Shapira N. Cheese 'refinement' with whey B-vitamin removal during precipitation potentially induces temporal 'functional' dietary shortage: homocysteine as a biomarker. Food Funct. 2014 Jul 25;5(7):1587-93. PMID: 24871488.

Food Funct. 2014 Jul 25;5(7):1587-93. doi: 10.1039/c4fo00148f.

Cheese 'refinement' with whey B-vitamin removal during precipitation potentially induces temporal 'functional' dietary shortage: homocysteine as a biomarker.

Shapira N(1).

Author information:
(1)Institute for Nutrition Research, Office: 5 Kehilat Jitomir, Tel Aviv 69405, Israel. nivnet@inter.net.il.

Cottage cheese 'refinement' with massive B-vitamin losses (≈70-84%) through whey removal during precipitation may potentially induce an acute imbalance between protein/methionine load and temporal inadequacy/shortage of nutrients critical for their metabolism, i.e. B6 and B12. The temporal effect of cottage cheese consumption was evaluated using increased plasma homocysteine as a B-vitamin shortage marker. In a double-blind study, healthy, normal-weight (BMI = 22-27), premenopausal women aged 25-45 years were first given a methionine load (100 mg kg(-1), n = 15), then cottage cheese alone (500 g, ≈50 g protein, ≈1200 mg methionine, n = 49) at breakfast, and then with added B6 (2 mg, n = 8) and/or B6 + folate (1 mg + 200 mcg, n = 7). Plasma homocysteine was measured preprandially (t0) and then postprandially 5 h (t5) and ≥6-24 h. Cheese-induced homocysteine increased 28.7% (p ≤ 0.001), ≈60% of the free methionine response, remaining higher through ≥6-8 h. Co-supplementation with B6 reduced the Hcy increase by 45.0% (to 14.9%, p = 0.025), and that with B6 + folate reduced the Hcy increase by 72.3% (to 7.5%, p = 0.556, NS). Homocysteine increased more in participants with lower baselines (<5 μM vs. ≥5 μM, p ≤ 0.001) following cheese, ≈3-fold (54.8% vs. 18.5%) or methionine, 47.3% (266.7% vs. 181.1%). Cheese B-vitamin depletion - i.e. to B6 ≈ 2.0-4.0 μg g(-1) protein, far below women's metabolic requirement (15-20 μg g(-1)) - appeared to induce acute relative shortage compared to methionine/protein loads, exemplified by greater homocysteine increases than with other animal proteins (previous data), more so with lower baseline homocysteine. Smaller increases following re-supplementation demonstrated potential for 'functional fortification'/co-supplementation. Unnoted cheese 'refinement', like white bread, potentially induces episodic vitamin shortage effects, warranting consideration for acute/cumulative implications, alternative processing/supplementation technologies, and food combinations, especially for at-risk populations (i.e. with genetic, hormonal/gender, or aging-related predispositions), and for cardiovascular, bone, and brain health.

PMID: 24871488  [PubMed - indexed for MEDLINE]

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