By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.
In the US, type 2 diabetes is increasing at an alarming rate. According to the CDC, there are now more than 34 million people living with diabetes and another 84 million Americans with prediabetes, a condition that leads to diabetes if not addressed in time. One of the reasons the numbers are climbing is the American obesity crisis: 61% of people with diagnosed diabetes are obese and another 28% are overweight.
As a cardiologist, I have always had a vested interest in the prevention and treatment of diabetes because of its strong link to heart disease. In fact, people with diabetes are up to four times more likely to develop heart disease than non-diabetics. So, as you can imagine, I’ve spent a lot of my time in practice explaining to diabetic patients that they could never truly have a healthy heart if they didn’t first address their blood sugar issues.
Thus it just makes sense to fortify ourselves with simple interventions that reduce the strain on our internal organs that regulate blood sugar issues in the body.
If there’s any good news, it’s this: Type 2 diabetes is a lifestyle disease, and as such, it can be managed—even reversed—with appropriate lifestyle changes. Considering that “diabesity” puts an enormous strain on the body, not to mention our health care system, it just makes sense to fortify ourselves with simple interventions. Aside from exercise, diet is the single most important factor in properly managing blood sugar levels.
Most people who have diabetes know that they need to avoid sugars and simple carbohydrates, which lead to major blood sugar spikes and a variety of other problems. Just as there are foods to avoid, there are also foods that people with diabetes—and even those who simply wish to prevent diabetes—should be eating due to their blood sugar-lowering properties.
Here are some of the top foods that lower blood sugar:
Not only are avocados delicious, research shows they also happen to contain a fat molecule that may help decrease insulin resistance—a precursor to diabetes where cells become unresponsive to the effects of insulin and can’t easily take up glucose from the blood.
Insulin resistance occurs when the cells’ mitochondria (“energy factories”) can’t burn fatty acids sufficiently and effectively. But in a study of obese mice with insulin resistance, a fat molecule in avocados called avocatin B (AvoB) given to the mice for 5 weeks helped ensure complete oxidation of fats. This led to slower weight gain and greater glucose tolerance, glucose utilization, and insulin sensitivity.
There are several fruits that people with diabetes should limit or avoid due to their high sugar content, but berries don’t fall in that category.
A recently published review looked at berries’ effect on insulin resistance and biomarkers of type 2 diabetes. The authors found that berries such as cranberries, blueberries, raspberries, and strawberries help lessen post-meal blood sugar surges in overweight/obese people with insulin resistance. They also improve cholesterol and blood pressure, among other markers. They concluded that existing evidence suggests, “berries have an emerging role in dietary strategies for the prevention of diabetes and its complications in adults.”
Berries are easy to enjoy. Eat them in their natural state, add them to salads or oatmeal, or blend them into smoothies. Just remember, moderation is key! Overindulging, even in berries (which are lower in sugar than other fruits), can still spike your blood sugar.
Cinnamon contains several antioxidants including cinnamaldehyde, which has been shown to reduce inflammation in arteries. In addition to its heart benefits, cinnamon is well known as one of the best foods to lower blood sugar, by enhancing the ability of insulin to metabolize glucose. This means sugars are burned at a faster rate, which aids in better blood sugar management.
In a meta-analysis of 10 studies (543 total patients), consumption of cinnamon was associated with a “statistically significant decrease in levels of fasting plasma glucose, total cholesterol, LDL cholesterol, and triglyceride levels, and an increase in HDL cholesterol levels.” Another earlier meta-analysis looked at eight studies and also concluded that cinnamon can significantly diminish fasting blood glucose levels in people with type 2 diabetes and prediabetes.
Even better, it doesn’t take a lot of cinnamon to help manage diabetes—a quarter teaspoon two or three times a day is all you need. Just sprinkle it into tomato sauce, yogurt, oatmeal, or tea, or take it in supplement form if the taste doesn’t appeal to you.
I love garlic—I can’t help it, I’m Italian! I use it in everything, most especially my homemade tomato sauces and stews. And while garlic’s pungency turns some people off, a little bad breath is a small price to pay for the many health benefits that garlic offers.
Garlic is a well-known antimicrobial, meaning it can fight off harmful invaders like viruses, bacteria, and parasites. It also has cardiovascular benefits, improving blood flow, blood pressure, and cholesterol levels. All this is thanks to a powerful compound called allicin.
Allicin has also been studied for its effects on blood sugar and diabetes, and the results are impressive.
A meta-analysis that examined nine studies involving a total of 768 diabetic patients found that a daily garlic (allicin) supplement (.05–1.5 g daily) led to a significant reduction of fasting blood glucose in as little as one week. Drops in hemoglobin A1C, as well as cholesterol levels, were also noted in the garlic users.
In conclusion, the authors wrote, “Current data confirms that garlic…plays positive and sustained roles in blood glucose, total cholesterol, and high/low density lipoprotein regulation in the management of type 2 diabetes mellitus.”
Nuts are an excellent snack food for several reasons. For one, they’re a rich source of monounsaturated fats, which protect the heart—a vulnerable organ in people with diabetes. In a trial that followed more than 16,000 men and women with diabetes, higher nut consumption was associated with lower risk of cardiovascular disease incidence and mortality.
Nuts are also low in carbohydrates, and relatively high in fiber and certain nutrients like magnesium. When eaten with carb-heavy foods, nuts can help blunt the body’s blood glycemic response.
And that’s not all. A meta-analysis of 12 studies concluded that enjoying tree nuts such as almonds slashed A1C and fasting glucose in people with diabetes, compared to those on nut-free diets.
Legumes, Potatoes, Rice & Pasta…With a Twist
For a long time, legumes such as beans, white potatoes, rice, and other starchy foods were thought to be dietary no-nos for people with diabetes. This is because typically, starchy foods quickly convert into sugar, wreaking havoc on glucose levels. But lots of research now suggests that legumes and other starchy foods, if prepared a certain way, turn into “resistant starches” which actually reduce, rather than raise, blood sugar.
Resistant starches are broken down much more slowly by the body than typical starches. Additionally, instead of being digested in the small intestine, they ferment in the large intestine (colon) with the help of gut bacteria. For this reason, the starch behaves more like fiber, which slows the body’s insulin response. As an added bonus, resistant starches feed the friendly bacteria in the intestines, contributing to better gut, immune, and overall health.
Foods that are naturally resistant starches include oats and green, unripe bananas and plantains. (The more these fruits ripen, the more they turn into regular starches.) You can also transform traditional starchy foods like potatoes, pasta, and rice into resistant starches through a process called starch retrogradation, which breaks down the starchy molecules amylose and amylopectin.
The key to this process is to cook the food as you normally would, then cool it for at least 12 hours in the refrigerator. When cooking rice, in particular, put a little coconut oil to the water. The oil binds to the starch, causing it to crystalize and turn resistant. Research shows adding coconut oil also cuts the calories of the rice by up to half!
You can eat the resistant starch cold, for example by adding cold beans to a salad or making potato salad. Or you can reheat, which fortunately doesn’t decrease or alter the resistant starch content.
Bottom line: If you have diabetes, you can still enjoy these once-forbidden foods. Just cook and cool, and you’ve created a food that lowers blood sugar.
A Diabetic Diet Can Be Delicious…and Fun
Having diabetes can be tough, and making dietary changes can be challenging. But as you can see, you don’t have to sacrifice taste for better health. There are plenty of delicious and nutritious foods that lower blood sugar, all of which can and should be part of your diet.
In conclusion, it’s hard not to notice that most of these foods that lower blood sugar also happen to be staples of my favorite and most highly recommended diet: the PAMM diet. Yet another reason I love this eating plan so much—it not only protects your heart, decreases inflammation, and shrinks your waistline, it also keeps your blood sugar in check. I say that’s a winning combination!
- National Diabetes Statistics Report 2020. Last accessed May 13, 2020.
- New CDC report: More than 100 million Americans have diabetes or pre-diabetes. July 18, 2017; last accessed May 18, 2020.
- Ahmed N, et al. Avocatin B protects against lipotoxicity and improves insulin sensitivity in diet-induced obesity. Mol Nutr Food Res. 2019 Dec;623(24):e1900688. Last accessed May 14, 2020.
- Allen RW, et al. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Ann Fam Med. 2013 Sep-Oct;11(5):452-9. Last accessed May 13, 2020.
- Davis P and Yokoyama W. Cinnamon intake lowers fasting blood glucose: meta-analysis. J Med Food. 2011 Sep;14(9):884-9. Last accessed May 14, 2020.
- Calvano A, et al. Dietary berries, insulin resistance and type 2 diabetes: an overview of human feeding trials. Food Funct. 2019 Oct 16;10(10):6227-43. Last accessed May 14, 2020.
- Wang J, et al. Effect of garlic supplement in the management of type 2 diabetes mellitus: a meta-analysis of randomized controlled trials. Food Nutr Res. 2017;61(1):1377571. Last accessed May 14, 2020.
- Macdonald, F. Scientists discover a simple way to cook rice that could halve the calories. Science Alert. 2018 Oct 14. Last accessed May 14, 2020.
- Liu G, et al. Nut consumption in relation to cardiovascular disease incidence and mortality among patients with diabetes mellitus. Circ Res. 2019 Mar 15;124(6):920-9. Last accessed May 14, 2020.
- Kendall CW, et al. Health benefits of nuts in prevention and management of diabetes. Asia Pac J Clin Nutr. 2010;19(1):110-6. Last accessed May 14, 2020.
- Viguiliouk E, et al. Effect of tree nuts on glycemic control in diabetes: a systematic review and meta-analysis of randomized controlled dietary trials. PLoS One. 2014 Jul 30;9(7):e103376. Last accessed May 14, 2020.
© 2020 Stephen Sinatra, M.D. All rights reserved.
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