Dietary Nuts and Pulses Beneficial in Diabetes

MONTREAL — A diet rich in pulses and nuts can improve glycemic control in type 2 diabetes patients to within ranges seen with pharmaceutical intervention, researchers reported at the World Diabetes Congress.

A meta-analysis of 41 trials of pulses, either alone or combined with low-glycemic or high-fiber diets, noted improved markers of long-term glycemic control (Diabetologia 2009;52:1479-95), reported Dr. John Sievenpiper of the risk factor modification center of St. Michael's Hospital, Toronto.

Another study, also conducted by his group, found that 75 g of mixed nuts daily for 3 months improved blood lipids and glycemic control in patients with type 2 diabetes, compared with a mixture of nuts and muffins, or muffins alone. “Whatever your favorite nut or form of nut, it's good to get it into your diet,” said Dr. Cyril Kendall of the University of Toronto's department of nutritional sciences.

Both researchers acknowledged long lists of industry relationships: serving on advisory boards for a number of food companies, as well as the International Nut Council, and the Canola and Flax Councils of Canada, and receiving consultant fees from Pulse Canada.

“These are very nice, confirmatory studies,” commented Dr. Jim Mann, an endocrinologist who was not connected to the analyses, but performed some of the first studies in the 1980s showing similar results.

“I believe implicitly that patients do respond to dietary advice. In fact, the degree of response for type 2 diabetes is quite often as great as it is for some of the medications, if people comply,” the professor of human nutrition and medicine at Edgar National Center for Diabetes Research in Dunedin, New Zealand, said in an interview. “Most physicians don't believe that people will adhere sufficiently to dietary advice to make a significant difference, and because physicians are not convinced, neither are their patients. It takes an enthusiastic physician to get an enthusiastic patient.”

Dietary pulses such as chickpeas, beans, lentils, and peas are characterized by a low glycemic index, high fiber content, high levels of amylose and resistant starches, and vegetable protein and various other antinutrients “which may act as enzyme inhibitors,” Dr. Sievenpiper said. “The effect is to decrease starch digestion and absorption and therefore postprandial glycemia.”

In his meta-analysis, “modest improvement in medium to long-term glycemic control was seen when [pulses] were given alone or in combination with dietary maneuvers to reduce the glycemic index in the diet.”

The analysis included 11 trials that examined consumption of pulses alone, which noted an overall decrease in standardized mean difference (SMD) of 0.71 in fasting blood glucose (FBG) and 0.62 in serum insulin. Similarly, 19 trials looking at consumption of pulses in low glycemic index diets noted an SMD decrease of 0.28 in glycosylated blood proteins—either hemoglobin A_1c or fructosamine. And in 11 trials examining pulses in high-fiber diets, there were SMD reductions in fasting blood glucose of 0.32 and in glycosylated blood protein of 0.27.

Based on these results, “we would expect about a 0.48% reduction in HbA_1c, and this level of benefit approaches that seen with acarbose, exceeds the [Food and Drug Administration] proposed clinically meaningful threshold of 0.3%, and lies at the lower limit of efficacy of what you might expect for oral agents,” Dr. Sievenpiper said.

The nut study randomized 117 patients with type 2 diabetes to consume either 75 g nuts, 38 g nuts and 1.5 bran muffins (150 kcal per muffin), or three muffins daily for 3 months. Nut portions included a mix of almonds, cashews, macadamias, pecans, pistachios, walnuts, and peanuts. All treatment portions were equivalent to 475 kcal/day and were designed to maintain rather than decrease body weight. The primary outcome of the study was change in HbA_1c and serum lipids.

The patients' baseline characteristics were similar across the groups. They ranged in age from 61 to 63 years, 75% were men, ethnic backgrounds were diverse, and body mass indexes ranged from 28.8 to 30.3 kg/m

All patients were being treated with oral hypoglycemic medication, and their mean HbA_1c level was 7.1%. Baseline lipid profiles were balanced across the groups, and the mean duration of diabetes was 7-8 years.

A total of 100 patients completed the study, with a similar dropout rate in each group.

An intention-to-treat analysis revealed that HbA_1c levels were significantly lower in the nuts-only group, compared with the nut-muffin combination group (6.88% versus 7.02%), although the latter was not significantly lower than the muffin-only group (7.06%), Dr. Kendall said. There was a significant dose response seen in LDL cholesterol level, which fell by 0.19 mmol/L in the full-nut group, compared with full-muffin group.

Weight change from baseline was not significant, although there was a trend toward more weight loss in the nuts-only group. This was particularly interesting, given that more daily calories were consumed in this group (2,072 kcal), compared with the muffin-only group (1,932 kcal), Dr. Kendall said.

Previous studies by Dr. Kendall and his colleagues, as well as other studies, have shown this same effect, he said. “What we've found is that nuts are not entirely digested and there's an excretion of about 15%-20% that are simply not absorbed and pass through the gastrointestinal tract.”

Previous unpublished work by his group has shown that nuts have favorable effects on postprandial glucose response to common carbohydrates such as white bread, potatoes, rice, and pasta. “You get a graded reduction in glycemic response depending on the dose of nuts,” Dr. Kendall said.

Dietary intake of pulses—such as chickpeas, beans, lentils, and peas—can help diabetic patients reduce postprandial glycemia.

Source © Tinka/Fotolia.com

MONTREAL — A diet rich in pulses and nuts can improve glycemic control in type 2 diabetes patients to within ranges seen with pharmaceutical intervention, researchers reported at the World Diabetes Congress.

A meta-analysis of 41 trials of pulses, either alone or combined with low-glycemic or high-fiber diets, noted improved markers of long-term glycemic control (Diabetologia 2009;52:1479-95), reported Dr. John Sievenpiper of the risk factor modification center of St. Michael's Hospital, Toronto.

Another study, also conducted by his group, found that 75 g of mixed nuts daily for 3 months improved blood lipids and glycemic control in patients with type 2 diabetes, compared with a mixture of nuts and muffins, or muffins alone. “Whatever your favorite nut or form of nut, it's good to get it into your diet,” said Dr. Cyril Kendall of the University of Toronto's department of nutritional sciences.

Both researchers acknowledged long lists of industry relationships: serving on advisory boards for a number of food companies, as well as the International Nut Council, and the Canola and Flax Councils of Canada, and receiving consultant fees from Pulse Canada.

“These are very nice, confirmatory studies,” commented Dr. Jim Mann, an endocrinologist who was not connected to the analyses, but performed some of the first studies in the 1980s showing similar results.

“I believe implicitly that patients do respond to dietary advice. In fact, the degree of response for type 2 diabetes is quite often as great as it is for some of the medications, if people comply,” the professor of human nutrition and medicine at Edgar National Center for Diabetes Research in Dunedin, New Zealand, said in an interview. “Most physicians don't believe that people will adhere sufficiently to dietary advice to make a significant difference, and because physicians are not convinced, neither are their patients. It takes an enthusiastic physician to get an enthusiastic patient.”

Dietary pulses such as chickpeas, beans, lentils, and peas are characterized by a low glycemic index, high fiber content, high levels of amylose and resistant starches, and vegetable protein and various other antinutrients “which may act as enzyme inhibitors,” Dr. Sievenpiper said. “The effect is to decrease starch digestion and absorption and therefore postprandial glycemia.”

In his meta-analysis, “modest improvement in medium to long-term glycemic control was seen when [pulses] were given alone or in combination with dietary maneuvers to reduce the glycemic index in the diet.”

The analysis included 11 trials that examined consumption of pulses alone, which noted an overall decrease in standardized mean difference (SMD) of 0.71 in fasting blood glucose (FBG) and 0.62 in serum insulin. Similarly, 19 trials looking at consumption of pulses in low glycemic index diets noted an SMD decrease of 0.28 in glycosylated blood proteins—either hemoglobin A_1c or fructosamine. And in 11 trials examining pulses in high-fiber diets, there were SMD reductions in fasting blood glucose of 0.32 and in glycosylated blood protein of 0.27.

Based on these results, “we would expect about a 0.48% reduction in HbA_1c, and this level of benefit approaches that seen with acarbose, exceeds the [Food and Drug Administration] proposed clinically meaningful threshold of 0.3%, and lies at the lower limit of efficacy of what you might expect for oral agents,” Dr. Sievenpiper said.

The nut study randomized 117 patients with type 2 diabetes to consume either 75 g nuts, 38 g nuts and 1.5 bran muffins (150 kcal per muffin), or three muffins daily for 3 months. Nut portions included a mix of almonds, cashews, macadamias, pecans, pistachios, walnuts, and peanuts. All treatment portions were equivalent to 475 kcal/day and were designed to maintain rather than decrease body weight. The primary outcome of the study was change in HbA_1c and serum lipids.

The patients' baseline characteristics were similar across the groups. They ranged in age from 61 to 63 years, 75% were men, ethnic backgrounds were diverse, and body mass indexes ranged from 28.8 to 30.3 kg/m

All patients were being treated with oral hypoglycemic medication, and their mean HbA_1c level was 7.1%. Baseline lipid profiles were balanced across the groups, and the mean duration of diabetes was 7-8 years.

A total of 100 patients completed the study, with a similar dropout rate in each group.

An intention-to-treat analysis revealed that HbA_1c levels were significantly lower in the nuts-only group, compared with the nut-muffin combination group (6.88% versus 7.02%), although the latter was not significantly lower than the muffin-only group (7.06%), Dr. Kendall said. There was a significant dose response seen in LDL cholesterol level, which fell by 0.19 mmol/L in the full-nut group, compared with full-muffin group.

Weight change from baseline was not significant, although there was a trend toward more weight loss in the nuts-only group. This was particularly interesting, given that more daily calories were consumed in this group (2,072 kcal), compared with the muffin-only group (1,932 kcal), Dr. Kendall said.

Previous studies by Dr. Kendall and his colleagues, as well as other studies, have shown this same effect, he said. “What we've found is that nuts are not entirely digested and there's an excretion of about 15%-20% that are simply not absorbed and pass through the gastrointestinal tract.”

Previous unpublished work by his group has shown that nuts have favorable effects on postprandial glucose response to common carbohydrates such as white bread, potatoes, rice, and pasta. “You get a graded reduction in glycemic response depending on the dose of nuts,” Dr. Kendall said.

Dietary intake of pulses—such as chickpeas, beans, lentils, and peas—can help diabetic patients reduce postprandial glycemia.

Source © Tinka/Fotolia.com

MONTREAL — A diet rich in pulses and nuts can improve glycemic control in type 2 diabetes patients to within ranges seen with pharmaceutical intervention, researchers reported at the World Diabetes Congress.

A meta-analysis of 41 trials of pulses, either alone or combined with low-glycemic or high-fiber diets, noted improved markers of long-term glycemic control (Diabetologia 2009;52:1479-95), reported Dr. John Sievenpiper of the risk factor modification center of St. Michael's Hospital, Toronto.

Another study, also conducted by his group, found that 75 g of mixed nuts daily for 3 months improved blood lipids and glycemic control in patients with type 2 diabetes, compared with a mixture of nuts and muffins, or muffins alone. “Whatever your favorite nut or form of nut, it's good to get it into your diet,” said Dr. Cyril Kendall of the University of Toronto's department of nutritional sciences.

Both researchers acknowledged long lists of industry relationships: serving on advisory boards for a number of food companies, as well as the International Nut Council, and the Canola and Flax Councils of Canada, and receiving consultant fees from Pulse Canada.

“These are very nice, confirmatory studies,” commented Dr. Jim Mann, an endocrinologist who was not connected to the analyses, but performed some of the first studies in the 1980s showing similar results.

“I believe implicitly that patients do respond to dietary advice. In fact, the degree of response for type 2 diabetes is quite often as great as it is for some of the medications, if people comply,” the professor of human nutrition and medicine at Edgar National Center for Diabetes Research in Dunedin, New Zealand, said in an interview. “Most physicians don't believe that people will adhere sufficiently to dietary advice to make a significant difference, and because physicians are not convinced, neither are their patients. It takes an enthusiastic physician to get an enthusiastic patient.”

Dietary pulses such as chickpeas, beans, lentils, and peas are characterized by a low glycemic index, high fiber content, high levels of amylose and resistant starches, and vegetable protein and various other antinutrients “which may act as enzyme inhibitors,” Dr. Sievenpiper said. “The effect is to decrease starch digestion and absorption and therefore postprandial glycemia.”

In his meta-analysis, “modest improvement in medium to long-term glycemic control was seen when [pulses] were given alone or in combination with dietary maneuvers to reduce the glycemic index in the diet.”

The analysis included 11 trials that examined consumption of pulses alone, which noted an overall decrease in standardized mean difference (SMD) of 0.71 in fasting blood glucose (FBG) and 0.62 in serum insulin. Similarly, 19 trials looking at consumption of pulses in low glycemic index diets noted an SMD decrease of 0.28 in glycosylated blood proteins—either hemoglobin A_1c or fructosamine. And in 11 trials examining pulses in high-fiber diets, there were SMD reductions in fasting blood glucose of 0.32 and in glycosylated blood protein of 0.27.

Based on these results, “we would expect about a 0.48% reduction in HbA_1c, and this level of benefit approaches that seen with acarbose, exceeds the [Food and Drug Administration] proposed clinically meaningful threshold of 0.3%, and lies at the lower limit of efficacy of what you might expect for oral agents,” Dr. Sievenpiper said.

The nut study randomized 117 patients with type 2 diabetes to consume either 75 g nuts, 38 g nuts and 1.5 bran muffins (150 kcal per muffin), or three muffins daily for 3 months. Nut portions included a mix of almonds, cashews, macadamias, pecans, pistachios, walnuts, and peanuts. All treatment portions were equivalent to 475 kcal/day and were designed to maintain rather than decrease body weight. The primary outcome of the study was change in HbA_1c and serum lipids.

The patients' baseline characteristics were similar across the groups. They ranged in age from 61 to 63 years, 75% were men, ethnic backgrounds were diverse, and body mass indexes ranged from 28.8 to 30.3 kg/m

All patients were being treated with oral hypoglycemic medication, and their mean HbA_1c level was 7.1%. Baseline lipid profiles were balanced across the groups, and the mean duration of diabetes was 7-8 years.

A total of 100 patients completed the study, with a similar dropout rate in each group.

An intention-to-treat analysis revealed that HbA_1c levels were significantly lower in the nuts-only group, compared with the nut-muffin combination group (6.88% versus 7.02%), although the latter was not significantly lower than the muffin-only group (7.06%), Dr. Kendall said. There was a significant dose response seen in LDL cholesterol level, which fell by 0.19 mmol/L in the full-nut group, compared with full-muffin group.

Weight change from baseline was not significant, although there was a trend toward more weight loss in the nuts-only group. This was particularly interesting, given that more daily calories were consumed in this group (2,072 kcal), compared with the muffin-only group (1,932 kcal), Dr. Kendall said.

Previous studies by Dr. Kendall and his colleagues, as well as other studies, have shown this same effect, he said. “What we've found is that nuts are not entirely digested and there's an excretion of about 15%-20% that are simply not absorbed and pass through the gastrointestinal tract.”

Previous unpublished work by his group has shown that nuts have favorable effects on postprandial glucose response to common carbohydrates such as white bread, potatoes, rice, and pasta. “You get a graded reduction in glycemic response depending on the dose of nuts,” Dr. Kendall said.

Dietary intake of pulses—such as chickpeas, beans, lentils, and peas—can help diabetic patients reduce postprandial glycemia.

Source © Tinka/Fotolia.com