FDA's soy-heart health claim: 25g of soy protein per day remains clinically relevant, says DuPont

22-Jan-2018 - Last updated on 23-Jan-2018 at 14:28 GMT

The FDA is not meeting its mandate for providing clear, evidence-based guidance that is practical and actionable, say DuPont in comments on the Agency’s proposal to revoke the soy protein heart health claim.

As reported by FoodNavigator-USA last year, the FDA proposed to revoke a health claim on the relationship between soy protein and reduced risk of heart disease, citing “inconsistent findings” from research published since the claim was authorized in 1999.

In a statement issued October 30, 2017, Dr. Susan Mayne, director of the FDA’s Center for Food Safety and Applied Nutrition, said the move followed an extensive scientific review.

“While some evidence continues to suggest a relationship between soy protein and a reduced risk of heart disease – including evidence reviewed by the FDA when the claim was authorized – the totality of currently available scientific evidence calls into question the certainty of this relationship.

“For example, some studies, published after the FDA authorized the health claim, show inconsistent findings concerning the ability of soy protein to lower heart-damaging low-density lipoprotein (LDL) cholesterol. Our review of that evidence has led us to conclude that the relationship between soy protein and heart disease does not meet the rigorous standard for an FDA-authorized health claim,” stated Dr Mayne.

Comments

Almost 850 comments have been filed in response to the proposed revocation of the health claim. The comment period was planned to close on January 16, 2018, but was recently extended to March 19, 2018.

“The original approval of the soy heart health claim was based on the available body of literature at the time, in 1999,” Michele Braun, Research Scientist, DuPont Nutrition & Health told FoodNavigator-USA. “Since then, numerous additional studies have been published that further support that soy protein is heart healthy and regular consumption of 25 grams of soy protein daily is effective in reducing cardiovascular disease risk.

“Studies support that soy protein is an effective food ingredient to achieve cholesterol lowering and the magnitude of its effect is clinically relevant. Heart disease remains the No. 1 killer in our society and an important health concern.

“In our comments to FDA, we stressed not only the strength of the evidence and state of the science, but also the applicability of the evidence in improving the diet and health of the U.S. population. The final decision from FDA should be data driven.”

Support but surprise

DuPont Nutrition and Health submitted a five-page comment on the proposal, stating that the company “support[s] FDA's initiative to take into consideration new evidence that has been generated from research conducted over the last 18 years”. However, FDA’s criteria for selecting which studies are included and why is “somewhat unclear”, states the company.

“Unlike some other health claims, the soy protein and CHD claim is extremely specific, stating incorporation of 25g of soy protein in a diet low in saturated fat and cholesterol may reduce risk of heart disease. In the original 1998 evaluation, FDA suggested there is a dose effect, observing clinical trials testing dose of 25g of soy protein per day led to clinically significant reductions of total- and LDL-cholesterol levels. It is therefore unexpected that the same specificity, selecting studies that tested efficacious dose, was not applied in selecting studies for this recent review conducted by FDA, where studies testing doses below the acknowledged 25g dose were considered,” stated DuPont in its comments.

DuPont also voices surprise that the agency did not build on the original evaluation, which was completed in 1999, to include more recent studies which may better reflecting the dietary patterns and health status of the current population.

Such an approach was taken by Janice Harland and Tanya Haffner for a systematic review and meta-analysis published in Atherosclerosis in 2008 (Vol. 200, No. 1, pp. 13-27). Harland and Haffner found that, “the inclusion of modest amounts soy protein (25g) into the diet of adults with normal or mildly elevated blood cholesterol resulted in small, highly significant reductions in total and LDL cholesterol, equivalent to 6% LDL reduction,” noted the DuPont comments.

25g of soy protein per day remains clinically relevant

Heart health © Getty Images pkstock — Image © Getty Images / pkstock

“Soy protein is an effective food ingredient to achieve cholesterol lowering,” stated the comments. “The magnitude of cholesterol lowering is clinically relevant and should be taken into consideration in the review conducted by the FDA. While dampened when compared to results obtained in early studies in this area prior to approval of the claim, the cholesterol lowering effect of inclusion of 25g of soy protein remains clinically relevant within the body of literature for soy and comparable to other components that bear FDA claims.

“In conclusion, by modifying the existing status of the soy heart health claim, FDA is not meeting their mandate for providing clear, evidence-based guidance that is practical and actionable. Soy protein is a lean, high quality source of plant protein that can support health across the lifespan. The considerable amount of existing consistent evidence that demonstrates inclusion of foods providing 25 g of soy protein per day can have a clinically relevant effect in individuals with normal to moderately elevated cholesterol levels. Soy protein can be included in the diet along with other recognized components that have a beneficial effect on heart health, in alignment with current Dietary Guidelines, suggest a greater shift toward plant-based eating.”

To read more of the comments, please click HERE.