How much broccoli sprouts per day

No health agency has set a daily amount of broccoli sprouts, and no trial has tried to find a best one. What the research offers instead is a list of amounts that researchers fed to people, and two studies that report what those grams held, with the assay named. This page sets both out. For the compound itself, see the sulforaphane overview.

How much broccoli sprouts did human trials use?

Between 20 g and 100 g of fresh sprouts a day, for one to ten weeks, and up to 200 g a day in one three-day study. The table lists each trial with its size and design, because a one-week study of twelve people and an eight-week controlled trial are not equal evidence.

The outcomes were all markers: constipation scores, blood levels of the inflammation marker IL-6, H. pylori breath and stool tests, cholesterol, and antioxidant enzymes in nasal cells. The 2018 constipation study declares financial support from Murakami Farm, a Japanese farm company. None of these studies measured a disease outcome. Only Riedl compared different daily amounts of fresh sprouts, and only over three days.

A diabetes trial used 5 or 10 g of dried sprout powder a day for four weeks. Powder is a concentrated, processed product, so its grams do not compare with fresh sprouts, and it is left out of the table for that reason. The broccoli sprouts section covers what the diabetes and H. pylori trials found.

How much sulforaphane is in a serving of broccoli sprouts?

Two of the studies above report it with the assay named, in one batch each, by different methods. The 2018 constipation study also gives a glucosinolate figure for its sprouts, but the paper does not state how it was measured, so the figure is not quoted here.

In the Clarke study, 68 g of fresh sprouts contained 218.4 µmol of glucoraphanin, the precursor of sulforaphane, measured by LC-MS/MS. That is about 3.2 µmol per gram, or roughly 96 mg of glucoraphanin in the serving. It is a precursor figure. How much becomes sulforaphane depends on the steps below.

In the Riedl study, the sprouts were blended, which let the plant enzyme convert glucoraphanin before anyone drank it. The blend held 0.283 µmol of sulforaphane per milliliter by cyclocondensation assay, a method that counts all isothiocyanates, not sulforaphane alone. By the authors' own conversion, 100 g of sprouts gave 51 µmol and 200 g gave 102 µmol. That is about 9 mg and 18 mg of sulforaphane. The sprouts were a patented commercial strain.

Neither figure transfers to your own jar. Glucoraphanin content varies between seed lots, and the how much sulforaphane per day page shows how much of a glucoraphanin dose is lost when the enzyme is missing. Verified figures, each with its method, go into the sulforaphane content by food table.

Does the way you eat them change the dose?

Yes. Sprouts keep glucoraphanin and the enzyme myrosinase apart until their cells break. A 2001 Johns Hopkins study found higher excretion of sulforaphane metabolites when volunteers chewed fresh sprouts well than when they swallowed them whole.

Clarke's comparison makes the same point from another side. People who ate fresh sprouts excreted about five times more sulforaphane metabolites than people who took a supplement of the same glucosinolate content with no active enzyme, measured by LC-MS/MS. Fresh, chewed sprouts carry their own enzyme. Boiling destroys it.

Can you eat too many broccoli sprouts?

No upper limit has been set, and the safety record is short. In the Riedl study, people took up to 200 g a day for three days with no serious adverse events. The adverse event table lists flatulence and increased urination at the 200 g dose. Murashima's twelve volunteers ate 100 g a day for a week, and the longest study here ran ten weeks at 30 g.

Nobody has tested large amounts over months. Raw sprouts of all kinds also carry a documented risk of bacterial contamination, which the broccoli sprouts section covers. For what trials of sulforaphane products have recorded, see sulforaphane side effects.

If you grow your own, the method is in how to grow broccoli sprouts.