Dear Dietitian,

Lately, my cholesterol level has gone up, and my doctor wants to put me on medication for it. I am hesitant to take medicine because of the side effects. I've read about a supplement, Citrus bergamot, that claims to lower cholesterol naturally. What do you know about this product?

Kathryn

Dear Kathryn,

Citrus bergamot is a fragrant citrus fruit. Its color is yellow or orange, depending on its ripeness. The fruit originated in Southeast Asia but was named for Bergamo, Italy, where it first gained popularity. 

In a review of twelve studies, bergamot was associated with a significant decrease in total cholesterol (TC) and low-density lipoprotein (LDL), or bad cholesterol. The reduction in TC varied from 12%-31%, and the decline in LDL was as much as 41%. The authors pointed out that the studies had limited scientific quality (1).

In a randomized, double-blind placebo-controlled study of sixty participants, those given a bergamot supplement for thirty days showed a substantial decrease in total cholesterol and low-density lipoprotein (LDL). Total cholesterol decreased from 262 to 196, and LDL went from 175 to 116. This study was small; however, a randomized, double-blind study is the gold standard of scientific studies (2).

Garlic is an inexpensive way to treat high cholesterol, but is it effective? Studies are mixed. A study using a mixture of fresh garlic and lemon juice showed an impressive 41-point decline in TC and a 30-point decrease in LDL. The study consisted of 112 volunteers and lasted eight weeks (3). 

In another well-designed study conducted at Stanford University, garlic did not have any effect on cholesterol levels. The results were published in the Archives of Internal Medicine. In this six-month study, 192 patients who had elevated LDL levels were given a sandwich or supplements with the equivalent of 4 grams of garlic per day. Participants were closely monitored to make sure they didn't gain or lose weight, affecting cholesterol levels. At the end of six months, LDL levels were unchanged. Senior author Christopher Gardner, PhD, assistant professor of medicine at the Stanford Research Center, said, "If garlic was going to work, in one form or another, then it would have worked in our study. The lack of effect was compelling and clear." (4)

If you have high cholesterol, talk to your doctor before adding a supplement to your medicine cabinet. Supplements may produce side effects and can interact with other medications.

Until next time, be healthy!

Dear Dietitian

References

1. Lamiquiz-Moneo I, Gine-Gonzales J, Alisente S, Bea A, Peres-Calahorra S, Marco-Benedi V. Effect of bergamot on lipid profile in humans: a systematic review. Critical Reviews in Food Science and Nutrition 2020 60 (18): 3133-3143. doi: 10.1080/10408398.2019.1677554
2. Nauman M, Johnson J. Clinical application of bergamot (Citrus bergamia) for reducing high cholesterol and cardiovascular disease markers. Integr Food Nutr Metab. 2019 Mar; 6(2):10.15761/IFNM.1000239.
3. Aslani N, Entezari M, Askari G, Maghsoudi Z, Maracy M. Effect of garlic and lemon juice mixture on lipid profile and some cardiovascular risk factors in people 30-60 years old with moderate hyperlipidaemia: a randomized clinical trial. Int J Prev Med. 2016; 7:95. Published online 2016 Jul 20. doi: 10.4103/2008-7802.187248.
4. Stanford study drives stake through claims that garlic lowers cholesterol levels (2007 Feb 26) Stanford Medicine News Center. https://med.stanford.edu/news/all-news/2007/02/stanford-study-drives-stake-through-claims-that-garlic-lowers-cholesterol-levels.html