Page 50 - Today's Dietitian (February 2020)

CPE Monthly

Dosage and Type garlic powder caused erosion and severe two times or more per week over seven
The majority of research on garlic sug- damage in the GI tracts of dogs. Enteric years had a 44% lower risk of developing
gests several promising benefits of this capsules caused reddening and, when lung cancer. 32
widely used bulb. The variety of dos- taken orally, produced damage in the Epidemiologic studies on the pos-
ages and types of garlic preparations dogs’ ileums. 29 sible link between garlic intake and the
appears to contribute significantly to Furthermore, long-term use of any prevention of other diseases are limited,
the different and sometimes inconsis- supplement raises concerns for toxic- and more research is needed. Neverthe-
tent observed effects of garlic. Thus, it ity. While garlic preparations such as less, culinary garlic has been used to
remains difficult to recommend tangible AGE appear to have no adverse effects help with ailments for centuries. 1
applications of the reviewed research to when consumed in varying doses, more Dietitians can instruct patients to
dietetics practice. More research, espe- research on the impact of garlic supple- increase their use of garlic in the kitchen
cially on the most effective, safe, and tol- ments over long periods of time is neces- by recommending recipes with garlic
erable types of garlic, is needed. sary. Without a strong base of research and teaching them how to crush or chop
The table on page 49 lists the main to support the suspected minimal side raw garlic cloves.
forms of commercially available garlic effects of garlic supplements, it’s dif-
supplements, the dosages at which they ficult to make recommendations for Implications for Dietitians
have been used in clinical trials or stud- a standardized type or dose. Another As the nutrition experts for clients,
ies using lab rats, and the demonstrated important consideration is that the FDA patients, and the general public, RDs
effects. doesn’t regulate supplements, which should be aware of the current evidence
It appears that AGE may be the most can lead to differences in content and for the health benefits of garlic. Stud-
well-tolerated form of garlic prepara- purity among supplements that claim to ies have demonstrated that garlic may
tion, in addition to being superior in have a specific amount and/or type of a improve hypertension, lower choles-
efficacy and bioavailability. The extrac- substance. The actual dose and the one terol, protect against cancer, prevent
tion procedure seems to increase the listed on the label may not always cor- bone loss, lower fasting blood sugar, and
potency of garlic and eliminate the odor respond. Supplements that have been strengthen the immune system. While
and irritating components of raw garlic tested by a third party may have a more raw and cooked garlic has been used for
that can cause heartburn, burning sen- accurate stated dosage. its medicinal properties for thousands
sations when handling, and related A serious concern surrounding the of years, emerging research points to
2
symptoms. AGE is suspected to be safer use of garlic supplementation is the pos- the potential of supplemental forms of
and less toxic than raw or powdered sible contraindications for people taking garlic, especially AGE. However, con-
garlic versions. 2,10 A study by Hoshino certain medications. Individuals taking cerns about the safety and efficacy of
and colleagues about the effects of garlic antihypertensive medications and/or garlic supplements remain, and recom-
preparations on the mucosa of the gas- warfarin (Coumadin) often are told to mendations for a standardized dose and
trointestinal (GI) tract of dogs found use garlic supplements with caution to type don’t exist. Until more research is
that AGE didn’t cause any negative prevent bleeding, since garlic also may available, dietitians and other health
effects. This is supported by Ried and prevent blood clotting. 2,30 However, a professionals should be cautious
29
colleagues’ research, which reported 2006 study by Macan and colleagues about recommending garlic supple-
a 92% acceptance rate of AGE from including 66 patients taking warfarin ments for health promotion and disease
human participants who took it. 10 found that those who also took 5 mL prevention.
30
Researchers also point to the more AGE per day for 12 weeks didn’t have an As garlic continues to gain recognition
stable nature of SAC in AGE when com- increased risk of hemorrhages compared as a functional food and possible alter-
pared with volatile compounds, such as with those who took a placebo. native or adjunctive therapy to modern
31
allicin. 2,10 Whereas allicin may quickly medications, the development of a stan-
disappear from the blood once digested, Note on Culinary Garlic dardized supplement tested for safety
SAC doesn’t; it’s thought to be one of the Most studies focus on the possible may not be far off. In the meantime, dieti-
most active components of garlic. The health benefits of garlic supplements, tians should continue to recommend a
2
stability of SAC makes AGE a supple- oils, and extracts, and rarely provide predominantly plant-based diet rich in
ment that can easily be standardized. information on raw or cooked garlic as vegetables, fruits, herbs, spices, and tra-
The minimal side effects associated with it would appear in everyday recipes to ditional flavorings such as garlic.
AGE make it an appealing alternative participants.
to current medications that can cause However, eating garlic and adding it Elizabeth Streit, MS, RDN, LD, is founder of
more serious side effects, such as statins to food is associated with health ben- the food blog and business It’s a Veg World
and antihypertensive drugs. efits in observational studies. Most of After All, a contributing writer for Healthline:
Other forms of garlic, such as dehy- the studies that assess the relationship Authority Nutrition, and an instructor at
drated raw garlic powder and even between dietary garlic intake and dis- Northwestern Health Sciences University.
enteric-coated capsules of garlic powder, ease risk are focused on cancer. An epi-
may damage GI mucosa and cause demiologic study by Jin and colleagues For references, view this article on our
stomach irritation. Hoshino and col- included close to 6,000 Chinese adults website at www.TodaysDietitian.com.
leagues found that dehydrated raw and found that people who ate raw garlic

50 TODAY’S DIETITIAN • FEBRUARY 2020