impairment. Unless you have had a decrease in memory due to an impairment of blood flow, ginkgo has not been proven to increase memory. Since ginkgo can be expensive (around $30 for a bottle of 60 capsules) it may not be the best (or least expensive) option for some people.
Dear Curious Carrot,
Beta-carotene has become an increasingly popular topic in the field of nutrition. High in antioxidants, beta-carotene is a nutrient found in foods like carrots, spinach, and kale. Recent studies have revealed possible links between adequate beta-carotene intake and slower progression of diseases like Age-Related Macular Degeneration and various types of cancer. However, excessive beta-carotene consumption has not been shown to fully prevent these diseases, and too much of it can actually be very harmful.
In the case of Age-Related Macular Degeneration, a study published in the Journal of the American Medical Association found an inverse association between above-average intake of beta-carotene (up to 13 times the average amount) and the development and progression of macular degeneration among the elderly. However, the 35% reduced risk demonstrated by this study cannot be attributed exclusively to beta-carotene, because other nutrients, including zinc and vitamins C and E, were consumed in excessive amounts as well.
In a different study, beta-carotene supplements taken along with increased Vitamin E, selenium, and zinc over a period of seven years was associated with lower total cancer incidence and all-cause mortality in men. Because many men are deficient in beta-carotene, they may benefit significantly from increased beta-carotene consumption (enough to bring them to what is referred to as a “baseline,” or average level). However, for women, many of whom do not experience natural beta-carotene deficiency due to their unique set of hormones and lipid and nutrient transport methods, supplementation had no measurable benefits. Further, the same study demonstrated that increased beta-carotene consumption in individuals experiencing the initial phases of cancer development was actually harmful.
A 2010 study published in the Journal of Nutrition demonstrates that although it is often said that natural sources of beta-carotene from fruits and vegetables are more easily absorbed by the body, foods and supplements fortified with beta-carotene and Vitamin A are not harmful to the average person when consumed in moderate quantities (approximately seven milligrams per day). However, the study notes that beta-carotene levels and intake requirements are highly variable, so it is difficult to make blanket statements about recommended daily intake.
A more recent study from March 2012 reported that above-average beta-carotene consumption does not prevent skin cancer and adenoma recurrence, lung cancer, or total cancer. In fact, the study cites a separate clinical experiment called the Beta-Carotene and Retinol Efficiency Trial, in which it was proven that lung cancer was 39% more likely among individuals who consumed high levels of beta-carotene and either smoked or were previously exposed to asbestos. At best, a U.S. Preventive Services Task Force (USPSTF) study found that beta-carotene had no effect on cancer or cardiovascular disease development among older adults, and that overall cancer development was actually facilitated by excessive beta-carotene consumption among heavy smokers. Therefore, the USPSTF does not recommend beta-carotene supplements, and reinforces that no supplements can take the place of a healthy diet. Indeed, there is no evidence that beta-carotene from natural food sources is harmful to smokers or any other population.
If you’re a Columbia student and you have more questions about beta-carotene or any other nutrient, you can make an appointment with a health care provider or registered dietician at Medical Services on the Morningside campus, or with Student Health at the Medical Center campus. In the meantime, for more information about nutrition, check out Columbia’s Get Balanced Guide for Healthier Eating, the other Get Balanced nutrition resources, as well as the related questions linked below.